nix-gh/src/libutil/compression.cc

433 lines
12 KiB
C++

#include "compression.hh"
#include "util.hh"
#include "finally.hh"
#include "logging.hh"
#include <lzma.h>
#include <bzlib.h>
#include <cstdio>
#include <cstring>
#include <brotli/decode.h>
#include <brotli/encode.h>
#include <iostream>
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) {
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;
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;
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()
{
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 || strm.avail_in)) {
checkInterrupt();
lzma_ret ret = lzma_code(&strm, data ? 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;
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()
{
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) {
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;
BrotliDecompressionSink(Sink & nextSink) : nextSink(nextSink)
{
state = BrotliDecoderCreateInstance(nullptr, nullptr, nullptr);
if (!state)
throw CompressionError("unable to initialize brotli decoder");
}
~BrotliDecompressionSink()
{
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 || avail_in)) {
checkInterrupt();
if (!BrotliDecoderDecompressStream(state,
&avail_in, &next_in,
&avail_out, &next_out,
nullptr))
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);
}
}
};
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 == "")
return make_ref<NoneSink>(nextSink);
else 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
printMsg(lvlError, "warning: 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()
{
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 || strm.avail_in)) {
checkInterrupt();
lzma_ret ret = lzma_code(&strm, data ? 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;
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()
{
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 || strm.avail_in)) {
checkInterrupt();
int ret = BZ2_bzCompress(&strm, data ? 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;
BrotliCompressionSink(Sink & nextSink) : nextSink(nextSink)
{
state = BrotliEncoderCreateInstance(nullptr, nullptr, nullptr);
if (!state)
throw CompressionError("unable to initialise brotli encoder");
}
~BrotliCompressionSink()
{
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 || avail_in)) {
checkInterrupt();
if (!BrotliEncoderCompressStream(state,
data ? BROTLI_OPERATION_PROCESS : BROTLI_OPERATION_FINISH,
&avail_in, &next_in,
&avail_out, &next_out,
nullptr))
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);
}
}
};
ref<CompressionSink> makeCompressionSink(const std::string & method, Sink & nextSink, const bool parallel)
{
if (method == "none")
return make_ref<NoneSink>(nextSink);
else 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;
}
}