luci-go/common/dirwalk: Code for walking a directory tree efficiently

common/dirwalk/tests/tools/walkdir/fileprocessor_print.go

Index: common/dirwalk/tests/tools/walkdir/fileprocessor_print.go
diff --git a/common/dirwalk/tests/tools/walkdir/fileprocessor_print.go b/common/dirwalk/tests/tools/walkdir/fileprocessor_print.go
new file mode 100644
index 0000000000000000000000000000000000000000..f86dc8735e9c271a0d8b8c06f36c762ca75e0fd2
--- /dev/null
+++ b/common/dirwalk/tests/tools/walkdir/fileprocessor_print.go
@@ -0,0 +1,31 @@
+// Copyright 2016 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package main
+
+import (
+	"fmt"
+	"io"
+)
+
+// PrintFileProcessor implements FileProcessor. It prints the path of each found file.
+type PrintFileProcessor struct {
+	BaseFileProcessor
+	obuf io.Writer
+}
+
+func (p *PrintFileProcessor) Dir(path string) {
+	fmt.Fprintln(p.obuf, "  dir", path)
+	p.BaseFileProcessor.Dir(path)
+}
+
+func (p *PrintFileProcessor) SmallFile(path string, r io.ReadCloser) {
+	fmt.Fprintln(p.obuf, "small", path)
+	p.BaseFileProcessor.SmallFile(path, r)
+}
+
+func (p *PrintFileProcessor) LargeFile(path string, r io.ReadCloser) {
+	fmt.Fprintln(p.obuf, "large", path)
+	p.BaseFileProcessor.LargeFile(path, r)
+}