// Copyright (c) 2013 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_SPDY_SPDY_BUFFER_H_
#define NET_SPDY_SPDY_BUFFER_H_
#include <cstddef>
#include <vector>
#include "base/basictypes.h"
#include "base/callback_forward.h"
#include "base/memory/ref_counted.h"
#include "base/memory/scoped_ptr.h"
#include "net/base/net_export.h"
namespace net {
class IOBuffer;
class SpdyFrame;
// SpdyBuffer is a class to hold data read from or to be written to a
// SPDY connection. It is similar to a DrainableIOBuffer but is not
// ref-counted and will include a way to get notified when Consume()
// is called.
//
// NOTE(akalin): This explicitly does not inherit from IOBuffer to
// avoid the needless ref-counting and to avoid working around the
// fact that IOBuffer member functions are not virtual.
class NET_EXPORT_PRIVATE SpdyBuffer {
public:
// The source of a call to a ConsumeCallback.
enum ConsumeSource {
// Called via a call to Consume().
CONSUME,
// Called via the SpdyBuffer being destroyed.
DISCARD
};
// A Callback that gets called when bytes are consumed with the
// (non-zero) number of bytes consumed and the source of the
// consume. May be called any number of times with CONSUME as the
// source followed by at most one call with DISCARD as the
// source. The sum of the number of bytes consumed equals the total
// size of the buffer.
typedef base::Callback<void(size_t, ConsumeSource)> ConsumeCallback;
// Construct with the data in the given frame. Assumes that data is
// owned by |frame| or outlives it.
explicit SpdyBuffer(scoped_ptr<SpdyFrame> frame);
// Construct with a copy of the given raw data. |data| must be
// non-NULL and |size| must be non-zero.
SpdyBuffer(const char* data, size_t size);
// If there are bytes remaining in the buffer, triggers a call to
// any consume callbacks with a DISCARD source.
~SpdyBuffer();
// Returns the remaining (unconsumed) data.
const char* GetRemainingData() const;
// Returns the number of remaining (unconsumed) bytes.
size_t GetRemainingSize() const;
// Add a callback to be called when bytes are consumed. The
// ConsumeCallback should not do anything complicated; ideally it
// should only update a counter. In particular, it must *not* cause
// the SpdyBuffer itself to be destroyed.
void AddConsumeCallback(const ConsumeCallback& consume_callback);
// Consume the given number of bytes, which must be positive but not
// greater than GetRemainingSize().
void Consume(size_t consume_size);
// Returns an IOBuffer pointing to the data starting at
// GetRemainingData(). Use with care; the returned IOBuffer is not
// updated when Consume() is called. However, it may still be used
// past the lifetime of this object.
//
// This is used with Socket::Write(), which takes an IOBuffer* that
// may be written to even after the socket itself is destroyed. (See
// http://crbug.com/249725 .)
IOBuffer* GetIOBufferForRemainingData();
private:
void ConsumeHelper(size_t consume_size, ConsumeSource consume_source);
// Ref-count the passed-in SpdyFrame to support the semantics of
// |GetIOBufferForRemainingData()|.
typedef base::RefCountedData<scoped_ptr<SpdyFrame> > SharedFrame;
class SharedFrameIOBuffer;
const scoped_refptr<SharedFrame> shared_frame_;
std::vector<ConsumeCallback> consume_callbacks_;
size_t offset_;
DISALLOW_COPY_AND_ASSIGN(SpdyBuffer);
};
} // namespace net
#endif // NET_SPDY_SPDY_BUFFER_H_