From e3fbd54cee3fffecbf4f7c384e0aad715fc68218 Mon Sep 17 00:00:00 2001 From: Julian Andres Klode Date: Mon, 28 Dec 2015 00:07:03 +0100 Subject: FileFd: (native) LZ4 support Implement native support for LZ4 compression, using the official lz4 library. --- apt-pkg/contrib/fileutl.cc | 160 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 160 insertions(+) (limited to 'apt-pkg/contrib/fileutl.cc') diff --git a/apt-pkg/contrib/fileutl.cc b/apt-pkg/contrib/fileutl.cc index e50cc694a..de215a50b 100644 --- a/apt-pkg/contrib/fileutl.cc +++ b/apt-pkg/contrib/fileutl.cc @@ -63,6 +63,9 @@ #ifdef HAVE_LZMA #include #endif +#ifdef HAVE_LZ4 + #include +#endif #include #include @@ -1494,6 +1497,158 @@ public: explicit Bz2FileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), bz2(nullptr) {} virtual ~Bz2FileFdPrivate() { InternalClose(""); } #endif +}; + /*}}}*/ +class APT_HIDDEN Lz4FileFdPrivate: public FileFdPrivate { /*{{{*/ + static constexpr unsigned long long BLK_SIZE = 64 * 1024; + static constexpr unsigned long long LZ4_HEADER_SIZE = 19; + static constexpr unsigned long long LZ4_FOOTER_SIZE = 4; +#ifdef HAVE_LZ4 + LZ4F_decompressionContext_t dctx; + LZ4F_compressionContext_t cctx; + LZ4F_errorCode_t res; + FileFd backend; + simple_buffer lz4_buffer; + // Count of bytes that the decompressor expects to read next, or buffer size. + size_t next_to_load = BLK_SIZE; +public: + virtual bool InternalOpen(int const iFd, unsigned int const Mode) override + { + if ((Mode & FileFd::ReadWrite) == FileFd::ReadWrite) + return _error->Error("lz4 only supports write or read mode"); + + if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) { + res = LZ4F_createCompressionContext(&cctx, LZ4F_VERSION); + lz4_buffer.reset(LZ4F_compressBound(BLK_SIZE, nullptr) + + LZ4_HEADER_SIZE + LZ4_FOOTER_SIZE); + } else { + res = LZ4F_createDecompressionContext(&dctx, LZ4F_VERSION); + lz4_buffer.reset(64 * 1024); + } + + filefd->Flags |= FileFd::Compressed; + + if (LZ4F_isError(res)) + return false; + + unsigned int flags = (Mode & (FileFd::WriteOnly|FileFd::ReadOnly)); + if (backend.OpenDescriptor(iFd, flags) == false) + return false; + + // Write the file header + if ((Mode & FileFd::WriteOnly) == FileFd::WriteOnly) + { + res = LZ4F_compressBegin(cctx, lz4_buffer.buffer, lz4_buffer.buffersize_max, nullptr); + if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false) + return false; + } + + return true; + } + virtual ssize_t InternalUnbufferedRead(void * const To, unsigned long long const Size) override + { + /* Keep reading as long as the compressor still wants to read */ + while (next_to_load) { + // Fill compressed buffer; + if (lz4_buffer.empty()) { + unsigned long long read; + /* Reset - if LZ4 decompressor wants to read more, allocate more */ + lz4_buffer.reset(next_to_load); + if (backend.Read(lz4_buffer.getend(), lz4_buffer.free(), &read) == false) + return -1; + lz4_buffer.bufferend += read; + + /* Expected EOF */ + if (read == 0) { + res = -1; + return filefd->FileFdError("LZ4F: %s %s", + filefd->FileName.c_str(), + _("Unexpected end of file")), -1; + } + } + // Drain compressed buffer as far as possible. + size_t in = lz4_buffer.size(); + size_t out = Size; + + res = LZ4F_decompress(dctx, To, &out, lz4_buffer.get(), &in, nullptr); + if (LZ4F_isError(res)) + return -1; + + next_to_load = res; + lz4_buffer.bufferstart += in; + + if (out != 0) + return out; + } + + return 0; + } + virtual bool InternalReadError() override + { + char const * const errmsg = LZ4F_getErrorName(res); + + return filefd->FileFdError("LZ4F: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Read error"), res, errmsg); + } + virtual ssize_t InternalWrite(void const * const From, unsigned long long const Size) override + { + unsigned long long const towrite = std::min(BLK_SIZE, Size); + + res = LZ4F_compressUpdate(cctx, + lz4_buffer.buffer, lz4_buffer.buffersize_max, + From, towrite, nullptr); + + if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false) + return -1; + + return towrite; + } + virtual bool InternalWriteError() override + { + char const * const errmsg = LZ4F_getErrorName(res); + + return filefd->FileFdError("LZ4F: %s %s (%zu: %s)", filefd->FileName.c_str(), _("Write error"), res, errmsg); + } + virtual bool InternalStream() const override { return true; } + + virtual bool InternalFlush() override + { + return backend.Flush(); + } + + virtual bool InternalClose(std::string const &) override + { + /* Reset variables */ + res = 0; + next_to_load = BLK_SIZE; + + if (cctx != nullptr) + { + res = LZ4F_compressEnd(cctx, lz4_buffer.buffer, lz4_buffer.buffersize_max, nullptr); + if (LZ4F_isError(res) || backend.Write(lz4_buffer.buffer, res) == false) + return false; + if (!backend.Flush()) + return false; + if (!backend.Close()) + return false; + + res = LZ4F_freeCompressionContext(cctx); + cctx = nullptr; + } + + if (dctx != nullptr) + { + res = LZ4F_freeDecompressionContext(dctx); + dctx = nullptr; + } + + return LZ4F_isError(res) == false; + } + + explicit Lz4FileFdPrivate(FileFd * const filefd) : FileFdPrivate(filefd), dctx(nullptr), cctx(nullptr) {} + virtual ~Lz4FileFdPrivate() { + InternalClose(""); + } +#endif }; /*}}}*/ class APT_HIDDEN LzmaFileFdPrivate: public FileFdPrivate { /*{{{*/ @@ -1968,6 +2123,7 @@ bool FileFd::Open(string FileName,unsigned int const Mode,CompressMode Compress, case Bzip2: name = "bzip2"; break; case Lzma: name = "lzma"; break; case Xz: name = "xz"; break; + case Lz4: name = "lz4"; break; case Auto: case Extension: // Unreachable @@ -2084,6 +2240,7 @@ bool FileFd::OpenDescriptor(int Fd, unsigned int const Mode, CompressMode Compre case Bzip2: name = "bzip2"; break; case Lzma: name = "lzma"; break; case Xz: name = "xz"; break; + case Lz4: name = "lz4"; break; case Auto: case Extension: if (AutoClose == true && Fd != -1) @@ -2145,6 +2302,9 @@ bool FileFd::OpenInternDescriptor(unsigned int const Mode, APT::Configuration::C APT_COMPRESS_INIT("xz", LzmaFileFdPrivate); APT_COMPRESS_INIT("lzma", LzmaFileFdPrivate); #endif +#ifdef HAVE_LZ4 + APT_COMPRESS_INIT("lz4", Lz4FileFdPrivate); +#endif #undef APT_COMPRESS_INIT else if (compressor.Name == "." || compressor.Binary.empty() == true) d = new DirectFileFdPrivate(this); 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