X-Git-Url: https://git.octo.it/?p=rrdtool.git;a=blobdiff_plain;f=src%2Frrd_rpncalc.c;h=df46901f030b89db7d14f6645ff91ec4b2c7158d;hp=42b9c1040334ff699ca6e01d7eeb7b173757dcd4;hb=f9e5bd6a9d41c4607291cbbd88280129184ab325;hpb=a278779cdf2ded56b89fc404d6914bff7ad7dcbd

diff --git a/src/rrd_rpncalc.c b/src/rrd_rpncalc.c
index 42b9c10..df46901 100644
--- a/src/rrd_rpncalc.c
+++ b/src/rrd_rpncalc.c
@@ -1,11 +1,12 @@
 /****************************************************************************
- * RRDtool 1.0.28  Copyright Tobias Oetiker, 1997 - 2000
+ * RRDtool 1.2rc6  Copyright by Tobi Oetiker, 1997-2005
  ****************************************************************************
  * rrd_rpncalc.c  RPN calculator functions
  ****************************************************************************/
 
 #include "rrd_tool.h"
 #include "rrd_rpncalc.h"
+#include "rrd_graph.h"
 #include <limits.h>
 
 short addop2str(enum op_en op, enum op_en op_type, char *op_str, 
@@ -14,119 +15,127 @@ int tzoffset(time_t); /* used to implement LTIME */
 
 short rpn_compact(rpnp_t *rpnp, rpn_cdefds_t **rpnc, short *count)
 {
-   short i;
-   *count = 0;
-   /* count the number of rpn nodes */
-   while(rpnp[*count].op != OP_END) (*count)++;
-   if (++(*count) > DS_CDEF_MAX_RPN_NODES) {
-	  rrd_set_error("Maximum %d RPN nodes permitted",
-		 DS_CDEF_MAX_RPN_NODES);
-	  return -1;
-   }
-
-   /* allocate memory */
-   *rpnc = (rpn_cdefds_t *) calloc(*count,sizeof(rpn_cdefds_t));
-   for (i = 0; rpnp[i].op != OP_END; i++)
-   {
-	  (*rpnc)[i].op = (char) rpnp[i].op;
-	  if (rpnp[i].op == OP_NUMBER) {
-		 /* rpnp.val is a double, rpnc.val is a short */
-         double temp = floor(rpnp[i].val);
-         if (temp < SHRT_MIN || temp > SHRT_MAX) {
-			rrd_set_error(
+    short i;
+    *count = 0;
+    /* count the number of rpn nodes */
+    while(rpnp[*count].op != OP_END) (*count)++;
+    if (++(*count) > DS_CDEF_MAX_RPN_NODES) {
+        rrd_set_error("Maximum %d RPN nodes permitted",
+                      DS_CDEF_MAX_RPN_NODES);
+        return -1;
+    }
+    
+    /* allocate memory */
+    *rpnc = (rpn_cdefds_t *) calloc(*count,sizeof(rpn_cdefds_t));
+    for (i = 0; rpnp[i].op != OP_END; i++)
+    {
+        (*rpnc)[i].op = (char) rpnp[i].op;
+        if (rpnp[i].op == OP_NUMBER) {
+            /* rpnp.val is a double, rpnc.val is a short */
+            double temp = floor(rpnp[i].val);
+            if (temp < SHRT_MIN || temp > SHRT_MAX) {
+                rrd_set_error(
 		    "constants must be integers in the interval (%d, %d)",
-			SHRT_MIN, SHRT_MAX);
-		    free(*rpnc);	
-			return -1;
-		 }
-		 (*rpnc)[i].val = (short) temp;
-	  } else if (rpnp[i].op == OP_VARIABLE) {
-		 (*rpnc)[i].val = (short) rpnp[i].ptr;
-	  }
-   }
-   /* terminate the sequence */
-   (*rpnc)[(*count) - 1].op = OP_END;
-   return 0;
+                    SHRT_MIN, SHRT_MAX);
+                free(*rpnc);	
+                return -1;
+            }
+            (*rpnc)[i].val = (short) temp;
+	  } else if (rpnp[i].op == OP_VARIABLE ||
+				 rpnp[i].op == OP_PREV_OTHER) {
+            (*rpnc)[i].val = (short) rpnp[i].ptr;
+        }
+    }
+    /* terminate the sequence */
+    (*rpnc)[(*count) - 1].op = OP_END;
+    return 0;
 }
 
 rpnp_t * rpn_expand(rpn_cdefds_t *rpnc)
 {
-   short i;
-   rpnp_t *rpnp;
-
-   /* DS_CDEF_MAX_RPN_NODES is small, so at the expense of some wasted
-	* memory we avoid any reallocs */
-   rpnp = (rpnp_t *) calloc(DS_CDEF_MAX_RPN_NODES,sizeof(rpnp_t));
-   if (rpnp == NULL) return NULL;
-   for (i = 0; rpnc[i].op != OP_END; ++i)
-   {
-	  rpnp[i].op = (long) rpnc[i].op;
-	  if (rpnp[i].op == OP_NUMBER) {
-		 rpnp[i].val = (double) rpnc[i].val;
-	  } else if (rpnp[i].op == OP_VARIABLE) {
-		 rpnp[i].ptr = (long) rpnc[i].val;
-	  }
-   }
-   /* terminate the sequence */
-   rpnp[i].op = OP_END;
-   return rpnp;
+    short i;
+    rpnp_t *rpnp;
+    
+    /* DS_CDEF_MAX_RPN_NODES is small, so at the expense of some wasted
+     * memory we avoid any reallocs */
+    rpnp = (rpnp_t *) calloc(DS_CDEF_MAX_RPN_NODES,sizeof(rpnp_t));
+    if (rpnp == NULL) return NULL;
+    for (i = 0; rpnc[i].op != OP_END; ++i)
+    {
+        rpnp[i].op = (long) rpnc[i].op;
+        if (rpnp[i].op == OP_NUMBER) {
+            rpnp[i].val = (double) rpnc[i].val;
+	  } else if (rpnp[i].op == OP_VARIABLE ||
+				 rpnp[i].op == OP_PREV_OTHER) {
+            rpnp[i].ptr = (long) rpnc[i].val;
+        }
+    }
+    /* terminate the sequence */
+    rpnp[i].op = OP_END;
+    return rpnp;
 }
 
