[Storage] Blob Storage Refactoring pt 1

storage/browser/blob/blob_url_request_job_factory.cc

 // Copyright (c) 2011 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 "storage/browser/blob/blob_url_request_job_factory.h"
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/strings/string_util.h"
 #include "net/base/request_priority.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_job_factory.h"
 #include "storage/browser/blob/blob_data_handle.h"
 #include "storage/browser/blob/blob_storage_context.h"
 #include "storage/browser/blob/blob_url_request_job.h"
 #include "storage/browser/fileapi/file_system_context.h"
 
 namespace storage {
 
 namespace {
 
 int kUserDataKey;  // The value is not important, the addr is a key.
 
-BlobDataHandle* GetRequestedBlobDataHandle(net::URLRequest* request) {
-  return static_cast<BlobDataHandle*>(request->GetUserData(&kUserDataKey));
+BlobDataSnapshotHandle* GetRequestedBlobDataHandle(net::URLRequest* request) {
+  return static_cast<BlobDataSnapshotHandle*>(
+      request->GetUserData(&kUserDataKey));
 }
 
 }  // namespace
 
 // static
 scoped_ptr<net::URLRequest> BlobProtocolHandler::CreateBlobRequest(
-    scoped_ptr<BlobDataHandle> blob_data_handle,
+    scoped_ptr<BlobDataSnapshotHandle> blob_data_handle,
     const net::URLRequestContext* request_context,
     net::URLRequest::Delegate* request_delegate) {
   const GURL kBlobUrl("blob://see_user_data/");
   scoped_ptr<net::URLRequest> request = request_context->CreateRequest(
       kBlobUrl, net::DEFAULT_PRIORITY, request_delegate, NULL);
   SetRequestedBlobDataHandle(request.get(), blob_data_handle.Pass());
   return request.Pass();
 }
 
 // static
 void BlobProtocolHandler::SetRequestedBlobDataHandle(
     net::URLRequest* request,
-    scoped_ptr<BlobDataHandle> blob_data_handle) {
+    scoped_ptr<BlobDataSnapshotHandle> blob_data_handle) {
   request->SetUserData(&kUserDataKey, blob_data_handle.release());
 }
 
 BlobProtocolHandler::BlobProtocolHandler(
     BlobStorageContext* context,
     storage::FileSystemContext* file_system_context,
     const scoped_refptr<base::MessageLoopProxy>& loop_proxy)
     : file_system_context_(file_system_context), file_loop_proxy_(loop_proxy) {
   if (context)
     context_ = context->AsWeakPtr();
 }
 
 BlobProtocolHandler::~BlobProtocolHandler() {
 }
 
 net::URLRequestJob* BlobProtocolHandler::MaybeCreateJob(
     net::URLRequest* request, net::NetworkDelegate* network_delegate) const {
   return new storage::BlobURLRequestJob(request,
                                         network_delegate,
                                         LookupBlobData(request),
                                         file_system_context_.get(),
                                         file_loop_proxy_.get());
 }
 
-scoped_refptr<storage::BlobData> BlobProtocolHandler::LookupBlobData(
+const storage::BlobDataSnapshot* BlobProtocolHandler::LookupBlobData(
     net::URLRequest* request) const {
-  BlobDataHandle* blob_data_handle = GetRequestedBlobDataHandle(request);
+  BlobDataSnapshotHandle* blob_data_handle =
+      GetRequestedBlobDataHandle(request);
   if (blob_data_handle)
     return blob_data_handle->data();
   if (!context_.get())
     return NULL;
 
   // Support looking up based on uuid, the FeedbackExtensionAPI relies on this.
   // TODO(michaeln): Replace this use case and others like it with a BlobReader
   // impl that does not depend on urlfetching to perform this function.
   const std::string kPrefix("blob:uuid/");
   if (!StartsWithASCII(request->url().spec(), kPrefix, true))
     return NULL;
   std::string uuid = request->url().spec().substr(kPrefix.length());
-  scoped_ptr<BlobDataHandle> handle = context_->GetBlobDataFromUUID(uuid);
-  return handle.get() ? handle->data() : NULL;
+  scoped_ptr<BlobDataSnapshotHandle> handle =
+      context_->GetBlobDataFromUUID(uuid);
+  const BlobDataSnapshot* snapshot = nullptr;
+  if (handle) {
+    snapshot = handle->data();
+    SetRequestedBlobDataHandle(request, handle.Pass());
+  }
+  return snapshot;
 }
 
 }  // namespace storage