fix: --no-cache

Separates out the logic
for detecting changes from the logic for updating the cache, fixing the case where both `--fail-on-change` and `--no-cache`
are enabled.

Closes #343

Signed-off-by: Brian McGee <[email protected]>

Author: brianmcgee

cache/cache.go

@@ -283,21 +283,12 @@ func Update(files []*walk.File) error {
 		bucket := tx.Bucket([]byte(pathsBucket))
 
 		for _, f := range files {
-			currentInfo, err := os.Stat(f.Path)
-			if err != nil {
-				return err
-			}
-
-			if !(f.Info.ModTime() == currentInfo.ModTime() && f.Info.Size() == currentInfo.Size()) {
-				stats.Add(stats.Formatted, 1)
-			}
-
 			entry := Entry{
-				Size:     currentInfo.Size(),
-				Modified: currentInfo.ModTime(),
+				Size:     f.Info.Size(),
+				Modified: f.Info.ModTime(),
 			}
 
-			if err = putEntry(bucket, f.RelPath, &entry); err != nil {
+			if err := putEntry(bucket, f.RelPath, &entry); err != nil {
 				return err
 			}
 		}

cli/cli.go

@@ -41,6 +41,7 @@ type Format struct {
 	globalExcludes []glob.Glob
 
 	filesCh     chan *walk.File
+	formattedCh chan *walk.File
 	processedCh chan *walk.File
 }
 

cli/format.go

@@ -149,96 +149,21 @@ func (f *Format) Run() (err error) {
 	f.filesCh = make(chan *walk.File, BatchSize*runtime.NumCPU())
 
 	// create a channel for files that have been processed
+	f.formattedCh = make(chan *walk.File, cap(f.filesCh))
+
+	// create a channel for files that have been formatted
 	f.processedCh = make(chan *walk.File, cap(f.filesCh))
 
 	// start concurrent processing tasks in reverse order
-	if !f.NoCache {
-		eg.Go(f.updateCache(ctx))
-	}
+	eg.Go(f.updateCache(ctx))
+	eg.Go(f.detectFormatted(ctx))
 	eg.Go(f.applyFormatters(ctx))
 	eg.Go(f.walkFilesystem(ctx))
 
 	// wait for everything to complete
 	return eg.Wait()
 }
 
-func (f *Format) updateCache(ctx context.Context) func() error {
-	return func() error {
-		// used to batch updates for more efficient txs
-		batch := make([]*walk.File, 0, BatchSize)
-
-		// apply a batch
-		processBatch := func() error {
-			if f.Stdin {
-				// do nothing
-				return nil
-			}
-			if err := cache.Update(batch); err != nil {
-				return err
-			}
-			batch = batch[:0]
-			return nil
-		}
-
-	LOOP:
-		for {
-			select {
-			// detect ctx cancellation
-			case <-ctx.Done():
-				return ctx.Err()
-			// respond to processed files
-			case file, ok := <-f.processedCh:
-				if !ok {
-					// channel has been closed, no further files to process
-					break LOOP
-				}
-
-				if f.Stdin {
-					// dump file into stdout
-					f, err := os.Open(file.Path)
-					if err != nil {
-						return fmt.Errorf("failed to open %s: %w", file.Path, err)
-					}
-					if _, err = io.Copy(os.Stdout, f); err != nil {
-						return fmt.Errorf("failed to copy %s to stdout: %w", file.Path, err)
-					}
-					if err = os.Remove(f.Name()); err != nil {
-						return fmt.Errorf("failed to remove temp file %s: %w", file.Path, err)
-					}
-
-					stats.Add(stats.Formatted, 1)
-					continue
-				}
-
-				// append to batch and process if we have enough
-				batch = append(batch, file)
-				if len(batch) == BatchSize {
-					if err := processBatch(); err != nil {
-						return err
-					}
-				}
-			}
-		}
-
-		// final flush
-		if err := processBatch(); err != nil {
-			return err
-		}
-
-		// if fail on change has been enabled, check that no files were actually formatted, throwing an error if so
-		if f.FailOnChange && stats.Value(stats.Formatted) != 0 {
-			return ErrFailOnChange
-		}
-
-		// print stats to stdout unless we are processing stdin and printing the results to stdout
-		if !f.Stdin {
-			stats.Print()
-		}
-
-		return nil
-	}
-}
-
 func (f *Format) walkFilesystem(ctx context.Context) func() error {
 	return func() error {
 		eg, ctx := errgroup.WithContext(ctx)
@@ -368,9 +293,9 @@ func (f *Format) applyFormatters(ctx context.Context) func() error {
 					}
 				}
 
-				// pass each file to the processed channel
+				// pass each file to the formatted channel
 				for _, task := range tasks {
-					f.processedCh <- task.File
+					f.formattedCh <- task.File
 				}
 
 				return nil
@@ -392,7 +317,7 @@ func (f *Format) applyFormatters(ctx context.Context) func() error {
 	return func() error {
 		defer func() {
 			// close processed channel
-			close(f.processedCh)
+			close(f.formattedCh)
 		}()
 
