Flesh out URLLoader's download_to_file function.

* tie the lifetime of the resulting temp file to the lifetime of the URLLoader
 (the plan is to later extend the lifetime of the temp file to support xhr.responseBlob)
* make it work in test_shell
* make it work for sync requests
* added OnDataDownloaded messages to report progress

A related BlobURL loading change.
* grab a reference to the blob early on to ensure it's still there when the 'job' is finally started.

TEST=manual and deletable_file_reference_unittest.cc
BUG=52486,56752

Review URL: http://codereview.chromium.org/3396029

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@60862 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 168 insertions, 0 deletions

diff --git a/webkit/blob/deletable_file_reference.cc b/webkit/blob/deletable_file_reference.cc
new file mode 100644
index 0000000..b005eeb
--- /dev/null
+++ b/webkit/blob/deletable_file_reference.cc
@@ -0,0 +1,63 @@
+// Copyright (c) 2010 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 "webkit/blob/deletable_file_reference.h"
+
+#include <map>
+#include "base/file_util.h"
+#include "base/file_util_proxy.h"
+#include "base/message_loop_proxy.h"
+#include "base/singleton.h"
+
+namespace webkit_blob {
+
+namespace {
+
+typedef std::map<FilePath, DeletableFileReference*> DeleteableFileMap;
+
+DeleteableFileMap* map() {
+  return Singleton<DeleteableFileMap>::get();
+}
+
+}  // namespace
+
+// static
+scoped_refptr<DeletableFileReference> DeletableFileReference::Get(
+    const FilePath& path) {
+  DeleteableFileMap::iterator found = map()->find(path);
+  DeletableFileReference* reference =
+      (found == map()->end()) ? NULL : found->second;
+  return scoped_refptr<DeletableFileReference>(reference);
+}
+
+// static
+scoped_refptr<DeletableFileReference> DeletableFileReference::GetOrCreate(
+    const FilePath& path, base::MessageLoopProxy* file_thread) {
+  DCHECK(file_thread);
+  typedef std::pair<DeleteableFileMap::iterator, bool> InsertResult;
+  InsertResult result = map()->insert(
+      DeleteableFileMap::value_type(path, NULL));
+  if (result.second == false)
+    return scoped_refptr<DeletableFileReference>(result.first->second);
+
+  // Wasn't in the map, create a new reference and store the pointer.
+  scoped_refptr<DeletableFileReference> reference =
+      new DeletableFileReference(path, file_thread);
+  result.first->second = reference.get();
+  return reference;
+}
+
+DeletableFileReference::DeletableFileReference(
+    const FilePath& path, base::MessageLoopProxy* file_thread)
+    : path_(path), file_thread_(file_thread) {
+  DCHECK(map()->find(path_)->second == NULL);
+}
+
+DeletableFileReference::~DeletableFileReference() {
+  DCHECK(map()->find(path_)->second == this);
+  map()->erase(path_);
+  base::FileUtilProxy::Delete(file_thread_, path_, NULL);
+}
+
+}  // namespace webkit_blob
diff --git a/webkit/blob/deletable_file_reference.h b/webkit/blob/deletable_file_reference.h
new file mode 100644
index 0000000..9578c10
--- /dev/null
+++ b/webkit/blob/deletable_file_reference.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2010 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.
+
+#ifndef WEBKIT_BLOB_DELETABLE_FILE_REFERENCE_H_
+#define WEBKIT_BLOB_DELETABLE_FILE_REFERENCE_H_
+#pragma once
+
+#include "base/file_path.h"
+#include "base/ref_counted.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace webkit_blob {
+
+// A refcounted wrapper around a FilePath that schedules the file
+// to be deleted upon final release.
+class DeletableFileReference : public base::RefCounted<DeletableFileReference> {
+ public:
+  // Returns a DeletableFileReference for the given path, if no reference
+  // for this path exists returns NULL.
+  static scoped_refptr<DeletableFileReference> Get(const FilePath& path);
+
+  // Returns a DeletableFileReference for the given path, creating a new
+  // reference if none yet exists.
+  static scoped_refptr<DeletableFileReference> GetOrCreate(
+      const FilePath& path, base::MessageLoopProxy* file_thread);
+
+  // The full file path.
+  const FilePath& path() const { return path_; }
+
+ private:
+  friend class base::RefCounted<DeletableFileReference>;
+
+  DeletableFileReference(
+      const FilePath& path, base::MessageLoopProxy* file_thread);
+  ~DeletableFileReference();
+
+  const FilePath path_;
+  scoped_refptr<base::MessageLoopProxy> file_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(DeletableFileReference);
+};
+
+}  // namespace webkit_blob
+
+#endif  // BASE_DELETABLE_FILE_REFERENCE_H_
diff --git a/webkit/blob/deletable_file_reference_unittest.cc b/webkit/blob/deletable_file_reference_unittest.cc
new file mode 100644
index 0000000..e4208a7
--- /dev/null
+++ b/webkit/blob/deletable_file_reference_unittest.cc
@@ -0,0 +1,54 @@
+// Copyright (c) 2010 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 "webkit/blob/deletable_file_reference.h"
+
+#include "base/file_util.h"
+#include "base/message_loop.h"
+#include "base/message_loop_proxy.h"
+#include "base/scoped_temp_dir.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace webkit_blob {
+
+TEST(DeletableFileReferenceTest, TestReferences) {
+  scoped_refptr<base::MessageLoopProxy> loop_proxy =
+      base::MessageLoopProxy::CreateForCurrentThread();
+  ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+
+  // Create a file.
+  FilePath file;
+  file_util::CreateTemporaryFileInDir(temp_dir.path(), &file);
+  EXPECT_TRUE(file_util::PathExists(file));
+
+  // Create a first reference to that file.
+  scoped_refptr<DeletableFileReference> reference1;
+  reference1 = DeletableFileReference::Get(file);
+  EXPECT_FALSE(reference1.get());
+  reference1 = DeletableFileReference::GetOrCreate(file, loop_proxy);
+  EXPECT_TRUE(reference1.get());
+  EXPECT_TRUE(file == reference1->path());
+
+  // Get a second reference to that file.
+  scoped_refptr<DeletableFileReference> reference2;
+  reference2 = DeletableFileReference::Get(file);
+  EXPECT_EQ(reference1.get(), reference2.get());
+  reference2 = DeletableFileReference::GetOrCreate(file, loop_proxy);
+  EXPECT_EQ(reference1.get(), reference2.get());
+
+  // Drop the first reference, the file and reference should still be there.
+  reference1 = NULL;
+  EXPECT_TRUE(DeletableFileReference::Get(file).get());
+  MessageLoop::current()->RunAllPending();
+  EXPECT_TRUE(file_util::PathExists(file));
+
+  // Drop the second reference, the file and reference should get deleted.
+  reference2 = NULL;
+  EXPECT_FALSE(DeletableFileReference::Get(file).get());
+  MessageLoop::current()->RunAllPending();
+  EXPECT_FALSE(file_util::PathExists(file));
+}
+
+}  // namespace webkit_blob
diff --git a/webkit/blob/webkit_blob.gypi b/webkit/blob/webkit_blob.gypi
index e057efb..eb4b3be 100644
--- a/webkit/blob/webkit_blob.gypi
+++ b/webkit/blob/webkit_blob.gypi
@@ -20,6 +20,8 @@
         'blob_storage_controller.h',
         'blob_url_request_job.cc',
         'blob_url_request_job.h',
+        'deletable_file_reference.cc',
+        'deletable_file_reference.h',
       ],
       'conditions': [
         ['inside_chromium_build==0', {