follow the normal code path for exiting rrd_update if there is a problem with rrdc...
[rrdtool.git] / src / rrd_update.c
index 608c314..dbf74df 100644 (file)
@@ -1,5 +1,6 @@
 /*****************************************************************************
- * RRDtool 1.2.23  Copyright by Tobi Oetiker, 1997-2007
+ * RRDtool 1.4.3  Copyright by Tobi Oetiker, 1997-2010
+ *                Copyright by Florian Forster, 2008
  *****************************************************************************
  * rrd_update.c  RRD Update Function
  *****************************************************************************
@@ -7,24 +8,23 @@
  *****************************************************************************/
 
 #include "rrd_tool.h"
-#include <sys/types.h>
-#include <fcntl.h>
-#ifdef HAVE_MMAP
- #include <sys/mman.h>
-#endif
 
 #if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
- #include <sys/locking.h>
- #include <sys/stat.h>
- #include <io.h>
+#include <sys/locking.h>
+#include <sys/stat.h>
+#include <io.h>
 #endif
 
+#include <locale.h>
+
 #include "rrd_hw.h"
 #include "rrd_rpncalc.h"
 
 #include "rrd_is_thread_safe.h"
 #include "unused.h"
 
+#include "rrd_client.h"
+
 #if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
 /*
  * WIN32 does not have gettimeofday    and struct timeval. This is a quick and dirty
 
 #ifndef __MINGW32__
 struct timeval {
-       time_t tv_sec; /* seconds */
-       long tv_usec;  /* microseconds */
+    time_t    tv_sec;   /* seconds */
+    long      tv_usec;  /* microseconds */
 };
 #endif
 
 struct __timezone {
-       int  tz_minuteswest; /* minutes W of Greenwich */
-       int  tz_dsttime;     /* type of dst correction */
+    int       tz_minuteswest;   /* minutes W of Greenwich */
+    int       tz_dsttime;   /* type of dst correction */
 };
 
-static int gettimeofday(struct timeval *t, struct __timezone *tz) {
+static int gettimeofday(
+    struct timeval *t,
+    struct __timezone *tz)
+{
 
-       struct _timeb current_time;
+    struct _timeb current_time;
 
-       _ftime(&current_time);
+    _ftime(&current_time);
 
-       t->tv_sec  = current_time.time;
-       t->tv_usec = current_time.millitm * 1000;
+    t->tv_sec = current_time.time;
+    t->tv_usec = current_time.millitm * 1000;
 
-       return 0;
+    return 0;
 }
 
 #endif
+
+/* FUNCTION PROTOTYPES */
+
+int       rrd_update_r(
+    const char *filename,
+    const char *tmplt,
+    int argc,
+    const char **argv);
+int       _rrd_update(
+    const char *filename,
+    const char *tmplt,
+    int argc,
+    const char **argv,
+    rrd_info_t *);
+
+static int allocate_data_structures(
+    rrd_t *rrd,
+    char ***updvals,
+    rrd_value_t **pdp_temp,
+    const char *tmplt,
+    long **tmpl_idx,
+    unsigned long *tmpl_cnt,
+    unsigned long **rra_step_cnt,
+    unsigned long **skip_update,
+    rrd_value_t **pdp_new);
+
+static int parse_template(
+    rrd_t *rrd,
+    const char *tmplt,
+    unsigned long *tmpl_cnt,
+    long *tmpl_idx);
+
+static int process_arg(
+    char *step_start,
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long rra_begin,
+    time_t *current_time,
+    unsigned long *current_time_usec,
+    rrd_value_t *pdp_temp,
+    rrd_value_t *pdp_new,
+    unsigned long *rra_step_cnt,
+    char **updvals,
+    long *tmpl_idx,
+    unsigned long tmpl_cnt,
+    rrd_info_t ** pcdp_summary,
+    int version,
+    unsigned long *skip_update,
+    int *schedule_smooth);
+
+static int parse_ds(
+    rrd_t *rrd,
+    char **updvals,
+    long *tmpl_idx,
+    char *input,
+    unsigned long tmpl_cnt,
+    time_t *current_time,
+    unsigned long *current_time_usec,
+    int version);
+
+static int get_time_from_reading(
+    rrd_t *rrd,
+    char timesyntax,
+    char **updvals,
+    time_t *current_time,
+    unsigned long *current_time_usec,
+    int version);
+
+static int update_pdp_prep(
+    rrd_t *rrd,
+    char **updvals,
+    rrd_value_t *pdp_new,
+    double interval);
+
+static int calculate_elapsed_steps(
+    rrd_t *rrd,
+    unsigned long current_time,
+    unsigned long current_time_usec,
+    double interval,
+    double *pre_int,
+    double *post_int,
+    unsigned long *proc_pdp_cnt);
+
+static void simple_update(
+    rrd_t *rrd,
+    double interval,
+    rrd_value_t *pdp_new);
+
+static int process_all_pdp_st(
+    rrd_t *rrd,
+    double interval,
+    double pre_int,
+    double post_int,
+    unsigned long elapsed_pdp_st,
+    rrd_value_t *pdp_new,
+    rrd_value_t *pdp_temp);
+
+static int process_pdp_st(
+    rrd_t *rrd,
+    unsigned long ds_idx,
+    double interval,
+    double pre_int,
+    double post_int,
+    long diff_pdp_st,
+    rrd_value_t *pdp_new,
+    rrd_value_t *pdp_temp);
+
+static int update_all_cdp_prep(
+    rrd_t *rrd,
+    unsigned long *rra_step_cnt,
+    unsigned long rra_begin,
+    rrd_file_t *rrd_file,
+    unsigned long elapsed_pdp_st,
+    unsigned long proc_pdp_cnt,
+    rrd_value_t **last_seasonal_coef,
+    rrd_value_t **seasonal_coef,
+    rrd_value_t *pdp_temp,
+    unsigned long *skip_update,
+    int *schedule_smooth);
+
+static int do_schedule_smooth(
+    rrd_t *rrd,
+    unsigned long rra_idx,
+    unsigned long elapsed_pdp_st);
+
+static int update_cdp_prep(
+    rrd_t *rrd,
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long *rra_step_cnt,
+    int rra_idx,
+    rrd_value_t *pdp_temp,
+    rrd_value_t *last_seasonal_coef,
+    rrd_value_t *seasonal_coef,
+    int current_cf);
+
+static void update_cdp(
+    unival *scratch,
+    int current_cf,
+    rrd_value_t pdp_temp_val,
+    unsigned long rra_step_cnt,
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt,
+    rrd_value_t xff,
+    int i,
+    int ii);
+
+static void initialize_cdp_val(
+    unival *scratch,
+    int current_cf,
+    rrd_value_t pdp_temp_val,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt);
+
+static void reset_cdp(
+    rrd_t *rrd,
+    unsigned long elapsed_pdp_st,
+    rrd_value_t *pdp_temp,
+    rrd_value_t *last_seasonal_coef,
+    rrd_value_t *seasonal_coef,
+    int rra_idx,
+    int ds_idx,
+    int cdp_idx,
+    enum cf_en current_cf);
+
+static rrd_value_t initialize_carry_over(
+    rrd_value_t pdp_temp_val,
+    int         current_cf,
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt);
+
+static rrd_value_t calculate_cdp_val(
+    rrd_value_t cdp_val,
+    rrd_value_t pdp_temp_val,
+    unsigned long elapsed_pdp_st,
+    int current_cf,
+    int i,
+    int ii);
+
+static int update_aberrant_cdps(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long rra_begin,
+    unsigned long elapsed_pdp_st,
+    rrd_value_t *pdp_temp,
+    rrd_value_t **seasonal_coef);
+
+static int write_to_rras(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long *rra_step_cnt,
+    unsigned long rra_begin,
+    time_t current_time,
+    unsigned long *skip_update,
+    rrd_info_t ** pcdp_summary);
+
+static int write_RRA_row(
+    rrd_file_t *rrd_file,
+    rrd_t *rrd,
+    unsigned long rra_idx,
+    unsigned short CDP_scratch_idx,
+    rrd_info_t ** pcdp_summary,
+    time_t rra_time);
+
+static int smooth_all_rras(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long rra_begin);
+
+#ifndef HAVE_MMAP
+static int write_changes_to_disk(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    int version);
+#endif
+
 /*
- * normilize time as returned by gettimeofday. usec part must
+ * normalize time as returned by gettimeofday. usec part must
  * be always >= 0
  */
-static void normalize_time(struct timeval *t)
+static void normalize_time(
+    struct timeval *t)
 {
-       if(t->tv_usec < 0) {
-               t->tv_sec--;
-               t->tv_usec += 1000000L;
-       }
+    if (t->tv_usec < 0) {
+        t->tv_sec--;
+        t->tv_usec += 1e6L;
+    }
 }
 
-/* Local prototypes */
-int LockRRD(FILE *rrd_file);
-#ifdef HAVE_MMAP
-info_t *write_RRA_row (rrd_t *rrd, unsigned long rra_idx, 
-                                       unsigned long *rra_current,
-                                       unsigned short CDP_scratch_idx,
-#ifndef DEBUG
-FILE UNUSED(*rrd_file),
-#else
-FILE *rrd_file,
-#endif
-                                       info_t *pcdp_summary, time_t *rra_time, void *rrd_mmaped_file);
-#else
-info_t *write_RRA_row (rrd_t *rrd, unsigned long rra_idx, 
-                                       unsigned long *rra_current,
-                                       unsigned short CDP_scratch_idx, FILE *rrd_file,
-                                       info_t *pcdp_summary, time_t *rra_time);
-#endif
-int rrd_update_r(const char *filename, const char *tmplt, int argc, const char **argv);
-int _rrd_update(const char *filename, const char *tmplt, int argc, const char **argv, 
-                                       info_t*);
+/*
+ * Sets current_time and current_time_usec based on the current time.
+ * current_time_usec is set to 0 if the version number is 1 or 2.
+ */
+static void initialize_time(
+    time_t *current_time,
+    unsigned long *current_time_usec,
+    int version)
+{
+    struct timeval tmp_time;    /* used for time conversion */
 
-#define IFDNAN(X,Y) (isnan(X) ? (Y) : (X));
+    gettimeofday(&tmp_time, 0);
+    normalize_time(&tmp_time);
+    *current_time = tmp_time.tv_sec;
+    if (version >= 3) {
+        *current_time_usec = tmp_time.tv_usec;
+    } else {
+        *current_time_usec = 0;
+    }
+}
 
+#define IFDNAN(X,Y) (isnan(X) ? (Y) : (X));
 
-info_t *rrd_update_v(int argc, char **argv)
+rrd_info_t *rrd_update_v(
+    int argc,
+    char **argv)
 {
-    char             *tmplt = NULL;          
-       info_t *result = NULL;
-       infoval rc;
-      rc.u_int = -1;
-    optind = 0; opterr = 0;  /* initialize getopt */
+    char     *tmplt = NULL;
+    rrd_info_t *result = NULL;
+    rrd_infoval_t rc;
+    char *opt_daemon = NULL;
+    struct option long_options[] = {
+        {"template", required_argument, 0, 't'},
+        {0, 0, 0, 0}
+    };
+
+    rc.u_int = -1;
+    optind = 0;
+    opterr = 0;         /* initialize getopt */
 
     while (1) {
-               static struct option long_options[] =
-                       {
-                               {"template",      required_argument, 0, 't'},
-                               {0,0,0,0}
-                       };
-               int option_index = 0;
-               int opt;
-               opt = getopt_long(argc, argv, "t:", 
-                                                 long_options, &option_index);
-               
-               if (opt == EOF)
-                       break;
-               
-               switch(opt) {
-               case 't':
-                       tmplt = optarg;
-                       break;
-               
-               case '?':
-                       rrd_set_error("unknown option '%s'",argv[optind-1]);
-                       goto end_tag;
-               }
+        int       option_index = 0;
+        int       opt;
+
+        opt = getopt_long(argc, argv, "t:", long_options, &option_index);
+
+        if (opt == EOF)
+            break;
+
+        switch (opt) {
+        case 't':
+            tmplt = optarg;
+            break;
+
+        case '?':
+            rrd_set_error("unknown option '%s'", argv[optind - 1]);
+            goto end_tag;
+        }
+    }
+
+    opt_daemon = getenv (ENV_RRDCACHED_ADDRESS);
+    if (opt_daemon != NULL) {
+        rrd_set_error ("The \"%s\" environment variable is defined, "
+                "but \"%s\" cannot work with rrdcached. Either unset "
+                "the environment variable or use \"update\" instead.",
+                ENV_RRDCACHED_ADDRESS, argv[0]);
+        goto end_tag;
     }
 
     /* need at least 2 arguments: filename, data. */
-    if (argc-optind < 2) {
-               rrd_set_error("Not enough arguments");
-               goto end_tag;
+    if (argc - optind < 2) {
+        rrd_set_error("Not enough arguments");
+        goto end_tag;
     }
     rc.u_int = 0;
-    result = info_push(NULL,sprintf_alloc("return_value"),RD_I_INT,rc);
-       rc.u_int = _rrd_update(argv[optind], tmplt,
-                     argc - optind - 1, (const char **)(argv + optind + 1), result);
+    result = rrd_info_push(NULL, sprintf_alloc("return_value"), RD_I_INT, rc);
+    rc.u_int = _rrd_update(argv[optind], tmplt,
+                           argc - optind - 1,
+                           (const char **) (argv + optind + 1), result);
     result->value.u_int = rc.u_int;
-end_tag:
+  end_tag:
     return result;
 }
 
-int
-rrd_update(int argc, char **argv)
+int rrd_update(
+    int argc,
+    char **argv)
 {
-    char             *tmplt = NULL;          
-    int rc;
-    optind = 0; opterr = 0;  /* initialize getopt */
+    struct option long_options[] = {
+        {"template", required_argument, 0, 't'},
+        {"daemon",   required_argument, 0, 'd'},
+        {0, 0, 0, 0}
+    };
+    int       option_index = 0;
+    int       opt;
+    char     *tmplt = NULL;
+    int       rc = -1;
+    char     *opt_daemon = NULL;
+
+    optind = 0;
+    opterr = 0;         /* initialize getopt */
 
     while (1) {
-               static struct option long_options[] =
-                       {
-                               {"template",      required_argument, 0, 't'},
-                               {0,0,0,0}
-                       };
-               int option_index = 0;
-               int opt;
-               opt = getopt_long(argc, argv, "t:", 
-                                                 long_options, &option_index);
-               
-               if (opt == EOF)
-                       break;
-               
-               switch(opt) {
-               case 't':
-                       tmplt = optarg;
-                       break;
-               
-               case '?':
-                       rrd_set_error("unknown option '%s'",argv[optind-1]);
-                       return(-1);
-               }
+        opt = getopt_long(argc, argv, "t:d:", long_options, &option_index);
+
+        if (opt == EOF)
+            break;
+
+        switch (opt) {
+        case 't':
+            tmplt = strdup(optarg);
+            break;
+
+        case 'd':
+            if (opt_daemon != NULL)
+                free (opt_daemon);
+            opt_daemon = strdup (optarg);
+            if (opt_daemon == NULL)
+            {
+                rrd_set_error("strdup failed.");
+                goto out;
+            }
+            break;
+
+        case '?':
+            rrd_set_error("unknown option '%s'", argv[optind - 1]);
+            goto out;
+        }
     }
 
     /* need at least 2 arguments: filename, data. */
-    if (argc-optind < 2) {
-               rrd_set_error("Not enough arguments");
+    if (argc - optind < 2) {
+        rrd_set_error("Not enough arguments");
+        goto out;
+    }
 
-               return -1;
+    {   /* try to connect to rrdcached */
+        int status = rrdc_connect(opt_daemon);
+        if (status != 0) {        
+             rc = status;           
+             goto out;           
+        }        
+    }
+
+    if ((tmplt != NULL) && rrdc_is_connected(opt_daemon))
+    {
+        rrd_set_error("The caching daemon cannot be used together with "
+                "templates yet.");
+        goto out;
+    }
+
+    if (! rrdc_is_connected(opt_daemon))
+    {
+      rc = rrd_update_r(argv[optind], tmplt,
+                        argc - optind - 1, (const char **) (argv + optind + 1));
+    }
+    else /* we are connected */
+    {
+        rc = rrdc_update (argv[optind], /* file */
+                          argc - optind - 1, /* values_num */
+                          (const char *const *) (argv + optind + 1)); /* values */
+        if (rc > 0)
+            rrd_set_error("Failed sending the values to rrdcached: %s",
+                          rrd_strerror (rc));
+    }
+
+  out:
+    if (tmplt != NULL)
+    {
+        free(tmplt);
+        tmplt = NULL;
+    }
+    if (opt_daemon != NULL)
+    {
+        free (opt_daemon);
+        opt_daemon = NULL;
     }
-       rc = rrd_update_r(argv[optind], tmplt,
-                     argc - optind - 1, (const char **)(argv + optind + 1));
     return rc;
 }
 
