| // Copyright 2019 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| |
| #include <blobfs/compression/compressor.h> |
| #include <blobfs/compression/zstd.h> |
| #include <fbl/algorithm.h> |
| #include <fbl/auto_call.h> |
| #include <fbl/macros.h> |
| #include <fbl/unique_ptr.h> |
| #include <fs/trace.h> |
| #include <zircon/types.h> |
| #include <zstd/zstd.h> |
| |
| namespace blobfs { |
| |
| constexpr int kCompressionLevel = 3; |
| |
| ZSTDCompressor::ZSTDCompressor(ZSTD_CCtx* stream, void* compressed_buffer, |
| size_t compressed_buffer_length) |
| : stream_(stream) { |
| output_.dst = compressed_buffer; |
| output_.size = compressed_buffer_length; |
| output_.pos = 0; |
| } |
| |
| ZSTDCompressor::~ZSTDCompressor() { |
| ZSTD_freeCStream(stream_); |
| } |
| |
| zx_status_t ZSTDCompressor::Create(size_t input_size, void* compression_buffer, |
| size_t compression_buffer_length, |
| fbl::unique_ptr<ZSTDCompressor>* out) { |
| if (BufferMax(input_size) > compression_buffer_length) { |
| return ZX_ERR_BUFFER_TOO_SMALL; |
| } |
| |
| ZSTD_CStream* stream = ZSTD_createCStream(); |
| if (stream == nullptr) { |
| return ZX_ERR_NO_MEMORY; |
| } |
| |
| auto compressor = |
| fbl::unique_ptr<ZSTDCompressor>(new ZSTDCompressor(stream, compression_buffer, |
| compression_buffer_length)); |
| |
| ssize_t r = ZSTD_initCStream(compressor->stream_, kCompressionLevel); |
| if (ZSTD_isError(r)) { |
| FS_TRACE_ERROR("[blobfs][zstd] Failed to initialize cstream: %s\n", ZSTD_getErrorName(r)); |
| return ZX_ERR_INTERNAL; |
| } |
| |
| *out = std::move(compressor); |
| return ZX_OK; |
| } |
| |
| size_t ZSTDCompressor::BufferMax(size_t blob_size) { |
| return ZSTD_compressBound(blob_size); |
| } |
| |
| zx_status_t ZSTDCompressor::Update(const void* input_data, size_t input_length) { |
| ZSTD_inBuffer input; |
| input.src = input_data; |
| input.size = input_length; |
| input.pos = 0; |
| |
| size_t r = ZSTD_compressStream(stream_, &output_, &input); |
| if (ZSTD_isError(r)) { |
| FS_TRACE_ERROR("[blobfs][zstd] Failed to compress: %s\n", ZSTD_getErrorName(r)); |
| return ZX_ERR_IO_DATA_INTEGRITY; |
| } else if (input.pos != input_length) { |
| // The only way this condition can occur is when the output buffer is full. |
| // |
| // From the ZSTD documentation: |
| // Note that the function may not consume the entire input, for example, because the |
| // output buffer is already full, in which case `input.pos < input.size`. |
| // |
| // If this is the case, a client must have not supplied an honest value for |
| // |input_size| when creating the ZSTDCompressor object, which requires that the |
| // output compression buffer be large enough to hold the "worst case" input size. |
| FS_TRACE_ERROR("[blobfs][zstd] Could not compress all input\n"); |
| return ZX_ERR_INVALID_ARGS; |
| } |
| |
| return ZX_OK; |
| } |
| |
| zx_status_t ZSTDCompressor::End() { |
| size_t r = ZSTD_flushStream(stream_, &output_); |
| if (ZSTD_isError(r)) { |
| FS_TRACE_ERROR("[blobfs][zstd] Failed to flush stream: %s\n", ZSTD_getErrorName(r)); |
| return ZX_ERR_IO_DATA_INTEGRITY; |
| } |
| r = ZSTD_endStream(stream_, &output_); |
| if (ZSTD_isError(r)) { |
| FS_TRACE_ERROR("[blobfs][zstd] Failed to end stream: %s\n", ZSTD_getErrorName(r)); |
| return ZX_ERR_IO_DATA_INTEGRITY; |
| } |
| |
| return ZX_OK; |
| } |
| |
| size_t ZSTDCompressor::Size() const { |
| return output_.pos; |
| } |
| |
| zx_status_t ZSTDDecompress(void* target_buf, size_t* target_size, const void* src_buf, |
| size_t* src_size) { |
| TRACE_DURATION("blobfs", "ZSTDDecompress", "target_size", *target_size, |
| "src_size", *src_size); |
| ZSTD_DStream* stream = ZSTD_createDStream(); |
| auto cleanup = fbl::MakeAutoCall([&stream] { |
| ZSTD_freeDStream(stream); |
| }); |
| |
| size_t r = ZSTD_initDStream(stream); |
| if (ZSTD_isError(r)) { |
| FS_TRACE_ERROR("[blobfs][zstd] Failed to initialize dstream: %s\n", ZSTD_getErrorName(r)); |
| return ZX_ERR_INTERNAL; |
| } |
| |
| ZSTD_inBuffer input; |
| input.src = src_buf; |
| input.size = *src_size; |
| input.pos = 0; |
| |
| ZSTD_outBuffer output; |
| output.dst = target_buf; |
| output.size = *target_size; |
| output.pos = 0; |
| |
| r = 0; |
| do { |
| r = ZSTD_decompressStream(stream, &output, &input); |
| if (ZSTD_isError(r)) { |
| FS_TRACE_ERROR("[blobfs][zstd] Failed to decompress: %s\n", ZSTD_getErrorName(r)); |
| return ZX_ERR_IO_DATA_INTEGRITY; |
| } |
| // Paraphrasing from the ZSTD Documentation: |
| // For any return value > 0, there is still decoding or flushing to do |
| // within the current frame. The return value is a hint for the next input size. |
| } while (r > 0); |
| |
| *src_size = input.pos; |
| *target_size = output.pos; |
| return ZX_OK; |
| } |
| |
| } // namespace blobfs |