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

common/dirwalk/walk_basic.go

+// 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 dirwalk
+
+import (
+        "io/ioutil"
+        "os"
+        "path/filepath"
+)
+
+// Trivial implementation of a directory tree walker using the WalkObserver
+// interface.
+func WalkBasic(root string, smallfile_limit int64, obs WalkObserver) {
+        filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
+                if err != nil {
+                        obs.Error(path, err)
+                        return nil
+                }
+
+                if info.IsDir() {
+                        return nil
+                }
+
+                if info.Size() < smallfile_limit {
+                        data, err := ioutil.ReadFile(path)
+                        if err != nil {
+                                obs.Error(path, err)
+                                return nil
+                        }
+                        if int64(len(data)) != info.Size() {
+                                panic("file size was wrong!")
+                        }
+                        obs.SmallFile(path, data)
+                } else {
+                        obs.LargeFile(path)
+                }
+                return nil
+        })
+        obs.Finished()
+}