 /* rpn_compact2str: convert a compact sequence of RPN operator nodes back
  * into a CDEF string. This function is used by rrd_dump.
  * arguments:
  *  rpnc: an array of compact RPN operator nodes
- *  rrd: a pointer an rrd header (only the ds_cnt and ds_def elements need 
- *   to be valid) for lookup of data source names by index
+ *  ds_def: a pointer to the data source definition section of an RRD header
+ *   for lookup of data source names by index
  *  str: out string, memory is allocated by the function, must be freed by the
  *   the caller */
 void rpn_compact2str(rpn_cdefds_t *rpnc,ds_def_t *ds_def,char **str)
 {
-   unsigned short i,offset = 0;
-   char buffer[7]; /* short as a string */
-
-   for (i = 0; rpnc[i].op != OP_END; i++)
-   {
-      if (i > 0) (*str)[offset++] = ',';
-
+    unsigned short i,offset = 0;
+    char buffer[7]; /* short as a string */
+    
+    for (i = 0; rpnc[i].op != OP_END; i++)
+    {
+        if (i > 0) (*str)[offset++] = ',';
+        
 #define add_op(VV,VVV) \
 	  if (addop2str(rpnc[i].op, VV, VVV, str, &offset) == 1) continue;
-
-	  if (rpnc[i].op == OP_NUMBER) {
-		 /* convert a short into a string */
-#ifdef WIN32
-		 _itoa(rpnc[i].val,buffer,10);
+        
+        if (rpnc[i].op == OP_NUMBER) {
+            /* convert a short into a string */
+#if defined(WIN32) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
+            _itoa(rpnc[i].val,buffer,10);
 #else
-		 sprintf(buffer,"%d",rpnc[i].val);
+            sprintf(buffer,"%d",rpnc[i].val);
 #endif
-		 add_op(OP_NUMBER,buffer)
+            add_op(OP_NUMBER,buffer)
+                }
+        
+        if (rpnc[i].op == OP_VARIABLE) {
+            char *ds_name = ds_def[rpnc[i].val].ds_nam;
+            add_op(OP_VARIABLE, ds_name)
+                }
+
+	  if (rpnc[i].op == OP_PREV_OTHER) {
+		char *ds_name = ds_def[rpnc[i].val].ds_nam;
+		add_op(OP_VARIABLE, ds_name)
 	  }
 
-	  if (rpnc[i].op == OP_VARIABLE) {
-		 char *ds_name = ds_def[rpnc[i].val].ds_nam;
-	     add_op(OP_VARIABLE, ds_name)
-	  }
 #undef add_op
-
+        
 #define add_op(VV,VVV) \
 	  if (addop2str(rpnc[i].op, VV, #VVV, str, &offset) == 1) continue;
-
-	  add_op(OP_ADD,+)
-	  add_op(OP_SUB,-)
-	  add_op(OP_MUL,*)
-	  add_op(OP_DIV,/)
-	  add_op(OP_MOD,%)
-	  add_op(OP_SIN,SIN)
-	  add_op(OP_COS,COS)
-	  add_op(OP_LOG,LOG)
-      add_op(OP_FLOOR,FLOOR)
+        
+          add_op(OP_ADD,+)
+          add_op(OP_SUB,-)
+          add_op(OP_MUL,*)
+          add_op(OP_DIV,/)
+          add_op(OP_MOD,%)
+          add_op(OP_SIN,SIN)
+          add_op(OP_COS,COS)
+          add_op(OP_LOG,LOG)
+          add_op(OP_FLOOR,FLOOR)
 	  add_op(OP_CEIL,CEIL)
 	  add_op(OP_EXP,EXP)
 	  add_op(OP_DUP,DUP)
 	  add_op(OP_EXC,EXC)
 	  add_op(OP_POP,POP)
 	  add_op(OP_LT,LT)
-      add_op(OP_LE,LE)
+          add_op(OP_LE,LE)
 	  add_op(OP_GT,GT)
 	  add_op(OP_GE,GE)
 	  add_op(OP_EQ,EQ)
@@ -137,71 +146,77 @@ void rpn_compact2str(rpn_cdefds_t *rpnc,ds_def_t *ds_def,char **str)
 	  add_op(OP_UNKN,UNKN)
 	  add_op(OP_UN,UN)
 	  add_op(OP_NEGINF,NEGINF)
+	  add_op(OP_NE,NE)
 	  add_op(OP_PREV,PREV)
 	  add_op(OP_INF,INF)
+	  add_op(OP_ISINF,ISINF)
 	  add_op(OP_NOW,NOW)
 	  add_op(OP_LTIME,LTIME)
 	  add_op(OP_TIME,TIME)
-
+	  add_op(OP_ATAN,ATAN)
+	  add_op(OP_SQRT,SQRT)
+	  add_op(OP_SORT,SORT)
+	  add_op(OP_REV,REV)
+	  add_op(OP_TREND,TREND)
 #undef add_op
-   }
-   (*str)[offset] = '\0';
+              }
+    (*str)[offset] = '\0';
 
