1 // Copyright 2020 The Android Open Source Project
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include "aemu/base/files/DecompressingStream.h"
16
17 #include "aemu/base/files/StreamSerializing.h"
18
19 #include "lz4.h"
20
21 #include <errno.h>
22 #include <cassert>
23
24 namespace android {
25 namespace base {
26
DecompressingStream(Stream & input)27 DecompressingStream::DecompressingStream(Stream& input) {
28 mLzStream = reinterpret_cast<void *>(LZ4_createStreamDecode());
29 loadBuffer(&input, &mBuffer);
30 }
31
~DecompressingStream()32 DecompressingStream::~DecompressingStream() {
33 LZ4_freeStreamDecode((LZ4_streamDecode_t*)mLzStream);
34 }
35
read(void * buffer,size_t size)36 ssize_t DecompressingStream::read(void* buffer, size_t size) {
37 assert(mBufferPos < mBuffer.size() ||
38 (mBufferPos == mBuffer.size() && size == 0));
39 if (!size) {
40 return 0;
41 }
42 int read = 0;
43 read = LZ4_decompress_fast_continue(
44 (LZ4_streamDecode_t*)mLzStream, mBuffer.data() + mBufferPos,
45 (char*)buffer, size);
46 if (!read) {
47 return -EIO;
48 }
49 mBufferPos += read;
50 assert(mBufferPos <= mBuffer.size());
51 return size;
52 }
53
write(const void *,size_t)54 ssize_t DecompressingStream::write(const void*, size_t) {
55 return -EPERM;
56 }
57
58 } // namespace base
59 } // namespace android
60