| // 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 "chrome/browser/data_usage/tab_id_provider.h" |
| |
| #include <vector> |
| |
| #include "base/bind.h" |
| #include "base/callback.h" |
| #include "base/location.h" |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "base/single_thread_task_runner.h" |
| #include "base/task_runner.h" |
| #include "base/task_runner_util.h" |
| |
| namespace chrome_browser_data_usage { |
| |
| namespace { |
| |
| // Convenience typedefs for clarity. |
| typedef base::Callback<int32_t(void)> TabIdGetter; |
| typedef base::Callback<void(int32_t)> TabIdCallback; |
| |
| } // namespace |
| |
| // Object that can run a list of callbacks that take tab IDs. New callbacks |
| // can only be added before it starts running the callbacks. Callbacks added |
| // will each be run exactly once. |
| class TabIdProvider::CallbackRunner { |
| public: |
| CallbackRunner() : is_done_(false), weak_ptr_factory_(this) {} |
| |
| ~CallbackRunner() { |
| // Ensure that no callbacks are abandoned without being run. |
| if (!is_done_) |
| RunAll(-1); |
| } |
| |
| // Adds a new callback to be run later. New callbacks must not be added after |
| // RunAll has been called. |
| void AddCallback(const TabIdCallback& callback) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK(!is_done_); |
| callbacks_.push_back(callback); |
| } |
| |
| // Runs all the callbacks in the order that they were added. This method must |
| // not be called more than once. |
| void RunAll(int32_t tab_id) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK(!is_done_); |
| is_done_ = true; |
| // It's safe to run the |callbacks_| while iterating through them because |
| // |callbacks_| can no longer be modified at this point, so it's impossible |
| // for one of the |callbacks_| to add more callbacks to this CallbackRunner. |
| for (const auto& callback : callbacks_) |
| callback.Run(tab_id); |
| callbacks_.clear(); |
| } |
| |
| base::WeakPtr<CallbackRunner> GetWeakPtr() { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| return weak_ptr_factory_.GetWeakPtr(); |
| } |
| |
| private: |
| base::ThreadChecker thread_checker_; |
| bool is_done_; |
| std::vector<TabIdCallback> callbacks_; |
| base::WeakPtrFactory<CallbackRunner> weak_ptr_factory_; |
| |
| DISALLOW_COPY_AND_ASSIGN(CallbackRunner); |
| }; |
| |
| TabIdProvider::TabIdProvider(base::TaskRunner* task_runner, |
| const tracked_objects::Location& from_here, |
| const TabIdGetter& tab_id_getter) |
| : is_tab_id_ready_(false), tab_id_(-1), weak_ptr_factory_(this) { |
| scoped_ptr<CallbackRunner> callback_runner(new CallbackRunner()); |
| weak_callback_runner_ = callback_runner->GetWeakPtr(); |
| callback_runner->AddCallback( |
| base::Bind(&TabIdProvider::OnTabIdReady, GetWeakPtr())); |
| |
| // The posted task takes ownership of |callback_runner|. If the task fails to |
| // be posted, then the destructor of |callback_runner| will pass a tab ID of |
| // -1 to OnTabIdReady, so that case doesn't need to be explicitly handled |
| // here. |
| base::PostTaskAndReplyWithResult( |
| task_runner, from_here, tab_id_getter, |
| base::Bind(&CallbackRunner::RunAll, |
| base::Owned(callback_runner.release()))); |
| } |
| |
| TabIdProvider::~TabIdProvider() {} |
| |
| void TabIdProvider::ProvideTabId(const TabIdCallback& callback) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| if (is_tab_id_ready_) { |
| callback.Run(tab_id_); |
| return; |
| } |
| if (weak_callback_runner_) { |
| weak_callback_runner_->AddCallback(callback); |
| return; |
| } |
| // If no cached tab ID is available and |weak_callback_runner_| has been |
| // destroyed, pass a tab ID of -1 to the callback indicating that no tab was |
| // found. |
| callback.Run(-1); |
| } |
| |
| base::WeakPtr<TabIdProvider> TabIdProvider::GetWeakPtr() { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| return weak_ptr_factory_.GetWeakPtr(); |
| } |
| |
| // static |
| const void* TabIdProvider::kUserDataKey = |
| static_cast<void*>(&TabIdProvider::kUserDataKey); |
| |
| void TabIdProvider::OnTabIdReady(int32_t tab_id) { |
| DCHECK(thread_checker_.CalledOnValidThread()); |
| DCHECK(!is_tab_id_ready_); |
| tab_id_ = tab_id; |
| is_tab_id_ready_ = true; |
| } |
| |
| } // namespace chrome_browser_data_usage |