 }
 
 short addop2str(enum op_en op, enum op_en op_type, char *op_str, 
-	    char **result_str, unsigned short *offset)
+                char **result_str, unsigned short *offset)
 {
-   if (op == op_type) {
-	  short op_len;
-	  op_len = strlen(op_str);
-	  *result_str =  (char *) rrd_realloc(*result_str,
-		 (op_len + 1 + *offset)*sizeof(char));
-      if (*result_str == NULL) {
-		 rrd_set_error("failed to alloc memory in addop2str");
-		 return -1;
-	  }
-	  strncpy(&((*result_str)[*offset]),op_str,op_len);
-	  *offset += op_len;
-	  return 1;
-   }
-   return 0;
+    if (op == op_type) {
+        short op_len;
+        op_len = strlen(op_str);
+        *result_str =  (char *) rrd_realloc(*result_str,
+                                            (op_len + 1 + *offset)*sizeof(char));
+        if (*result_str == NULL) {
+            rrd_set_error("failed to alloc memory in addop2str");
+            return -1;
+        }
+        strncpy(&((*result_str)[*offset]),op_str,op_len);
+        *offset += op_len;
+        return 1;
+    }
+    return 0;
 }
 
 void parseCDEF_DS(char *def,rrd_t *rrd, int ds_idx)
 {
-   rpnp_t *rpnp = NULL;
-   rpn_cdefds_t *rpnc = NULL;
-   short count, i;
-
-   rpnp = rpn_parse((void*) rrd, def, &lookup_DS);
-   if (rpnp == NULL) {
-	  rrd_set_error("failed to parse computed data source %s", def);
-	  return;
-   }
-   /* Check for OP nodes not permitted in COMPUTE DS.
-    * Moved this check from within rpn_compact() because it really is
-	* COMPUTE DS specific. This is less efficient, but creation doesn't
-	* occur too often. */
-   for (i = 0; rpnp[i].op != OP_END; i++) {
-      if (rpnp[i].op == OP_TIME || rpnp[i].op == OP_LTIME || 
-		  rpnp[i].op == OP_PREV)
-	  {
-		 rrd_set_error(
-		 "operators time, ltime and prev not supported with DS COMPUTE");
-		 free(rpnp);
-		 return;
-	  }
-   }
-   if (rpn_compact(rpnp,&rpnc,&count) == -1) {
-	  free(rpnp);
-	  return;
-   }
-   /* copy the compact rpn representation over the ds_def par array */
-   memcpy((void*) &(rrd -> ds_def[ds_idx].par[DS_cdef]),
-		  (void*) rpnc, count*sizeof(rpn_cdefds_t));
-   free(rpnp);
-   free(rpnc);
+    rpnp_t *rpnp = NULL;
+    rpn_cdefds_t *rpnc = NULL;
+    short count, i;
+    
+    rpnp = rpn_parse((void*) rrd, def, &lookup_DS);
+    if (rpnp == NULL) {
+        rrd_set_error("failed to parse computed data source %s", def);
+        return;
+    }
+    /* Check for OP nodes not permitted in COMPUTE DS.
+     * Moved this check from within rpn_compact() because it really is
+     * COMPUTE DS specific. This is less efficient, but creation doesn't
+     * occur too often. */
+    for (i = 0; rpnp[i].op != OP_END; i++) {
+        if (rpnp[i].op == OP_TIME || rpnp[i].op == OP_LTIME || 
+            rpnp[i].op == OP_PREV || rpnp[i].op == OP_COUNT)
+        {
+            rrd_set_error(
+                "operators time, ltime, prev and count not supported with DS COMPUTE");
+            free(rpnp);
+            return;
+        }
+    }
+    if (rpn_compact(rpnp,&rpnc,&count) == -1) {
+        free(rpnp);
+        return;
+    }
+    /* copy the compact rpn representation over the ds_def par array */
+    memcpy((void*) &(rrd -> ds_def[ds_idx].par[DS_cdef]),
+           (void*) rpnc, count*sizeof(rpn_cdefds_t));
+    free(rpnp);
+    free(rpnc);
 }
 
 /* lookup a data source name in the rrd struct and return the index,
@@ -211,18 +226,18 @@ void parseCDEF_DS(char *def,rrd_t *rrd, int ds_idx)
  */
 long lookup_DS(void *rrd_vptr,char *ds_name)
 {
-   int i;
-   rrd_t *rrd; 
-   
-   rrd = (rrd_t *) rrd_vptr;
-
-   for (i = 0; i < rrd -> stat_head -> ds_cnt; ++i)
-   {
-      if(strcmp(ds_name,rrd -> ds_def[i].ds_nam) == 0)
-		 return i;
-   }
-   /* the caller handles a bad data source name in the rpn string */
-   return -1;
+    unsigned int i;
+    rrd_t *rrd; 
+    
+    rrd = (rrd_t *) rrd_vptr;
+    
+    for (i = 0; i < rrd -> stat_head -> ds_cnt; ++i)
+    {
+        if(strcmp(ds_name,rrd -> ds_def[i].ds_nam) == 0)
+            return i;
+    }
+    /* the caller handles a bad data source name in the rpn string */
+    return -1;
 }
 
