Rework all readers to be async

main.go

@@ -41,17 +41,30 @@ func main() {
 	log.Printf("Recurse: %s", *recurse)
 	log.Printf("File: %s", *file)
 
-	var instructions []LinkInstruction
+	instructions := make(chan LinkInstruction, 1000)
+	status := make(chan error)
 	if *recurse != "" {
-		instructions, _ = ReadFromFilesRecursively(*recurse)
+		ReadFromFilesRecursively(*recurse, instructions, status)
 	} else if *file != "" {
-		instructions, _ = ReadFromFile(*file)
+		ReadFromFile(*file, instructions, status, true)
 	} else if len(os.Args) > 1 {
-		instructions, _ = ReadFromArgs()
+		ReadFromArgs(instructions, status)
 	} else {
-		instructions, _ = ReadFromStdin()
+		ReadFromStdin(instructions, status)
 	}
 
+	go func() {
+		for {
+			err, ok := <-status
+			if !ok {
+				break
+			}
+			if err != nil {
+				log.Println(err)
+			}
+		}
+	}()
+
 	if len(instructions) == 0 {
 		log.Printf("No input provided")
 		log.Printf("Provide input as: ")
@@ -62,7 +75,12 @@ func main() {
 		os.Exit(1)
 	}
 	var wg sync.WaitGroup
-	for _, instruction := range instructions {
+	for {
+		instruction, ok := <-instructions
+		if !ok {
+			log.Printf("No more instructions to process")
+			break
+		}
 		log.Printf("Processing: %s", instruction.String())
 		status := make(chan error)
 		go instruction.RunAsync(status)
@@ -74,46 +92,61 @@ func main() {
 		wg.Done()
 	}
 	wg.Wait()
+	log.Println("All done")
 }
 
-func ReadFromFilesRecursively(input string) ([]LinkInstruction, error) {
+func ReadFromFilesRecursively(input string, output chan LinkInstruction, status chan error) {
+	defer close(output)
+	defer close(status)
+
 	input = NormalizePath(input)
 	log.Printf("Reading input from files recursively starting in %s%s%s", PathColor, input, DefaultColor)
-	var instructions []LinkInstruction
 
 	files, err := GetSyncFilesRecursively(input)
 	if err != nil {
-		log.Fatalf("Failed to get sync files recursively: %s%+v%s", ErrorColor, err, DefaultColor)
+		log.Printf("Failed to get sync files recursively: %s%+v%s", ErrorColor, err, DefaultColor)
+		status <- err
+		return
 	}
 
+	var wg sync.WaitGroup
 	for _, file := range files {
-		file = NormalizePath(file)
+		fileCopy := file
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			fileCopy = NormalizePath(fileCopy)
 
 			// This "has" to be done because instructions are resolved in relation to cwd
-		fileDir := DirRegex.FindStringSubmatch(file)
+			fileDir := DirRegex.FindStringSubmatch(fileCopy)
 			if fileDir == nil {
-			log.Printf("Failed to extract directory from %s%s%s", SourceColor, file, DefaultColor)
-			continue
+				log.Printf("Failed to extract directory from %s%s%s", SourceColor, fileCopy, DefaultColor)
+				return
 			}
-		log.Printf("Changing directory to %s%s%s (for %s%s%s)", PathColor, fileDir[1], DefaultColor, PathColor, file, DefaultColor)
+			log.Printf("Changing directory to %s%s%s (for %s%s%s)", PathColor, fileDir[1], DefaultColor, PathColor, fileCopy, DefaultColor)
 			err := os.Chdir(fileDir[1])
 			if err != nil {
 				log.Printf("Failed to change directory to %s%s%s: %s%+v%s", SourceColor, fileDir[1], DefaultColor, ErrorColor, err, DefaultColor)
-			continue
+				return
 			}
 
-		fileInstructions, _ := ReadFromFile(file)
-		instructions = append(instructions, fileInstructions...)
+			ReadFromFile(fileCopy, output, status, false)
+		}()
 	}
-	return instructions, nil
+	wg.Wait()
 }
-func ReadFromFile(input string) ([]LinkInstruction, error) {
+func ReadFromFile(input string, output chan LinkInstruction, status chan error, doclose bool) {
+	if doclose {
+		defer close(output)
+		defer close(status)
+	}
+
 	input = NormalizePath(input)
 	log.Printf("Reading input from file: %s%s%s", PathColor, input, DefaultColor)
-	var instructions []LinkInstruction
 	file, err := os.Open(input)
 	if err != nil {
 		log.Fatalf("Failed to open file %s%s%s: %s%+v%s", SourceColor, input, DefaultColor, ErrorColor, err, DefaultColor)
+		return
 	}
 	defer file.Close()
 
@@ -125,32 +158,34 @@ func ReadFromFile(input string) ([]LinkInstruction, error) {
 			log.Printf("Error parsing line: %s'%s'%s, error: %s%+v%s", SourceColor, line, DefaultColor, ErrorColor, err, DefaultColor)
 			continue
 		}
-		instructions = append(instructions, instruction)
+		output <- instruction
 	}
-	log.Printf("Read %d instructions from file", len(instructions))
-	return instructions, nil
 }
-func ReadFromArgs() ([]LinkInstruction, error) {
+func ReadFromArgs(output chan LinkInstruction, status chan error) {
+	defer close(output)
+	defer close(status)
+
 	log.Printf("Reading input from args")
-	var instructions []LinkInstruction
 	for _, arg := range os.Args[1:] {
 		instruction, err := ParseInstruction(arg)
 		if err != nil {
 			log.Printf("Error parsing arg: %s'%s'%s, error: %s%+v%s", SourceColor, arg, DefaultColor, ErrorColor, err, DefaultColor)
 			continue
 		}
-		instructions = append(instructions, instruction)
+		output <- instruction
 	}
-	log.Printf("Read %d instructions from args", len(instructions))
-	return instructions, nil
 }
-func ReadFromStdin() ([]LinkInstruction, error) {
+func ReadFromStdin(output chan LinkInstruction, status chan error) {
+	defer close(output)
+	defer close(status)
+	
 	log.Printf("Reading input from stdin")
-	var instructions []LinkInstruction
 
 	info, err := os.Stdin.Stat()
 	if err != nil {
 		log.Fatalf("Failed to stat stdin: %s%+v%s", ErrorColor, err, DefaultColor)
+		status <- err
+		return
 	}
 	if info.Mode()&os.ModeNamedPipe != 0 {
 		scanner := bufio.NewScanner(os.Stdin)
@@ -161,13 +196,12 @@ func ReadFromStdin() ([]LinkInstruction, error) {
 				log.Printf("Error parsing line: %s'%s'%s, error: %s%+v%s", SourceColor, line, DefaultColor, ErrorColor, err, DefaultColor)
 				continue
 			}
-			instructions = append(instructions, instruction)
+			output <- instruction
 		}
 		if err := scanner.Err(); err != nil {
 			log.Fatalf("Error reading from stdin: %s%+v%s", ErrorColor, err, DefaultColor)
+			status <- err
+			return
 		}
 	}
-
-	log.Printf("Read %d instructions from stdin", len(instructions))
-	return instructions, nil
 }