Copy folder recursively for syncfsToLocalfs export.

chrome/browser/extensions/api/developer_private/developer_private_api.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/extensions/api/developer_private/developer_private_api.h"
 
 #include "apps/app_load_service.h"
 #include "apps/app_restore_service.h"
 #include "apps/saved_files_service.h"
 #include "base/base64.h"
@@ skipping 816 matching lines @@
   if (!file_util::Delete(project_path, true/*recursive*/)) {
     SetError("Error in copying files from sync filesystem.");
     content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
         base::Bind(&DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
                        SendResponse,
                    this,
                    false));
     return;
   }
 
+  pendingCallbacksCount_ = 1;
+
   content::BrowserThread::PostTask(content::BrowserThread::IO, FROM_HERE,
       base::Bind(&DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
                  ReadSyncFileSystemDirectory,
-                 this, project_path));
+                 this, project_path, project_path.BaseName()));
 }
 
 void DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
-    ReadSyncFileSystemDirectory(const base::FilePath& project_path) {
+    ReadSyncFileSystemDirectory(const base::FilePath& project_path,
+                                const base::FilePath& current_path) {
   std::string origin_url(
       Extension::GetBaseURLFromExtensionId(extension_id()).spec());
   fileapi::FileSystemURL url(sync_file_system::CreateSyncableFileSystemURL(
       GURL(origin_url),
-      project_path.BaseName()));
+      current_path));
 
   context_->operation_runner()->ReadDirectory(
       url, base::Bind(&DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
-                      ReadSyncFileSystemDirectoryCb, this, project_path));
+                      ReadSyncFileSystemDirectoryCb,
+                      this, project_path, current_path));
 }
 
 void DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
     ReadSyncFileSystemDirectoryCb(
     const base::FilePath& project_path,
+    const base::FilePath& current_path,
     base::PlatformFileError status,
     const fileapi::FileSystemOperation::FileEntryList& file_list,
     bool has_more) {
 
   if (status != base::PLATFORM_FILE_OK) {
     DLOG(ERROR) << "Error in copying files from sync filesystem.";
     return;
   }
 
-  // Create an empty project folder if there are no files.
-  if (!file_list.size()) {
-    content::BrowserThread::PostTask(content::BrowserThread::FILE, FROM_HERE,
-      base::Bind(&DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
-                     CreateFolderAndSendResponse,
-                 this,
-                 project_path));
-    return;
-  }
-
-  pendingCallbacksCount_ = file_list.size();
+  pendingCallbacksCount_ += file_list.size();

[miket_OOO, 2013/06/12 19:39:24]

This is pretty confusing. You're adding N to pendingCallbacksCount_, but only
decrementing it once later in this method. There seems to be some kind of
recursion going on, but it's not at all obvious how it works.

Can you add more comments to explain it?

[Gaurav, 2013/06/21 22:11:00]

Done.

 
   for (size_t i = 0; i < file_list.size(); ++i) {
+    if (file_list[i].is_directory) {
+      ReadSyncFileSystemDirectory(project_path.Append(file_list[i].name),
+                                  current_path.Append(file_list[i].name));
+      continue;

[miket_OOO, 2013/06/12 19:39:24]

This is a good example of why it's confusing. It seems like you're adding the
whole file list size, but then doing the recursive call (the only thing that
subtracts from pendingCallbacksCount_) only once for each directory. What if
something in the list isn't a directory? Won't pendingCallbacksCount_ stay
positive forever? Code comments here would help.

[Gaurav, 2013/06/21 22:11:00]

Done.

+    }
+
     std::string origin_url(
         Extension::GetBaseURLFromExtensionId(extension_id()).spec());
     fileapi::FileSystemURL url(sync_file_system::CreateSyncableFileSystemURL(
         GURL(origin_url),
-        project_path.BaseName().Append(file_list[i].name)));
+        current_path.Append(file_list[i].name)));
     base::FilePath target_path = project_path;
     target_path = target_path.Append(file_list[i].name);
 
     context_->operation_runner()->CreateSnapshotFile(
         url,
         base::Bind(
             &DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
                 SnapshotFileCallback,
             this,
             target_path));
+
+  }
+  pendingCallbacksCount_--;
+  if (!pendingCallbacksCount_) {
+    content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
+        base::Bind(&DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
+                       SendResponse,
+                   this,
+                   success_));
   }
 }
 
-void DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
-    CreateFolderAndSendResponse(const base::FilePath& project_path) {
-  if (!(success_ = file_util::CreateDirectory(project_path))) {
-    SetError("Error in copying files from sync filesystem.");
-  }
-  content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
-      base::Bind(&DeveloperPrivateExportSyncfsFolderToLocalfsFunction::
-                     SendResponse,
-                 this,
-                 success_));
-}
-
 void DeveloperPrivateExportSyncfsFolderToLocalfsFunction::SnapshotFileCallback(
     const base::FilePath& target_path,
     base::PlatformFileError result,
     const base::PlatformFileInfo& file_info,
     const base::FilePath& src_path,
     const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
   if (result != base::PLATFORM_FILE_OK) {
     SetError("Error in copying files from sync filesystem.");
     success_ = false;
     return;
@@ skipping 217 matching lines @@
 
   #undef   SET_STRING
   return true;
 }
 
 DeveloperPrivateGetStringsFunction::~DeveloperPrivateGetStringsFunction() {}
 
 } // namespace api
 
 } // namespace extensions