removed multiple returns from bf_storage routines and introduced comm…

…it function

bf_storage.c

@@ -1,58 +1,70 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
 #include "bf_types.h"
 
-const char inprogress_sf[] = ".inprogress";
+#define BYTES_FOR_PID sizeof('.') + sizeof('-') + 2.5 * sizeof(pid_t) + sizeof('\0') + 1
+/* bytes for decimal record of int := 
+:= ceil(log10(INT_MAX)) + sign + zero-byte (+ 1 to avoid real ceil call)
+*/
+
 //Storage operations
+int _bf_commit_snapshot(const char *src, const char *dst) {
+    int ret = -1;
+    if (rename(src, dst) == 0) {
+        ret = 0;
+    } else {
+        fputs("Unable to rename inprogress snapshot into actual location.\n",
+            stderr);
+    }
+    return ret;
+}
+
 int bf_dump_to_file(const bloom_filter_t *bf, const char *fname)
 {
+    int ret = -1;
     fputs("Saving snapshot...\n", stderr);
 
-    char *inprogress_fn = malloc(strlen(fname) + sizeof(inprogress_sf));
-    strcpy(inprogress_fn, fname);
-    strcat(inprogress_fn, inprogress_sf);
+    char *inprogress_fn = malloc(strlen(fname) + BYTES_FOR_PID);
+    sprintf(inprogress_fn, "%s.%d", fname, getpid());
 
     size_t shouldwrite = (bf->m + (CHAR_BIT - 1)) / CHAR_BIT;
     FILE *f = fopen(inprogress_fn, "wb");
 
     if (f) {
         size_t bwritten = fwrite(bf->space, 1, shouldwrite, f);
-        if (bwritten != shouldwrite) {
-            fprintf(stderr, "Should write: %ld bytes. Written %ld bytes.\n", shouldwrite, bwritten);
-            free(inprogress_fn);
-            return -1;
-        }
-        fclose(f);
-        if (rename(inprogress_fn, fname) == 0) {
-            free(inprogress_fn);
-            return 0;
+        if (bwritten == shouldwrite) {
+            fclose(f);
+            ret = _bf_commit_snapshot(inprogress_fn, fname);
         } else {
-            free(inprogress_fn);
-            fputs("Unable to rename inprogress snapshot into actual location.\n", stderr);
-            return -1;
+            fprintf(stderr, "Should write: %ld bytes. Written %ld bytes.\n",
+                shouldwrite, bwritten);
         }
     } else {
         fputs("Error opening file for writting.\n", stderr);
-        free(inprogress_fn);
-        return -1;
     }
+    free(inprogress_fn);
+    return ret;
 }
 
 int bf_load_from_file(bloom_filter_t *bf, const char *fname)
 {
+    int ret = -1;
     FILE *f = fopen(fname, "rb");
     if (f) {
         size_t shouldread = (bf->m + (CHAR_BIT - 1)) / CHAR_BIT;
         size_t bread = fread(bf->space, 1, shouldread, f);
-        if (bread != shouldread) {
-            fprintf(stderr, "Should read: %ld bytes. Read %ld bytes.\n", shouldread, bread);
-            return -1;
+        if (bread == shouldread) {
+            fclose(f);
+            ret = 0;
+        } else {
+            fprintf(stderr, "Should read: %ld bytes. Read %ld bytes.\n",
+                shouldread, bread);
         }
-        fclose(f);
-        return 0;
     } else {
         fputs("Error opening file for reading.\n", stderr);
-        return -1;
     }
+    return ret;
 }