| // Copyright 2025 The Chromium Authors |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef TOOLS_ANDROID_DEVIL_UTIL_ZST_DECOMPRESSOR_H_ |
| #define TOOLS_ANDROID_DEVIL_UTIL_ZST_DECOMPRESSOR_H_ |
| |
| #include <istream> |
| |
| // Forward declarations. |
| struct ZSTD_inBuffer_s; |
| typedef ZSTD_inBuffer_s ZSTD_inBuffer; |
| struct ZSTD_outBuffer_s; |
| typedef ZSTD_outBuffer_s ZSTD_outBuffer; |
| struct ZSTD_DCtx_s; |
| typedef ZSTD_DCtx_s ZSTD_DCtx; |
| |
| class ZstDecompressor { |
| public: |
| // The user is responsible for closing the input_stream if necessary. |
| explicit ZstDecompressor(std::istream& input_stream); |
| ~ZstDecompressor(); |
| |
| struct DecompressedContent { |
| char* buffer; |
| size_t size; |
| }; |
| |
| // Decompress the next portion of the input_stream. Repeatedly call this |
| // function to decompress the entirety of input_stream. |
| // After execution, this sets output->buffer to a buffer holding decompressed |
| // content, and sets output->size to the byte count of decompressed content. |
| // The user does not need to free the memory pointed to by the output->buffer. |
| // A second call to this function overrides the buffer returned by the first |
| // call. In other words, the user should finish using the buffer before making |
| // a second call to this function. |
| // Return true if the entirety of input_stream has been decompressed, and |
| // false otherwise. |
| bool DecompressStreaming(DecompressedContent* output); |
| |
| private: |
| // The input stream where we are reading the compressed content from. |
| std::istream& input_stream_; |
| // A buffer containing a portion of the input_stream that we have read. |
| char* input_buffer_; |
| // The size of the contents stored in the input buffer. |
| size_t input_buffer_size_; |
| // A struct containing the input buffer, the size of the contents of input |
| // buffer, and the position where the zstd library function stopped reading. |
| // The position field is updated by the zstd library functions. |
| ZSTD_inBuffer* input_struct_; |
| // A buffer where the decompressed content is placed into. This is returned to |
| // the caller of DecompressStreaming(). |
| char* output_buffer_; |
| // The size of the output buffer. Indicates how large the buffer is. |
| size_t output_buffer_size_; |
| // A struct containing the output buffer, the size of the output buffer, |
| // and the position where the zstd library function stopped writing. |
| // The position field is updated by the zstd library functions. |
| ZSTD_outBuffer* output_struct_; |
| // A context object needed by the zstd library functions. |
| ZSTD_DCtx* ctx_; |
| // The return value of the last call to the zstd library functions. |
| // Equals 0 when there is no more work to be done. |
| size_t last_return_value_; |
| }; |
| |
| #endif // TOOLS_ANDROID_DEVIL_UTIL_ZST_DECOMPRESSOR_H_ |
