[cmd provider] add support of match size in logs

internal/util.go

@@ -86,13 +86,32 @@ func GetJSON(url string, obj interface{}, client *http.Client) (*http.Response,
 	return resp, json.Unmarshal(body, obj)
 }
 
-func ExtractSizeFromRsyncLog(content []byte) string {
-	// (?m) flag enables multi-line mode
-	re := regexp.MustCompile(`(?m)^Total file size: ([0-9\.]+[KMGTP]?) bytes`)
-	matches := re.FindAllSubmatch(content, -1)
-	// fmt.Printf("%q\n", matches)
-	if len(matches) == 0 {
+// FindAllSubmatchInFile calls re.FindAllSubmatch to find matches in given file
+func FindAllSubmatchInFile(fileName string, re *regexp.Regexp) (matches [][][]byte, err error) {
+	if fileName == "/dev/null" {
+		err = errors.New("Invalid log file")
+		return
+	}
+	if content, err := ioutil.ReadFile(fileName); err == nil {
+		matches = re.FindAllSubmatch(content, -1)
+		// fmt.Printf("FindAllSubmatchInFile: %q\n", matches)
+	}
+	return
+}
+
+// ExtractSizeFromLog uses a regexp to extract the size from log files
+func ExtractSizeFromLog(logFile string, re *regexp.Regexp) string {
+	matches, _ := FindAllSubmatchInFile(logFile, re)
+	if matches == nil || len(matches) == 0 {
 		return ""
 	}
+	// return the first capture group of the last occurrence
 	return string(matches[len(matches)-1][1])
 }
+
+// ExtractSizeFromRsyncLog extracts the size from rsync logs
+func ExtractSizeFromRsyncLog(logFile string) string {
+	// (?m) flag enables multi-line mode
+	re := regexp.MustCompile(`(?m)^Total file size: ([0-9\.]+[KMGTP]?) bytes`)
+	return ExtractSizeFromLog(logFile, re)
+}