added posix_fadvise support (untested) ... this should help performance by

[rrdtool.git] / src / rrd_create.c

diff --git a/src/rrd_create.c b/src/rrd_create.c
index 7a08b9c..521c726 100644 (file)
--- a/src/rrd_create.c
+++ b/src/rrd_create.c
@@ -1,5 +1,5 @@
 /*****************************************************************************
- * RRDtool 1.2.9  Copyright by Tobi Oetiker, 1997-2005
+ * RRDtool 1.2.23  Copyright by Tobi Oetiker, 1997-2007
  *****************************************************************************
  * rrd_create.c  creates new rrds
  *****************************************************************************/
@@ -10,9 +10,9 @@
 
 #include "rrd_is_thread_safe.h"
 
-unsigned long FnvHash(char *str);
+unsigned long FnvHash(const char *str);
 int create_hw_contingent_rras(rrd_t *rrd, unsigned short period, unsigned long hashed_name);
-void parseGENERIC_DS(char *def,rrd_t *rrd, int ds_idx);
+void parseGENERIC_DS(const char *def,rrd_t *rrd, int ds_idx);
 
 int
 rrd_create(int argc, char **argv) 
@@ -78,19 +78,22 @@ rrd_create(int argc, char **argv)
            return(-1);
        }
     }
-
+    if (optind == argc) {
+         rrd_set_error("what is the name of the rrd file you want to create?");
+         return -1;
+    }
     rc = rrd_create_r(argv[optind],
                      pdp_step, last_up,
-                     argc - optind - 1, argv + optind + 1);
+                     argc - optind - 1, (const char **)(argv + optind + 1));
     
     return rc;
 }
 
 /* #define DEBUG */
 int
-rrd_create_r(char *filename,
+rrd_create_r(const char *filename,
             unsigned long pdp_step, time_t last_up,
-            int argc, char **argv) 
+            int argc, const char **argv) 
 {
     rrd_t             rrd;
     long              i;
@@ -436,7 +439,7 @@ rrd_create_r(char *filename,
     return rrd_create_fn(filename, &rrd);
 }
 
-void parseGENERIC_DS(char *def,rrd_t *rrd, int ds_idx)
+void parseGENERIC_DS(const char *def,rrd_t *rrd, int ds_idx)
 {
     char minstr[DS_NAM_SIZE], maxstr[DS_NAM_SIZE];     
     /*
@@ -544,18 +547,23 @@ create_hw_contingent_rras(rrd_t *rrd, unsigned short period, unsigned long hashe
 /* create and empty rrd file according to the specs given */
 
 int
-rrd_create_fn(char *file_name, rrd_t *rrd)
+rrd_create_fn(const char *file_name, rrd_t *rrd)
 {
     unsigned long    i,ii;
     FILE             *rrd_file;
     rrd_value_t      *unknown;
     int        unkn_cnt;
-    
+
+    long rrd_head_size;
+
     if ((rrd_file = fopen(file_name,"wb")) == NULL ) {
        rrd_set_error("creating '%s': %s",file_name, rrd_strerror(errno));
        free(rrd->stat_head);
+        rrd->stat_head = NULL; 
        free(rrd->ds_def);
+        rrd->ds_def = NULL; 
        free(rrd->rra_def);
+        rrd->rra_def = NULL;
        return(-1);
     }
     
@@ -652,7 +660,8 @@ rrd_create_fn(char *file_name, rrd_t *rrd)
         rrd->rra_ptr->cur_row = rrd->rra_def[i].row_cnt - 1;
         fwrite( rrd->rra_ptr, sizeof(rra_ptr_t),1,rrd_file);
     }
-    
+    rrd_head_size = ftell(rrd_file);
+
     /* write the empty data area */
     if ((unknown = (rrd_value_t *)malloc(512 * sizeof(rrd_value_t))) == NULL) {
        rrd_set_error("allocating unknown");
@@ -681,6 +690,23 @@ rrd_create_fn(char *file_name, rrd_t *rrd)
        return(-1);
     }
     
+#ifdef POSIX_FADVISE
+    /* this file is not going to be read again any time
+       soon, so we drop everything except the header portion from
+       the buffer cache. for this to work, we have to fdsync the file
+       first though. This will not be all that fast, but 'good' data
+       like other rrdfiles headers will stay in cache. Now this only works if creating
+       a single rrd file is not too large, but I assume this should not be the case
+       in general. Otherwhise we would have to sync and release while writing all
+       the unknown data. */
+    fdatasync(fileno(rrd_file));
+    if (0 != posix_fadvise(fileno(rrd_file), rrd_head_size, 0, POSIX_FADV_DONTNEED)) {
+        rrd_set_error("setting POSIX_FADV_DONTNEED on '%s': %s",file_name, rrd_strerror(errno));
+        fclose(rrd_file);
+        return(-1);
+    }    
+#endif
+
     fclose(rrd_file);    
     rrd_free(rrd);
     return (0);