-int
-rrd_update_r(const char *filename, const char *tmplt, int argc, const char **argv)
+int rrd_update_r(
+    const char *filename,
+    const char *tmplt,
+    int argc,
+    const char **argv)
 {
-   return _rrd_update(filename, tmplt, argc, argv, NULL);
+    return _rrd_update(filename, tmplt, argc, argv, NULL);
 }
 
-int
-_rrd_update(const char *filename, const char *tmplt, int argc, const char **argv, 
-   info_t *pcdp_summary)
+int rrd_update_v_r(
+    const char *filename,
+    const char *tmplt,
+    int argc,
+    const char **argv,
+    rrd_info_t * pcdp_summary)
 {
+    return _rrd_update(filename, tmplt, argc, argv, pcdp_summary);
+}
 
-    int              arg_i = 2;
-    short            j;
-    unsigned long    i,ii,iii=1;
-
-    unsigned long    rra_begin;          /* byte pointer to the rra
-                                         * area in the rrd file.  this
-                                         * pointer never changes value */
-    unsigned long    rra_start;          /* byte pointer to the rra
-                                         * area in the rrd file.  this
-                                         * pointer changes as each rrd is
-                                         * processed. */
-    unsigned long    rra_current;        /* byte pointer to the current write
-                                         * spot in the rrd file. */
-    unsigned long    rra_pos_tmp;        /* temporary byte pointer. */
-    double           interval,
-                     pre_int,post_int;   /* interval between this and
-                                         * the last run */
-    unsigned long    proc_pdp_st;        /* which pdp_st was the last
-                                         * to be processed */
-    unsigned long    occu_pdp_st;        /* when was the pdp_st
-                                         * before the last update
-                                         * time */
-    unsigned long    proc_pdp_age;       /* how old was the data in
-                                         * the pdp prep area when it
-                                         * was last updated */
-    unsigned long    occu_pdp_age;       /* how long ago was the last
-                                         * pdp_step time */
-    rrd_value_t      *pdp_new;           /* prepare the incoming data
-                                         * to be added the the
-                                         * existing entry */
-    rrd_value_t      *pdp_temp;          /* prepare the pdp values 
-                                         * to be added the the
-                                         * cdp values */
-
-    long             *tmpl_idx;          /* index representing the settings
-                                           transported by the tmplt index */
-    unsigned long    tmpl_cnt = 2;       /* time and data */
-
-    FILE             *rrd_file;
-    rrd_t            rrd;
-    time_t           current_time = 0;
-    time_t           rra_time = 0;      /* time of update for a RRA */
-    unsigned long    current_time_usec=0;/* microseconds part of current time */
-    struct timeval   tmp_time;           /* used for time conversion */
-
-    char             **updvals;
-    int              schedule_smooth = 0;
-       rrd_value_t      *seasonal_coef = NULL, *last_seasonal_coef = NULL;
-                                        /* a vector of future Holt-Winters seasonal coefs */
-    unsigned long    elapsed_pdp_st;
-                                        /* number of elapsed PDP steps since last update */
-    unsigned long    *rra_step_cnt = NULL;
-                                        /* number of rows to be updated in an RRA for a data
-                                         * value. */
-    unsigned long    start_pdp_offset;
-                                        /* number of PDP steps since the last update that
-                                         * are assigned to the first CDP to be generated
-                                         * since the last update. */
-    unsigned short   scratch_idx;
-                                        /* index into the CDP scratch array */
-    enum cf_en       current_cf;
-                                        /* numeric id of the current consolidation function */
-    rpnstack_t       rpnstack; /* used for COMPUTE DS */
-    int                     version;  /* rrd version */
-    char             *endptr; /* used in the conversion */
-
-#ifdef HAVE_MMAP
-    void            *rrd_mmaped_file;
-    unsigned long    rrd_filesize;
-#endif
-
+int _rrd_update(
+    const char *filename,
+    const char *tmplt,
+    int argc,
+    const char **argv,
+    rrd_info_t * pcdp_summary)
+{
 
-    rpnstack_init(&rpnstack);
+    int       arg_i = 2;
+
+    unsigned long rra_begin;    /* byte pointer to the rra
+                                 * area in the rrd file.  this
+                                 * pointer never changes value */
+    rrd_value_t *pdp_new;   /* prepare the incoming data to be added 
+                             * to the existing entry */
+    rrd_value_t *pdp_temp;  /* prepare the pdp values to be added 
+                             * to the cdp values */
+
+    long     *tmpl_idx; /* index representing the settings
+                         * transported by the tmplt index */
+    unsigned long tmpl_cnt = 2; /* time and data */
+    rrd_t     rrd;
+    time_t    current_time = 0;
+    unsigned long current_time_usec = 0;    /* microseconds part of current time */
+    char    **updvals;
+    int       schedule_smooth = 0;
+
+    /* number of elapsed PDP steps since last update */
+    unsigned long *rra_step_cnt = NULL;
+
+    int       version;  /* rrd version */
+    rrd_file_t *rrd_file;
+    char     *arg_copy; /* for processing the argv */
+    unsigned long *skip_update; /* RRAs to advance but not write */
 
     /* need at least 1 arguments: data. */
     if (argc < 1) {
-       rrd_set_error("Not enough arguments");
-       return -1;
+        rrd_set_error("Not enough arguments");
+        goto err_out;
     }
-    
-    
 
-    if(rrd_open(filename,&rrd_file,&rrd, RRD_READWRITE)==-1){
-       return -1;
+    rrd_init(&rrd);
+    if ((rrd_file = rrd_open(filename, &rrd, RRD_READWRITE)) == NULL) {
+        goto err_free;
     }
+    /* We are now at the beginning of the rra's */
+    rra_begin = rrd_file->header_len;
 
-    /* initialize time */
     version = atoi(rrd.stat_head->version);
-    gettimeofday(&tmp_time, 0);
-    normalize_time(&tmp_time);
-    current_time = tmp_time.tv_sec;
-    if(version >= 3) {
-        current_time_usec = tmp_time.tv_usec;
-    }
-    else {
-       current_time_usec = 0;
-    }
 
-    rra_current = rra_start = rra_begin = ftell(rrd_file);
-    /* This is defined in the ANSI C standard, section 7.9.5.3:
-
-        When a file is opened with udpate mode ('+' as the second
-        or third character in the ... list of mode argument
-        variables), both input and ouptut may be performed on the
-        associated stream.  However, ...  input may not be directly
-        followed by output without an intervening call to a file
-        positioning function, unless the input oepration encounters
-        end-of-file. */
-#ifdef HAVE_MMAP
-    fseek(rrd_file, 0, SEEK_END);
-    rrd_filesize = ftell(rrd_file);
-    fseek(rrd_file, rra_current, SEEK_SET);
-#else
-    fseek(rrd_file, 0, SEEK_CUR);
-#endif
+    initialize_time(&current_time, &current_time_usec, version);
 
-    
     /* get exclusive lock to whole file.
      * lock gets removed when we close the file.
      */
-    if (LockRRD(rrd_file) != 0) {
-      rrd_set_error("could not lock RRD");
-      rrd_free(&rrd);
-      fclose(rrd_file);
-      return(-1);   
-    } 
+    if (rrd_lock(rrd_file) != 0) {
+        rrd_set_error("could not lock RRD");
+        goto err_close;
+    }
+
+    if (allocate_data_structures(&rrd, &updvals,
+                                 &pdp_temp, tmplt, &tmpl_idx, &tmpl_cnt,
+                                 &rra_step_cnt, &skip_update,
+                                 &pdp_new) == -1) {
+        goto err_close;
+    }
 
-    if((updvals = malloc( sizeof(char*) * (rrd.stat_head->ds_cnt+1)))==NULL){
-       rrd_set_error("allocating updvals pointer array");
-       rrd_free(&rrd);
-        fclose(rrd_file);
-       return(-1);
+    /* loop through the arguments. */
+    for (arg_i = 0; arg_i < argc; arg_i++) {
+        if ((arg_copy = strdup(argv[arg_i])) == NULL) {
+            rrd_set_error("failed duplication argv entry");
+            break;
+        }
+        if (process_arg(arg_copy, &rrd, rrd_file, rra_begin,
+                        &current_time, &current_time_usec, pdp_temp, pdp_new,
+                        rra_step_cnt, updvals, tmpl_idx, tmpl_cnt,
+                        &pcdp_summary, version, skip_update,
+                        &schedule_smooth) == -1) {
+            if (rrd_test_error()) { /* Should have error string always here */
+                char     *save_error;
+
+                /* Prepend file name to error message */
+                if ((save_error = strdup(rrd_get_error())) != NULL) {
+                    rrd_set_error("%s: %s", filename, save_error);
+                    free(save_error);
+                }
+            }
+            free(arg_copy);
+            break;
+        }
+        free(arg_copy);
+    }
+
+    free(rra_step_cnt);
+
+    /* if we got here and if there is an error and if the file has not been
+     * written to, then close things up and return. */
+    if (rrd_test_error()) {
+        goto err_free_structures;
+    }
+#ifndef HAVE_MMAP
+    if (write_changes_to_disk(&rrd, rrd_file, version) == -1) {
+        goto err_free_structures;
     }
+#endif
 
-    if ((pdp_temp = malloc(sizeof(rrd_value_t)
-                          *rrd.stat_head->ds_cnt))==NULL){
-       rrd_set_error("allocating pdp_temp ...");
-       free(updvals);
-       rrd_free(&rrd);
-        fclose(rrd_file);
-       return(-1);
+    /* calling the smoothing code here guarantees at most one smoothing
+     * operation per rrd_update call. Unfortunately, it is possible with bulk
+     * updates, or a long-delayed update for smoothing to occur off-schedule.
+     * This really isn't critical except during the burn-in cycles. */
+    if (schedule_smooth) {
+        smooth_all_rras(&rrd, rrd_file, rra_begin);
     }
 
-    if ((tmpl_idx = malloc(sizeof(unsigned long)
-                          *(rrd.stat_head->ds_cnt+1)))==NULL){
-       rrd_set_error("allocating tmpl_idx ...");
-       free(pdp_temp);
-       free(updvals);
-       rrd_free(&rrd);
-        fclose(rrd_file);
-       return(-1);
+/*    rrd_dontneed(rrd_file,&rrd); */
+    rrd_free(&rrd);
+    rrd_close(rrd_file);
+
+    free(pdp_new);
+    free(tmpl_idx);
+    free(pdp_temp);
+    free(skip_update);
+    free(updvals);
+    return 0;
+
+  err_free_structures:
+    free(pdp_new);
+    free(tmpl_idx);
+    free(pdp_temp);
+    free(skip_update);
+    free(updvals);
+  err_close:
+    rrd_close(rrd_file);
+  err_free:
+    rrd_free(&rrd);
+  err_out:
+    return -1;
+}
+
+/*
+ * Allocate some important arrays used, and initialize the template.
+ *
+ * When it returns, either all of the structures are allocated
+ * or none of them are.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int allocate_data_structures(
+    rrd_t *rrd,
+    char ***updvals,
+    rrd_value_t **pdp_temp,
+    const char *tmplt,
+    long **tmpl_idx,
+    unsigned long *tmpl_cnt,
+    unsigned long **rra_step_cnt,
+    unsigned long **skip_update,
+    rrd_value_t **pdp_new)
+{
+    unsigned  i, ii;
+    if ((*updvals = (char **) malloc(sizeof(char *)
+                                     * (rrd->stat_head->ds_cnt + 1))) == NULL) {
+        rrd_set_error("allocating updvals pointer array.");
+        return -1;
+    }
+    if ((*pdp_temp = (rrd_value_t *) malloc(sizeof(rrd_value_t)
+                                            * rrd->stat_head->ds_cnt)) ==
+        NULL) {
+        rrd_set_error("allocating pdp_temp.");
+        goto err_free_updvals;
+    }
+    if ((*skip_update = (unsigned long *) malloc(sizeof(unsigned long)
+                                                 *
+                                                 rrd->stat_head->rra_cnt)) ==
+        NULL) {
+        rrd_set_error("allocating skip_update.");
+        goto err_free_pdp_temp;
+    }
+    if ((*tmpl_idx = (long *) malloc(sizeof(unsigned long)
+                                     * (rrd->stat_head->ds_cnt + 1))) == NULL) {
+        rrd_set_error("allocating tmpl_idx.");
+        goto err_free_skip_update;
     }
+    if ((*rra_step_cnt = (unsigned long *) malloc(sizeof(unsigned long)
+                                                  *
+                                                  (rrd->stat_head->
+                                                   rra_cnt))) == NULL) {
+        rrd_set_error("allocating rra_step_cnt.");
+        goto err_free_tmpl_idx;
+    }
+
     /* initialize tmplt redirector */
     /* default config example (assume DS 1 is a CDEF DS)
        tmpl_idx[0] -> 0; (time)
        tmpl_idx[1] -> 1; (DS 0)
        tmpl_idx[2] -> 3; (DS 2)
        tmpl_idx[3] -> 4; (DS 3) */
-    tmpl_idx[0] = 0; /* time */
-    for (i = 1, ii = 1 ; i <= rrd.stat_head->ds_cnt ; i++) 
-       {
-          if (dst_conv(rrd.ds_def[i-1].dst) != DST_CDEF)
-             tmpl_idx[ii++]=i;
-       }
-    tmpl_cnt= ii;
-
-    if (tmplt) {
-       /* we should work on a writeable copy here */
-       char *dsname;
-       unsigned int tmpl_len;
-       char *tmplt_copy = strdup(tmplt);
-       dsname = tmplt_copy;
-       tmpl_cnt = 1; /* the first entry is the time */
-       tmpl_len = strlen(tmplt_copy);
-       for(i=0;i<=tmpl_len ;i++) {
-           if (tmplt_copy[i] == ':' || tmplt_copy[i] == '\0') {
-               tmplt_copy[i] = '\0';
-               if (tmpl_cnt>rrd.stat_head->ds_cnt){
-                   rrd_set_error("tmplt contains more DS definitions than RRD");
-                   free(updvals); free(pdp_temp);
-                   free(tmpl_idx); rrd_free(&rrd);
-                   fclose(rrd_file); return(-1);
-               }
-               if ((tmpl_idx[tmpl_cnt++] = ds_match(&rrd,dsname)) == -1){
-                   rrd_set_error("unknown DS name '%s'",dsname);
-                   free(updvals); free(pdp_temp);
-                   free(tmplt_copy);
-                   free(tmpl_idx); rrd_free(&rrd);
-                   fclose(rrd_file); return(-1);
-               } else {
-                 /* the first element is always the time */
-                 tmpl_idx[tmpl_cnt-1]++; 
-                 /* go to the next entry on the tmplt_copy */
-                 dsname = &tmplt_copy[i+1];
-                  /* fix the damage we did before */
-                  if (i<tmpl_len) {
-                     tmplt_copy[i]=':';
-                  } 
-
-               }
-           }       
-       }
-       free(tmplt_copy);
+    (*tmpl_idx)[0] = 0; /* time */
+    for (i = 1, ii = 1; i <= rrd->stat_head->ds_cnt; i++) {
+        if (dst_conv(rrd->ds_def[i - 1].dst) != DST_CDEF)
+            (*tmpl_idx)[ii++] = i;
     }
-    if ((pdp_new = malloc(sizeof(rrd_value_t)
-                         *rrd.stat_head->ds_cnt))==NULL){
-       rrd_set_error("allocating pdp_new ...");
-       free(updvals);
-       free(pdp_temp);
-       free(tmpl_idx);
-       rrd_free(&rrd);
-        fclose(rrd_file);
-       return(-1);
+    *tmpl_cnt = ii;
+
+    if (tmplt != NULL) {
+        if (parse_template(rrd, tmplt, tmpl_cnt, *tmpl_idx) == -1) {
+            goto err_free_rra_step_cnt;
+        }
     }
 