 /* rpn_parse : parse a string and generate a rpnp array; modified
@@ -239,15 +254,15 @@ rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
     long steps=-1;    
     rpnp_t  *rpnp;
     char vname[30];
-
+    
     rpnp=NULL;
-
+    
     while(*expr){
 	if ((rpnp = (rpnp_t *) rrd_realloc(rpnp, (++steps + 2)* 
 				       sizeof(rpnp_t)))==NULL){
 	    return NULL;
 	}
-
+        
 	else if((sscanf(expr,"%lf%n",&rpnp[steps].val,&pos) == 1) && (expr[pos] == ',')){
  	    rpnp[steps].op = OP_NUMBER;
 	    expr+=pos;
@@ -259,6 +274,21 @@ rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
 	    expr+=strlen(#VVV); \
 	}
 
+
+#define match_op_param(VV,VVV) \
+        else if (sscanf(expr, #VVV "(" DEF_NAM_FMT ")",vname) == 1) { \
+          int length = 0; \
+          if ((length = strlen(#VVV)+strlen(vname)+2, \
+              expr[length] == ',' || expr[length] == '\0') ) { \
+             rpnp[steps].op = VV; \
+             rpnp[steps].ptr = (*lookup)(key_hash,vname); \
+             if (rpnp[steps].ptr < 0) { \
+			   free(rpnp); \
+			   return NULL; \
+			 } else expr+=length; \
+          } \
+        }
+
 	match_op(OP_ADD,+)
 	match_op(OP_SUB,-)
 	match_op(OP_MUL,*)
@@ -273,6 +303,7 @@ rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
 	match_op(OP_DUP,DUP)
 	match_op(OP_EXC,EXC)
 	match_op(OP_POP,POP)
+	match_op(OP_LTIME,LTIME)
 	match_op(OP_LT,LT)
 	match_op(OP_LE,LE)
 	match_op(OP_GT,GT)
@@ -286,28 +317,35 @@ rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
 	match_op(OP_UNKN,UNKN)
 	match_op(OP_UN,UN)
 	match_op(OP_NEGINF,NEGINF)
+	match_op(OP_NE,NE)
+	match_op(OP_COUNT,COUNT)
+	match_op_param(OP_PREV_OTHER,PREV)
 	match_op(OP_PREV,PREV)
 	match_op(OP_INF,INF)
+	match_op(OP_ISINF,ISINF)
 	match_op(OP_NOW,NOW)
-	match_op(OP_LTIME,LTIME)
 	match_op(OP_TIME,TIME)
-
+	match_op(OP_ATAN,ATAN)
+	match_op(OP_SQRT,SQRT)
+	match_op(OP_SORT,SORT)
+	match_op(OP_REV,REV)
+	match_op(OP_TREND,TREND)
 #undef match_op
 
 
-	else if ((sscanf(expr,"%29[_A-Za-z0-9]%n",
-			 vname,&pos) == 1) 
-		 && ((rpnp[steps].ptr = (*lookup)(key_hash,vname)) != -1)){
-	    rpnp[steps].op = OP_VARIABLE;
-	    expr+=pos;
-	}	   
-
+            else if ((sscanf(expr, DEF_NAM_FMT "%n",
+                             vname,&pos) == 1) 
+                     && ((rpnp[steps].ptr = (*lookup)(key_hash,vname)) != -1)){
+                rpnp[steps].op = OP_VARIABLE;
+                expr+=pos;
+            }	   
+        
 	else {
 	    free(rpnp);
 	    return NULL;
 	}
 	if (*expr == 0)
-	  break;
+            break;
 	if (*expr == ',')
 	    expr++;
 	else {
@@ -322,9 +360,9 @@ rpn_parse(void *key_hash,char *expr,long (*lookup)(void *,char*)){
 void
 rpnstack_init(rpnstack_t *rpnstack)
 {
-   rpnstack -> s = NULL;
-   rpnstack -> dc_stacksize = 0;
-   rpnstack -> dc_stackblock = 100;
+    rpnstack -> s = NULL;
+    rpnstack -> dc_stacksize = 0;
+    rpnstack -> dc_stackblock = 100;
 }
 
 void
@@ -335,6 +373,14 @@ rpnstack_free(rpnstack_t *rpnstack)
    rpnstack -> dc_stacksize = 0;
 }
 
+static int
+rpn_compare_double(const void *x, const void *y)
+{
+	double	diff = *((const double *)x) - *((const double *)y);
+	
+	return (diff < 0) ? -1 : (diff > 0) ? 1 : 0;
+}
+
 /* rpn_calc: run the RPN calculator; also performs variable substitution;
  * moved and modified from data_calc() originally included in rrd_graph.c 
  * arguments:
@@ -354,336 +400,375 @@ short
 rpn_calc(rpnp_t *rpnp, rpnstack_t *rpnstack, long data_idx, 
 		rrd_value_t *output, int output_idx)
 {
-   int rpi;
-   long stptr = -1;
+    int rpi;
+    long stptr = -1;
+   
+    /* process each op from the rpn in turn */
+    for (rpi=0; rpnp[rpi].op != OP_END; rpi++){
+	/* allocate or grow the stack */
+	if (stptr + 5 > rpnstack -> dc_stacksize){
+	    /* could move this to a separate function */
+	    rpnstack -> dc_stacksize += rpnstack -> dc_stackblock;		
+	    rpnstack -> s = rrd_realloc(rpnstack -> s,
+			(rpnstack -> dc_stacksize)*sizeof(*(rpnstack -> s)));
+	    if (rpnstack -> s == NULL){
+		rrd_set_error("RPN stack overflow");
+		return -1;
+	    }
+	}
 
