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authorJulian Andres Klode <jak@debian.org>2015-12-28 00:07:03 +0100
committerJulian Andres Klode <jak@debian.org>2016-01-07 14:28:27 +0100
commite3fbd54cee3fffecbf4f7c384e0aad715fc68218 (patch)
treef6376dd48b8f6917c2bd36dca183f1d6eeb5c07f /apt-pkg/contrib/fileutl.cc
parentd4cfc24887851fa55f93a1a3c09f662b80f97729 (diff)
FileFd: (native) LZ4 support
Implement native support for LZ4 compression, using the official lz4 library.
Diffstat (limited to 'apt-pkg/contrib/fileutl.cc')
-rw-r--r--apt-pkg/contrib/fileutl.cc160
1 files changed, 160 insertions, 0 deletions
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 <lzma.h>
#endif
+#ifdef HAVE_LZ4
+ #include <lz4frame.h>
+#endif
#include <endian.h>
#include <stdint.h>
@@ -1496,6 +1499,158 @@ public:
#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 { /*{{{*/
#ifdef HAVE_LZMA
struct LZMAFILE {
@@ -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);