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// 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_handler.h"
#include "content/common/content_export.h"
#include "net/base/io_buffer.h"
namespace net {
class URLRequest;
}
namespace content {
// 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).
class CONTENT_EXPORT InterceptingResourceHandler
: public LayeredResourceHandler {
public:
InterceptingResourceHandler(std::unique_ptr<ResourceHandler> next_handler,
net::URLRequest* request);
~InterceptingResourceHandler() override;
// ResourceHandler implementation:
bool OnResponseStarted(ResourceResponse* response, bool* defer) override;
bool OnWillRead(scoped_refptr<net::IOBuffer>* buf,
int* buf_size,
int min_size) override;
bool OnReadCompleted(int bytes_read, bool* defer) 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:
enum class State {
// In this 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,
// In this state, the InterceptingResourceHandler is waiting to copy the
// read buffer to the next handler if it was replaced. This is needed
// because MimeTypeResourceHandler may call OnWillRead before calling
// OnResponseStarted, that is before the InterceptingResourceHandler
// replaces the original ResourceHandler of the request. Therefore, the
// data read at that time should be copied to the new ResourceHandler.
WAITING_FOR_BUFFER_COPY,
// In this state, 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.
DONE,
};
void SendPayloadToOldHandler();
State state_;
std::unique_ptr<ResourceHandler> new_handler_;
std::string payload_for_old_handler_;
// 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_;
size_t first_read_buffer_size_;
scoped_refptr<net::IOBuffer> first_read_buffer_copy_;
DISALLOW_COPY_AND_ASSIGN(InterceptingResourceHandler);
};
} // namespace content
#endif // CONTENT_BROWSER_LOADER_INTERCEPTING_RESOURCE_HANDLER_H_
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