// Copyright (c) 2012 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.
#ifndef NET_URL_REQUEST_URL_REQUEST_JOB_MANAGER_H_
#define NET_URL_REQUEST_URL_REQUEST_JOB_MANAGER_H_
#include <map>
#include <string>
#include <vector>
#include "base/synchronization/lock.h"
#include "base/threading/platform_thread.h"
#include "net/url_request/url_request.h"
template <typename T> struct DefaultSingletonTraits;
namespace net {
// This class is responsible for managing the set of protocol factories and
// request interceptors that determine how an URLRequestJob gets created to
// handle an URLRequest.
//
// MULTI-THREADING NOTICE:
// URLRequest is designed to have all consumers on a single thread, and
// so no attempt is made to support ProtocolFactory or Interceptor instances
// being registered/unregistered or in any way poked on multiple threads.
// However, we do support checking for supported schemes FROM ANY THREAD
// (i.e., it is safe to call SupportsScheme on any thread).
//
class URLRequestJobManager {
public:
// Returns the singleton instance.
static URLRequestJobManager* GetInstance();
// Instantiate an URLRequestJob implementation based on the registered
// interceptors and protocol factories. This will always succeed in
// returning a job unless we are--in the extreme case--out of memory.
URLRequestJob* CreateJob(URLRequest* request,
NetworkDelegate* network_delegate) const;
// Allows interceptors to hijack the request after examining the new location
// of a redirect. Returns NULL if no interceptor intervenes.
URLRequestJob* MaybeInterceptRedirect(URLRequest* request,
NetworkDelegate* network_delegate,
const GURL& location) const;
// Allows interceptors to hijack the request after examining the response
// status and headers. This is also called when there is no server response
// at all to allow interception of failed requests due to network errors.
// Returns NULL if no interceptor intervenes.
URLRequestJob* MaybeInterceptResponse(
URLRequest* request, NetworkDelegate* network_delegate) const;
// Returns true if there is a protocol factory registered for the given
// scheme. Note: also returns true if there is a built-in handler for the
// given scheme.
bool SupportsScheme(const std::string& scheme) const;
// Register a protocol factory associated with the given scheme. The factory
// parameter may be null to clear any existing association. Returns the
// previously registered protocol factory if any.
URLRequest::ProtocolFactory* RegisterProtocolFactory(
const std::string& scheme, URLRequest::ProtocolFactory* factory);
// Register/unregister a request interceptor.
void RegisterRequestInterceptor(URLRequest::Interceptor* interceptor);
void UnregisterRequestInterceptor(URLRequest::Interceptor* interceptor);
private:
typedef std::map<std::string, URLRequest::ProtocolFactory*> FactoryMap;
typedef std::vector<URLRequest::Interceptor*> InterceptorList;
friend struct DefaultSingletonTraits<URLRequestJobManager>;
URLRequestJobManager();
~URLRequestJobManager();
// The first guy to call this function sets the allowed thread. This way we
// avoid needing to define that thread externally. Since we expect all
// callers to be on the same thread, we don't worry about threads racing to
// set the allowed thread.
bool IsAllowedThread() const {
#if 0
if (!allowed_thread_initialized_) {
allowed_thread_ = base::PlatformThread::CurrentId();
allowed_thread_initialized_ = true;
}
return allowed_thread_ == base::PlatformThread::CurrentId();
#else
// The previous version of this check used GetCurrentThread on Windows to
// get thread handles to compare. Unfortunately, GetCurrentThread returns
// a constant pseudo-handle (0xFFFFFFFE), and therefore IsAllowedThread
// always returned true. The above code that's turned off is the correct
// code, but causes the tree to turn red because some caller isn't
// respecting our thread requirements. We're turning off the check for now;
// bug http://b/issue?id=1338969 has been filed to fix things and turn the
// check back on.
return true;
}
// We use this to assert that CreateJob and the registration functions all
// run on the same thread.
mutable base::PlatformThreadId allowed_thread_;
mutable bool allowed_thread_initialized_;
#endif
mutable base::Lock lock_;
FactoryMap factories_;
InterceptorList interceptors_;
DISALLOW_COPY_AND_ASSIGN(URLRequestJobManager);
};
} // namespace net
#endif // NET_URL_REQUEST_URL_REQUEST_JOB_MANAGER_H_