| /* |
| * Copyright 2010 Google Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| // Author: sligocki@google.com (Shawn Ligocki) |
| |
| #include "net/instaweb/http/public/wait_url_async_fetcher.h" |
| |
| #include <vector> |
| |
| #include "base/logging.h" |
| #include "pagespeed/kernel/base/abstract_mutex.h" |
| #include "pagespeed/kernel/base/basictypes.h" |
| #include "pagespeed/kernel/base/scoped_ptr.h" |
| #include "pagespeed/kernel/base/stl_util.h" |
| #include "pagespeed/kernel/base/string.h" |
| |
| namespace net_instaweb { |
| |
| class WaitUrlAsyncFetcher::DelayedFetch { |
| public: |
| DelayedFetch(UrlAsyncFetcher* base_fetcher, const GoogleString& url, |
| MessageHandler* handler, AsyncFetch* base_fetch) |
| : base_fetcher_(base_fetcher), url_(url), handler_(handler), |
| base_fetch_(base_fetch) { |
| } |
| |
| void FetchNow() { |
| base_fetcher_->Fetch(url_, handler_, base_fetch_); |
| } |
| |
| private: |
| UrlAsyncFetcher* base_fetcher_; |
| |
| GoogleString url_; |
| MessageHandler* handler_; |
| AsyncFetch* base_fetch_; |
| |
| DISALLOW_COPY_AND_ASSIGN(DelayedFetch); |
| }; |
| |
| WaitUrlAsyncFetcher::~WaitUrlAsyncFetcher() {} |
| |
| void WaitUrlAsyncFetcher::Fetch(const GoogleString& url, |
| MessageHandler* handler, |
| AsyncFetch* base_fetch) { |
| DelayedFetch* delayed_fetch = |
| new DelayedFetch(url_fetcher_, url, handler, base_fetch); |
| bool bypass_delay = |
| (do_not_delay_urls_.find(url) != do_not_delay_urls_.end()); |
| |
| { |
| ScopedMutex lock(mutex_.get()); |
| if (!pass_through_mode_ && !bypass_delay) { |
| // Don't call the blocking fetcher until CallCallbacks. |
| delayed_fetches_.push_back(delayed_fetch); |
| return; |
| } |
| } |
| // pass_through_mode_ == true || bypass_delay |
| delayed_fetch->FetchNow(); |
| delete delayed_fetch; |
| } |
| |
| bool WaitUrlAsyncFetcher::CallCallbacksAndSwitchModesHelper(bool new_mode) { |
| bool prev_mode = false; |
| std::vector<DelayedFetch*> fetches; |
| { |
| // Don't hold the mutex while we call our callbacks. Transfer |
| // the to a local vector and release the mutex as quickly as possible. |
| ScopedMutex lock(mutex_.get()); |
| fetches.swap(delayed_fetches_); |
| prev_mode = pass_through_mode_; |
| pass_through_mode_ = new_mode; |
| } |
| for (int i = 0, n = fetches.size(); i < n; ++i) { |
| fetches[i]->FetchNow(); |
| } |
| STLDeleteElements(&fetches); |
| return prev_mode; |
| } |
| |
| void WaitUrlAsyncFetcher::CallCallbacks() { |
| DCHECK(!pass_through_mode_); |
| CallCallbacksAndSwitchModesHelper(false); |
| } |
| |
| bool WaitUrlAsyncFetcher::SetPassThroughMode(bool new_mode) { |
| bool old_mode = false; |
| if (new_mode) { |
| // This is structured so that we only need to grab the mutex once. |
| old_mode = CallCallbacksAndSwitchModesHelper(true); |
| } else { |
| // We are turning pass-through-mode back off |
| ScopedMutex lock(mutex_.get()); |
| old_mode = pass_through_mode_; |
| pass_through_mode_ = false; |
| } |
| return old_mode; |
| } |
| |
| void WaitUrlAsyncFetcher::DoNotDelay(const GoogleString& url) { |
| do_not_delay_urls_.insert(url); |
| } |
| |
| } // namespace net_instaweb |