-   /* process each op from the rpn in turn */
-   for (rpi=0; rpnp[rpi].op != OP_END; rpi++){
-	  /* allocate or grow the stack */
-      if (stptr + 5 > rpnstack -> dc_stacksize){
-			/* could move this to a separate function */
-		    rpnstack -> dc_stacksize += rpnstack -> dc_stackblock;		
-		    rpnstack -> s = rrd_realloc(rpnstack -> s,
-			   (rpnstack -> dc_stacksize)*sizeof(*(rpnstack -> s)));
-		    if (rpnstack -> s == NULL){
-			rrd_set_error("RPN stack overflow");
-			return -1;
-		    }
-	  }
-	  switch (rpnp[rpi].op){
-		case OP_NUMBER:
-		    rpnstack -> s[++stptr] = rpnp[rpi].val;
-		    break;
-		case OP_VARIABLE:
-            /* make sure we pull the correct value from the *.data array 
-		     * adjust the pointer into the array acordingly. 
-			 * Advance the ptr one row in the rra (skip over
-			 * non-relevant data sources) */
-		    if (data_idx % rpnp[rpi].step == 0){
-			   rpnp[rpi].data += rpnp[rpi].ds_cnt;
-		    }
+#define stackunderflow(MINSIZE)				\
+	if(stptr<MINSIZE){				\
+	    rrd_set_error("RPN stack underflow");	\
+	    return -1;					\
+	}
+
+	switch (rpnp[rpi].op){
+	    case OP_NUMBER:
+		rpnstack -> s[++stptr] = rpnp[rpi].val;
+		break;
+	    case OP_VARIABLE:
+		/* Sanity check: VDEFs shouldn't make it here */
+		if (rpnp[rpi].ds_cnt == 0) {
+		    rrd_set_error("VDEF made it into rpn_calc... aborting");
+		    return -1;
+		} else {
+		    /* make sure we pull the correct value from
+		     * the *.data array. Adjust the pointer into
+		     * the array acordingly. Advance the ptr one
+		     * row in the rra (skip over non-relevant
+		     * data sources)
+		     */
 		    rpnstack -> s[++stptr] =  *(rpnp[rpi].data);
-		    break;
-		case OP_PREV:
-		    if ((output_idx-1) <= 0) {
-               rpnstack -> s[++stptr] = DNAN;
-            } else {
-               rpnstack -> s[++stptr] = output[output_idx-1];
-            }
-		    break;
-		case OP_UNKN:
-		    rpnstack -> s[++stptr] = DNAN; 
-		    break;
-		case OP_INF:
-		    rpnstack -> s[++stptr] = DINF; 
-		    break;
-		case OP_NEGINF:
-		    rpnstack -> s[++stptr] = -DINF; 
-		    break;
-		case OP_NOW:
-		    rpnstack -> s[++stptr] = (double)time(NULL);
-		    break;
-		case OP_TIME:
-			/* HACK: this relies on the data_idx being the time,
-			 * which the within-function scope is unaware of */
-		    rpnstack -> s[++stptr] = (double) data_idx;
-		    break;
-		case OP_LTIME:
-		    rpnstack -> s[++stptr] = (double) tzoffset(data_idx) + (double)data_idx;
-		    break;
-		case OP_ADD:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] 
-			   + rpnstack -> s[stptr];
-		    stptr--;
-		    break;
-		case OP_SUB:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] - rpnstack -> s[stptr];
-		    stptr--;
-		    break;
-		case OP_MUL:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr-1] = (rpnstack -> s[stptr-1]) * (rpnstack -> s[stptr]);
-		    stptr--;
-		    break;
-		case OP_DIV:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] / rpnstack -> s[stptr];
-		    stptr--;
-		    break;
-		case OP_MOD:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr-1] = fmod(rpnstack -> s[stptr-1],rpnstack -> s[stptr]);
-		    stptr--;
-		    break;
-		case OP_SIN:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr] = sin(rpnstack -> s[stptr]);
-		    break;
-		case OP_COS:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr] = cos(rpnstack -> s[stptr]);
-		    break;
-		case OP_CEIL:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr] = ceil(rpnstack -> s[stptr]);
-		    break;
-		case OP_FLOOR:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr] = floor(rpnstack -> s[stptr]);
-		    break;
-		case OP_LOG:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr] = log(rpnstack -> s[stptr]);
-		    break;
-		case OP_DUP:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr+1] = rpnstack -> s[stptr];
-		    stptr++;
-		    break;
-		case OP_POP:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    stptr--;
-		    break;
-		case OP_EXC:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    } else {
-		      double dummy;
-		      dummy = rpnstack -> s[stptr] ;
-		      rpnstack -> s[stptr] = rpnstack -> s[stptr-1];
-		      rpnstack -> s[stptr-1] = dummy;
-		    }
-		    break;
-		case OP_EXP:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack -> s[stptr] = exp(rpnstack -> s[stptr]);
-		    break;
-		case OP_LT:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    if (isnan(rpnstack -> s[stptr-1])) 
-			;
-		    else if (isnan(rpnstack -> s[stptr]))
-		        rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
-		    else
-			    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] < rpnstack -> s[stptr] ? 1.0 : 0.0;
-		    stptr--;
-		    break;
-		case OP_LE:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    if (isnan(rpnstack -> s[stptr-1])) 
-			;
-		    else if (isnan(rpnstack -> s[stptr]))
-		        rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
-		    else
-			    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <= rpnstack -> s[stptr] ? 1.0 : 0.0;
-		    stptr--;
-		    break;
-		case OP_GT:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    if (isnan(rpnstack -> s[stptr-1])) 
-			;
-		    else if (isnan(rpnstack -> s[stptr]))
-		        rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
-		    else