 		// iterate the files channel
@@ -402,7 +327,7 @@ func (f *Format) applyFormatters(ctx context.Context) func() error {
 			if format.PathMatches(file.RelPath, f.globalExcludes) {
 				log.Debugf("path matched global excludes: %s", file.RelPath)
 				// mark it as processed and continue to the next
-				f.processedCh <- file
+				f.formattedCh <- file
 				continue
 			}
 
@@ -421,7 +346,7 @@ func (f *Format) applyFormatters(ctx context.Context) func() error {
 				}
 				log.Logf(f.OnUnmatched, "no formatter for path: %s", file.RelPath)
 				// mark it as processed and continue to the next
-				f.processedCh <- file
+				f.formattedCh <- file
 			} else {
 				// record the match
 				stats.Add(stats.Matched, 1)
@@ -444,6 +369,127 @@ func (f *Format) applyFormatters(ctx context.Context) func() error {
 	}
 }
 
+func (f *Format) detectFormatted(ctx context.Context) func() error {
+	return func() error {
+		defer func() {
+			// close formatted channel
+			close(f.processedCh)
+		}()
+
+		for {
+			select {
+
+			// detect ctx cancellation
+			case <-ctx.Done():
+				return ctx.Err()
+			// take the next file that has been processed
+			case file, ok := <-f.formattedCh:
+				if !ok {
+					// channel has been closed, no further files to process
+					return nil
+				}
+
+				// look up current file info
+				currentInfo, err := os.Stat(file.Path)
+				if err != nil {
+					return fmt.Errorf("failed to stat processed file: %w", err)
+				}
+
+				// check if the file has changed
+				if !(file.Info.ModTime() == currentInfo.ModTime() && file.Info.Size() == currentInfo.Size()) {
+					// record the change
+					stats.Add(stats.Formatted, 1)
+					// update the file info
+					file.Info = currentInfo
+				}
+
+				// mark as processed
+				f.processedCh <- file
+			}
+		}
+	}
+}
+
+func (f *Format) updateCache(ctx context.Context) func() error {
+	return func() error {
+		// used to batch updates for more efficient txs
+		batch := make([]*walk.File, 0, BatchSize)
+
+		// apply a batch
+		processBatch := func() error {
+			// if we are processing from stdin that means we are outputting to stdout, no caching involved
+			// if f.NoCache is set that means either the user explicitly disabled the cache or we failed to open on
+			if f.Stdin || f.NoCache {
+				// do nothing
+				return nil
+			}
+
+			// pass the batch to the cache for updating
+			if err := cache.Update(batch); err != nil {
+				return err
+			}
+			batch = batch[:0]
+			return nil
+		}
+
+	LOOP:
+		for {
+			select {
+			// detect ctx cancellation
+			case <-ctx.Done():
+				return ctx.Err()
+			// respond to formatted files
+			case file, ok := <-f.processedCh:
+				if !ok {
+					// channel has been closed, no further files to process
+					break LOOP
+				}
+
+				if f.Stdin {
+					// dump file into stdout
+					f, err := os.Open(file.Path)
+					if err != nil {
+						return fmt.Errorf("failed to open %s: %w", file.Path, err)
+					}
+					if _, err = io.Copy(os.Stdout, f); err != nil {
+						return fmt.Errorf("failed to copy %s to stdout: %w", file.Path, err)
+					}
+					if err = os.Remove(f.Name()); err != nil {
+						return fmt.Errorf("failed to remove temp file %s: %w", file.Path, err)
+					}
+
+					continue
+				}
+
+				// append to batch and process if we have enough
+				batch = append(batch, file)
+				if len(batch) == BatchSize {
+					if err := processBatch(); err != nil {
+						return err
+					}
+				}
+			}
+		}
+
+		// final flush
+		if err := processBatch(); err != nil {
+			return err
+		}
+
+		// if fail on change has been enabled, check that no files were actually formatted, throwing an error if so
+		if f.FailOnChange && stats.Value(stats.Formatted) != 0 {
+			return ErrFailOnChange
+		}
+
+		// print stats to stdout unless we are processing stdin and printing the results to stdout
+		if !f.Stdin {
+			stats.Print()
+		}
+
+		return nil
+	}
+}
+
 func findUp(searchDir string, fileName string) (path string, dir string, err error) {
 	for _, dir := range eachDir(searchDir) {
 		path := filepath.Join(dir, fileName)

cli/format_test.go

@@ -364,6 +364,11 @@ func TestFailOnChange(t *testing.T) {
 	test.WriteConfig(t, configPath, cfg)
 	_, err := cmd(t, "--fail-on-change", "--config-file", configPath, "--tree-root", tempDir)
 	as.ErrorIs(err, ErrFailOnChange)
+
+	// test with no cache
+	test.WriteConfig(t, configPath, cfg)
+	_, err = cmd(t, "--fail-on-change", "--config-file", configPath, "--tree-root", tempDir, "--no-cache")
+	as.ErrorIs(err, ErrFailOnChange)
 }
 
 func TestBustCacheOnFormatterChange(t *testing.T) {