diff options
Diffstat (limited to 'third_party/nix/src/libutil/compression.cc')
| -rw-r--r-- | third_party/nix/src/libutil/compression.cc | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/third_party/nix/src/libutil/compression.cc b/third_party/nix/src/libutil/compression.cc new file mode 100644 index 000000000000..d7084ab7f15d --- /dev/null +++ b/third_party/nix/src/libutil/compression.cc @@ -0,0 +1,405 @@ +#include "compression.hh" + +#include <cstdio> +#include <cstring> +#include <iostream> + +#include <brotli/decode.h> +#include <brotli/encode.h> +#include <bzlib.h> +#include <lzma.h> + +#include "finally.hh" +#include "glog/logging.h" +#include "util.hh" + +namespace nix { + +// Don't feed brotli too much at once. +struct ChunkedCompressionSink : CompressionSink { + uint8_t outbuf[32 * 1024]; + + void write(const unsigned char* data, size_t len) override { + const size_t CHUNK_SIZE = sizeof(outbuf) << 2; + while (len != 0u) { + size_t n = std::min(CHUNK_SIZE, len); + writeInternal(data, n); + data += n; + len -= n; + } + } + + virtual void writeInternal(const unsigned char* data, size_t len) = 0; +}; + +struct NoneSink : CompressionSink { + Sink& nextSink; + explicit NoneSink(Sink& nextSink) : nextSink(nextSink) {} + void finish() override { flush(); } + void write(const unsigned char* data, size_t len) override { + nextSink(data, len); + } +}; + +struct XzDecompressionSink : CompressionSink { + Sink& nextSink; + uint8_t outbuf[BUFSIZ]; + lzma_stream strm = LZMA_STREAM_INIT; + bool finished = false; + + explicit XzDecompressionSink(Sink& nextSink) : nextSink(nextSink) { + lzma_ret ret = lzma_stream_decoder(&strm, UINT64_MAX, LZMA_CONCATENATED); + if (ret != LZMA_OK) { + throw CompressionError("unable to initialise lzma decoder"); + } + + strm.next_out = outbuf; + strm.avail_out = sizeof(outbuf); + } + + ~XzDecompressionSink() override { lzma_end(&strm); } + + void finish() override { + CompressionSink::flush(); + write(nullptr, 0); + } + + void write(const unsigned char* data, size_t len) override { + strm.next_in = data; + strm.avail_in = len; + + while (!finished && ((data == nullptr) || (strm.avail_in != 0u))) { + checkInterrupt(); + + lzma_ret ret = lzma_code(&strm, data != nullptr ? LZMA_RUN : LZMA_FINISH); + if (ret != LZMA_OK && ret != LZMA_STREAM_END) { + throw CompressionError("error %d while decompressing xz file", ret); + } + + finished = ret == LZMA_STREAM_END; + + if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) { + nextSink(outbuf, sizeof(outbuf) - strm.avail_out); + strm.next_out = outbuf; + strm.avail_out = sizeof(outbuf); + } + } + } +}; + +struct BzipDecompressionSink : ChunkedCompressionSink { + Sink& nextSink; + bz_stream strm; + bool finished = false; + + explicit BzipDecompressionSink(Sink& nextSink) : nextSink(nextSink) { + memset(&strm, 0, sizeof(strm)); + int ret = BZ2_bzDecompressInit(&strm, 0, 0); + if (ret != BZ_OK) { + throw CompressionError("unable to initialise bzip2 decoder"); + } + + strm.next_out = (char*)outbuf; + strm.avail_out = sizeof(outbuf); + } + + ~BzipDecompressionSink() override { BZ2_bzDecompressEnd(&strm); } + + void finish() override { + flush(); + write(nullptr, 0); + } + + void writeInternal(const unsigned char* data, size_t len) override { + assert(len <= std::numeric_limits<decltype(strm.avail_in)>::max()); + + strm.next_in = (char*)data; + strm.avail_in = len; + + while (strm.avail_in != 0u) { + checkInterrupt(); + + int ret = BZ2_bzDecompress(&strm); + if (ret != BZ_OK && ret != BZ_STREAM_END) { + throw CompressionError("error while decompressing bzip2 file"); + } + + finished = ret == BZ_STREAM_END; + + if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) { + nextSink(outbuf, sizeof(outbuf) - strm.avail_out); + strm.next_out = (char*)outbuf; + strm.avail_out = sizeof(outbuf); + } + } + } +}; + +struct BrotliDecompressionSink : ChunkedCompressionSink { + Sink& nextSink; + BrotliDecoderState* state; + bool finished = false; + + explicit BrotliDecompressionSink(Sink& nextSink) : nextSink(nextSink) { + state = BrotliDecoderCreateInstance(nullptr, nullptr, nullptr); + if (state == nullptr) { + throw CompressionError("unable to initialize brotli decoder"); + } + } + + ~BrotliDecompressionSink() override { BrotliDecoderDestroyInstance(state); } + + void finish() override { + flush(); + writeInternal(nullptr, 0); + } + + void writeInternal(const unsigned char* data, size_t len) override { + const uint8_t* next_in = data; + size_t avail_in = len; + uint8_t* next_out = outbuf; + size_t avail_out = sizeof(outbuf); + + while (!finished && ((data == nullptr) || (avail_in != 0u))) { + checkInterrupt(); + + if (BrotliDecoderDecompressStream(state, &avail_in, &next_in, &avail_out, + &next_out, nullptr) == 0u) { + throw CompressionError("error while decompressing brotli file"); + } + + if (avail_out < sizeof(outbuf) || avail_in == 0) { + nextSink(outbuf, sizeof(outbuf) - avail_out); + next_out = outbuf; + avail_out = sizeof(outbuf); + } + + finished = (BrotliDecoderIsFinished(state) != 0); + } + } +}; + +ref<std::string> decompress(const std::string& method, const std::string& in) { + StringSink ssink; + auto sink = makeDecompressionSink(method, ssink); + (*sink)(in); + sink->finish(); + return ssink.s; +} + +ref<CompressionSink> makeDecompressionSink(const std::string& method, + Sink& nextSink) { + if (method == "none" || method.empty()) { + return make_ref<NoneSink>(nextSink); + } + if (method == "xz") { + return make_ref<XzDecompressionSink>(nextSink); + } else if (method == "bzip2") { + return make_ref<BzipDecompressionSink>(nextSink); + } else if (method == "br") { + return make_ref<BrotliDecompressionSink>(nextSink); + } else { + throw UnknownCompressionMethod("unknown compression method '%s'", method); + } +} + +struct XzCompressionSink : CompressionSink { + Sink& nextSink; + uint8_t outbuf[BUFSIZ]; + lzma_stream strm = LZMA_STREAM_INIT; + bool finished = false; + + XzCompressionSink(Sink& nextSink, bool parallel) : nextSink(nextSink) { + lzma_ret ret; + bool done = false; + + if (parallel) { +#ifdef HAVE_LZMA_MT + lzma_mt mt_options = {}; + mt_options.flags = 0; + mt_options.timeout = 300; // Using the same setting as the xz cmd line + mt_options.preset = LZMA_PRESET_DEFAULT; + mt_options.filters = NULL; + mt_options.check = LZMA_CHECK_CRC64; + mt_options.threads = lzma_cputhreads(); + mt_options.block_size = 0; + if (mt_options.threads == 0) { + mt_options.threads = 1; + } + // FIXME: maybe use lzma_stream_encoder_mt_memusage() to control the + // number of threads. + ret = lzma_stream_encoder_mt(&strm, &mt_options); + done = true; +#else + LOG(ERROR) << "parallel XZ compression requested but not supported, " + << "falling back to single-threaded compression"; +#endif + } + + if (!done) { + ret = lzma_easy_encoder(&strm, 6, LZMA_CHECK_CRC64); + } + + if (ret != LZMA_OK) { + throw CompressionError("unable to initialise lzma encoder"); + } + + // FIXME: apply the x86 BCJ filter? + + strm.next_out = outbuf; + strm.avail_out = sizeof(outbuf); + } + + ~XzCompressionSink() override { lzma_end(&strm); } + + void finish() override { + CompressionSink::flush(); + write(nullptr, 0); + } + + void write(const unsigned char* data, size_t len) override { + strm.next_in = data; + strm.avail_in = len; + + while (!finished && ((data == nullptr) || (strm.avail_in != 0u))) { + checkInterrupt(); + + lzma_ret ret = lzma_code(&strm, data != nullptr ? LZMA_RUN : LZMA_FINISH); + if (ret != LZMA_OK && ret != LZMA_STREAM_END) { + throw CompressionError("error %d while compressing xz file", ret); + } + + finished = ret == LZMA_STREAM_END; + + if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) { + nextSink(outbuf, sizeof(outbuf) - strm.avail_out); + strm.next_out = outbuf; + strm.avail_out = sizeof(outbuf); + } + } + } +}; + +struct BzipCompressionSink : ChunkedCompressionSink { + Sink& nextSink; + bz_stream strm; + bool finished = false; + + explicit BzipCompressionSink(Sink& nextSink) : nextSink(nextSink) { + memset(&strm, 0, sizeof(strm)); + int ret = BZ2_bzCompressInit(&strm, 9, 0, 30); + if (ret != BZ_OK) { + throw CompressionError("unable to initialise bzip2 encoder"); + } + + strm.next_out = (char*)outbuf; + strm.avail_out = sizeof(outbuf); + } + + ~BzipCompressionSink() override { BZ2_bzCompressEnd(&strm); } + + void finish() override { + flush(); + writeInternal(nullptr, 0); + } + + void writeInternal(const unsigned char* data, size_t len) override { + assert(len <= std::numeric_limits<decltype(strm.avail_in)>::max()); + + strm.next_in = (char*)data; + strm.avail_in = len; + + while (!finished && ((data == nullptr) || (strm.avail_in != 0u))) { + checkInterrupt(); + + int ret = BZ2_bzCompress(&strm, data != nullptr ? BZ_RUN : BZ_FINISH); + if (ret != BZ_RUN_OK && ret != BZ_FINISH_OK && ret != BZ_STREAM_END) { + throw CompressionError("error %d while compressing bzip2 file", ret); + } + + finished = ret == BZ_STREAM_END; + + if (strm.avail_out < sizeof(outbuf) || strm.avail_in == 0) { + nextSink(outbuf, sizeof(outbuf) - strm.avail_out); + strm.next_out = (char*)outbuf; + strm.avail_out = sizeof(outbuf); + } + } + } +}; + +struct BrotliCompressionSink : ChunkedCompressionSink { + Sink& nextSink; + uint8_t outbuf[BUFSIZ]; + BrotliEncoderState* state; + bool finished = false; + + explicit BrotliCompressionSink(Sink& nextSink) : nextSink(nextSink) { + state = BrotliEncoderCreateInstance(nullptr, nullptr, nullptr); + if (state == nullptr) { + throw CompressionError("unable to initialise brotli encoder"); + } + } + + ~BrotliCompressionSink() override { BrotliEncoderDestroyInstance(state); } + + void finish() override { + flush(); + writeInternal(nullptr, 0); + } + + void writeInternal(const unsigned char* data, size_t len) override { + const uint8_t* next_in = data; + size_t avail_in = len; + uint8_t* next_out = outbuf; + size_t avail_out = sizeof(outbuf); + + while (!finished && ((data == nullptr) || (avail_in != 0u))) { + checkInterrupt(); + + if (BrotliEncoderCompressStream(state, + data != nullptr ? BROTLI_OPERATION_PROCESS + : BROTLI_OPERATION_FINISH, + &avail_in, &next_in, &avail_out, + &next_out, nullptr) == 0) { + throw CompressionError("error while compressing brotli compression"); + } + + if (avail_out < sizeof(outbuf) || avail_in == 0) { + nextSink(outbuf, sizeof(outbuf) - avail_out); + next_out = outbuf; + avail_out = sizeof(outbuf); + } + + finished = (BrotliEncoderIsFinished(state) != 0); + } + } +}; + +ref<CompressionSink> makeCompressionSink(const std::string& method, + Sink& nextSink, const bool parallel) { + if (method == "none") { + return make_ref<NoneSink>(nextSink); + } + if (method == "xz") { + return make_ref<XzCompressionSink>(nextSink, parallel); + } else if (method == "bzip2") { + return make_ref<BzipCompressionSink>(nextSink); + } else if (method == "br") { + return make_ref<BrotliCompressionSink>(nextSink); + } else { + throw UnknownCompressionMethod(format("unknown compression method '%s'") % + method); + } +} + +ref<std::string> compress(const std::string& method, const std::string& in, + const bool parallel) { + StringSink ssink; + auto sink = makeCompressionSink(method, ssink, parallel); + (*sink)(in); + sink->finish(); + return ssink.s; +} + +} // namespace nix |