cipd: accept a function in EnsureFile

client/cipd/client.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Package cipd implements client side of Chrome Infra Package Deployer.
 //
 // Binary package file format (in free form representation):
 //   <binary package> := <zipped data>
 //   <zipped data> := DeterministicZip(<all input files> + <manifest json>)
 //   <manifest json> := File{
@@ skipping 458 matching lines @@
         f(cache)
 
         if cache.Dirty() {
                 // It's tiny in size (and protobuf can't serialize to io.Reader anyway). Dump
                 // it to disk via FileSystem object to deal with possible concurrent updates,
                 // missing directories, etc.
                 fs := local.NewFileSystem(filepath.Dir(path), client.Logger)
                 start = time.Now()
                 out, err := cache.Save()
                 if err == nil {
-                        err = fs.EnsureFile(path, bytes.NewReader(out))
+                        err = local.EnsureFile(fs, path, bytes.NewReader(out))
                 }
                 loadSaveTime += time.Since(start)
                 if err != nil {
                         client.Logger.Warningf("cipd: failed to update tag cache - %s", err)
                 }
         }
 
         if loadSaveTime > time.Second {
                 client.Logger.Warningf("cipd: loading and saving tag cache with %d entries took %s", cache.Len(), loadSaveTime)
         }
@@ skipping 550 matching lines @@
 }
 
 // buildInstanceIDMap builds mapping {package name -> instance ID}.
 func buildInstanceIDMap(pins []common.Pin) map[string]string {
         out := map[string]string{}
         for _, p := range pins {
                 out[p.PackageName] = p.InstanceID
         }
         return out
 }