-			    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] > rpnstack -> s[stptr] ? 1.0 : 0.0;
-		    stptr--;
-		    break;
-		case OP_GE:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    if (isnan(rpnstack -> s[stptr-1])) 
-			;
-		    else if (isnan(rpnstack -> s[stptr]))
-		        rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
-		    else
-			    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >= rpnstack -> s[stptr] ? 1.0 : 0.0;
-		    stptr--;
-		    break;
-		case OP_EQ:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    if (isnan(rpnstack -> s[stptr-1])) 
-			;
-		    else if (isnan(rpnstack -> s[stptr]))
-		        rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
-		    else
-			    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] == rpnstack -> s[stptr] ? 1.0 : 0.0;
-		    stptr--;
-		    break;
-		case OP_IF:
-		    if(stptr<2){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    rpnstack->s[stptr-2] = rpnstack->s[stptr-2] != 0.0 ? rpnstack->s[stptr-1] : rpnstack->s[stptr];
-		    stptr--;
-		    stptr--;
-		    break;
-		case OP_MIN:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    if (isnan(rpnstack->s[stptr-1])) 
-			;
-		    else if (isnan(rpnstack->s[stptr]))
-		        rpnstack->s[stptr-1] = rpnstack->s[stptr];
-		    else if (rpnstack->s[stptr-1] > rpnstack->s[stptr])
-		        rpnstack->s[stptr-1] = rpnstack->s[stptr];
-		    stptr--;
-		    break;
-		case OP_MAX:
-		    if(stptr<1){
-			rrd_set_error("RPN stack underflow");
-			return -1;
-		    }
-		    if (isnan(rpnstack->s[stptr-1])) 
-			;
-		    else if (isnan(rpnstack->s[stptr]))
-		        rpnstack->s[stptr-1] = rpnstack->s[stptr];
-		    else if (rpnstack->s[stptr-1] < rpnstack->s[stptr])
-		        rpnstack->s[stptr-1] = rpnstack->s[stptr];
-		    stptr--;
-		    break;
-		case OP_LIMIT:
-		    if(stptr<2){
-			rrd_set_error("RPN stack underflow");
-			free(rpnstack->s);
-			return -1;
+		    if (data_idx % rpnp[rpi].step == 0){
+			rpnp[rpi].data += rpnp[rpi].ds_cnt;
 		    }
-		    if (isnan(rpnstack->s[stptr-2])) 
-			;
-		    else if (isnan(rpnstack->s[stptr-1]))
-		        rpnstack->s[stptr-2] = rpnstack->s[stptr-1];
-		    else if (isnan(rpnstack->s[stptr]))
-		        rpnstack->s[stptr-2] = rpnstack->s[stptr];
-		    else if (rpnstack->s[stptr-2] < rpnstack->s[stptr-1])
-		        rpnstack->s[stptr-2] = DNAN;
-		    else if (rpnstack->s[stptr-2] > rpnstack->s[stptr])
-		        rpnstack->s[stptr-2] = DNAN;
-		    stptr-=2;
-		    break;
-		case OP_UN:
-		    if(stptr<0){
-			rrd_set_error("RPN stack underflow");
-			return -1;
+		}
+		break;
+	    case OP_COUNT:
+	    	rpnstack -> s[++stptr] = (output_idx+1); /* Note: Counter starts at 1 */
+	    	break;
+	    case OP_PREV:
+		if ((output_idx) <= 0) {
+		    rpnstack -> s[++stptr] = DNAN;
+		} else {
+		    rpnstack -> s[++stptr] = output[output_idx-1];
+		}
+		break;
+	case OP_PREV_OTHER:
+	  if ((output_idx) <= 0) {
+		rpnstack -> s[++stptr] = DNAN;
+	  } else {
+		rpnstack -> s[++stptr] = rpnp[rpnp[rpi].ptr].data[output_idx-1];
+	  }
+	  break;
+	    case OP_UNKN:
+		rpnstack -> s[++stptr] = DNAN; 
+		break;
+	    case OP_INF:
+		rpnstack -> s[++stptr] = DINF; 
+		break;
+	    case OP_NEGINF:
+		rpnstack -> s[++stptr] = -DINF; 
+		break;
+	    case OP_NOW:
+		rpnstack -> s[++stptr] = (double)time(NULL);
+		break;
+	    case OP_TIME:
+		/* HACK: this relies on the data_idx being the time,
+		** which the within-function scope is unaware of */
+		rpnstack -> s[++stptr] = (double) data_idx;
+		break;
+	    case OP_LTIME:
+		rpnstack -> s[++stptr] =
+			(double) tzoffset(data_idx) + (double)data_idx;
+		break;
+	    case OP_ADD:
+		stackunderflow(1);
+		rpnstack -> s[stptr-1]	= rpnstack -> s[stptr-1] 
+					+ rpnstack -> s[stptr];
+		stptr--;
+		break;
+	    case OP_SUB:
+		stackunderflow(1);
+		rpnstack -> s[stptr-1]	= rpnstack -> s[stptr-1]
+					- rpnstack -> s[stptr];
+		stptr--;
+		break;
+	    case OP_MUL:
+		stackunderflow(1);
+		rpnstack -> s[stptr-1]	= (rpnstack -> s[stptr-1])
+					* (rpnstack -> s[stptr]);
+		stptr--;
+		break;
+	    case OP_DIV:
+		stackunderflow(1);
+		rpnstack -> s[stptr-1]	= rpnstack -> s[stptr-1]
+					/ rpnstack -> s[stptr];
+		stptr--;
+		break;
+	    case OP_MOD:
+		stackunderflow(1);
+		rpnstack -> s[stptr-1]= fmod(	rpnstack -> s[stptr-1]
+						,rpnstack -> s[stptr]);
+		stptr--;
+		break;
+	    case OP_SIN:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = sin(rpnstack -> s[stptr]);
+		break;
+	    case OP_ATAN:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = atan(rpnstack -> s[stptr]);
+		break;
+	    case OP_COS:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = cos(rpnstack -> s[stptr]);
+		break;
+	    case OP_CEIL:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = ceil(rpnstack -> s[stptr]);
+		break;
+	    case OP_FLOOR:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = floor(rpnstack -> s[stptr]);
+		break;
+	    case OP_LOG:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = log(rpnstack -> s[stptr]);
+		break;
+	    case OP_DUP:
+		stackunderflow(0);
+		rpnstack -> s[stptr+1] = rpnstack -> s[stptr];
+		stptr++;
+		break;
+	    case OP_POP:
+		stackunderflow(0);
+		stptr--;
+		break;
+	    case OP_EXC:
+		stackunderflow(1);
+		{
+		    double dummy;
+		    dummy = rpnstack -> s[stptr] ;
