1 //
2 // Copyright (C) 2009 The Android Open Source Project
3 //
4 // Licensed under the Apache License, Version 2.0 (the "License");
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
7 //
8 // http://www.apache.org/licenses/LICENSE-2.0
9 //
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
15 //
16
17 #include "update_engine/payload_consumer/bzip_extent_writer.h"
18
19 using google::protobuf::RepeatedPtrField;
20
21 namespace chromeos_update_engine {
22
23 namespace {
24 const brillo::Blob::size_type kOutputBufferLength = 16 * 1024;
25 }
26
~BzipExtentWriter()27 BzipExtentWriter::~BzipExtentWriter() {
28 TEST_AND_RETURN(BZ2_bzDecompressEnd(&stream_) == BZ_OK);
29 TEST_AND_RETURN(input_buffer_.empty());
30 }
31
Init(const RepeatedPtrField<Extent> & extents,uint32_t block_size)32 bool BzipExtentWriter::Init(const RepeatedPtrField<Extent>& extents,
33 uint32_t block_size) {
34 // Init bzip2 stream
35 int rc = BZ2_bzDecompressInit(&stream_,
36 0, // verbosity. (0 == silent)
37 0); // 0 = faster algo, more memory
38
39 TEST_AND_RETURN_FALSE(rc == BZ_OK);
40
41 return next_->Init(extents, block_size);
42 }
43
Write(const void * bytes,size_t count)44 bool BzipExtentWriter::Write(const void* bytes, size_t count) {
45 brillo::Blob output_buffer(kOutputBufferLength);
46
47 // Copy the input data into |input_buffer_| only if |input_buffer_| already
48 // contains unconsumed data. Otherwise, process the data directly from the
49 // source.
50 const uint8_t* input = reinterpret_cast<const uint8_t*>(bytes);
51 const uint8_t* input_end = input + count;
52 if (!input_buffer_.empty()) {
53 input_buffer_.insert(input_buffer_.end(), input, input_end);
54 input = input_buffer_.data();
55 input_end = input + input_buffer_.size();
56 }
57 stream_.next_in = reinterpret_cast<char*>(const_cast<uint8_t*>(input));
58 stream_.avail_in = input_end - input;
59
60 for (;;) {
61 stream_.next_out = reinterpret_cast<char*>(output_buffer.data());
62 stream_.avail_out = output_buffer.size();
63
64 int rc = BZ2_bzDecompress(&stream_);
65 TEST_AND_RETURN_FALSE(rc == BZ_OK || rc == BZ_STREAM_END);
66
67 if (stream_.avail_out == output_buffer.size())
68 break; // got no new bytes
69
70 TEST_AND_RETURN_FALSE(next_->Write(
71 output_buffer.data(), output_buffer.size() - stream_.avail_out));
72
73 if (rc == BZ_STREAM_END)
74 CHECK_EQ(stream_.avail_in, 0u);
75 if (stream_.avail_in == 0)
76 break; // no more input to process
77 }
78
79 // Store unconsumed data (if any) in |input_buffer_|.
80 if (stream_.avail_in || !input_buffer_.empty()) {
81 brillo::Blob new_input_buffer(input_end - stream_.avail_in, input_end);
82 new_input_buffer.swap(input_buffer_);
83 }
84
85 return true;
86 }
87
88 } // namespace chromeos_update_engine
89