-#ifdef HAVE_MMAP
-    rrd_mmaped_file = mmap(0, 
-                       rrd_filesize, 
-                       PROT_READ | PROT_WRITE, 
-                       MAP_SHARED, 
-                       fileno(rrd_file), 
-                       0);
-    if (rrd_mmaped_file == MAP_FAILED) {
-        rrd_set_error("error mmapping file %s", filename);
-       free(updvals);
-       free(pdp_temp);
-       free(tmpl_idx);
-       rrd_free(&rrd);
-        fclose(rrd_file);
-       return(-1);
+    if ((*pdp_new = (rrd_value_t *) malloc(sizeof(rrd_value_t)
+                                           * rrd->stat_head->ds_cnt)) == NULL) {
+        rrd_set_error("allocating pdp_new.");
+        goto err_free_rra_step_cnt;
     }
-#ifdef HAVE_MADVISE
-    /* when we use mmaping we tell the kernel the mmap equivalent
-       of POSIX_FADV_RANDOM */
-    madvise(rrd_mmaped_file,rrd_filesize,MADV_RANDOM);
-#endif
-#endif    
-    /* loop through the arguments. */
-    for(arg_i=0; arg_i<argc;arg_i++) {
-       char *stepper = strdup(argv[arg_i]);
-        char *step_start = stepper;
-       char *p;
-       char *parsetime_error = NULL;
-       enum {atstyle, normal} timesyntax;
-       struct rrd_time_value ds_tv;
-        if (stepper == NULL){
-                rrd_set_error("failed duplication argv entry");
-               free(step_start);
-                free(updvals);
-                free(pdp_temp);  
-                free(tmpl_idx);
-                rrd_free(&rrd);
-#ifdef HAVE_MMAP
-               munmap(rrd_mmaped_file, rrd_filesize);
-#endif
-                fclose(rrd_file);
-                return(-1);
-         }
-       /* initialize all ds input to unknown except the first one
-           which has always got to be set */
-       for(ii=1;ii<=rrd.stat_head->ds_cnt;ii++) updvals[ii] = "U";
-       updvals[0]=stepper;
-       /* separate all ds elements; first must be examined separately
-          due to alternate time syntax */
-       if ((p=strchr(stepper,'@'))!=NULL) {
-           timesyntax = atstyle;
-           *p = '\0';
-           stepper = p+1;
-       } else if ((p=strchr(stepper,':'))!=NULL) {
-           timesyntax = normal;
-           *p = '\0';
-           stepper = p+1;
-       } else {
-           rrd_set_error("expected timestamp not found in data source from %s",
-                         argv[arg_i]);
-           free(step_start);
-           break;
-       }
-       ii=1;
-       updvals[tmpl_idx[ii]] = stepper;
-       while (*stepper) {
-           if (*stepper == ':') {
-               *stepper = '\0';
-               ii++;
-               if (ii<tmpl_cnt){                   
-                   updvals[tmpl_idx[ii]] = stepper+1;
-               }
-           }
-           stepper++;
-       }
-
-       if (ii != tmpl_cnt-1) {
-           rrd_set_error("expected %lu data source readings (got %lu) from %s",
-                         tmpl_cnt-1, ii, argv[arg_i]);
-           free(step_start);
-           break;
-       }
-       
-        /* get the time from the reading ... handle N */
-       if (timesyntax == atstyle) {
-            if ((parsetime_error = parsetime(updvals[0], &ds_tv))) {
-                rrd_set_error("ds time: %s: %s", updvals[0], parsetime_error );
-               free(step_start);
-               break;
-           }
-           if (ds_tv.type == RELATIVE_TO_END_TIME ||
-               ds_tv.type == RELATIVE_TO_START_TIME) {
-               rrd_set_error("specifying time relative to the 'start' "
-                             "or 'end' makes no sense here: %s",
-                             updvals[0]);
-               free(step_start);
-               break;
-           }
-
-           current_time = mktime(&ds_tv.tm) + ds_tv.offset;
-           current_time_usec = 0; /* FIXME: how to handle usecs here ? */
-           
-       } else if (strcmp(updvals[0],"N")==0){
-           gettimeofday(&tmp_time, 0);
-           normalize_time(&tmp_time);
-           current_time = tmp_time.tv_sec;
-           current_time_usec = tmp_time.tv_usec;
-       } else {
-           double tmp;
-           tmp = strtod(updvals[0], 0);
-           current_time = floor(tmp);
-           current_time_usec = (long)((tmp-(double)current_time) * 1000000.0);
-       }
-       /* dont do any correction for old version RRDs */
-       if(version < 3) 
-           current_time_usec = 0;
-       
-       if(current_time < rrd.live_head->last_up || 
-         (current_time == rrd.live_head->last_up && 
-          (long)current_time_usec <= (long)rrd.live_head->last_up_usec)) {
-           rrd_set_error("illegal attempt to update using time %ld when "
-                         "last update time is %ld (minimum one second step)",
-                         current_time, rrd.live_head->last_up);
-           free(step_start);
-           break;
-       }
-       
-       
-       /* seek to the beginning of the rra's */
-       if (rra_current != rra_begin) {
-#ifndef HAVE_MMAP
-           if(fseek(rrd_file, rra_begin, SEEK_SET) != 0) {
-               rrd_set_error("seek error in rrd");
-               free(step_start);
-               break;
-           }
-#endif
-           rra_current = rra_begin;
-       }
-       rra_start = rra_begin;
-
-       /* when was the current pdp started */
-       proc_pdp_age = rrd.live_head->last_up % rrd.stat_head->pdp_step;
-       proc_pdp_st = rrd.live_head->last_up - proc_pdp_age;
-
-       /* when did the last pdp_st occur */
-       occu_pdp_age = current_time % rrd.stat_head->pdp_step;
-       occu_pdp_st = current_time - occu_pdp_age;
-
-       /* interval = current_time - rrd.live_head->last_up; */
-       interval    = (double)(current_time - rrd.live_head->last_up) 
-                   + (double)((long)current_time_usec - (long)rrd.live_head->last_up_usec)/1000000.0;
-
-       if (occu_pdp_st > proc_pdp_st){
-           /* OK we passed the pdp_st moment*/
-           pre_int =  (long)occu_pdp_st - rrd.live_head->last_up; /* how much of the input data
-                                                             * occurred before the latest
-                                                             * pdp_st moment*/
-           pre_int -= ((double)rrd.live_head->last_up_usec)/1000000.0; /* adjust usecs */
-           post_int = occu_pdp_age;                         /* how much after it */
-           post_int += ((double)current_time_usec)/1000000.0;  /* adjust usecs */
-       } else {
-           pre_int = interval;
-           post_int = 0;
-       }
 
