Draft: rotate cdr csv log when reach max row

#5211
Rotate cdr csv when reaching the max row.
The log before rotation will be store as _old.csv
A count file will be created to store the row count, to prevent getting the row by reading the whole log.

cdr/cdr_csv.c

@@ -48,6 +48,8 @@
 
 #define CSV_LOG_DIR "/cdr-csv"
 #define CSV_MASTER  "/Master.csv"
+#define CSV_MASTER_OLD    "/Master_old.csv"
+#define CSV_MASTER_COUNT  "/Master_count"
 
 #define DATE_FORMAT "%Y-%m-%d %T"
 
@@ -57,8 +59,11 @@ static int loguniqueid = 0;
 static int loguserfield = 0;
 static int loaded = 0;
 static int newcdrcolumns = 0;
+static int maxrow = 100; /* max row stored in csv file before rotate */
 static const char config[] = "cdr.conf";
 static char file_csv_master[PATH_MAX];
+static char file_csv_old[PATH_MAX];
+static char file_csv_master_count[PATH_MAX];
 
 /* #define CSV_LOGUNIQUEID 1 */
 /* #define CSV_LOGUSERFIELD 1 */
@@ -113,6 +118,7 @@ static int load_config(int reload)
 	loguniqueid = 0;
 	loguserfield = 0;
 	newcdrcolumns = 0;
+	maxrow = 100;
 
 	if (!(v = ast_variable_browse(cfg, "csv"))) {
 		ast_config_destroy(cfg);
@@ -123,6 +129,10 @@ static int load_config(int reload)
 	ast_mutex_lock(&f_lock);
 	snprintf(file_csv_master, sizeof(file_csv_master),
 		"%s/%s/%s", ast_config_AST_LOG_DIR, CSV_LOG_DIR, CSV_MASTER);
+    snprintf(file_csv_old, sizeof(file_csv_old),
+		"%s/%s/%s", ast_config_AST_LOG_DIR, CSV_LOG_DIR, CSV_MASTER_OLD);
+    snprintf(file_csv_master_count, sizeof(file_csv_master_count),
+		"%s/%s/%s", ast_config_AST_LOG_DIR, CSV_LOG_DIR, CSV_MASTER_COUNT);
 	ast_mutex_unlock(&f_lock);
 
 	for (; v; v = v->next) {
@@ -137,6 +147,8 @@ static int load_config(int reload)
 			loguserfield = ast_true(v->value);
 		} else if (!strcasecmp(v->name, "newcdrcolumns")) {
 			newcdrcolumns = ast_true(v->value);
+		} else if (!strcasecmp(v->name, "maxrow")) {
+			maxrow = atoi(v->value);
 		}
 
 	}
@@ -303,19 +315,54 @@ static int build_csv_record(char *buf, size_t bufsize, struct ast_cdr *cdr)
 	return -1;
 }
 
-static int writefile(char *s, char *file_path)
+static int getrowcount(char *file_path_count)
 {
-	FILE *f;
-	/* because of the absolutely unconditional need for the
-	   highest reliability possible in writing billing records,
-	   we open write and close the log file each time */
-	if (!(f = fopen(file_path, "a"))) {
-		ast_log(LOG_ERROR, "Unable to open file %s : %s\n", file_path, strerror(errno));
+    /* get current recorded count from file*/
+    FILE *f;
+    int rowcount = 0;
+    if (!(f = fopen(file_path_count, "a+"))) {
+		ast_log(LOG_ERROR, "Unable to open file %s : %s\n", file_path_count, strerror(errno));
 		return -1;
 	}
-	fputs(s, f);
-	fflush(f); /* be particularly anal here */
-	fclose(f);
+    fscanf(f, "%d", &rowcount);
+    fflush(f);
+    fclose(f);
+    return rowcount;
+}
+
+static int writerowcount(char *file_path_count, int count)
+{
+    /* write count number to file */
+    FILE *f;
+    if (!(f = fopen(file_path_count, "w"))) {
+        ast_log(LOG_ERROR, "Unable to open file %s : %s\n", file_path_count, strerror(errno));
+        return -1;
+    }
+    fprintf(f, "%d\n", count);
+    fflush(f);
+    fclose(f);
+    return 0;
+}
+
+static int writefile(char *s, char *file_path, char *file_path_old, char *file_path_count)
+{
+    FILE *f;
+    int rowcount = getrowcount(file_path_count);
+    /* because of the absolutely unconditional need for the
+       highest reliability possible in writing billing records,
+       we open write and close the log file each time */
+    if (rowcount >= maxrow) {
+        rename(file_path, file_path_old); /* rotate(rename as back up) when reach max row */
+        rowcount = 0; /* clear row count */
+    }
+    if (!(f = fopen(file_path, "a"))) {
+        ast_log(LOG_ERROR, "Unable to open file %s : %s\n", file_path, strerror(errno));
+        return -1;
+    }
+    fputs(s, f);
+    fflush(f); /* be particularly anal here */
+    fclose(f);
+    writerowcount(file_path_count, rowcount+1); /* update row count record */
 
 	return 0;
 }
@@ -324,12 +371,16 @@ static int writefile(char *s, char *file_path)
 static int writefile_account(char *s, char *acc)
 {
 	char file_account[PATH_MAX];
+	char file_account_old[PATH_MAX];
+	char file_account_count[PATH_MAX];
 	if (strchr(acc, '/') || (acc[0] == '.')) {
 		ast_log(LOG_WARNING, "Account code '%s' insecure for writing file\n", acc);
 		return -1;
 	}
 	snprintf(file_account, sizeof(file_account), "%s/%s/%s.csv", ast_config_AST_LOG_DIR,CSV_LOG_DIR, acc);
-	return writefile(s, file_account);
+    snprintf(file_account_old, sizeof(file_account_old), "%s/%s/%s_old.csv", ast_config_AST_LOG_DIR,CSV_LOG_DIR, acc);
+    snprintf(file_account_count, sizeof(file_account_count), "%s/%s/%s_count", ast_config_AST_LOG_DIR,CSV_LOG_DIR, acc);
+	return writefile(s, file_account, file_account_old, file_account_count);
 }
 
 static int csv_log(struct ast_cdr *cdr)
@@ -348,7 +399,7 @@ static int csv_log(struct ast_cdr *cdr)
 	}
 
 	ast_mutex_lock(&f_lock);
-	if (writefile(buf, file_csv_master))
+	if (writefile(buf, file_csv_master, file_csv_old, file_csv_master_count))
 		ast_log(LOG_WARNING, "Unable to write CSV record to master '%s' : %s\n", file_csv_master, strerror(errno));
 
 	if (accountlogs && !ast_strlen_zero(cdr->accountcode)) {