+		    rpnstack -> s[stptr] = rpnstack -> s[stptr-1];
+		    rpnstack -> s[stptr-1] = dummy;
+		}
+		break;
+	    case OP_EXP:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = exp(rpnstack -> s[stptr]);
+		break;
+	    case OP_LT:
+		stackunderflow(1);
+		if (isnan(rpnstack -> s[stptr-1])) 
+		    ;
+		else if (isnan(rpnstack -> s[stptr]))
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+		else
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <
+					rpnstack -> s[stptr] ? 1.0 : 0.0;
+		stptr--;
+		break;
+	    case OP_LE:
+		stackunderflow(1);
+		if (isnan(rpnstack -> s[stptr-1])) 
+		    ;
+		else if (isnan(rpnstack -> s[stptr]))
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+		else
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] <=
+					rpnstack -> s[stptr] ? 1.0 : 0.0;
+		stptr--;
+		break;
+	    case OP_GT:
+		stackunderflow(1);
+		if (isnan(rpnstack -> s[stptr-1])) 
+		    ;
+		else if (isnan(rpnstack -> s[stptr]))
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+		else
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >
+					rpnstack -> s[stptr] ? 1.0 : 0.0;
+		stptr--;
+		break;
+	    case OP_GE:
+		stackunderflow(1);
+		if (isnan(rpnstack -> s[stptr-1])) 
+		    ;
+		else if (isnan(rpnstack -> s[stptr]))
+       		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+		else
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] >=
+					rpnstack -> s[stptr] ? 1.0 : 0.0;
+		stptr--;
+		break;
+	    case OP_NE:
+		stackunderflow(1);
+		if (isnan(rpnstack -> s[stptr-1]))
+		    ;
+		else if (isnan(rpnstack -> s[stptr]))
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+		else
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] ==
+					rpnstack -> s[stptr] ? 0.0 : 1.0;
+		stptr--;
+		break;
+	    case OP_EQ:
+		stackunderflow(1);
+		if (isnan(rpnstack -> s[stptr-1])) 
+		    ;
+		else if (isnan(rpnstack -> s[stptr]))
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr];
+		else
+		    rpnstack -> s[stptr-1] = rpnstack -> s[stptr-1] ==
+					rpnstack -> s[stptr] ? 1.0 : 0.0;
+		stptr--;
+		break;
+	    case OP_IF:
+		stackunderflow(2);
+		rpnstack->s[stptr-2] = rpnstack->s[stptr-2] != 0.0 ?
+				rpnstack->s[stptr-1] : rpnstack->s[stptr];
+		stptr--;
+		stptr--;
+		break;
+	    case OP_MIN:
+		stackunderflow(1);
+		if (isnan(rpnstack->s[stptr-1])) 
+		    ;
+		else if (isnan(rpnstack->s[stptr]))
+		    rpnstack->s[stptr-1] = rpnstack->s[stptr];
+		else if (rpnstack->s[stptr-1] > rpnstack->s[stptr])
+		    rpnstack->s[stptr-1] = rpnstack->s[stptr];
+		stptr--;
+		break;
+	    case OP_MAX:
+		stackunderflow(1);
+		if (isnan(rpnstack->s[stptr-1])) 
+               ;
+		else if (isnan(rpnstack->s[stptr]))
+		    rpnstack->s[stptr-1] = rpnstack->s[stptr];
+		else if (rpnstack->s[stptr-1] < rpnstack->s[stptr])
+		    rpnstack->s[stptr-1] = rpnstack->s[stptr];
+		stptr--;
+		break;
+	    case OP_LIMIT:
+		stackunderflow(2);
+		if (isnan(rpnstack->s[stptr-2])) 
+		    ;
+		else if (isnan(rpnstack->s[stptr-1]))
+		    rpnstack->s[stptr-2] = rpnstack->s[stptr-1];
+		else if (isnan(rpnstack->s[stptr]))
+		    rpnstack->s[stptr-2] = rpnstack->s[stptr];
+		else if (rpnstack->s[stptr-2] < rpnstack->s[stptr-1])
+		    rpnstack->s[stptr-2] = DNAN;
+		else if (rpnstack->s[stptr-2] > rpnstack->s[stptr])
+		    rpnstack->s[stptr-2] = DNAN;
+		stptr-=2;
+       		break;
+	    case OP_UN:
+		stackunderflow(0);
+		rpnstack->s[stptr] = isnan(rpnstack->s[stptr]) ? 1.0 : 0.0;
+		break;
+	    case OP_ISINF:
+		stackunderflow(0);
+		rpnstack->s[stptr] = isinf(rpnstack->s[stptr]) ? 1.0 : 0.0;
+		break;
+	    case OP_SQRT:
+		stackunderflow(0);
+		rpnstack -> s[stptr] = sqrt(rpnstack -> s[stptr]);
+		break;
+	    case OP_SORT:
+		stackunderflow(0);
+		{
+		    int	spn = (int)rpnstack -> s[stptr--];
+
+		    stackunderflow(spn-1);
+		    qsort(rpnstack -> s + stptr-spn+1, spn, sizeof(double),
+			  rpn_compare_double);
+		}
+		break;
+	    case OP_REV:
+		stackunderflow(0);
+		{
+		    int	spn = (int)rpnstack -> s[stptr--];
+		    double *p, *q;
+
+		    stackunderflow(spn-1);
+
+		    p = rpnstack -> s + stptr-spn+1;
+		    q = rpnstack -> s + stptr;
+		    while (p < q) {
+			    double	x = *q;
+			    
+			    *q-- = *p;
+			    *p++ = x;
 		    }
-		    rpnstack->s[stptr] = isnan(rpnstack->s[stptr]) ? 1.0 : 0.0;
-		    break;
-		case OP_END:
-		    break;
 		}
-	    }
-	    if(stptr!=0){
-		rrd_set_error("RPN final stack size != 1");
-		return -1;
-	    }
-
-	    output[output_idx] = rpnstack->s[0];
-		return 0;
+		break;
+	    case OP_TREND:
+		stackunderflow(1);
+		if ((rpi < 2) || (rpnp[rpi-2].op != OP_VARIABLE)) {
+		    rrd_set_error("malformed trend arguments");
+		    return -1;
+		} else {
+		    time_t dur = (time_t)rpnstack -> s[stptr];
+		    time_t step = (time_t)rpnp[rpi-2].step;
+
+		    if (output_idx > (int)ceil((float)dur / (float)step)) {
+			double accum = 0.0;
+			int i = 0;
+		
+			do {
+			    accum += rpnp[rpi-2].data[rpnp[rpi-2].ds_cnt * i--];
+			    dur -= step;
+			} while (dur > 0);
+
+			rpnstack -> s[--stptr] = (accum / -i);
+		    } else
+			rpnstack -> s[--stptr] = DNAN;
+		}
+		break;
+	    case OP_END:
+		break;
+       }
+#undef stackunderflow
+   }
+   if(stptr!=0){
+       rrd_set_error("RPN final stack size != 1");
+       return -1;
+   }
+   
+   output[output_idx] = rpnstack->s[0];
+   return 0;
 }
 