-#ifdef DEBUG
-       printf(
-              "proc_pdp_age %lu\t"
-              "proc_pdp_st %lu\t" 
-              "occu_pfp_age %lu\t" 
-              "occu_pdp_st %lu\t"
-              "int %lf\t"
-              "pre_int %lf\t"
-              "post_int %lf\n", proc_pdp_age, proc_pdp_st, 
-               occu_pdp_age, occu_pdp_st,
-              interval, pre_int, post_int);
-#endif
-    
-       /* process the data sources and update the pdp_prep 
-        * area accordingly */
-       for(i=0;i<rrd.stat_head->ds_cnt;i++){
-           enum dst_en dst_idx;
-           dst_idx= dst_conv(rrd.ds_def[i].dst);
-
-            /* make sure we do not build diffs with old last_ds values */
-           if(rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt < interval) {
-               strncpy(rrd.pdp_prep[i].last_ds,"U",LAST_DS_LEN-1);
-               rrd.pdp_prep[i].last_ds[LAST_DS_LEN-1]='\0';
-           }
-
-           /* NOTE: DST_CDEF should never enter this if block, because
-             * updvals[i+1][0] is initialized to 'U'; unless the caller
-            * accidently specified a value for the DST_CDEF. To handle 
-             * this case, an extra check is required. */
-
-           if((updvals[i+1][0] != 'U') &&
-                  (dst_idx != DST_CDEF) &&
-              rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt >= interval) {
-              double rate = DNAN;
-              /* the data source type defines how to process the data */
-               /* pdp_new contains rate * time ... eg the bytes
-                * transferred during the interval. Doing it this way saves
-                * a lot of math operations */
-               
-
-               switch(dst_idx){
-               case DST_COUNTER:
-               case DST_DERIVE:
-                   if(rrd.pdp_prep[i].last_ds[0] != 'U'){
-                      for(ii=0;updvals[i+1][ii] != '\0';ii++){
-                            if((updvals[i+1][ii] < '0' || updvals[i+1][ii] > '9') && (ii != 0 && updvals[i+1][ii] != '-')){
-                                 rrd_set_error("not a simple integer: '%s'",updvals[i+1]);
-                                 break;
-                            }
-                       }
-                       if (rrd_test_error()){
-                            break;
-                       }
-                      pdp_new[i]= rrd_diff(updvals[i+1],rrd.pdp_prep[i].last_ds);
-                      if(dst_idx == DST_COUNTER) {
-                         /* simple overflow catcher suggested by Andres Kroonmaa */
-                         /* this will fail terribly for non 32 or 64 bit counters ... */
-                         /* are there any others in SNMP land ? */
-                         if (pdp_new[i] < (double)0.0 ) 
-                           pdp_new[i] += (double)4294967296.0 ;  /* 2^32 */
-                         if (pdp_new[i] < (double)0.0 ) 
-                           pdp_new[i] += (double)18446744069414584320.0; /* 2^64-2^32 */;
-                      }
-                      rate = pdp_new[i] / interval;
-                   }
-                  else {
-                    pdp_new[i]= DNAN;          
-                  }
-                  break;
-               case DST_ABSOLUTE:
-                    errno = 0;
-                    pdp_new[i] = strtod(updvals[i+1],&endptr);
-                    if (errno > 0){
-                        rrd_set_error("converting  '%s' to float: %s",updvals[i+1],rrd_strerror(errno));
-                        break;
-                    };
-                    if (endptr[0] != '\0'){
-                        rrd_set_error("conversion of '%s' to float not complete: tail '%s'",updvals[i+1],endptr);
-                        break;
+    return 0;
+
+  err_free_rra_step_cnt:
+    free(*rra_step_cnt);
+  err_free_tmpl_idx:
+    free(*tmpl_idx);
+  err_free_skip_update:
+    free(*skip_update);
+  err_free_pdp_temp:
+    free(*pdp_temp);
+  err_free_updvals:
+    free(*updvals);
+    return -1;
+}
+
+/*
+ * Parses tmplt and puts an ordered list of DS's into tmpl_idx.
+ *
+ * Returns 0 on success.
+ */
+static int parse_template(
+    rrd_t *rrd,
+    const char *tmplt,
+    unsigned long *tmpl_cnt,
+    long *tmpl_idx)
+{
+    char     *dsname, *tmplt_copy;
+    unsigned int tmpl_len, i;
+    int       ret = 0;
+
+    *tmpl_cnt = 1;      /* the first entry is the time */
+
+    /* we should work on a writeable copy here */
+    if ((tmplt_copy = strdup(tmplt)) == NULL) {
+        rrd_set_error("error copying tmplt '%s'", tmplt);
+        ret = -1;
+        goto out;
+    }
+
+    dsname = tmplt_copy;
+    tmpl_len = strlen(tmplt_copy);
+    for (i = 0; i <= tmpl_len; i++) {
+        if (tmplt_copy[i] == ':' || tmplt_copy[i] == '\0') {
+            tmplt_copy[i] = '\0';
+            if (*tmpl_cnt > rrd->stat_head->ds_cnt) {
+                rrd_set_error("tmplt contains more DS definitions than RRD");
+                ret = -1;
+                goto out_free_tmpl_copy;
+            }
+            if ((tmpl_idx[(*tmpl_cnt)++] = ds_match(rrd, dsname) + 1) == 0) {
+                rrd_set_error("unknown DS name '%s'", dsname);
+                ret = -1;
+                goto out_free_tmpl_copy;
+            }
+            /* go to the next entry on the tmplt_copy */
+            if (i < tmpl_len)
+                dsname = &tmplt_copy[i + 1];
+        }
+    }
+  out_free_tmpl_copy:
+    free(tmplt_copy);
+  out:
+    return ret;
+}
+
+/*
+ * Parse an update string, updates the primary data points (PDPs)
+ * and consolidated data points (CDPs), and writes changes to the RRAs.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int process_arg(
+    char *step_start,
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long rra_begin,
+    time_t *current_time,
+    unsigned long *current_time_usec,
+    rrd_value_t *pdp_temp,
+    rrd_value_t *pdp_new,
+    unsigned long *rra_step_cnt,
+    char **updvals,
+    long *tmpl_idx,
+    unsigned long tmpl_cnt,
+    rrd_info_t ** pcdp_summary,
+    int version,
+    unsigned long *skip_update,
+    int *schedule_smooth)
+{
+    rrd_value_t *seasonal_coef = NULL, *last_seasonal_coef = NULL;
+
+    /* a vector of future Holt-Winters seasonal coefs */
+    unsigned long elapsed_pdp_st;
+
+    double    interval, pre_int, post_int;  /* interval between this and
+                                             * the last run */
+    unsigned long proc_pdp_cnt;
+
+    if (parse_ds(rrd, updvals, tmpl_idx, step_start, tmpl_cnt,
+                 current_time, current_time_usec, version) == -1) {
+        return -1;
+    }
+
+    interval = (double) (*current_time - rrd->live_head->last_up)
+        + (double) ((long) *current_time_usec -
+                    (long) rrd->live_head->last_up_usec) / 1e6f;
+
+    /* process the data sources and update the pdp_prep 
+     * area accordingly */
+    if (update_pdp_prep(rrd, updvals, pdp_new, interval) == -1) {
+        return -1;
+    }
+
+    elapsed_pdp_st = calculate_elapsed_steps(rrd,
+                                             *current_time,
+                                             *current_time_usec, interval,
+                                             &pre_int, &post_int,
+                                             &proc_pdp_cnt);
+
+    /* has a pdp_st moment occurred since the last run ? */
+    if (elapsed_pdp_st == 0) {
+        /* no we have not passed a pdp_st moment. therefore update is simple */
+        simple_update(rrd, interval, pdp_new);
+    } else {
+        /* an pdp_st has occurred. */
+        if (process_all_pdp_st(rrd, interval,
+                               pre_int, post_int,
+                               elapsed_pdp_st, pdp_new, pdp_temp) == -1) {
+            return -1;
+        }
+        if (update_all_cdp_prep(rrd, rra_step_cnt,
+                                rra_begin, rrd_file,
+                                elapsed_pdp_st,
+                                proc_pdp_cnt,
+                                &last_seasonal_coef,
+                                &seasonal_coef,
+                                pdp_temp,
+                                skip_update, schedule_smooth) == -1) {
+            goto err_free_coefficients;
+        }
+        if (update_aberrant_cdps(rrd, rrd_file, rra_begin,
+                                 elapsed_pdp_st, pdp_temp,
+                                 &seasonal_coef) == -1) {
+            goto err_free_coefficients;
+        }
+        if (write_to_rras(rrd, rrd_file, rra_step_cnt, rra_begin,
+                          *current_time, skip_update,
+                          pcdp_summary) == -1) {
+            goto err_free_coefficients;
+        }
+    }                   /* endif a pdp_st has occurred */
+    rrd->live_head->last_up = *current_time;
+    rrd->live_head->last_up_usec = *current_time_usec;
+
+    if (version < 3) {
+        *rrd->legacy_last_up = rrd->live_head->last_up;
+    }
+    free(seasonal_coef);
+    free(last_seasonal_coef);
+    return 0;
+
+  err_free_coefficients:
+    free(seasonal_coef);
+    free(last_seasonal_coef);
+    return -1;
+}
+
+/*
+ * Parse a DS string (time + colon-separated values), storing the
+ * results in current_time, current_time_usec, and updvals.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int parse_ds(
+    rrd_t *rrd,
+    char **updvals,
+    long *tmpl_idx,
+    char *input,
+    unsigned long tmpl_cnt,
+    time_t *current_time,
+    unsigned long *current_time_usec,
+    int version)
+{
+    char     *p;
+    unsigned long i;
+    char      timesyntax;
+
+    updvals[0] = input;
+    /* initialize all ds input to unknown except the first one
+       which has always got to be set */
+    for (i = 1; i <= rrd->stat_head->ds_cnt; i++)
+        updvals[i] = "U";
+
+    /* separate all ds elements; first must be examined separately
+       due to alternate time syntax */
+    if ((p = strchr(input, '@')) != NULL) {
+        timesyntax = '@';
+    } else if ((p = strchr(input, ':')) != NULL) {
+        timesyntax = ':';
+    } else {
+        rrd_set_error("expected timestamp not found in data source from %s",
+                      input);
+        return -1;
+    }
+    *p = '\0';
+    i = 1;
+    updvals[tmpl_idx[i++]] = p + 1;
+    while (*(++p)) {
+        if (*p == ':') {
+            *p = '\0';
+            if (i < tmpl_cnt) {
+                updvals[tmpl_idx[i++]] = p + 1;
+            }
+            else {
+                rrd_set_error("found extra data on update argument: %s",p+1);
+                return -1;
+            }                
+        }
+    }
+
+    if (i != tmpl_cnt) {
+        rrd_set_error("expected %lu data source readings (got %lu) from %s",
+                      tmpl_cnt - 1, i - 1, input);
+        return -1;
+    }
+
+    if (get_time_from_reading(rrd, timesyntax, updvals,
+                              current_time, current_time_usec,
+                              version) == -1) {
+        return -1;
+    }
+    return 0;
+}
+
+/*
+ * Parse the time in a DS string, store it in current_time and 
+ * current_time_usec and verify that it's later than the last
+ * update for this DS.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int get_time_from_reading(
+    rrd_t *rrd,
+    char timesyntax,
+    char **updvals,
+    time_t *current_time,
+    unsigned long *current_time_usec,
+    int version)
+{
+    double    tmp;
+    char     *parsetime_error = NULL;
+    char     *old_locale;
+    rrd_time_value_t ds_tv;
+    struct timeval tmp_time;    /* used for time conversion */
+
+    /* get the time from the reading ... handle N */
+    if (timesyntax == '@') {    /* at-style */
+        if ((parsetime_error = rrd_parsetime(updvals[0], &ds_tv))) {
+            rrd_set_error("ds time: %s: %s", updvals[0], parsetime_error);
+            return -1;
+        }
+        if (ds_tv.type == RELATIVE_TO_END_TIME ||
+            ds_tv.type == RELATIVE_TO_START_TIME) {
+            rrd_set_error("specifying time relative to the 'start' "
+                          "or 'end' makes no sense here: %s", updvals[0]);
+            return -1;
+        }
+        *current_time = mktime(&ds_tv.tm) +ds_tv.offset;
+        *current_time_usec = 0; /* FIXME: how to handle usecs here ? */
+    } else if (strcmp(updvals[0], "N") == 0) {
+        gettimeofday(&tmp_time, 0);
+        normalize_time(&tmp_time);
+        *current_time = tmp_time.tv_sec;
+        *current_time_usec = tmp_time.tv_usec;
+    } else {
+        old_locale = setlocale(LC_NUMERIC, NULL);
+        setlocale(LC_NUMERIC, "C");
+        errno = 0;
+        tmp = strtod(updvals[0], 0);
+        if (errno > 0) {
+            rrd_set_error("converting '%s' to float: %s",
+                updvals[0], rrd_strerror(errno));
+            return -1;
+        };
+        setlocale(LC_NUMERIC, old_locale);
+        if (tmp < 0.0){
+            gettimeofday(&tmp_time, 0);
+            tmp = (double)tmp_time.tv_sec + (double)tmp_time.tv_usec * 1e-6f + tmp;
+        }
+
+        *current_time = floor(tmp);
+        *current_time_usec = (long) ((tmp - (double) *current_time) * 1e6f);
+    }
+    /* dont do any correction for old version RRDs */
+    if (version < 3)
+        *current_time_usec = 0;
+
+    if (*current_time < rrd->live_head->last_up ||
+        (*current_time == rrd->live_head->last_up &&
+         (long) *current_time_usec <= (long) rrd->live_head->last_up_usec)) {
+        rrd_set_error("illegal attempt to update using time %ld when "
+                      "last update time is %ld (minimum one second step)",
+                      *current_time, rrd->live_head->last_up);
+        return -1;
+    }
+    return 0;
+}
+
+/*
+ * Update pdp_new by interpreting the updvals according to the DS type
+ * (COUNTER, GAUGE, etc.).
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int update_pdp_prep(
+    rrd_t *rrd,
+    char **updvals,
+    rrd_value_t *pdp_new,
+    double interval)
+{
+    unsigned long ds_idx;
+    int       ii;
+    char     *endptr;   /* used in the conversion */
+    double    rate;
+    char     *old_locale;
+    enum dst_en dst_idx;
+
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+        dst_idx = dst_conv(rrd->ds_def[ds_idx].dst);
+
+        /* make sure we do not build diffs with old last_ds values */
+        if (rrd->ds_def[ds_idx].par[DS_mrhb_cnt].u_cnt < interval) {
+            strncpy(rrd->pdp_prep[ds_idx].last_ds, "U", LAST_DS_LEN - 1);
+            rrd->pdp_prep[ds_idx].last_ds[LAST_DS_LEN - 1] = '\0';
+        }
+
+        /* NOTE: DST_CDEF should never enter this if block, because
+         * updvals[ds_idx+1][0] is initialized to 'U'; unless the caller
+         * accidently specified a value for the DST_CDEF. To handle this case,
+         * an extra check is required. */
+
+        if ((updvals[ds_idx + 1][0] != 'U') &&
+            (dst_idx != DST_CDEF) &&
+            rrd->ds_def[ds_idx].par[DS_mrhb_cnt].u_cnt >= interval) {
+            rate = DNAN;
+
+            /* pdp_new contains rate * time ... eg the bytes transferred during
+             * the interval. Doing it this way saves a lot of math operations
+             */
+            switch (dst_idx) {
+            case DST_COUNTER:
+            case DST_DERIVE:
+                /* Check if this is a valid integer. `U' is already handled in
+                 * another branch. */
+                for (ii = 0; updvals[ds_idx + 1][ii] != 0; ii++) {
+                    if ((ii == 0) && (dst_idx == DST_DERIVE)
+                            && (updvals[ds_idx + 1][ii] == '-'))
+                        continue;
+
+                    if ((updvals[ds_idx + 1][ii] < '0')
+                            || (updvals[ds_idx + 1][ii] > '9')) {
+                        rrd_set_error("not a simple %s integer: '%s'",
+                                (dst_idx == DST_DERIVE) ? "signed" : "unsigned",
+                                updvals[ds_idx + 1]);
+                        return -1;
                     }
-                   rate = pdp_new[i] / interval;                 
-                   break;
-               case DST_GAUGE:
-                    errno = 0;
-                    pdp_new[i] = strtod(updvals[i+1],&endptr) * interval;
-                    if (errno > 0){
-                        rrd_set_error("converting  '%s' to float: %s",updvals[i+1],rrd_strerror(errno));
-                        break;
-                    };
-                    if (endptr[0] != '\0'){
-                        rrd_set_error("conversion of '%s' to float not complete: tail '%s'",updvals[i+1],endptr);
-                        break;
+                } /* for (ii = 0; updvals[ds_idx + 1][ii] != 0; ii++) */
+
+                if (rrd->pdp_prep[ds_idx].last_ds[0] != 'U') {
+                    pdp_new[ds_idx] =
+                        rrd_diff(updvals[ds_idx + 1],
+                                 rrd->pdp_prep[ds_idx].last_ds);
+                    if (dst_idx == DST_COUNTER) {
+                        /* simple overflow catcher. This will fail
+                         * terribly for non 32 or 64 bit counters
+                         * ... are there any others in SNMP land?
+                         */
+                        if (pdp_new[ds_idx] < (double) 0.0)
+                            pdp_new[ds_idx] += (double) 4294967296.0;   /* 2^32 */
+                        if (pdp_new[ds_idx] < (double) 0.0)
+                            pdp_new[ds_idx] += (double) 18446744069414584320.0; /* 2^64-2^32 */
                     }
-                   rate = pdp_new[i] / interval;                  
-                   break;
-               default:
-                   rrd_set_error("rrd contains unknown DS type : '%s'",
-                                 rrd.ds_def[i].dst);
-                   break;
-               }
-               /* break out of this for loop if the error string is set */
-               if (rrd_test_error()){
-                   break;
-               }
-              /* make sure pdp_temp is neither too large or too small
-               * if any of these occur it becomes unknown ...
-               * sorry folks ... */
-              if ( ! isnan(rate) && 
-                   (( ! isnan(rrd.ds_def[i].par[DS_max_val].u_val) &&
-                        rate > rrd.ds_def[i].par[DS_max_val].u_val ) ||     
-                   ( ! isnan(rrd.ds_def[i].par[DS_min_val].u_val) &&
-                       rate < rrd.ds_def[i].par[DS_min_val].u_val ))){
-                 pdp_new[i] = DNAN;
-              }               
-           } else {
-               /* no news is news all the same */
-               pdp_new[i] = DNAN;
-           }
-
-           
-           /* make a copy of the command line argument for the next run */
+                    rate = pdp_new[ds_idx] / interval;
+                } else {
+                    pdp_new[ds_idx] = DNAN;
+                }
+                break;
+            case DST_ABSOLUTE:
+                old_locale = setlocale(LC_NUMERIC, NULL);
+                setlocale(LC_NUMERIC, "C");
+                errno = 0;
+                pdp_new[ds_idx] = strtod(updvals[ds_idx + 1], &endptr);
+                if (errno > 0) {
+                    rrd_set_error("converting '%s' to float: %s",
+                                  updvals[ds_idx + 1], rrd_strerror(errno));
+                    return -1;
+                };
+                setlocale(LC_NUMERIC, old_locale);
+                if (endptr[0] != '\0') {
+                    rrd_set_error
+                        ("conversion of '%s' to float not complete: tail '%s'",
+                         updvals[ds_idx + 1], endptr);
+                    return -1;
+                }
+                rate = pdp_new[ds_idx] / interval;
+                break;
+            case DST_GAUGE:
+                old_locale = setlocale(LC_NUMERIC, NULL);
+                setlocale(LC_NUMERIC, "C");
+                errno = 0;
+                pdp_new[ds_idx] =
+                    strtod(updvals[ds_idx + 1], &endptr) * interval;
+                if (errno) {
+                    rrd_set_error("converting '%s' to float: %s",
+                                  updvals[ds_idx + 1], rrd_strerror(errno));
+                    return -1;
+                };
+                setlocale(LC_NUMERIC, old_locale);
+                if (endptr[0] != '\0') {
+                    rrd_set_error
+                        ("conversion of '%s' to float not complete: tail '%s'",
+                         updvals[ds_idx + 1], endptr);
+                    return -1;
+                }
+                rate = pdp_new[ds_idx] / interval;
+                break;
+            default:
+                rrd_set_error("rrd contains unknown DS type : '%s'",
+                              rrd->ds_def[ds_idx].dst);
+                return -1;
+            }
+            /* break out of this for loop if the error string is set */
+            if (rrd_test_error()) {
+                return -1;
+            }
+            /* make sure pdp_temp is neither too large or too small
+             * if any of these occur it becomes unknown ...
+             * sorry folks ... */
+            if (!isnan(rate) &&
+                ((!isnan(rrd->ds_def[ds_idx].par[DS_max_val].u_val) &&
+                  rate > rrd->ds_def[ds_idx].par[DS_max_val].u_val) ||
+                 (!isnan(rrd->ds_def[ds_idx].par[DS_min_val].u_val) &&
+                  rate < rrd->ds_def[ds_idx].par[DS_min_val].u_val))) {
+                pdp_new[ds_idx] = DNAN;
+            }
+        } else {
+            /* no news is news all the same */
+            pdp_new[ds_idx] = DNAN;
+        }
+
+
+        /* make a copy of the command line argument for the next run */
 #ifdef DEBUG
-           fprintf(stderr,
-                   "prep ds[%lu]\t"
-                   "last_arg '%s'\t"
-                   "this_arg '%s'\t"
-                   "pdp_new %10.2f\n",
-                   i,
-                   rrd.pdp_prep[i].last_ds,
-                   updvals[i+1], pdp_new[i]);
+        fprintf(stderr, "prep ds[%lu]\t"
+                "last_arg '%s'\t"
+                "this_arg '%s'\t"
+                "pdp_new %10.2f\n",
+                ds_idx, rrd->pdp_prep[ds_idx].last_ds, updvals[ds_idx + 1],
+                pdp_new[ds_idx]);
 #endif
-           strncpy(rrd.pdp_prep[i].last_ds, updvals[i+1],LAST_DS_LEN-1);
-           rrd.pdp_prep[i].last_ds[LAST_DS_LEN-1]='\0';
-       }
-       /* break out of the argument parsing loop if the error_string is set */
-       if (rrd_test_error()){
-           free(step_start);
-           break;
-       }
-       /* has a pdp_st moment occurred since the last run ? */
-
-       if (proc_pdp_st == occu_pdp_st){
-           /* no we have not passed a pdp_st moment. therefore update is simple */
-
-           for(i=0;i<rrd.stat_head->ds_cnt;i++){
-               if(isnan(pdp_new[i])) {            
-                   /* this is not realy accurate if we use subsecond data arival time
-                      should have thought of it when going subsecond resolution ...
-                       sorry next format change we will have it! */
-                   rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt += floor(interval);          
-               } else {
-                    if (isnan( rrd.pdp_prep[i].scratch[PDP_val].u_val )){
-                       rrd.pdp_prep[i].scratch[PDP_val].u_val= pdp_new[i];
-                    } else {
-                       rrd.pdp_prep[i].scratch[PDP_val].u_val+= pdp_new[i];
-                    }
-               }
-#ifdef DEBUG
-               fprintf(stderr,
-                       "NO PDP  ds[%lu]\t"
-                       "value %10.2f\t"
-                       "unkn_sec %5lu\n",
-                       i,
-                       rrd.pdp_prep[i].scratch[PDP_val].u_val,
-                       rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt);
-#endif
-           }   
-       } else {
-           /* an pdp_st has occurred. */
-
-           /* in pdp_prep[].scratch[PDP_val].u_val we have collected rate*seconds which 
-            * occurred up to the last run.        
-           pdp_new[] contains rate*seconds from the latest run.
-           pdp_temp[] will contain the rate for cdp */
-
-           for(i=0;i<rrd.stat_head->ds_cnt;i++){
-               /* update pdp_prep to the current pdp_st. */
-                double pre_unknown = 0.0;              
-               if(isnan(pdp_new[i]))
-                    /* a final bit of unkonwn to be added bevore calculation
-                    * we use a tempaorary variable for this so that we 
-                    * don't have to turn integer lines before using the value */                
-                   pre_unknown = pre_int;
-               else {
-                    if (isnan( rrd.pdp_prep[i].scratch[PDP_val].u_val )){
-                       rrd.pdp_prep[i].scratch[PDP_val].u_val=         pdp_new[i]/interval*pre_int;
-                    } else {
-                       rrd.pdp_prep[i].scratch[PDP_val].u_val+= pdp_new[i]/interval*pre_int;
-                    }
-                }
-               
-
-               /* if too much of the pdp_prep is unknown we dump it */
-               if ( 
-                   /* removed because this does not agree with the definition
-                      a heart beat can be unknown */
-                   /* (rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt 
-                    > rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt) || */
-                   /* if the interval is larger thatn mrhb we get NAN */
-                   (interval > rrd.ds_def[i].par[DS_mrhb_cnt].u_cnt) ||
-                   (occu_pdp_st-proc_pdp_st <= 
-                    rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt)) {
-                   pdp_temp[i] = DNAN;
-               } else {
-                   pdp_temp[i] = rrd.pdp_prep[i].scratch[PDP_val].u_val
-                       / ((double)(occu_pdp_st - proc_pdp_st
-                                    - rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt)
-                            -pre_unknown);
-               }
-
-               /* process CDEF data sources; remember each CDEF DS can
-                * only reference other DS with a lower index number */
-           if (dst_conv(rrd.ds_def[i].dst) == DST_CDEF) {
-                  rpnp_t *rpnp;
-                  rpnp = rpn_expand((rpn_cdefds_t *) &(rrd.ds_def[i].par[DS_cdef]));
-                  /* substitue data values for OP_VARIABLE nodes */
-                  for (ii = 0; rpnp[ii].op != OP_END; ii++)
-                  {
-                         if (rpnp[ii].op == OP_VARIABLE) {
-                                rpnp[ii].op = OP_NUMBER;
-                                rpnp[ii].val =  pdp_temp[rpnp[ii].ptr];
-                         }
-                  }
-                  /* run the rpn calculator */
-                  if (rpn_calc(rpnp,&rpnstack,0,pdp_temp,i) == -1) {
-                         free(rpnp);
-                         break; /* exits the data sources pdp_temp loop */
-                  }
-               }
-        
-               /* make pdp_prep ready for the next run */
-               if(isnan(pdp_new[i])){
-                   /* this is not realy accurate if we use subsecond data arival time
-                      should have thought of it when going subsecond resolution ...
-                       sorry next format change we will have it! */
-                   rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt = floor(post_int);
-                   rrd.pdp_prep[i].scratch[PDP_val].u_val = DNAN;
-               } else {
-                   rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt = 0;
-                   rrd.pdp_prep[i].scratch[PDP_val].u_val = 
-                       pdp_new[i]/interval*post_int;
-               }
+        strncpy(rrd->pdp_prep[ds_idx].last_ds, updvals[ds_idx + 1],
+                LAST_DS_LEN - 1);
+        rrd->pdp_prep[ds_idx].last_ds[LAST_DS_LEN - 1] = '\0';
+    }
+    return 0;
+}
 
