[Offline pages] Adding in memory request queue store with tests

components/offline_pages/background/request_queue_in_memory_store.cc

+// Copyright 2016 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 "components/offline_pages/background/request_queue_in_memory_store.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/thread_task_runner_handle.h"
+#include "components/offline_pages/background/save_page_request.h"
+
+namespace offline_pages {
+
+RequestQueueInMemoryStore::RequestQueueInMemoryStore() {}
+
+RequestQueueInMemoryStore::~RequestQueueInMemoryStore() {}
+
+void RequestQueueInMemoryStore::GetRequests(
+    const GetRequestsCallback& callback) {
+  std::vector<SavePageRequest> result_requests;
+  for (const auto& id_request_pair : requests_)
+    result_requests.push_back(id_request_pair.second);
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback, true, result_requests));
+}
+
+void RequestQueueInMemoryStore::AddOrUpdateRequest(
+    const SavePageRequest& request,
+    const UpdateCallback& callback) {
+  RequestsMap::iterator iter = requests_.find(request.request_id());
+  UpdateStatus status = UpdateStatus::kAdded;
+  if (iter != requests_.end()) {
+    requests_.erase(iter);
+    status = UpdateStatus::kUpdated;
+  }
+  requests_.insert(std::make_pair(request.request_id(), request));
+  base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
+                                                base::Bind(callback, status));
+}
+
+void RequestQueueInMemoryStore::RemoveRequests(
+    const std::vector<int64_t>& request_ids,
+    const RemoveCallback& callback) {
+  // In case the |request_ids| is empty, the result will be true, but the count
+  // of deleted pages will be empty.
+  bool result = true;
+  int count = 0;
+  RequestsMap::iterator iter;
+  for (auto request_id : request_ids) {
+    iter = requests_.find(request_id);
+    if (iter != requests_.end()) {
+      requests_.erase(iter);
+      ++count;
+    } else {
+      result = false;
+    }
+  }
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback, result, count));
+}
+
+void RequestQueueInMemoryStore::Reset(const ResetCallback& callback) {
+  requests_.clear();
+  base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
+                                                base::Bind(callback, true));
+}
+
+}  // namespace offline_pages