| // 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. |
| |
| #ifndef CONTENT_BROWSER_LOADER_INTERCEPTING_RESOURCE_HANDLER_H_ |
| #define CONTENT_BROWSER_LOADER_INTERCEPTING_RESOURCE_HANDLER_H_ |
| |
| #include <memory> |
| #include <string> |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/weak_ptr.h" |
| #include "content/browser/loader/layered_resource_handler.h" |
| #include "content/browser/loader/resource_controller.h" |
| #include "content/browser/loader/resource_handler.h" |
| #include "content/common/content_export.h" |
| #include "net/base/io_buffer.h" |
| #include "net/url_request/url_request_status.h" |
| |
| namespace net { |
| class URLRequest; |
| } |
| |
| namespace content { |
| |
| class ResourceController; |
| |
| // ResourceHandler that initiates special handling of the response if needed, |
| // based on the response's MIME type (starts downloads, sends data to some |
| // plugin types via a special channel). |
| // |
| // An InterceptingResourceHandler holds two handlers (|next_handler| and |
| // |new_handler|). It assumes the following: |
| // - OnResponseStarted on |next_handler| never sets |*defer|. |
| // - OnResponseCompleted on |next_handler| never sets |*defer|. |
| class CONTENT_EXPORT InterceptingResourceHandler |
| : public LayeredResourceHandler { |
| public: |
| InterceptingResourceHandler(std::unique_ptr<ResourceHandler> next_handler, |
| net::URLRequest* request); |
| ~InterceptingResourceHandler() override; |
| |
| // ResourceHandler implementation: |
| void OnResponseStarted( |
| network::ResourceResponse* response, |
| std::unique_ptr<ResourceController> controller) override; |
| void OnWillRead(scoped_refptr<net::IOBuffer>* buf, |
| int* buf_size, |
| std::unique_ptr<ResourceController> controller) override; |
| void OnReadCompleted(int bytes_read, |
| std::unique_ptr<ResourceController> controller) override; |
| void OnResponseCompleted( |
| const net::URLRequestStatus& status, |
| std::unique_ptr<ResourceController> controller) override; |
| |
| // Replaces the next handler with |new_handler|, sending |
| // |payload_for_old_handler| to the old handler. Must be called after |
| // OnWillStart and OnRequestRedirected and before OnResponseStarted. One |
| // OnWillRead call is permitted beforehand. |new_handler|'s OnWillStart and |
| // OnRequestRedirected methods will not be called. |
| void UseNewHandler(std::unique_ptr<ResourceHandler> new_handler, |
| const std::string& payload_for_old_handler); |
| |
| // Used in tests. |
| ResourceHandler* new_handler_for_testing() const { |
| return new_handler_.get(); |
| } |
| |
| private: |
| // ResourceController subclass that calls into the InterceptingResourceHandler |
| // on cancel/resume. |
| class Controller; |
| |
| enum class State { |
| // The InterceptingResourceHandler is waiting for the mime type of the |
| // response to be identified, to check if the next handler should be |
| // replaced with an appropriate one. |
| STARTING, |
| |
| // The InterceptingResourceHandler is starting the process of swapping |
| // handlers. |
| SWAPPING_HANDLERS, |
| |
| // States where the InterceptingResourceHandler passes the initial |
| // OnWillRead call to the old handler, and then waits for the resulting |
| // buffer read buffer. |
| SENDING_ON_WILL_READ_TO_OLD_HANDLER, |
| WAITING_FOR_OLD_HANDLERS_BUFFER, |
| |
| // The InterceptingResourceHandler is sending the payload given via |
| // UseNewHandler to the old handler. The first state starts retrieving a |
| // buffer from the old handler, the second state copies as much of the data |
| // as possible to the received buffer and passes it to the old handler. |
| SENDING_PAYLOAD_TO_OLD_HANDLER, |
| RECEIVING_BUFFER_FROM_OLD_HANDLER, |
