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// 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 CONTENT_BROWSER_STREAMS_STREAM_H_
#define CONTENT_BROWSER_STREAMS_STREAM_H_
#include "base/basictypes.h"
#include "base/memory/ref_counted.h"
#include "content/browser/download/byte_stream.h"
#include "content/common/content_export.h"
#include "googleurl/src/gurl.h"
namespace net {
class IOBuffer;
}
namespace content {
class StreamReadObserver;
class StreamRegistry;
class StreamWriteObserver;
// A stream that sends data from an arbitrary source to an internal URL
// that can be read by an internal consumer. It will continue to pull from the
// original URL as long as there is data available. It can be read from
// multiple clients, but only one can be reading at a time. This allows a
// reader to consume part of the stream, then pass it along to another client
// to continue processing the stream.
class CONTENT_EXPORT Stream : public base::RefCountedThreadSafe<Stream> {
public:
enum StreamState {
STREAM_HAS_DATA,
STREAM_COMPLETE,
STREAM_EMPTY,
};
// Creates a stream useable from the |security_origin|.
Stream(StreamRegistry* registry,
StreamWriteObserver* write_observer,
const GURL& security_origin,
const GURL& url);
// Sets the reader of this stream. Returns true on success, or false if there
// is already a reader.
bool SetReadObserver(StreamReadObserver* observer);
// Removes the read observer. |observer| must be the current observer.
void RemoveReadObserver(StreamReadObserver* observer);
// Adds the data in |buffer| to the stream. Takes ownership of |buffer|.
void AddData(scoped_refptr<net::IOBuffer> buffer, size_t size);
// Notifies this stream that it will not be receiving any more data.
void Finalize();
// Reads a maximum of |buf_size| from the stream into |buf|. Sets
// |*bytes_read| to the number of bytes actually read.
// Returns STREAM_HAS_DATA if data was read, STREAM_EMPTY if no data was read,
// and STREAM_COMPLETE if the stream is finalized and all data has been read.
StreamState ReadRawData(net::IOBuffer* buf, int buf_size, int* bytes_read);
// Indicates whether there is space in the buffer to add more data.
bool can_add_data() const { return can_add_data_; }
const GURL& url() const { return url_; }
const GURL& security_origin() const { return security_origin_; }
private:
friend class base::RefCountedThreadSafe<Stream>;
virtual ~Stream();
void OnSpaceAvailable();
void OnDataAvailable();
size_t bytes_read_;
bool can_add_data_;
GURL security_origin_;
GURL url_;
scoped_refptr<net::IOBuffer> data_;
size_t data_length_;
scoped_ptr<ByteStreamWriter> writer_;
scoped_ptr<ByteStreamReader> reader_;
StreamRegistry* registry_;
StreamReadObserver* read_observer_;
StreamWriteObserver* write_observer_;
DISALLOW_COPY_AND_ASSIGN(Stream);
};
} // namespace content
#endif // CONTENT_BROWSER_STREAMS_STREAM_H_
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