Now only save CHANGED files to database (before changes of course)

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"flag"
 	"fmt"
 	"os"
@@ -180,25 +181,34 @@ func main() {
 			}
 			fileDataStr := string(fileData)
 
+			isChanged := false
+			logger.Debug("Running isolate commands for file %q", file)
+			fileDataStr, err = RunIsolateCommands(association, file, fileDataStr, &fileMutex)
+			if err != nil && err != NothingToDo {
+				logger.Error("Failed to run isolate commands for file %q: %v", file, err)
+				return
+			}
+			if err != NothingToDo {
+				isChanged = true
+			}
+
+			logger.Debug("Running other commands for file %q", file)
+			fileDataStr, err = RunOtherCommands(file, fileDataStr, association, &fileMutex, commandLoggers)
+			if err != nil && err != NothingToDo {
+				logger.Error("Failed to run other commands for file %q: %v", file, err)
+				return
+			}
+			if err != NothingToDo {
+				isChanged = true
+			}
+
+			if isChanged {
 				logger.Debug("Saving file %q to database", file)
 				err = db.SaveFile(file, fileData)
 				if err != nil {
 					logger.Error("Failed to save file %q to database: %v", file, err)
 					return
 				}
-
-			logger.Debug("Running isolate commands for file %q", file)
-			fileDataStr, err = RunIsolateCommands(association, file, fileDataStr, &fileMutex)
-			if err != nil {
-				logger.Error("Failed to run isolate commands for file %q: %v", file, err)
-				return
-			}
-
-			logger.Debug("Running other commands for file %q", file)
-			fileDataStr, err = RunOtherCommands(file, fileDataStr, association, &fileMutex, commandLoggers)
-			if err != nil {
-				logger.Error("Failed to run other commands for file %q: %v", file, err)
-				return
 			}
 
 			logger.Debug("Writing file %q", file)
@@ -346,6 +356,8 @@ func CreateExampleConfig() {
 	logger.Info("Wrote example_cook.yml")
 }
 
+var NothingToDo = errors.New("nothing to do")
+
 func RunOtherCommands(file string, fileDataStr string, association utils.FileCommandAssociation, fileMutex *sync.Mutex, commandLoggers map[string]*logger.Logger) (string, error) {
 	// Aggregate all the modifications and execute them
 	modifications := []utils.ReplaceCommand{}
@@ -377,7 +389,7 @@ func RunOtherCommands(file string, fileDataStr string, association utils.FileCom
 
 	if len(modifications) == 0 {
 		logger.Warning("No modifications found for file %q", file)
-		return fileDataStr, nil
+		return fileDataStr, NothingToDo
 	}
 
 	// Sort commands in reverse order for safe replacements
@@ -394,6 +406,7 @@ func RunOtherCommands(file string, fileDataStr string, association utils.FileCom
 }
 
 func RunIsolateCommands(association utils.FileCommandAssociation, file string, fileDataStr string, fileMutex *sync.Mutex) (string, error) {
+	anythingDone := false
 	for _, isolateCommand := range association.IsolateCommands {
 		logger.Info("Processing file %q with isolate command %q", file, isolateCommand.Regex)
 		modifications, err := processor.ProcessRegex(fileDataStr, isolateCommand, file)
@@ -406,6 +419,7 @@ func RunIsolateCommands(association utils.FileCommandAssociation, file string, f
 			logger.Warning("No modifications found for file %q", file)
 			continue
 		}
+		anythingDone = true
 
 		var count int
 		fileDataStr, count = utils.ExecuteModifications(modifications, fileDataStr)
@@ -417,5 +431,8 @@ func RunIsolateCommands(association utils.FileCommandAssociation, file string, f
 
 		logger.Info("Executed %d isolate modifications for file %q", count, file)
 	}
+	if !anythingDone {
+		return fileDataStr, NothingToDo
+	}
 	return fileDataStr, nil
 }