| |
| // The InterceptingResourcHandler is calling the new handler's |
| // OnResponseStarted method and waiting for its completion via Resume(). |
| // After completion, the InterceptingResourceHandler will transition to |
| // SENDING_ON_RESPONSE_STARTED_TO_NEW_HANDLER on success. |
| SENDING_ON_WILL_START_TO_NEW_HANDLER, |
| |
| // The InterceptingResourcHandler is calling the new handler's |
| // OnResponseStarted method and waiting for its completion via Resume(). |
| // After completion, the InterceptingResourceHandler will transition to |
| // WAITING_FOR_ON_READ_COMPLETED on success. |
| SENDING_ON_RESPONSE_STARTED_TO_NEW_HANDLER, |
| |
| // The InterceptingResourcHandler is waiting for OnReadCompleted to be |
| // called. |
| WAITING_FOR_ON_READ_COMPLETED, |
| |
| // The two phases of uploading previously received data stored in |
| // |first_read_buffer_double_| to the new handler, which is now stored in |
| // |next_handler_|. The first state gets a buffer to write to, and the next |
| // copies all the data it can to that buffer. |
| SENDING_BUFFER_TO_NEW_HANDLER, |
| SENDING_BUFFER_TO_NEW_HANDLER_WAITING_FOR_BUFFER, |
| |
| // The InterceptingResourceHandler has replaced its next ResourceHandler if |
| // needed, and has ensured the buffered read data was properly transmitted |
| // to the new ResourceHandler. The InterceptingResourceHandler now acts as |
| // a pass-through ResourceHandler. |
| PASS_THROUGH, |
| }; |
| |
| // Runs necessary operations depending on |state_|. |
| void DoLoop(); |
| |
| void ResumeInternal(); |
| |
| void SendOnWillReadToOldHandler(); |
| void OnBufferReceived(); |
| void SendOnResponseStartedToOldHandler(); |
| void SendPayloadToOldHandler(); |
| void ReceivedBufferFromOldHandler(); |
| void SendFirstReadBufferToNewHandler(); |
| void SendOnResponseStartedToNewHandler(); |
| void ReceivedBufferFromNewHandler(); |
| |
| State state_ = State::STARTING; |
| |
| std::unique_ptr<ResourceHandler> new_handler_; |
| std::string payload_for_old_handler_; |
| size_t payload_bytes_written_ = 0; |
| |
| // Result of the first read, that may have to be passed to an alternate |
| // ResourceHandler instead of the original ResourceHandler. |
| scoped_refptr<net::IOBuffer> first_read_buffer_; |
| // Instead of |first_read_buffer_|, this handler creates an IOBuffer with |
| // the same size and return it to the client. |
| scoped_refptr<net::IOBuffer> first_read_buffer_double_; |
| int first_read_buffer_size_ = 0; |
| int first_read_buffer_bytes_read_ = 0; |
| int first_read_buffer_bytes_written_ = 0; |
| |
| // Information about the new handler's buffer while copying data from |
| // |first_read_buffer_double_| to the new handler's buffer. |
| // Note that when these are used, the old handler has been destroyed, and |
| // |next_handler_| is now the new one. |
| scoped_refptr<net::IOBuffer> new_handler_read_buffer_; |
| int new_handler_read_buffer_size_ = 0; |
| |
| // Pointers to parent-owned read buffer and its size. Only used for first |
| // OnWillRead call. |
| scoped_refptr<net::IOBuffer>* parent_read_buffer_ = nullptr; |
| int* parent_read_buffer_size_ = nullptr; |
| |
| scoped_refptr<network::ResourceResponse> response_; |
| |
| // Next two values are used to handle synchronous Resume calls without a |
| // PostTask. |
| |
| // True if the code is currently within a DoLoop. |
| bool in_do_loop_ = false; |
| // True if the request was resumed while |in_do_loop_| was true; |
| bool advance_to_next_state_ = false; |
| |
| base::WeakPtrFactory<InterceptingResourceHandler> weak_ptr_factory_{this}; |
| |
| DISALLOW_COPY_AND_ASSIGN(InterceptingResourceHandler); |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_LOADER_INTERCEPTING_RESOURCE_HANDLER_H_ |