| // 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 BLIMP_NET_COMPRESSED_PACKET_WRITER_H_ |
| #define BLIMP_NET_COMPRESSED_PACKET_WRITER_H_ |
| |
| #include "base/memory/weak_ptr.h" |
| #include "blimp/net/blimp_net_export.h" |
| #include "blimp/net/packet_writer.h" |
| #include "net/base/completion_callback.h" |
| #include "net/base/io_buffer.h" |
| #include "third_party/zlib/zlib.h" |
| |
| namespace blimp { |
| |
| // Filter object which wraps a PacketWriter, adding a DEFLATE compression step |
| // to outgoing packets. |
| // |
| // Each packet is appended as a DEFLATE block to a long-lived compression |
| // stream. |
| // Blocks are explicitly flushed at each packet boundary, which prevents zlib's |
| // internal buffers from introducing unwanted output latency. |
| // Gzip headers and CRC checks are omitted from the stream output. |
| class BLIMP_NET_EXPORT CompressedPacketWriter : public PacketWriter { |
| public: |
| // |source|: The PacketWriter which will receive compressed packets. |
| explicit CompressedPacketWriter(std::unique_ptr<PacketWriter> sink); |
| ~CompressedPacketWriter() override; |
| |
| // PacketWriter implementation. |
| void WritePacket(const scoped_refptr<net::DrainableIOBuffer>& buf, |
| const net::CompletionCallback& cb) override; |
| |
| private: |
| // Compresses |src_buf| into |dest_buf|. |
| // On success, returns a >= 0 value indicating the length of the |
| // compressed payload. |
| // On failure, returns a negative value indicating the error code |
| // (see net_errors.h). |
| int Compress(const scoped_refptr<net::DrainableIOBuffer>& src_buf, |
| const scoped_refptr<net::GrowableIOBuffer>& dest_buf); |
| |
| z_stream zlib_stream_; |
| std::unique_ptr<PacketWriter> sink_; |
| scoped_refptr<net::GrowableIOBuffer> compressed_buf_; |
| size_t uncompressed_size_total_ = 0u; |
| size_t compressed_size_total_ = 0u; |
| |
| DISALLOW_COPY_AND_ASSIGN(CompressedPacketWriter); |
| }; |
| |
| } // namespace blimp |
| |
| #endif // BLIMP_NET_COMPRESSED_PACKET_WRITER_H_ |