 /* figure out what the local timezone offset for any point in
    time was. Return it in seconds */
 int
 tzoffset( time_t now ){
-  int gm_sec, gm_min, gm_hour, gm_yday, gm_year,
-    l_sec, l_min, l_hour, l_yday, l_year;
-  struct tm *t;
-  int off;
-  t = gmtime(&now);
-  gm_sec = t->tm_sec;
-  gm_min = t->tm_min;
-  gm_hour = t->tm_hour;
-  gm_yday = t->tm_yday;
-  gm_year = t->tm_year;
-  t = localtime(&now);
-  l_sec = t->tm_sec;
-  l_min = t->tm_min;
-  l_hour = t->tm_hour;
-  l_yday = t->tm_yday;
-  l_year = t->tm_year;
-  off = (l_sec-gm_sec)+(l_min-gm_min)*60+(l_hour-gm_hour)*3600; 
-  if ( l_yday > gm_yday || l_year > gm_year){
+    int gm_sec, gm_min, gm_hour, gm_yday, gm_year,
+        l_sec, l_min, l_hour, l_yday, l_year;
+    struct tm t;
+    int off;
+    gmtime_r(&now, &t);
+    gm_sec = t.tm_sec;
+    gm_min = t.tm_min;
+    gm_hour = t.tm_hour;
+    gm_yday = t.tm_yday;
+    gm_year = t.tm_year;
+    localtime_r(&now, &t);
+    l_sec = t.tm_sec;
+    l_min = t.tm_min;
+    l_hour = t.tm_hour;
+    l_yday = t.tm_yday;
+    l_year = t.tm_year;
+    off = (l_sec-gm_sec)+(l_min-gm_min)*60+(l_hour-gm_hour)*3600; 
+    if ( l_yday > gm_yday || l_year > gm_year){
         off += 24*3600;
-  } else if ( l_yday < gm_yday || l_year < gm_year){
+    } else if ( l_yday < gm_yday || l_year < gm_year){
         off -= 24*3600;
-  }
-
-  return off;
+    }
+   return off;
 }
+