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| 1 // Copyright 2015 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "blimp/net/compressed_packet_reader.h" | |
| 6 | |
| 7 #include <algorithm> | |
| 8 #include <iostream> | |
| 9 #include <utility> | |
| 10 | |
| 11 #include "base/callback_helpers.h" | |
| 12 #include "base/logging.h" | |
| 13 #include "base/memory/weak_ptr.h" | |
| 14 #include "base/message_loop/message_loop.h" | |
| 15 #include "base/sys_byteorder.h" | |
| 16 #include "blimp/net/common.h" | |
| 17 #include "net/base/io_buffer.h" | |
| 18 #include "net/base/net_errors.h" | |
| 19 #include "net/socket/stream_socket.h" | |
| 20 | |
| 21 namespace blimp { | |
| 22 namespace { | |
| 23 | |
| 24 constexpr double kInitialDecompressionBufferSizeFactor = 1.5; | |
| 25 constexpr double kDecompressionGrowthFactor = 2.0; | |
| 26 | |
| 27 } // namespace | |
| 28 | |
| 29 CompressedPacketReader::CompressedPacketReader( | |
| 30 std::unique_ptr<PacketReader> source) | |
| 31 : source_(std::move(source)), | |
| 32 compressed_buf_(new net::GrowableIOBuffer), | |
| 33 weak_factory_(this) { | |
| 34 DCHECK(source_); | |
| 35 | |
| 36 memset(&zlib_stream_, 0, sizeof(z_stream)); | |
| 37 | |
| 38 // MAX_WBITS means we are using the maximal window size for decompression; | |
| 39 // a negative value means that we are ignoring headers and CRC checks. | |
| 40 int init_result = inflateInit2(&zlib_stream_, -MAX_WBITS); | |
| 41 DCHECK_EQ(Z_OK, init_result); | |
| 42 } | |
| 43 | |
| 44 CompressedPacketReader::~CompressedPacketReader() { | |
| 45 inflateEnd(&zlib_stream_); | |
| 46 } | |
| 47 | |
| 48 void CompressedPacketReader::ReadPacket( | |
| 49 const scoped_refptr<net::GrowableIOBuffer>& decompressed_buf, | |
| 50 const net::CompletionCallback& callback) { | |
| 51 DCHECK(decompressed_buf); | |
| 52 DCHECK(!callback.is_null()); | |
| 53 | |
| 54 source_->ReadPacket( | |
| 55 compressed_buf_, | |
| 56 base::Bind(&CompressedPacketReader::OnCompressedPacketReceived, | |
| 57 weak_factory_.GetWeakPtr(), decompressed_buf, callback)); | |
| 58 } | |
| 59 | |
| 60 void CompressedPacketReader::OnCompressedPacketReceived( | |
| 61 const scoped_refptr<net::GrowableIOBuffer> decompressed_buf, | |
| 62 const net::CompletionCallback& callback, | |
| 63 int result) { | |
| 64 if (result <= 0) { | |
| 65 callback.Run(result); | |
| 66 return; | |
| 67 } | |
| 68 | |
| 69 callback.Run(DecompressPacket(decompressed_buf, result)); | |
| 70 } | |
| 71 | |
| 72 int CompressedPacketReader::DecompressPacket( | |
| 73 const scoped_refptr<net::GrowableIOBuffer>& decompressed_buf, | |
| 74 int size_compressed) { | |
| 75 scoped_refptr<net::DrainableIOBuffer> drainable_input( | |
| 76 new net::DrainableIOBuffer(compressed_buf_.get(), size_compressed)); | |
| 77 | |
| 78 // Prepare the sink for decompressed data. | |
| 79 decompressed_buf->set_offset(0); | |
| 80 const int min_size = kInitialDecompressionBufferSizeFactor * size_compressed; | |
| 81 if (decompressed_buf->capacity() < min_size) { | |
| 82 decompressed_buf->SetCapacity(min_size); | |
| 83 } | |
| 84 | |
| 85 // Repeatedly decompress |drainable_input| until it's fully consumed, growing | |
| 86 // |decompressed_buf| as necessary to accomodate the decompressed output. | |
| 87 do { | |
| 88 zlib_stream_.next_in = reinterpret_cast<uint8_t*>(drainable_input->data()); | |
| 89 zlib_stream_.avail_in = drainable_input->BytesRemaining(); | |
| 90 zlib_stream_.next_out = | |
| 91 reinterpret_cast<uint8_t*>(decompressed_buf->data()); | |
| 92 zlib_stream_.avail_out = decompressed_buf->RemainingCapacity(); | |
| 93 int inflate_result = inflate(&zlib_stream_, Z_SYNC_FLUSH); | |
| 94 if (inflate_result != Z_OK) { | |
| 95 DLOG(ERROR) << "inflate() returned unexpected error code: " | |
| 96 << inflate_result; | |
| 97 return net::ERR_UNEXPECTED; | |
| 98 } | |
| 99 | |
| 100 // Process the inflate() result. | |
| 101 const int bytes_in = | |
| 102 drainable_input->BytesRemaining() - zlib_stream_.avail_in; | |
| 103 const int bytes_out = | |
| 104 (decompressed_buf->RemainingCapacity() - zlib_stream_.avail_out); | |
| 105 drainable_input->DidConsume(bytes_in); | |
| 106 decompressed_buf->set_offset(decompressed_buf->offset() + bytes_out); | |
| 107 if (static_cast<size_t>(decompressed_buf->offset()) > | |
| 108 kMaxPacketPayloadSizeBytes) { | |
| 109 DLOG(ERROR) | |
| 110 << "Decompressed buffer size exceeds allowable limits; aborting."; | |
| 111 return net::ERR_FILE_TOO_BIG; | |
| 112 } | |
| 113 | |
| 114 if (drainable_input->BytesRemaining() > 0) { | |
| 115 // Output buffer isn't large enough to fit the compressed input, so | |
| 116 // enlarge it. | |
| 117 DCHECK_GT(zlib_stream_.avail_in, 0u); | |
| 118 DCHECK_EQ(0u, zlib_stream_.avail_out); | |
| 119 | |
| 120 decompressed_buf->SetCapacity( | |
| 121 std::min(static_cast<size_t>(kDecompressionGrowthFactor * | |
| 122 decompressed_buf->capacity()), | |
| 123 kMaxPacketPayloadSizeBytes + 1)); | |
| 124 VLOG(2) << "Increase buffer size to " << decompressed_buf->capacity() | |
| 125 << " bytes."; | |
| 126 } | |
| 127 } while (zlib_stream_.avail_in > 0); | |
| 128 | |
| 129 int total_decompressed_size = decompressed_buf->offset(); | |
| 130 decompressed_buf->set_offset(0); | |
| 131 return total_decompressed_size; | |
| 132 } | |
| 133 | |
| 134 } // namespace blimp | |
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