[BlobAsync] Patch 1: BlobStorageRegistry

storage/browser/blob/blob_storage_registry.cc

+// 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.
+
+#include "storage/browser/blob/blob_storage_registry.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/location.h"
+#include "base/logging.h"
+#include "base/message_loop/message_loop.h"
+#include "base/stl_util.h"
+#include "url/gurl.h"
+
+namespace storage {
+using BlobState = BlobStorageRegistry::BlobState;
+
+namespace {
+// We can't use GURL directly for these hash fragment manipulations
+// since it doesn't have specific knowlege of the BlobURL format. GURL
+// treats BlobURLs as if they were PathURLs which don't support hash
+// fragments.
+
+bool BlobUrlHasRef(const GURL& url) {
+  return url.spec().find('#') != std::string::npos;
+}
+
+GURL ClearBlobUrlRef(const GURL& url) {
+  size_t hash_pos = url.spec().find('#');
+  if (hash_pos == std::string::npos)
+    return url;
+  return GURL(url.spec().substr(0, hash_pos));
+}
+
+}  // namespace
+
+BlobStorageRegistry::Entry::Entry(int refcount, BlobState state)
+    : refcount(refcount), state(state), exceeded_memory(false) {}
+
+BlobStorageRegistry::Entry::~Entry() {}
+
+bool BlobStorageRegistry::Entry::TestAndSetState(BlobState expected,
+                                                 BlobState set) {
+  if (state != expected)
+    return false;
+  state = set;
+  return true;
+}
+
+BlobStorageRegistry::BlobStorageRegistry() {}
+
+BlobStorageRegistry::~BlobStorageRegistry() {
+  // Note: We don't bother calling the construction complete callbacks, as we
+  // are only being destructed at the end of the life of the browser process.
+  // So it shouldn't matter.
+}
+
+BlobStorageRegistry::Entry* BlobStorageRegistry::CreateEntry(
+    const std::string& uuid) {
+  DCHECK(!ContainsKey(blob_map_, uuid));
+  Entry* entry = new Entry(1, BlobState::RESERVED);
+  blob_map_.add(uuid, make_scoped_ptr(entry));
+  return entry;
+}
+
+bool BlobStorageRegistry::DeleteEntry(const std::string& uuid) {
+  return blob_map_.erase(uuid) == 1;
+}
+
+BlobStorageRegistry::Entry* BlobStorageRegistry::GetEntry(
+    const std::string& uuid) {
+  BlobMap::iterator found = blob_map_.find(uuid);
+  if (found == blob_map_.end())
+    return nullptr;
+  return found->second;
+}
+
+bool BlobStorageRegistry::CreateUrlMapping(const GURL& blob_url,
+                                           const std::string& uuid) {
+  DCHECK(!BlobUrlHasRef(blob_url));
+  if (blob_map_.find(uuid) == blob_map_.end() || IsURLMapped(blob_url))
+    return false;
+  url_to_uuid_[blob_url] = uuid;
+  return true;
+}
+
+bool BlobStorageRegistry::DeleteURLMapping(const GURL& blob_url,
+                                           std::string* uuid) {
+  DCHECK(!BlobUrlHasRef(blob_url));
+  URLMap::iterator found = url_to_uuid_.find(blob_url);
+  if (found == url_to_uuid_.end())
+    return false;
+  if (uuid)
+    uuid->assign(found->second);
+  url_to_uuid_.erase(found);
+  return true;
+}
+
+bool BlobStorageRegistry::IsURLMapped(const GURL& blob_url) const {
+  return ContainsKey(url_to_uuid_, blob_url);
+}
+
+BlobStorageRegistry::Entry* BlobStorageRegistry::GetEntryFromURL(
+    const GURL& url,
+    std::string* uuid) {
+  URLMap::iterator found =
+      url_to_uuid_.find(BlobUrlHasRef(url) ? ClearBlobUrlRef(url) : url);
+  if (found == url_to_uuid_.end())
+    return nullptr;
+  Entry* entry = GetEntry(found->second);
+  if (entry && uuid)
+    uuid->assign(found->second);
+  return entry;
+}
+
+}  // namespace storage