ServiceWorker: Confirm the liveness of the associated context before handling message

content/browser/service_worker/service_worker_provider_host_registry.cc

+// Copyright 2014 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 "content/browser/service_worker/service_worker_provider_host_registry.h"
+
+#include "content/browser/service_worker/service_worker_provider_host.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace content {
+
+ServiceWorkerProviderHostRegistry::Iterator::~Iterator() {}
+
+ServiceWorkerProviderHost*
+ServiceWorkerProviderHostRegistry::Iterator::GetProviderHost() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(!IsAtEnd());
+  return provider_host_iterator_->GetCurrentValue();
+}
+
+void ServiceWorkerProviderHostRegistry::Iterator::Advance() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK(!IsAtEnd());
+  DCHECK(!provider_host_iterator_->IsAtEnd());
+  DCHECK(!provider_iterator_->IsAtEnd());
+
+  // Advance the inner iterator. If an element is reached, we're done.
+  provider_host_iterator_->Advance();
+  if (!provider_host_iterator_->IsAtEnd())
+    return;
+
+  // Advance the outer iterator until an element is reached, or end is hit.
+  while (true) {
+    provider_iterator_->Advance();
+    if (provider_iterator_->IsAtEnd())
+      return;
+    ProviderMap* provider_map = provider_iterator_->GetCurrentValue();
+    provider_host_iterator_.reset(new ProviderMap::iterator(provider_map));
+    if (!provider_host_iterator_->IsAtEnd())
+      return;
+  }
+}
+
+bool ServiceWorkerProviderHostRegistry::Iterator::IsAtEnd() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  return provider_iterator_->IsAtEnd() &&
+         (!provider_host_iterator_ || provider_host_iterator_->IsAtEnd());
+}
+
+ServiceWorkerProviderHostRegistry::Iterator::Iterator(
+    ProcessToProviderMap* map)
+    : map_(map) {
+  DCHECK(map);
+  Initialize();
+}
+
+void ServiceWorkerProviderHostRegistry::Iterator::Initialize() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  provider_iterator_.reset(new ProcessToProviderMap::iterator(map_));
+  // Advance to the first element.
+  while (!provider_iterator_->IsAtEnd()) {
+    ProviderMap* provider_map = provider_iterator_->GetCurrentValue();
+    provider_host_iterator_.reset(new ProviderMap::iterator(provider_map));
+    if (!provider_host_iterator_->IsAtEnd())
+      return;
+    provider_iterator_->Advance();
+  }
+}
+
+ServiceWorkerProviderHostRegistry::ServiceWorkerProviderHostRegistry() {
+}
+
+ServiceWorkerProviderHostRegistry::~ServiceWorkerProviderHostRegistry() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+}
+
+ServiceWorkerProviderHost* ServiceWorkerProviderHostRegistry::GetProviderHost(
+    int process_id, int provider_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  ProviderMap* map = GetProviderMapForProcess(process_id);
+  if (!map)
+    return NULL;
+  return map->Lookup(provider_id);
+}
+
+void ServiceWorkerProviderHostRegistry::AddProviderHost(
+    scoped_ptr<ServiceWorkerProviderHost> host) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  ServiceWorkerProviderHost* host_ptr = host.release();   // we take ownership
+  ProviderMap* map = GetProviderMapForProcess(host_ptr->process_id());
+  if (!map) {
+    map = new ProviderMap;
+    providers_.AddWithID(map, host_ptr->process_id());
+  }
+  map->AddWithID(host_ptr, host_ptr->provider_id());
+}
+
+void ServiceWorkerProviderHostRegistry::RemoveProviderHost(
+    int process_id, int provider_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  ProviderMap* map = GetProviderMapForProcess(process_id);
+  DCHECK(map);
+  map->Remove(provider_id);
+}
+
+void ServiceWorkerProviderHostRegistry::RemoveAllProviderHostsForProcess(
+    int process_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (providers_.Lookup(process_id))
+    providers_.Remove(process_id);
+}
+
+scoped_ptr<ServiceWorkerProviderHostRegistry::Iterator>
+ServiceWorkerProviderHostRegistry::GetProviderHostIterator() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  return make_scoped_ptr(new Iterator(&providers_));
+}
+
+}  // namespace content