-#ifdef DEBUG
-               fprintf(stderr,
-                       "PDP UPD ds[%lu]\t"
-                       "pdp_temp %10.2f\t"
-                       "new_prep %10.2f\t"
-                       "new_unkn_sec %5lu\n",
-                       i, pdp_temp[i],
-                       rrd.pdp_prep[i].scratch[PDP_val].u_val,
-                       rrd.pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt);
-#endif
-           }
+/*
+ * How many PDP steps have elapsed since the last update? Returns the answer,
+ * and stores the time between the last update and the last PDP in pre_time,
+ * and the time between the last PDP and the current time in post_int.
+ */
+static int calculate_elapsed_steps(
+    rrd_t *rrd,
+    unsigned long current_time,
+    unsigned long current_time_usec,
+    double interval,
+    double *pre_int,
+    double *post_int,
+    unsigned long *proc_pdp_cnt)
+{
+    unsigned long proc_pdp_st;  /* which pdp_st was the last to be processed */
+    unsigned long occu_pdp_st;  /* when was the pdp_st before the last update
+                                 * time */
+    unsigned long proc_pdp_age; /* how old was the data in the pdp prep area 
+                                 * when it was last updated */
+    unsigned long occu_pdp_age; /* how long ago was the last pdp_step time */
+
+    /* when was the current pdp started */
+    proc_pdp_age = rrd->live_head->last_up % rrd->stat_head->pdp_step;
+    proc_pdp_st = rrd->live_head->last_up - proc_pdp_age;
+
+    /* when did the last pdp_st occur */
+    occu_pdp_age = current_time % rrd->stat_head->pdp_step;
+    occu_pdp_st = current_time - occu_pdp_age;
+
+    if (occu_pdp_st > proc_pdp_st) {
+        /* OK we passed the pdp_st moment */
+        *pre_int = (long) occu_pdp_st - rrd->live_head->last_up;    /* how much of the input data
+                                                                     * occurred before the latest
+                                                                     * pdp_st moment*/
+        *pre_int -= ((double) rrd->live_head->last_up_usec) / 1e6f; /* adjust usecs */
+        *post_int = occu_pdp_age;   /* how much after it */
+        *post_int += ((double) current_time_usec) / 1e6f;   /* adjust usecs */
+    } else {
+        *pre_int = interval;
+        *post_int = 0;
+    }
 
-               /* if there were errors during the last loop, bail out here */
-           if (rrd_test_error()){
-              free(step_start);
-              break;
-           }
+    *proc_pdp_cnt = proc_pdp_st / rrd->stat_head->pdp_step;
 
