prevent memprof file overwrites for small intervals

Previously, the timestamp was accurate only down to seconds. For smaller intervals,
this would truncate the previous file(s). Now, for small intervals, the number of
microseconds is appended to the file name.

Added the possibility to disable timestamps in the memory profile file names and use
increments of 1 instead.

Updated the memory profiling integration tests.

cmd/cgr-engine/cgr-engine.go

@@ -59,6 +59,7 @@ var (
 	memProfDir        = cgrEngineFlags.String(utils.MemProfDirCgr, utils.EmptyString, "Directory for memory profiles")
 	memProfInterval   = cgrEngineFlags.Duration(utils.MemProfIntervalCgr, 15*time.Second, "Interval between memory profile saves")
 	memProfMaxFiles   = cgrEngineFlags.Int(utils.MemProfMaxFilesCgr, 1, "Number of memory profiles to keep (most recent)")
+	memProfTimestamp  = cgrEngineFlags.Bool(utils.MemProfTimestampCgr, false, "Add timestamp to memory profile files")
 	scheduledShutdown = cgrEngineFlags.Duration(utils.ScheduledShutdownCgr, 0, "Shutdown the engine after the specified duration")
 	singleCPU         = cgrEngineFlags.Bool(utils.SingleCpuCgr, false, "Run on a single CPU core")
 	syslogger         = cgrEngineFlags.String(utils.LoggerCfg, utils.EmptyString, "Logger type <*syslog|*stdout>")
@@ -694,9 +695,10 @@ func main() {
 
 	if *memProfDir != utils.EmptyString {
 		if err := cS.StartMemoryProfiling(cores.MemoryProfilingParams{
-			DirPath:  *memProfDir,
-			Interval: *memProfInterval,
-			MaxFiles: *memProfMaxFiles,
+			DirPath:      *memProfDir,
+			Interval:     *memProfInterval,
+			MaxFiles:     *memProfMaxFiles,
+			UseTimestamp: *memProfTimestamp,
 		}); err != nil {
 			utils.Logger.Err(fmt.Sprintf("<%s> %v", utils.CoreS, err))
 			return

cmd/cgr-engine/cgr-engine_flags_test.go

@@ -98,6 +98,13 @@ func TestCgrEngineFlags(t *testing.T) {
 			defaultVal: 1,
 			want:       3,
 		},
+		{
+			name:       "memProfTimestamp",
+			flags:      []string{"-memprof_timestamp"},
+			flagVar:    memProfTimestamp,
+			defaultVal: false,
+			want:       true,
+		},
 		{
 			name:       "scheduledShutdown",
 			flags:      []string{"-scheduled_shutdown", "1h"},