1 /*
2 * Copyright (C) 2020 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 "src/trace_processor/util/gzip_utils.h"
18
19 #include <cstddef>
20 #include <cstdint>
21 #include <memory>
22 #include <vector>
23
24 #include "perfetto/base/build_config.h"
25
26 #if PERFETTO_BUILDFLAG(PERFETTO_ZLIB)
27 #include <zconf.h>
28 #include <zlib.h>
29 #else
30 struct z_stream_s {};
31 #endif
32
33 namespace perfetto::trace_processor::util {
34
35 #if PERFETTO_BUILDFLAG(PERFETTO_ZLIB) // Real Implementation
36
GzipDecompressor(InputMode mode)37 GzipDecompressor::GzipDecompressor(InputMode mode)
38 : z_stream_(new z_stream_s()) {
39 z_stream_->zalloc = nullptr;
40 z_stream_->zfree = nullptr;
41 z_stream_->opaque = nullptr;
42 // zlib uses a window size of -15..-8 to indicate it's a raw inflate stream
43 // (i.e. there's no zlib or gzip header).
44 int wbits = (mode == InputMode::kRawDeflate) ? -15 : 32 + MAX_WBITS;
45 inflateInit2(z_stream_.get(), wbits);
46 }
47
Reset()48 void GzipDecompressor::Reset() {
49 inflateReset(z_stream_.get());
50 }
51
Feed(const uint8_t * data,size_t size)52 void GzipDecompressor::Feed(const uint8_t* data, size_t size) {
53 // This const_cast is not harmfull as zlib will not modify the data in this
54 // pointer. This is only necessary because of the build flags we use to be
55 // compatible with other embedders.
56 z_stream_->next_in = const_cast<uint8_t*>(data);
57 z_stream_->avail_in = static_cast<uInt>(size);
58 }
59
ExtractOutput(uint8_t * out,size_t out_size)60 GzipDecompressor::Result GzipDecompressor::ExtractOutput(uint8_t* out,
61 size_t out_size) {
62 if (z_stream_->avail_in == 0)
63 return Result{ResultCode::kNeedsMoreInput, 0};
64
65 z_stream_->next_out = out;
66 z_stream_->avail_out = static_cast<uInt>(out_size);
67
68 int ret = inflate(z_stream_.get(), Z_NO_FLUSH);
69 switch (ret) {
70 case Z_NEED_DICT:
71 case Z_DATA_ERROR:
72 case Z_MEM_ERROR:
73 // Ignore inflateEnd error as we will error out anyway.
74 inflateEnd(z_stream_.get());
75 return Result{ResultCode::kError, 0};
76 case Z_STREAM_END:
77 return Result{ResultCode::kEof, out_size - z_stream_->avail_out};
78 case Z_BUF_ERROR:
79 return Result{ResultCode::kNeedsMoreInput, 0};
80 default:
81 return Result{ResultCode::kOk, out_size - z_stream_->avail_out};
82 }
83 }
84
AvailIn() const85 size_t GzipDecompressor::AvailIn() const {
86 return z_stream_->avail_in;
87 }
88
operator ()(z_stream_s * stream) const89 void GzipDecompressor::Deleter::operator()(z_stream_s* stream) const {
90 inflateEnd(stream);
91 delete stream;
92 }
93
94 #else // Dummy Implementation
95
96 GzipDecompressor::GzipDecompressor(InputMode) {}
97 void GzipDecompressor::Reset() {}
98 void GzipDecompressor::Feed(const uint8_t*, size_t) {}
99 GzipDecompressor::Result GzipDecompressor::ExtractOutput(uint8_t*, size_t) {
100 return Result{ResultCode::kError, 0};
101 }
102 size_t GzipDecompressor::AvailIn() const {
103 return 0;
104 }
105 void GzipDecompressor::Deleter::operator()(z_stream_s*) const {}
106
107 #endif // PERFETTO_BUILDFLAG(PERFETTO_ZLIB)
108
109 // static
DecompressFully(const uint8_t * data,size_t len)110 std::vector<uint8_t> GzipDecompressor::DecompressFully(const uint8_t* data,
111 size_t len) {
112 std::vector<uint8_t> whole_data;
113 GzipDecompressor decompressor;
114 auto decom_output_consumer = [&](const uint8_t* buf, size_t buf_len) {
115 whole_data.insert(whole_data.end(), buf, buf + buf_len);
116 };
117 decompressor.FeedAndExtract(data, len, decom_output_consumer);
118 return whole_data;
119 }
120
121 } // namespace perfetto::trace_processor::util
122