-               /* compute the number of elapsed pdp_st moments */
-               elapsed_pdp_st = (occu_pdp_st - proc_pdp_st) / rrd.stat_head -> pdp_step;
 #ifdef DEBUG
-               fprintf(stderr,"elapsed PDP steps: %lu\n", elapsed_pdp_st);
+    printf("proc_pdp_age %lu\t"
+           "proc_pdp_st %lu\t"
+           "occu_pfp_age %lu\t"
+           "occu_pdp_st %lu\t"
+           "int %lf\t"
+           "pre_int %lf\t"
+           "post_int %lf\n", proc_pdp_age, proc_pdp_st,
+           occu_pdp_age, occu_pdp_st, interval, *pre_int, *post_int);
 #endif
-               if (rra_step_cnt == NULL)
-               {
-                  rra_step_cnt = (unsigned long *) 
-                         malloc((rrd.stat_head->rra_cnt)* sizeof(unsigned long));
-               }
-
-           for(i = 0, rra_start = rra_begin;
-               i < rrd.stat_head->rra_cnt;
-           rra_start += rrd.rra_def[i].row_cnt * rrd.stat_head -> ds_cnt * sizeof(rrd_value_t),
-               i++)
-               {
-               current_cf = cf_conv(rrd.rra_def[i].cf_nam);
-               start_pdp_offset = rrd.rra_def[i].pdp_cnt -
-                  (proc_pdp_st / rrd.stat_head -> pdp_step) % rrd.rra_def[i].pdp_cnt;
-        if (start_pdp_offset <= elapsed_pdp_st) {
-           rra_step_cnt[i] = (elapsed_pdp_st - start_pdp_offset) / 
-                     rrd.rra_def[i].pdp_cnt + 1;
-           } else {
-                  rra_step_cnt[i] = 0;
-               }
-
-               if (current_cf == CF_SEASONAL || current_cf == CF_DEVSEASONAL) 
-               {
-                  /* If this is a bulk update, we need to skip ahead in the seasonal
-                       * arrays so that they will be correct for the next observed value;
-                       * note that for the bulk update itself, no update will occur to
-                       * DEVSEASONAL or SEASONAL; futhermore, HWPREDICT and DEVPREDICT will
-                       * be set to DNAN. */
-           if (rra_step_cnt[i] > 2) 
-                  {
-                         /* skip update by resetting rra_step_cnt[i],
-                          * note that this is not data source specific; this is due
-                          * to the bulk update, not a DNAN value for the specific data
-                          * source. */
-                         rra_step_cnt[i] = 0;
-              lookup_seasonal(&rrd,i,rra_start,rrd_file,elapsed_pdp_st, 
-                            &last_seasonal_coef);
-                     lookup_seasonal(&rrd,i,rra_start,rrd_file,elapsed_pdp_st + 1,
-                            &seasonal_coef);
-                  }
-               
-                 /* periodically run a smoother for seasonal effects */
-                 /* Need to use first cdp parameter buffer to track
-                  * burnin (burnin requires a specific smoothing schedule).
-                  * The CDP_init_seasonal parameter is really an RRA level,
-                  * not a data source within RRA level parameter, but the rra_def
-                  * is read only for rrd_update (not flushed to disk). */
-                 iii = i*(rrd.stat_head -> ds_cnt);
-                 if (rrd.cdp_prep[iii].scratch[CDP_init_seasonal].u_cnt 
-                         <= BURNIN_CYCLES)
-                 {
-                    if (rrd.rra_ptr[i].cur_row + elapsed_pdp_st 
-                                > rrd.rra_def[i].row_cnt - 1) {
-                          /* mark off one of the burnin cycles */
-                          ++(rrd.cdp_prep[iii].scratch[CDP_init_seasonal].u_cnt);
-                      schedule_smooth = 1;
-                        }  
-                 } else {
-                        /* someone has no doubt invented a trick to deal with this
-                         * wrap around, but at least this code is clear. */
-                        if (rrd.rra_def[i].par[RRA_seasonal_smooth_idx].u_cnt >
-                            rrd.rra_ptr[i].cur_row)
-                        {
-                                /* here elapsed_pdp_st = rra_step_cnt[i] because of 1-1
-                                 * mapping between PDP and CDP */
-                                if (rrd.rra_ptr[i].cur_row + elapsed_pdp_st
-                                       >= rrd.rra_def[i].par[RRA_seasonal_smooth_idx].u_cnt)
-                                {
+
+    /* compute the number of elapsed pdp_st moments */
+    return (occu_pdp_st - proc_pdp_st) / rrd->stat_head->pdp_step;
+}
+
+/*
+ * Increment the PDP values by the values in pdp_new, or else initialize them.
+ */
+static void simple_update(
+    rrd_t *rrd,
+    double interval,
+    rrd_value_t *pdp_new)
+{
+    int       i;
+
+    for (i = 0; i < (signed) rrd->stat_head->ds_cnt; i++) {
+        if (isnan(pdp_new[i])) {
+            /* this is not really accurate if we use subsecond data arrival time
+               should have thought of it when going subsecond resolution ...
+               sorry next format change we will have it! */
+            rrd->pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt +=
+                floor(interval);
+        } else {
+            if (isnan(rrd->pdp_prep[i].scratch[PDP_val].u_val)) {
+                rrd->pdp_prep[i].scratch[PDP_val].u_val = pdp_new[i];
+            } else {
+                rrd->pdp_prep[i].scratch[PDP_val].u_val += pdp_new[i];
+            }
+        }
 #ifdef DEBUG
-                                       fprintf(stderr,
-                                       "schedule_smooth 1: cur_row %lu, elapsed_pdp_st %lu, smooth idx %lu\n",
-                    rrd.rra_ptr[i].cur_row, elapsed_pdp_st, 
-                                       rrd.rra_def[i].par[RRA_seasonal_smooth_idx].u_cnt);
+        fprintf(stderr,
+                "NO PDP  ds[%i]\t"
+                "value %10.2f\t"
+                "unkn_sec %5lu\n",
+                i,
+                rrd->pdp_prep[i].scratch[PDP_val].u_val,
+                rrd->pdp_prep[i].scratch[PDP_unkn_sec_cnt].u_cnt);
 #endif
-                                       schedule_smooth = 1;
-                                }
-             } else {
-                                /* can't rely on negative numbers because we are working with
-                                 * unsigned values */
-                                /* Don't need modulus here. If we've wrapped more than once, only
-                                 * one smooth is executed at the end. */
-                                if (rrd.rra_ptr[i].cur_row + elapsed_pdp_st >= rrd.rra_def[i].row_cnt
-                                       && rrd.rra_ptr[i].cur_row + elapsed_pdp_st - rrd.rra_def[i].row_cnt
-                                       >= rrd.rra_def[i].par[RRA_seasonal_smooth_idx].u_cnt)
-                                {
+    }
+}
+
+/*
+ * Call process_pdp_st for each DS.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int process_all_pdp_st(
+    rrd_t *rrd,
+    double interval,
+    double pre_int,
+    double post_int,
+    unsigned long elapsed_pdp_st,
+    rrd_value_t *pdp_new,
+    rrd_value_t *pdp_temp)
+{
+    unsigned long ds_idx;
+
+    /* in pdp_prep[].scratch[PDP_val].u_val we have collected
+       rate*seconds which occurred up to the last run.
+       pdp_new[] contains rate*seconds from the latest run.
+       pdp_temp[] will contain the rate for cdp */
+
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+        if (process_pdp_st(rrd, ds_idx, interval, pre_int, post_int,
+                           elapsed_pdp_st * rrd->stat_head->pdp_step,
+                           pdp_new, pdp_temp) == -1) {
+            return -1;
+        }
 #ifdef DEBUG
-                                       fprintf(stderr,
-                                       "schedule_smooth 2: cur_row %lu, elapsed_pdp_st %lu, smooth idx %lu\n",
-                    rrd.rra_ptr[i].cur_row, elapsed_pdp_st, 
-                                       rrd.rra_def[i].par[RRA_seasonal_smooth_idx].u_cnt);
+        fprintf(stderr, "PDP UPD ds[%lu]\t"
+                "elapsed_pdp_st %lu\t"
+                "pdp_temp %10.2f\t"
+                "new_prep %10.2f\t"
+                "new_unkn_sec %5lu\n",
+                ds_idx,
+                elapsed_pdp_st,
+                pdp_temp[ds_idx],
+                rrd->pdp_prep[ds_idx].scratch[PDP_val].u_val,
+                rrd->pdp_prep[ds_idx].scratch[PDP_unkn_sec_cnt].u_cnt);
 #endif
-                                       schedule_smooth = 1;
-                                }
-                        }
-                 }
-
-             rra_current = ftell(rrd_file); 
-               } /* if cf is DEVSEASONAL or SEASONAL */
-
-        if (rrd_test_error()) break;
-
-                   /* update CDP_PREP areas */
-                   /* loop over data soures within each RRA */
-                   for(ii = 0;
-                       ii < rrd.stat_head->ds_cnt;
-                       ii++)
-                       {
-                       
-                       /* iii indexes the CDP prep area for this data source within the RRA */
-                       iii=i*rrd.stat_head->ds_cnt+ii;
-
-                       if (rrd.rra_def[i].pdp_cnt > 1) {
-                         
-                          if (rra_step_cnt[i] > 0) {
-                          /* If we are in this block, as least 1 CDP value will be written to
-                               * disk, this is the CDP_primary_val entry. If more than 1 value needs
-                               * to be written, then the "fill in" value is the CDP_secondary_val
-                               * entry. */
-                                 if (isnan(pdp_temp[ii]))
-                  {
-                                        rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].u_cnt += start_pdp_offset;
-                                        rrd.cdp_prep[iii].scratch[CDP_secondary_val].u_val = DNAN;
-                                 } else {
-                                        /* CDP_secondary value is the RRA "fill in" value for intermediary
-                                         * CDP data entries. No matter the CF, the value is the same because
-                                         * the average, max, min, and last of a list of identical values is
-                                         * the same, namely, the value itself. */
-                                        rrd.cdp_prep[iii].scratch[CDP_secondary_val].u_val = pdp_temp[ii];
-                                 }
-                     
-                                 if (rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].u_cnt
-                                     > rrd.rra_def[i].pdp_cnt*
-                                     rrd.rra_def[i].par[RRA_cdp_xff_val].u_val)
-                                 {
-                                        rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = DNAN;
-                                        /* initialize carry over */
-                                        if (current_cf == CF_AVERAGE) {
-                                                  if (isnan(pdp_temp[ii])) { 
-                                                         rrd.cdp_prep[iii].scratch[CDP_val].u_val = DNAN;
-                                                  } else {
-                                                         rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii] *
-                                                                ((elapsed_pdp_st - start_pdp_offset) % rrd.rra_def[i].pdp_cnt);
-                                                  }
-                                        } else {
-                                               rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                        }
-                                 } else {
-                                        rrd_value_t cum_val, cur_val; 
-                                    switch (current_cf) {
-                                               case CF_AVERAGE:
-                                                 cum_val = IFDNAN(rrd.cdp_prep[iii].scratch[CDP_val].u_val, 0.0);
-                                                 cur_val = IFDNAN(pdp_temp[ii],0.0);
-                          rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val =
-                                              (cum_val + cur_val * start_pdp_offset) /
-                                          (rrd.rra_def[i].pdp_cnt
-                                              -rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].u_cnt);
-                                                  /* initialize carry over value */
-                                                  if (isnan(pdp_temp[ii])) { 
-                                                         rrd.cdp_prep[iii].scratch[CDP_val].u_val = DNAN;
-                                                  } else {
-                                                         rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii] *
-                                                                ((elapsed_pdp_st - start_pdp_offset) % rrd.rra_def[i].pdp_cnt);
-                                                  }
-                                                  break;
-                                               case CF_MAXIMUM:
-                                                 cum_val = IFDNAN(rrd.cdp_prep[iii].scratch[CDP_val].u_val, -DINF);
-                                                 cur_val = IFDNAN(pdp_temp[ii],-DINF);
+    }
+    return 0;
+}
+
+/*
+ * Process an update that occurs after one of the PDP moments.
+ * Increments the PDP value, sets NAN if time greater than the
+ * heartbeats have elapsed, processes CDEFs.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int process_pdp_st(
+    rrd_t *rrd,
+    unsigned long ds_idx,
+    double interval,
+    double pre_int,
+    double post_int,
+    long diff_pdp_st,   /* number of seconds in full steps passed since last update */
+    rrd_value_t *pdp_new,
+    rrd_value_t *pdp_temp)
+{
+    int       i;
+
+    /* update pdp_prep to the current pdp_st. */
+    double    pre_unknown = 0.0;
+    unival   *scratch = rrd->pdp_prep[ds_idx].scratch;
+    unsigned long mrhb = rrd->ds_def[ds_idx].par[DS_mrhb_cnt].u_cnt;
+
+    rpnstack_t rpnstack;    /* used for COMPUTE DS */
+
+    rpnstack_init(&rpnstack);
+
+
+    if (isnan(pdp_new[ds_idx])) {
+        /* a final bit of unknown to be added before calculation
+           we use a temporary variable for this so that we
+           don't have to turn integer lines before using the value */
+        pre_unknown = pre_int;
+    } else {
+        if (isnan(scratch[PDP_val].u_val)) {
+            scratch[PDP_val].u_val = 0;
+        }
+        scratch[PDP_val].u_val += pdp_new[ds_idx] / interval * pre_int;
+    }
+
+    /* if too much of the pdp_prep is unknown we dump it */
+    /* if the interval is larger thatn mrhb we get NAN */
+    if ((interval > mrhb) ||
+        (rrd->stat_head->pdp_step / 2.0 <
+         (signed) scratch[PDP_unkn_sec_cnt].u_cnt)) {
+        pdp_temp[ds_idx] = DNAN;
+    } else {
+        pdp_temp[ds_idx] = scratch[PDP_val].u_val /
+            ((double) (diff_pdp_st - scratch[PDP_unkn_sec_cnt].u_cnt) -
+             pre_unknown);
+    }
+
+    /* process CDEF data sources; remember each CDEF DS can
+     * only reference other DS with a lower index number */
+    if (dst_conv(rrd->ds_def[ds_idx].dst) == DST_CDEF) {
+        rpnp_t   *rpnp;
+
+        rpnp =
+            rpn_expand((rpn_cdefds_t *) &(rrd->ds_def[ds_idx].par[DS_cdef]));
+        if(rpnp == NULL) {
+          rpnstack_free(&rpnstack);
+          return -1;
+        }
+        /* substitute data values for OP_VARIABLE nodes */
+        for (i = 0; rpnp[i].op != OP_END; i++) {
+            if (rpnp[i].op == OP_VARIABLE) {
+                rpnp[i].op = OP_NUMBER;
+                rpnp[i].val = pdp_temp[rpnp[i].ptr];
+            }
+        }
+        /* run the rpn calculator */
+        if (rpn_calc(rpnp, &rpnstack, 0, pdp_temp, ds_idx) == -1) {
+            free(rpnp);
+            rpnstack_free(&rpnstack);
+            return -1;
+        }
+        free(rpnp);
+    }
+
+    /* make pdp_prep ready for the next run */
+    if (isnan(pdp_new[ds_idx])) {
+        /* this is not realy accurate if we use subsecond data arival time
+           should have thought of it when going subsecond resolution ...
+           sorry next format change we will have it! */
+        scratch[PDP_unkn_sec_cnt].u_cnt = floor(post_int);
+        scratch[PDP_val].u_val = DNAN;
+    } else {
+        scratch[PDP_unkn_sec_cnt].u_cnt = 0;
+        scratch[PDP_val].u_val = pdp_new[ds_idx] / interval * post_int;
+    }
+    rpnstack_free(&rpnstack);
+    return 0;
+}
+
+/*
+ * Iterate over all the RRAs for a given DS and:
+ * 1. Decide whether to schedule a smooth later
+ * 2. Decide whether to skip updating SEASONAL and DEVSEASONAL
+ * 3. Update the CDP
+ *
+ * Returns 0 on success, -1 on error
+ */
+static int update_all_cdp_prep(
+    rrd_t *rrd,
+    unsigned long *rra_step_cnt,
+    unsigned long rra_begin,
+    rrd_file_t *rrd_file,
+    unsigned long elapsed_pdp_st,
+    unsigned long proc_pdp_cnt,
+    rrd_value_t **last_seasonal_coef,
+    rrd_value_t **seasonal_coef,
+    rrd_value_t *pdp_temp,
+    unsigned long *skip_update,
+    int *schedule_smooth)
+{
+    unsigned long rra_idx;
+
+    /* index into the CDP scratch array */
+    enum cf_en current_cf;
+    unsigned long rra_start;
+
+    /* number of rows to be updated in an RRA for a data value. */
+    unsigned long start_pdp_offset;
+
+    rra_start = rra_begin;
+    for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; rra_idx++) {
+        current_cf = cf_conv(rrd->rra_def[rra_idx].cf_nam);
+        start_pdp_offset =
+            rrd->rra_def[rra_idx].pdp_cnt -
+            proc_pdp_cnt % rrd->rra_def[rra_idx].pdp_cnt;
+        skip_update[rra_idx] = 0;
+        if (start_pdp_offset <= elapsed_pdp_st) {
+            rra_step_cnt[rra_idx] = (elapsed_pdp_st - start_pdp_offset) /
+                rrd->rra_def[rra_idx].pdp_cnt + 1;
+        } else {
+            rra_step_cnt[rra_idx] = 0;
+        }
+
+        if (current_cf == CF_SEASONAL || current_cf == CF_DEVSEASONAL) {
+            /* If this is a bulk update, we need to skip ahead in the seasonal arrays
+             * so that they will be correct for the next observed value; note that for
+             * the bulk update itself, no update will occur to DEVSEASONAL or SEASONAL;
+             * futhermore, HWPREDICT and DEVPREDICT will be set to DNAN. */
+            if (rra_step_cnt[rra_idx] > 1) {
+                skip_update[rra_idx] = 1;
+                lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                elapsed_pdp_st, last_seasonal_coef);
+                lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                elapsed_pdp_st + 1, seasonal_coef);
+            }
+            /* periodically run a smoother for seasonal effects */
+            if (do_schedule_smooth(rrd, rra_idx, elapsed_pdp_st)) {
 #ifdef DEBUG
-                                                 if (isnan(rrd.cdp_prep[iii].scratch[CDP_val].u_val) &&
-                                                         isnan(pdp_temp[ii])) {
-                                                    fprintf(stderr,
-                                                               "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!",
-                                                               i,ii);
-                                                        exit(-1);
-                                                 }
+                fprintf(stderr,
+                        "schedule_smooth: cur_row %lu, elapsed_pdp_st %lu, smooth idx %lu\n",
+                        rrd->rra_ptr[rra_idx].cur_row, elapsed_pdp_st,
+                        rrd->rra_def[rra_idx].par[RRA_seasonal_smooth_idx].
+                        u_cnt);
 #endif
-                                                 if (cur_val > cum_val)
-                                                        rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = cur_val;
-                                                 else
-                                                        rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = cum_val;
-                                                 /* initialize carry over value */
-                                                 rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                                 break;
-                                               case CF_MINIMUM:
-                                                 cum_val = IFDNAN(rrd.cdp_prep[iii].scratch[CDP_val].u_val, DINF);
-                                                 cur_val = IFDNAN(pdp_temp[ii],DINF);
+                *schedule_smooth = 1;
+            }
+        }
+        if (rrd_test_error())
+            return -1;
+
+        if (update_cdp_prep
+            (rrd, elapsed_pdp_st, start_pdp_offset, rra_step_cnt, rra_idx,
+             pdp_temp, *last_seasonal_coef, *seasonal_coef,
+             current_cf) == -1) {
+            return -1;
+        }
+        rra_start +=
+            rrd->rra_def[rra_idx].row_cnt * rrd->stat_head->ds_cnt *
+            sizeof(rrd_value_t);
+    }
+    return 0;
+}
+
+/* 
+ * Are we due for a smooth? Also increments our position in the burn-in cycle.
+ */
+static int do_schedule_smooth(
+    rrd_t *rrd,
+    unsigned long rra_idx,
+    unsigned long elapsed_pdp_st)
+{
+    unsigned long cdp_idx = rra_idx * (rrd->stat_head->ds_cnt);
+    unsigned long cur_row = rrd->rra_ptr[rra_idx].cur_row;
+    unsigned long row_cnt = rrd->rra_def[rra_idx].row_cnt;
+    unsigned long seasonal_smooth_idx =
+        rrd->rra_def[rra_idx].par[RRA_seasonal_smooth_idx].u_cnt;
+    unsigned long *init_seasonal =
+        &(rrd->cdp_prep[cdp_idx].scratch[CDP_init_seasonal].u_cnt);
+
+    /* Need to use first cdp parameter buffer to track burnin (burnin requires
+     * a specific smoothing schedule).  The CDP_init_seasonal parameter is
+     * really an RRA level, not a data source within RRA level parameter, but
+     * the rra_def is read only for rrd_update (not flushed to disk). */
+    if (*init_seasonal > BURNIN_CYCLES) {
+        /* someone has no doubt invented a trick to deal with this wrap around,
+         * but at least this code is clear. */
+        if (seasonal_smooth_idx > cur_row) {
+            /* here elapsed_pdp_st = rra_step_cnt[rra_idx] because of 1-1 mapping
+             * between PDP and CDP */
+            return (cur_row + elapsed_pdp_st >= seasonal_smooth_idx);
+        }
+        /* can't rely on negative numbers because we are working with
+         * unsigned values */
+        return (cur_row + elapsed_pdp_st >= row_cnt
+                && cur_row + elapsed_pdp_st >= row_cnt + seasonal_smooth_idx);
+    }
+    /* mark off one of the burn-in cycles */
+    return (cur_row + elapsed_pdp_st >= row_cnt && ++(*init_seasonal));
+}
+
+/*
+ * For a given RRA, iterate over the data sources and call the appropriate
+ * consolidation function.
+ *
+ * Returns 0 on success, -1 on error.
+ */
+static int update_cdp_prep(
+    rrd_t *rrd,
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long *rra_step_cnt,
+    int rra_idx,
+    rrd_value_t *pdp_temp,
+    rrd_value_t *last_seasonal_coef,
+    rrd_value_t *seasonal_coef,
+    int current_cf)
+{
+    unsigned long ds_idx, cdp_idx;
+
+    /* update CDP_PREP areas */
+    /* loop over data soures within each RRA */
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+
+        cdp_idx = rra_idx * rrd->stat_head->ds_cnt + ds_idx;
+
+        if (rrd->rra_def[rra_idx].pdp_cnt > 1) {
+            update_cdp(rrd->cdp_prep[cdp_idx].scratch, current_cf,
+                       pdp_temp[ds_idx], rra_step_cnt[rra_idx],
+                       elapsed_pdp_st, start_pdp_offset,
+                       rrd->rra_def[rra_idx].pdp_cnt,
+                       rrd->rra_def[rra_idx].par[RRA_cdp_xff_val].u_val,
+                       rra_idx, ds_idx);
+        } else {
+            /* Nothing to consolidate if there's one PDP per CDP. However, if
+             * we've missed some PDPs, let's update null counters etc. */
+            if (elapsed_pdp_st > 2) {
+                reset_cdp(rrd, elapsed_pdp_st, pdp_temp, last_seasonal_coef,
+                          seasonal_coef, rra_idx, ds_idx, cdp_idx,
+                          (enum cf_en)current_cf);
+            }
+        }
+
+        if (rrd_test_error())
+            return -1;
+    }                   /* endif data sources loop */
+    return 0;
+}
+
+/*
+ * Given the new reading (pdp_temp_val), update or initialize the CDP value,
+ * primary value, secondary value, and # of unknowns.
+ */
+static void update_cdp(
+    unival *scratch,
+    int current_cf,
+    rrd_value_t pdp_temp_val,
+    unsigned long rra_step_cnt,
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt,
+    rrd_value_t xff,
+    int i,
+    int ii)
+{
+    /* shorthand variables */
+    rrd_value_t *cdp_val = &scratch[CDP_val].u_val;
+    rrd_value_t *cdp_primary_val = &scratch[CDP_primary_val].u_val;
+    rrd_value_t *cdp_secondary_val = &scratch[CDP_secondary_val].u_val;
+    unsigned long *cdp_unkn_pdp_cnt = &scratch[CDP_unkn_pdp_cnt].u_cnt;
+
+    if (rra_step_cnt) {
+        /* If we are in this block, as least 1 CDP value will be written to
+         * disk, this is the CDP_primary_val entry. If more than 1 value needs
+         * to be written, then the "fill in" value is the CDP_secondary_val
+         * entry. */
+        if (isnan(pdp_temp_val)) {
+            *cdp_unkn_pdp_cnt += start_pdp_offset;
+            *cdp_secondary_val = DNAN;
+        } else {
+            /* CDP_secondary value is the RRA "fill in" value for intermediary
+             * CDP data entries. No matter the CF, the value is the same because
+             * the average, max, min, and last of a list of identical values is
+             * the same, namely, the value itself. */
+            *cdp_secondary_val = pdp_temp_val;
+        }
+
+        if (*cdp_unkn_pdp_cnt > pdp_cnt * xff) {
+            *cdp_primary_val = DNAN;
+        } else {
+            initialize_cdp_val(scratch, current_cf, pdp_temp_val,
+                               start_pdp_offset, pdp_cnt);
+        }
+        *cdp_val =
+            initialize_carry_over(pdp_temp_val,current_cf,
+                                  elapsed_pdp_st,
+                                  start_pdp_offset, pdp_cnt);
+               /* endif meets xff value requirement for a valid value */
+        /* initialize carry over CDP_unkn_pdp_cnt, this must after CDP_primary_val
+         * is set because CDP_unkn_pdp_cnt is required to compute that value. */
+        if (isnan(pdp_temp_val))
+            *cdp_unkn_pdp_cnt = (elapsed_pdp_st - start_pdp_offset) % pdp_cnt;
+        else
+            *cdp_unkn_pdp_cnt = 0;
+    } else {            /* rra_step_cnt[i]  == 0 */
+
 #ifdef DEBUG
-                                                 if (isnan(rrd.cdp_prep[iii].scratch[CDP_val].u_val) &&
-                                                         isnan(pdp_temp[ii])) {
-                                                    fprintf(stderr,
-                                                               "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!",
-                                                               i,ii);
-                                                        exit(-1);
-                                                 }
+        if (isnan(*cdp_val)) {
+            fprintf(stderr, "schedule CDP_val update, RRA %d DS %d, DNAN\n",
+                    i, ii);
+        } else {
+            fprintf(stderr, "schedule CDP_val update, RRA %d DS %d, %10.2f\n",
+                    i, ii, *cdp_val);
+        }
 #endif
-                                                 if (cur_val < cum_val)
-                                                        rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = cur_val;
-                                                 else
-                                                        rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = cum_val;
-                                                 /* initialize carry over value */
-                                                 rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                                 break;
-                                               case CF_LAST:
-                                               default:
-                                                  rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = pdp_temp[ii];
-                                                  /* initialize carry over value */
-                                                  rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                               break;
-                                        }
-                                 } /* endif meets xff value requirement for a valid value */
-                                 /* initialize carry over CDP_unkn_pdp_cnt, this must after CDP_primary_val
-                                  * is set because CDP_unkn_pdp_cnt is required to compute that value. */
-                                 if (isnan(pdp_temp[ii]))
-                                        rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].u_cnt = 
-                                               (elapsed_pdp_st - start_pdp_offset) % rrd.rra_def[i].pdp_cnt;
-                                 else
-                                        rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].u_cnt = 0;
-               } else  /* rra_step_cnt[i]  == 0 */
-                          {
+        if (isnan(pdp_temp_val)) {
+            *cdp_unkn_pdp_cnt += elapsed_pdp_st;
+        } else {
+            *cdp_val =
+                calculate_cdp_val(*cdp_val, pdp_temp_val, elapsed_pdp_st,
+                                  current_cf, i, ii);
+        }
+    }
+}
+
+/*
+ * Set the CDP_primary_val and CDP_val to the appropriate initial value based
+ * on the type of consolidation function.
+ */
+static void initialize_cdp_val(
+    unival *scratch,
+    int current_cf,
+    rrd_value_t pdp_temp_val,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt)
+{
+    rrd_value_t cum_val, cur_val;
+
+    switch (current_cf) {
+    case CF_AVERAGE:
+        cum_val = IFDNAN(scratch[CDP_val].u_val, 0.0);
+        cur_val = IFDNAN(pdp_temp_val, 0.0);
+        scratch[CDP_primary_val].u_val =
+            (cum_val + cur_val * start_pdp_offset) /
+            (pdp_cnt - scratch[CDP_unkn_pdp_cnt].u_cnt);
+        break;
+    case CF_MAXIMUM: 
+        cum_val = IFDNAN(scratch[CDP_val].u_val, -DINF);
+        cur_val = IFDNAN(pdp_temp_val, -DINF);
+
+#if 0
 #ifdef DEBUG
-                                 if (isnan(rrd.cdp_prep[iii].scratch[CDP_val].u_val)) {
-                                 fprintf(stderr,"schedule CDP_val update, RRA %lu DS %lu, DNAN\n",
-                                        i,ii);
-                                 } else {
-                                 fprintf(stderr,"schedule CDP_val update, RRA %lu DS %lu, %10.2f\n",
-                                        i,ii,rrd.cdp_prep[iii].scratch[CDP_val].u_val);
-                                 }
+        if (isnan(scratch[CDP_val].u_val) && isnan(pdp_temp)) {
+            fprintf(stderr,
+                    "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!",
+                    i, ii);
+            exit(-1);
+        }
 #endif
-                                 if (isnan(pdp_temp[ii])) {
-                                rrd.cdp_prep[iii].scratch[CDP_unkn_pdp_cnt].u_cnt += elapsed_pdp_st;
-                                 } else if (isnan(rrd.cdp_prep[iii].scratch[CDP_val].u_val))
-                                 {
-                                        if (current_cf == CF_AVERAGE) {
-                                           rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii] *
-                                                  elapsed_pdp_st;
-                                        } else {
-                                           rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                        }
-#ifdef DEBUG
-                                        fprintf(stderr,"Initialize CDP_val for RRA %lu DS %lu: %10.2f\n",
-                                           i,ii,rrd.cdp_prep[iii].scratch[CDP_val].u_val);
 #endif
-                                 } else {
-                                        switch (current_cf) {
-                                        case CF_AVERAGE:
-                                           rrd.cdp_prep[iii].scratch[CDP_val].u_val += pdp_temp[ii] *
-                                                  elapsed_pdp_st;
-                                               break;
-                                        case CF_MINIMUM:
-                                               if (pdp_temp[ii] < rrd.cdp_prep[iii].scratch[CDP_val].u_val)
-                                                  rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                               break; 
-                                        case CF_MAXIMUM:
-                                               if (pdp_temp[ii] > rrd.cdp_prep[iii].scratch[CDP_val].u_val)
-                                                  rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                               break; 
-                                        case CF_LAST:
-                                        default:
-                                               rrd.cdp_prep[iii].scratch[CDP_val].u_val = pdp_temp[ii];
-                                               break;
-                                        }
-                                 }
-                          }
-                       } else { /* rrd.rra_def[i].pdp_cnt == 1 */
-                          if (elapsed_pdp_st > 2)
-                          {
-                                  switch (current_cf) {
-                                  case CF_AVERAGE:
-                                  default:
-                                 rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val=pdp_temp[ii];
-                                 rrd.cdp_prep[iii].scratch[CDP_secondary_val].u_val=pdp_temp[ii];
-                                         break;
-                   case CF_SEASONAL:
-                                  case CF_DEVSEASONAL:
-                                         /* need to update cached seasonal values, so they are consistent
-                                          * with the bulk update */
-                      /* WARNING: code relies on the fact that CDP_hw_last_seasonal and
-                                          * CDP_last_deviation are the same. */
-                      rrd.cdp_prep[iii].scratch[CDP_hw_last_seasonal].u_val =
-                                                last_seasonal_coef[ii];
-                                         rrd.cdp_prep[iii].scratch[CDP_hw_seasonal].u_val =
-                                                seasonal_coef[ii];
-                                         break;
-                   case CF_HWPREDICT:
-                                         /* need to update the null_count and last_null_count.
-                                          * even do this for non-DNAN pdp_temp because the
-                                          * algorithm is not learning from batch updates. */
-                                         rrd.cdp_prep[iii].scratch[CDP_null_count].u_cnt += 
-                                                elapsed_pdp_st;
-                                         rrd.cdp_prep[iii].scratch[CDP_last_null_count].u_cnt += 
-                                                elapsed_pdp_st - 1;
-                                         /* fall through */
-                                  case CF_DEVPREDICT:
-                                 rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = DNAN;
-                                 rrd.cdp_prep[iii].scratch[CDP_secondary_val].u_val = DNAN;
-                                         break;
-                   case CF_FAILURES:
-                                         /* do not count missed bulk values as failures */
-                                 rrd.cdp_prep[iii].scratch[CDP_primary_val].u_val = 0;
-                                 rrd.cdp_prep[iii].scratch[CDP_secondary_val].u_val = 0;
-                                         /* need to reset violations buffer.
-                                          * could do this more carefully, but for now, just
-                                          * assume a bulk update wipes away all violations. */
-                      erase_violations(&rrd, iii, i);
-                                         break;
-                                  }
-                          } 
-                       } /* endif rrd.rra_def[i].pdp_cnt == 1 */
-
-                       if (rrd_test_error()) break;
-
-                       } /* endif data sources loop */
-        } /* end RRA Loop */
-
-               /* this loop is only entered if elapsed_pdp_st < 3 */
-               for (j = elapsed_pdp_st, scratch_idx = CDP_primary_val; 
-                        j > 0 && j < 3; j--, scratch_idx = CDP_secondary_val)
-               {
-              for(i = 0, rra_start = rra_begin;
-                  i < rrd.stat_head->rra_cnt;
-              rra_start += rrd.rra_def[i].row_cnt * rrd.stat_head -> ds_cnt * sizeof(rrd_value_t),
-                  i++)
-                  {
-                         if (rrd.rra_def[i].pdp_cnt > 1) continue;
-
-                 current_cf = cf_conv(rrd.rra_def[i].cf_nam);
-                         if (current_cf == CF_SEASONAL || current_cf == CF_DEVSEASONAL)
-                         {
-                        lookup_seasonal(&rrd,i,rra_start,rrd_file,
-                                   elapsed_pdp_st + (scratch_idx == CDP_primary_val ? 1 : 2),
-                               &seasonal_coef);
-                 rra_current = ftell(rrd_file);
-                         }
-                         if (rrd_test_error()) break;
-                     /* loop over data soures within each RRA */
-                     for(ii = 0;
-                         ii < rrd.stat_head->ds_cnt;
-                         ii++)
-                         {
-                            update_aberrant_CF(&rrd,pdp_temp[ii],current_cf,
-                                       i*(rrd.stat_head->ds_cnt) + ii,i,ii,
-                                   scratch_idx, seasonal_coef);
-                         }
-           } /* end RRA Loop */
-                  if (rrd_test_error()) break;
-           } /* end elapsed_pdp_st loop */
-
-               if (rrd_test_error()) break;
-
-               /* Ready to write to disk */
-               /* Move sequentially through the file, writing one RRA at a time.
-                * Note this architecture divorces the computation of CDP with
-                * flushing updated RRA entries to disk. */
-           for(i = 0, rra_start = rra_begin;
-               i < rrd.stat_head->rra_cnt;
-           rra_start += rrd.rra_def[i].row_cnt * rrd.stat_head -> ds_cnt * sizeof(rrd_value_t),
-               i++) {
-               /* is th5Aere anything to write for this RRA? If not, continue. */
-        if (rra_step_cnt[i] == 0) continue;
-
-               /* write the first row */
+        if (cur_val > cum_val)
+            scratch[CDP_primary_val].u_val = cur_val;
+        else
+            scratch[CDP_primary_val].u_val = cum_val;
+        break;
+    case CF_MINIMUM:
+        cum_val = IFDNAN(scratch[CDP_val].u_val, DINF);
+        cur_val = IFDNAN(pdp_temp_val, DINF);
+#if 0
 #ifdef DEBUG
-        fprintf(stderr,"  -- RRA Preseek %ld\n",ftell(rrd_file));
+        if (isnan(scratch[CDP_val].u_val) && isnan(pdp_temp)) {
+            fprintf(stderr,
+                    "RRA %lu, DS %lu, both CDP_val and pdp_temp are DNAN!", i,
+                    ii);
+            exit(-1);
+        }
 #endif
-           rrd.rra_ptr[i].cur_row++;
-           if (rrd.rra_ptr[i].cur_row >= rrd.rra_def[i].row_cnt)
-                  rrd.rra_ptr[i].cur_row = 0; /* wrap around */
-               /* positition on the first row */
-               rra_pos_tmp = rra_start +
-                  (rrd.stat_head->ds_cnt)*(rrd.rra_ptr[i].cur_row)*sizeof(rrd_value_t);
-               if(rra_pos_tmp != rra_current) {
-#ifndef HAVE_MMAP
-                  if(fseek(rrd_file, rra_pos_tmp, SEEK_SET) != 0){
-                     rrd_set_error("seek error in rrd");
-                     break;
-                  }
 #endif
-                  rra_current = rra_pos_tmp;
-               }
+        if (cur_val < cum_val)
+            scratch[CDP_primary_val].u_val = cur_val;
+        else
+            scratch[CDP_primary_val].u_val = cum_val;
+        break;
+    case CF_LAST:
+    default:
+        scratch[CDP_primary_val].u_val = pdp_temp_val;
+        break;
+    }
+}
+
+/*
+ * Update the consolidation function for Holt-Winters functions as
+ * well as other functions that don't actually consolidate multiple
+ * PDPs.
+ */
+static void reset_cdp(
+    rrd_t *rrd,
+    unsigned long elapsed_pdp_st,
+    rrd_value_t *pdp_temp,
+    rrd_value_t *last_seasonal_coef,
+    rrd_value_t *seasonal_coef,
+    int rra_idx,
+    int ds_idx,
+    int cdp_idx,
+    enum cf_en current_cf)
+{
+    unival   *scratch = rrd->cdp_prep[cdp_idx].scratch;
+
+    switch (current_cf) {
+    case CF_AVERAGE:
+    default:
+        scratch[CDP_primary_val].u_val = pdp_temp[ds_idx];
+        scratch[CDP_secondary_val].u_val = pdp_temp[ds_idx];
+        break;
+    case CF_SEASONAL:
+    case CF_DEVSEASONAL:
+        /* need to update cached seasonal values, so they are consistent
+         * with the bulk update */
+        /* WARNING: code relies on the fact that CDP_hw_last_seasonal and
+         * CDP_last_deviation are the same. */
+        scratch[CDP_hw_last_seasonal].u_val = last_seasonal_coef[ds_idx];
+        scratch[CDP_hw_seasonal].u_val = seasonal_coef[ds_idx];
+        break;
+    case CF_HWPREDICT:
+    case CF_MHWPREDICT:
+        /* need to update the null_count and last_null_count.
+         * even do this for non-DNAN pdp_temp because the
+         * algorithm is not learning from batch updates. */
+        scratch[CDP_null_count].u_cnt += elapsed_pdp_st;
+        scratch[CDP_last_null_count].u_cnt += elapsed_pdp_st - 1;
+        /* fall through */
+    case CF_DEVPREDICT:
+        scratch[CDP_primary_val].u_val = DNAN;
+        scratch[CDP_secondary_val].u_val = DNAN;
+        break;
+    case CF_FAILURES:
+        /* do not count missed bulk values as failures */
+        scratch[CDP_primary_val].u_val = 0;
+        scratch[CDP_secondary_val].u_val = 0;
+        /* need to reset violations buffer.
+         * could do this more carefully, but for now, just
+         * assume a bulk update wipes away all violations. */
+        erase_violations(rrd, cdp_idx, rra_idx);
+        break;
+    }
+}
+
+static rrd_value_t initialize_carry_over(
+    rrd_value_t pdp_temp_val,
+    int current_cf,
+    unsigned long elapsed_pdp_st,
+    unsigned long start_pdp_offset,
+    unsigned long pdp_cnt)
+{
+    unsigned long pdp_into_cdp_cnt = ((elapsed_pdp_st - start_pdp_offset) % pdp_cnt);
+    if ( pdp_into_cdp_cnt == 0 || isnan(pdp_temp_val)){
+        switch (current_cf) {
+        case CF_MAXIMUM:
+            return -DINF;
+        case CF_MINIMUM:
+            return DINF;
+        case CF_AVERAGE:
+            return 0;
+        default:
+            return DNAN;
+        }        
+    } 
+    else {
+        switch (current_cf) {
+        case CF_AVERAGE:
+            return pdp_temp_val *  pdp_into_cdp_cnt ;
+        default:
+            return pdp_temp_val;
+        }        
+    }        
+}
 
+/*
+ * Update or initialize a CDP value based on the consolidation
+ * function.
+ *
+ * Returns the new value.
+ */
+static rrd_value_t calculate_cdp_val(
+    rrd_value_t cdp_val,
+    rrd_value_t pdp_temp_val,
+    unsigned long elapsed_pdp_st,
+    int current_cf,
 #ifdef DEBUG
-           fprintf(stderr,"  -- RRA Postseek %ld\n",ftell(rrd_file));
-#endif
-               scratch_idx = CDP_primary_val;
-               if (pcdp_summary != NULL)
-               {
-                  rra_time = (current_time - current_time 
-                  % (rrd.rra_def[i].pdp_cnt*rrd.stat_head->pdp_step))
-                  - ((rra_step_cnt[i]-1)*rrd.rra_def[i].pdp_cnt*rrd.stat_head->pdp_step);
-               }
-#ifdef HAVE_MMAP
-               pcdp_summary = write_RRA_row(&rrd, i, &rra_current, scratch_idx, rrd_file, 
-                  pcdp_summary, &rra_time, rrd_mmaped_file);
+    int i,
+    int ii
 #else
-               pcdp_summary = write_RRA_row(&rrd, i, &rra_current, scratch_idx, rrd_file, 
-                  pcdp_summary, &rra_time);
-#endif
-               if (rrd_test_error()) break;
-
-               /* write other rows of the bulk update, if any */
-               scratch_idx = CDP_secondary_val;
-               for ( ; rra_step_cnt[i] > 1; rra_step_cnt[i]--)
-               {
-                  if (++rrd.rra_ptr[i].cur_row == rrd.rra_def[i].row_cnt)
-                  {
-#ifdef DEBUG
-              fprintf(stderr,"Wraparound for RRA %s, %lu updates left\n",
-                         rrd.rra_def[i].cf_nam, rra_step_cnt[i] - 1);
+    int UNUSED(i),
+    int UNUSED(ii)
 #endif
-                         /* wrap */
-                         rrd.rra_ptr[i].cur_row = 0;
-                         /* seek back to beginning of current rra */
-                     if (fseek(rrd_file, rra_start, SEEK_SET) != 0)
-                         {
-                        rrd_set_error("seek error in rrd");
-                        break;
-                         }
+    )
+{
+    if (isnan(cdp_val)) {
+        if (current_cf == CF_AVERAGE) {
+            pdp_temp_val *= elapsed_pdp_st;
+        }
 #ifdef DEBUG
-                 fprintf(stderr,"  -- Wraparound Postseek %ld\n",ftell(rrd_file));
-#endif
-                         rra_current = rra_start;
-                  }
-                  if (pcdp_summary != NULL)
-                  {
-                     rra_time = (current_time - current_time 
-                     % (rrd.rra_def[i].pdp_cnt*rrd.stat_head->pdp_step))
-                     - ((rra_step_cnt[i]-2)*rrd.rra_def[i].pdp_cnt*rrd.stat_head->pdp_step);
-                  }
-#ifdef HAVE_MMAP
-                  pcdp_summary = write_RRA_row(&rrd, i, &rra_current, scratch_idx, rrd_file,
-                     pcdp_summary, &rra_time, rrd_mmaped_file);
-#else
-                  pcdp_summary = write_RRA_row(&rrd, i, &rra_current, scratch_idx, rrd_file,
-                     pcdp_summary, &rra_time);
+        fprintf(stderr, "Initialize CDP_val for RRA %d DS %d: %10.2f\n",
+                i, ii, pdp_temp_val);
 #endif
-               }
-               
-               if (rrd_test_error())
-                 break;
-               } /* RRA LOOP */
-
-           /* break out of the argument parsing loop if error_string is set */
-           if (rrd_test_error()){
-                  free(step_start);
-                  break;
-           } 
-           
-       } /* endif a pdp_st has occurred */ 
-       rrd.live_head->last_up = current_time;
-       rrd.live_head->last_up_usec = current_time_usec; 
-       free(step_start);
-    } /* function argument loop */
-
-    if (seasonal_coef != NULL) free(seasonal_coef);
-    if (last_seasonal_coef != NULL) free(last_seasonal_coef);
-       if (rra_step_cnt != NULL) free(rra_step_cnt);
-    rpnstack_free(&rpnstack);
-
-#ifdef HAVE_MMAP
-    if (munmap(rrd_mmaped_file, rrd_filesize) == -1) {
-            rrd_set_error("error writing(unmapping) file: %s", filename);
-    }
-#endif    
-    /* if we got here and if there is an error and if the file has not been
-     * written to, then close things up and return. */
-    if (rrd_test_error()) {
-       free(updvals);
-       free(tmpl_idx);
-       rrd_free(&rrd);
-       free(pdp_temp);
-       free(pdp_new);
-       fclose(rrd_file);
-       return(-1);
-    }
-
-    /* aargh ... that was tough ... so many loops ... anyway, its done.
-     * we just need to write back the live header portion now*/
-
-    if (fseek(rrd_file, (sizeof(stat_head_t)
-                        + sizeof(ds_def_t)*rrd.stat_head->ds_cnt 
-                        + sizeof(rra_def_t)*rrd.stat_head->rra_cnt),
-             SEEK_SET) != 0) {
-       rrd_set_error("seek rrd for live header writeback");
-       free(updvals);
-       free(tmpl_idx);
-       rrd_free(&rrd);
-       free(pdp_temp);
-       free(pdp_new);
-       fclose(rrd_file);
-       return(-1);
+        return pdp_temp_val;
     }
+    if (current_cf == CF_AVERAGE)
+        return cdp_val + pdp_temp_val * elapsed_pdp_st;
+    if (current_cf == CF_MINIMUM)
+        return (pdp_temp_val < cdp_val) ? pdp_temp_val : cdp_val;
+    if (current_cf == CF_MAXIMUM)
+        return (pdp_temp_val > cdp_val) ? pdp_temp_val : cdp_val;
+
+    return pdp_temp_val;
+}
 
-    if(version >= 3) {
-           if(fwrite( rrd.live_head,
-                      sizeof(live_head_t), 1, rrd_file) != 1){
-               rrd_set_error("fwrite live_head to rrd");
-               free(updvals);
-               rrd_free(&rrd);
-               free(tmpl_idx);
-               free(pdp_temp);
-               free(pdp_new);
-               fclose(rrd_file);
-               return(-1);
-           }
-    }
-    else {
-           if(fwrite( &rrd.live_head->last_up,
-                      sizeof(time_t), 1, rrd_file) != 1){
-               rrd_set_error("fwrite live_head to rrd");
-               free(updvals);
-               rrd_free(&rrd);
-               free(tmpl_idx);
-               free(pdp_temp);
-               free(pdp_new);
-               fclose(rrd_file);
-               return(-1);
-           }
-    }
-           
-
-    if(fwrite( rrd.pdp_prep,
-              sizeof(pdp_prep_t),
-              rrd.stat_head->ds_cnt, rrd_file) != rrd.stat_head->ds_cnt){
-       rrd_set_error("ftwrite pdp_prep to rrd");
-       free(updvals);
-       rrd_free(&rrd);
-       free(tmpl_idx);
-       free(pdp_temp);
-       free(pdp_new);
-       fclose(rrd_file);
-       return(-1);
+/*
+ * For each RRA, update the seasonal values and then call update_aberrant_CF
+ * for each data source.
+ *
+ * Return 0 on success, -1 on error.
+ */
+static int update_aberrant_cdps(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long rra_begin,
+    unsigned long elapsed_pdp_st,
+    rrd_value_t *pdp_temp,
+    rrd_value_t **seasonal_coef)
+{
+    unsigned long rra_idx, ds_idx, j;
+
+    /* number of PDP steps since the last update that
+     * are assigned to the first CDP to be generated
+     * since the last update. */
+    unsigned short scratch_idx;
+    unsigned long rra_start;
+    enum cf_en current_cf;
+
+    /* this loop is only entered if elapsed_pdp_st < 3 */
+    for (j = elapsed_pdp_st, scratch_idx = CDP_primary_val;
+         j > 0 && j < 3; j--, scratch_idx = CDP_secondary_val) {
+        rra_start = rra_begin;
+        for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; rra_idx++) {
+            if (rrd->rra_def[rra_idx].pdp_cnt == 1) {
+                current_cf = cf_conv(rrd->rra_def[rra_idx].cf_nam);
+                if (current_cf == CF_SEASONAL || current_cf == CF_DEVSEASONAL) {
+                    if (scratch_idx == CDP_primary_val) {
+                        lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                        elapsed_pdp_st + 1, seasonal_coef);
+                    } else {
+                        lookup_seasonal(rrd, rra_idx, rra_start, rrd_file,
+                                        elapsed_pdp_st + 2, seasonal_coef);
+                    }
+                }
+                if (rrd_test_error())
+                    return -1;
+                /* loop over data soures within each RRA */
+                for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+                    update_aberrant_CF(rrd, pdp_temp[ds_idx], current_cf,
+                                       rra_idx * (rrd->stat_head->ds_cnt) +
+                                       ds_idx, rra_idx, ds_idx, scratch_idx,
+                                       *seasonal_coef);
+                }
+            }
+            rra_start += rrd->rra_def[rra_idx].row_cnt
+                * rrd->stat_head->ds_cnt * sizeof(rrd_value_t);
+        }
     }
+    return 0;
+}
 
-    if(fwrite( rrd.cdp_prep,
-              sizeof(cdp_prep_t),
-              rrd.stat_head->rra_cnt *rrd.stat_head->ds_cnt, rrd_file) 
-       != rrd.stat_head->rra_cnt *rrd.stat_head->ds_cnt){
-
-       rrd_set_error("ftwrite cdp_prep to rrd");
-       free(updvals);
-       free(tmpl_idx);
-       rrd_free(&rrd);
-       free(pdp_temp);
-       free(pdp_new);
-       fclose(rrd_file);
-       return(-1);
-    }
+/* 
+ * Move sequentially through the file, writing one RRA at a time.  Note this
+ * architecture divorces the computation of CDP with flushing updated RRA
+ * entries to disk.
+ *
+ * Return 0 on success, -1 on error.
+ */
+static int write_to_rras(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long *rra_step_cnt,
+    unsigned long rra_begin,
+    time_t current_time,
+    unsigned long *skip_update,
+    rrd_info_t ** pcdp_summary)
+{
+    unsigned long rra_idx;
+    unsigned long rra_start;
+    time_t    rra_time = 0; /* time of update for a RRA */
 
-    if(fwrite( rrd.rra_ptr,
-              sizeof(rra_ptr_t), 
-              rrd.stat_head->rra_cnt,rrd_file) != rrd.stat_head->rra_cnt){
-       rrd_set_error("fwrite rra_ptr to rrd");
-       free(updvals);
-       free(tmpl_idx);
-       rrd_free(&rrd);
-       free(pdp_temp);
-       free(pdp_new);
-       fclose(rrd_file);
-       return(-1);
-    }
+    unsigned long ds_cnt = rrd->stat_head->ds_cnt;
     
-#ifdef HAVE_POSIX_FADVISExxx
+    /* Ready to write to disk */
+    rra_start = rra_begin;
 
-    /* with update we have write ops, so they will probably not be done by now, this means
-       the buffers will not get freed. But calling this for the whole file - header
-       will let the data off the hook as soon as it is written when if it is from a previous
-       update cycle. Calling fdsync to force things is much too hard here. */
+    for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; rra_idx++) {
+        rra_def_t *rra_def = &rrd->rra_def[rra_idx];
+        rra_ptr_t *rra_ptr = &rrd->rra_ptr[rra_idx];
 
-    if (0 != posix_fadvise(fileno(rrd_file), rra_begin, 0, POSIX_FADV_DONTNEED)) {
-         rrd_set_error("setting POSIX_FADV_DONTNEED on '%s': %s",filename, rrd_strerror(errno));
-         fclose(rrd_file);
-         return(-1);
-    } 
-#endif
+        /* for cdp_prep */
+        unsigned short scratch_idx;
+        unsigned long step_subtract;
 
-    /* OK now close the files and free the memory */
-    if(fclose(rrd_file) != 0){
-       rrd_set_error("closing rrd");
-       free(updvals);
-       free(tmpl_idx);
-       rrd_free(&rrd);
-       free(pdp_temp);
-       free(pdp_new);
-       return(-1);
-    }
+        for (scratch_idx = CDP_primary_val,
+                 step_subtract = 1;
+             rra_step_cnt[rra_idx] > 0;
+             rra_step_cnt[rra_idx]--,
+                 scratch_idx = CDP_secondary_val,
+                 step_subtract = 2) {
 
-    /* calling the smoothing code here guarantees at most
-        * one smoothing operation per rrd_update call. Unfortunately,
-        * it is possible with bulk updates, or a long-delayed update
-        * for smoothing to occur off-schedule. This really isn't
-        * critical except during the burning cycles. */
-       if (schedule_smooth)
-       {
-         rrd_file = fopen(filename,"rb+");
-          
-
-         rra_start = rra_begin;
-         for (i = 0; i < rrd.stat_head -> rra_cnt; ++i)
-         {
-           if (cf_conv(rrd.rra_def[i].cf_nam) == CF_DEVSEASONAL ||
-               cf_conv(rrd.rra_def[i].cf_nam) == CF_SEASONAL)
-           {
+            size_t rra_pos_new;
 #ifdef DEBUG
-             fprintf(stderr,"Running smoother for rra %ld\n",i);
+            fprintf(stderr, "  -- RRA Preseek %ld\n", rrd_file->pos);
 #endif
-             apply_smoother(&rrd,i,rra_start,rrd_file);
-             if (rrd_test_error())
-               break;
-           }
-           rra_start += rrd.rra_def[i].row_cnt
-             *rrd.stat_head->ds_cnt*sizeof(rrd_value_t);
-         }
-#ifdef HAVE_POSIX_FADVISExxx
-          /* same procedure as above ... */
-          if (0 != posix_fadvise(fileno(rrd_file), rra_begin, 0, POSIX_FADV_DONTNEED)) {
-             rrd_set_error("setting POSIX_FADV_DONTNEED on '%s': %s",filename, rrd_strerror(errno));
-             fclose(rrd_file);
-             return(-1);
-          } 
+            /* increment, with wrap-around */
+            if (++rra_ptr->cur_row >= rra_def->row_cnt)
+              rra_ptr->cur_row = 0;
+
+            /* we know what our position should be */
+            rra_pos_new = rra_start
+              + ds_cnt * rra_ptr->cur_row * sizeof(rrd_value_t);
+
+            /* re-seek if the position is wrong or we wrapped around */
+            if ((size_t)rra_pos_new != rrd_file->pos) {
+                if (rrd_seek(rrd_file, rra_pos_new, SEEK_SET) != 0) {
+                    rrd_set_error("seek error in rrd");
+                    return -1;
+                }
+            }
+#ifdef DEBUG
+            fprintf(stderr, "  -- RRA Postseek %ld\n", rrd_file->pos);
 #endif
-         fclose(rrd_file);
-       }
-    rrd_free(&rrd);
-    free(updvals);
-    free(tmpl_idx);
-    free(pdp_new);
-    free(pdp_temp);
-    return(0);
+
+            if (skip_update[rra_idx])
+                continue;
+
+            if (*pcdp_summary != NULL) {
+                unsigned long step_time = rra_def->pdp_cnt * rrd->stat_head->pdp_step;
+
+                rra_time = (current_time - current_time % step_time)
+                    - ((rra_step_cnt[rra_idx] - step_subtract) * step_time);
+            }
+
+            if (write_RRA_row
+                (rrd_file, rrd, rra_idx, scratch_idx,
+                 pcdp_summary, rra_time) == -1)
+                return -1;
+
+            rrd_notify_row(rrd_file, rra_idx, rra_pos_new, rra_time);
+        }
+
+        rra_start += rra_def->row_cnt * ds_cnt * sizeof(rrd_value_t);
+    } /* RRA LOOP */
+
+    return 0;
 }
 
 /*
- * get exclusive lock to whole file.
- * lock gets removed when we close the file
+ * Write out one row of values (one value per DS) to the archive.
  *
- * returns 0 on success
+ * Returns 0 on success, -1 on error.
  */
-int
-LockRRD(FILE *rrdfile)
+static int write_RRA_row(
+    rrd_file_t *rrd_file,
+    rrd_t *rrd,
+    unsigned long rra_idx,
+    unsigned short CDP_scratch_idx,
+    rrd_info_t ** pcdp_summary,
+    time_t rra_time)
 {
-    int        rrd_fd;         /* File descriptor for RRD */
-    int        rcstat;
+    unsigned long ds_idx, cdp_idx;
+    rrd_infoval_t iv;
 
-    rrd_fd = fileno(rrdfile);
+    for (ds_idx = 0; ds_idx < rrd->stat_head->ds_cnt; ds_idx++) {
+        /* compute the cdp index */
+        cdp_idx = rra_idx * (rrd->stat_head->ds_cnt) + ds_idx;
+#ifdef DEBUG
+        fprintf(stderr, "  -- RRA WRITE VALUE %e, at %ld CF:%s\n",
+                rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val,
+                rrd_file->pos, rrd->rra_def[rra_idx].cf_nam);
+#endif
+        if (*pcdp_summary != NULL) {
+            iv.u_val = rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val;
+            /* append info to the return hash */
+            *pcdp_summary = rrd_info_push(*pcdp_summary,
+                                          sprintf_alloc
+                                          ("[%lli]RRA[%s][%lu]DS[%s]", 
+                                           (long long)rra_time,
+                                           rrd->rra_def[rra_idx].cf_nam,
+                                           rrd->rra_def[rra_idx].pdp_cnt,
+                                           rrd->ds_def[ds_idx].ds_nam),
+                                           RD_I_VAL, iv);
+        }
+        errno = 0;
+        if (rrd_write(rrd_file,
+                      &(rrd->cdp_prep[cdp_idx].scratch[CDP_scratch_idx].
+                        u_val), sizeof(rrd_value_t)) != sizeof(rrd_value_t)) {
+            rrd_set_error("writing rrd: %s", rrd_strerror(errno));
+            return -1;
+        }
+    }
+    return 0;
+}
 
-       {
-#if defined(_WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
-    struct _stat st;
+/*
+ * Call apply_smoother for all DEVSEASONAL and SEASONAL RRAs.
+ *
+ * Returns 0 on success, -1 otherwise
+ */
+static int smooth_all_rras(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    unsigned long rra_begin)
+{
+    unsigned long rra_start = rra_begin;
+    unsigned long rra_idx;
+
+    for (rra_idx = 0; rra_idx < rrd->stat_head->rra_cnt; ++rra_idx) {
+        if (cf_conv(rrd->rra_def[rra_idx].cf_nam) == CF_DEVSEASONAL ||
+            cf_conv(rrd->rra_def[rra_idx].cf_nam) == CF_SEASONAL) {
+#ifdef DEBUG
+            fprintf(stderr, "Running smoother for rra %lu\n", rra_idx);
+#endif
+            apply_smoother(rrd, rra_idx, rra_start, rrd_file);
+            if (rrd_test_error())
+                return -1;
+        }
+        rra_start += rrd->rra_def[rra_idx].row_cnt
+            * rrd->stat_head->ds_cnt * sizeof(rrd_value_t);
+    }
+    return 0;
+}
 
-    if ( _fstat( rrd_fd, &st ) == 0 ) {
-           rcstat = _locking ( rrd_fd, _LK_NBLCK, st.st_size );
+#ifndef HAVE_MMAP
+/*
+ * Flush changes to disk (unless we're using mmap)
+ *
+ * Returns 0 on success, -1 otherwise
+ */
+static int write_changes_to_disk(
+    rrd_t *rrd,
+    rrd_file_t *rrd_file,
+    int version)
+{
+    /* we just need to write back the live header portion now */
+    if (rrd_seek(rrd_file, (sizeof(stat_head_t)
+                            + sizeof(ds_def_t) * rrd->stat_head->ds_cnt
+                            + sizeof(rra_def_t) * rrd->stat_head->rra_cnt),
+                 SEEK_SET) != 0) {
+        rrd_set_error("seek rrd for live header writeback");
+        return -1;
+    }
+    if (version >= 3) {
+        if (rrd_write(rrd_file, rrd->live_head,
+                      sizeof(live_head_t) * 1) != sizeof(live_head_t) * 1) {
+            rrd_set_error("rrd_write live_head to rrd");
+            return -1;
+        }
     } else {
-           rcstat = -1;
+        if (rrd_write(rrd_file, rrd->legacy_last_up,
+                      sizeof(time_t) * 1) != sizeof(time_t) * 1) {
+            rrd_set_error("rrd_write live_head to rrd");
+            return -1;
+        }
     }
-#else
-    struct flock       lock;
-    lock.l_type = F_WRLCK;    /* exclusive write lock */
-    lock.l_len = 0;          /* whole file */
-    lock.l_start = 0;        /* start of file */
-    lock.l_whence = SEEK_SET;   /* end of file */
 
-    rcstat = fcntl(rrd_fd, F_SETLK, &lock);
-#endif
-       }
 
-    return(rcstat);
-}
+    if (rrd_write(rrd_file, rrd->pdp_prep,
+                  sizeof(pdp_prep_t) * rrd->stat_head->ds_cnt)
+        != (ssize_t) (sizeof(pdp_prep_t) * rrd->stat_head->ds_cnt)) {
+        rrd_set_error("rrd_write pdp_prep to rrd");
+        return -1;
+    }
 
+    if (rrd_write(rrd_file, rrd->cdp_prep,
+                  sizeof(cdp_prep_t) * rrd->stat_head->rra_cnt *
+                  rrd->stat_head->ds_cnt)
+        != (ssize_t) (sizeof(cdp_prep_t) * rrd->stat_head->rra_cnt *
+                      rrd->stat_head->ds_cnt)) {
 
-#ifdef HAVE_MMAP
-info_t
-*write_RRA_row (rrd_t *rrd, unsigned long rra_idx, unsigned long *rra_current,
-              unsigned short CDP_scratch_idx, 
-#ifndef DEBUG
-FILE UNUSED(*rrd_file),
-#else
-FILE *rrd_file,
-#endif
-                  info_t *pcdp_summary, time_t *rra_time, void *rrd_mmaped_file)
-#else
-info_t
-*write_RRA_row (rrd_t *rrd, unsigned long rra_idx, unsigned long *rra_current,
-              unsigned short CDP_scratch_idx, FILE *rrd_file,
-                  info_t *pcdp_summary, time_t *rra_time)
-#endif
-{
-   unsigned long ds_idx, cdp_idx;
-   infoval iv;
-  
-   for (ds_idx = 0; ds_idx < rrd -> stat_head -> ds_cnt; ds_idx++)
-   {
-      /* compute the cdp index */
-      cdp_idx =rra_idx * (rrd -> stat_head->ds_cnt) + ds_idx;
-#ifdef DEBUG
-         fprintf(stderr,"  -- RRA WRITE VALUE %e, at %ld CF:%s\n",
-            rrd -> cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val,ftell(rrd_file),
-            rrd -> rra_def[rra_idx].cf_nam);
-#endif 
-      if (pcdp_summary != NULL)
-         {
-            iv.u_val = rrd -> cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val;
-            /* append info to the return hash */
-                pcdp_summary = info_push(pcdp_summary,
-                sprintf_alloc("[%d]RRA[%s][%lu]DS[%s]",
-                *rra_time, rrd->rra_def[rra_idx].cf_nam, 
-                rrd->rra_def[rra_idx].pdp_cnt, rrd->ds_def[ds_idx].ds_nam),
-         RD_I_VAL, iv);
-         }
-#ifdef HAVE_MMAP
-         memcpy((char *)rrd_mmaped_file + *rra_current,
-                         &(rrd -> cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val),
-                         sizeof(rrd_value_t));
-#else
-         if(fwrite(&(rrd -> cdp_prep[cdp_idx].scratch[CDP_scratch_idx].u_val),
-                sizeof(rrd_value_t),1,rrd_file) != 1)
-         { 
-            rrd_set_error("writing rrd");
-            return 0;
-         }
-#endif
-         *rra_current += sizeof(rrd_value_t);
-       }
-       return (pcdp_summary);
+        rrd_set_error("rrd_write cdp_prep to rrd");
+        return -1;
+    }
+
+    if (rrd_write(rrd_file, rrd->rra_ptr,
+                  sizeof(rra_ptr_t) * rrd->stat_head->rra_cnt)
+        != (ssize_t) (sizeof(rra_ptr_t) * rrd->stat_head->rra_cnt)) {
+        rrd_set_error("rrd_write rra_ptr to rrd");
+        return -1;
+    }
+    return 0;
 }
+#endif