lix/src/libutil/compression.cc
Eelco Dolstra 538a64e8c3 Add a Store::addToStore() variant that accepts a NAR
As a side effect, this ensures that signatures are propagated when
copying paths between stores.

Also refactored import/export to make use of this.
2016-05-04 16:15:54 +02:00

201 lines
5.2 KiB
C++
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

#include "compression.hh"
#include "util.hh"
#include "finally.hh"
#include <lzma.h>
#include <bzlib.h>
#include <cstdio>
#include <cstring>
namespace nix {
static ref<std::string> compressXZ(const std::string & in)
{
lzma_stream strm(LZMA_STREAM_INIT);
// FIXME: apply the x86 BCJ filter?
lzma_ret ret = lzma_easy_encoder(
&strm, 6, LZMA_CHECK_CRC64);
if (ret != LZMA_OK)
throw Error("unable to initialise lzma encoder");
Finally free([&]() { lzma_end(&strm); });
lzma_action action = LZMA_RUN;
uint8_t outbuf[BUFSIZ];
ref<std::string> res = make_ref<std::string>();
strm.next_in = (uint8_t *) in.c_str();
strm.avail_in = in.size();
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
while (true) {
checkInterrupt();
if (strm.avail_in == 0)
action = LZMA_FINISH;
lzma_ret ret = lzma_code(&strm, action);
if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
res->append((char *) outbuf, sizeof(outbuf) - strm.avail_out);
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
}
if (ret == LZMA_STREAM_END)
return res;
if (ret != LZMA_OK)
throw Error("error while compressing xz file");
}
}
static ref<std::string> decompressXZ(const std::string & in)
{
lzma_stream strm(LZMA_STREAM_INIT);
lzma_ret ret = lzma_stream_decoder(
&strm, UINT64_MAX, LZMA_CONCATENATED);
if (ret != LZMA_OK)
throw Error("unable to initialise lzma decoder");
Finally free([&]() { lzma_end(&strm); });
lzma_action action = LZMA_RUN;
uint8_t outbuf[BUFSIZ];
ref<std::string> res = make_ref<std::string>();
strm.next_in = (uint8_t *) in.c_str();
strm.avail_in = in.size();
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
while (true) {
checkInterrupt();
if (strm.avail_in == 0)
action = LZMA_FINISH;
lzma_ret ret = lzma_code(&strm, action);
if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
res->append((char *) outbuf, sizeof(outbuf) - strm.avail_out);
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
}
if (ret == LZMA_STREAM_END)
return res;
if (ret != LZMA_OK)
throw Error("error while decompressing xz file");
}
}
static ref<std::string> compressBzip2(const std::string & in)
{
bz_stream strm;
memset(&strm, 0, sizeof(strm));
int ret = BZ2_bzCompressInit(&strm, 9, 0, 30);
if (ret != BZ_OK)
throw Error("unable to initialise bzip2 encoder");
Finally free([&]() { BZ2_bzCompressEnd(&strm); });
int action = BZ_RUN;
char outbuf[BUFSIZ];
ref<std::string> res = make_ref<std::string>();
strm.next_in = (char *) in.c_str();
strm.avail_in = in.size();
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
while (true) {
checkInterrupt();
if (strm.avail_in == 0)
action = BZ_FINISH;
int ret = BZ2_bzCompress(&strm, action);
if (strm.avail_out == 0 || ret == BZ_STREAM_END) {
res->append(outbuf, sizeof(outbuf) - strm.avail_out);
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
}
if (ret == BZ_STREAM_END)
return res;
if (ret != BZ_OK && ret != BZ_FINISH_OK)
Error("error while compressing bzip2 file");
}
return res;
}
static ref<std::string> decompressBzip2(const std::string & in)
{
bz_stream strm;
memset(&strm, 0, sizeof(strm));
int ret = BZ2_bzDecompressInit(&strm, 0, 0);
if (ret != BZ_OK)
throw Error("unable to initialise bzip2 decoder");
Finally free([&]() { BZ2_bzDecompressEnd(&strm); });
char outbuf[BUFSIZ];
ref<std::string> res = make_ref<std::string>();
strm.next_in = (char *) in.c_str();
strm.avail_in = in.size();
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
while (true) {
checkInterrupt();
int ret = BZ2_bzDecompress(&strm);
if (strm.avail_out == 0 || ret == BZ_STREAM_END) {
res->append(outbuf, sizeof(outbuf) - strm.avail_out);
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
}
if (ret == BZ_STREAM_END)
return res;
if (ret != BZ_OK)
throw Error("error while decompressing bzip2 file");
}
}
ref<std::string> compress(const std::string & method, const std::string & in)
{
if (method == "none")
return make_ref<std::string>(in);
else if (method == "xz")
return compressXZ(in);
else if (method == "bzip2")
return compressBzip2(in);
else
throw UnknownCompressionMethod(format("unknown compression method %s") % method);
}
ref<std::string> decompress(const std::string & method, const std::string & in)
{
if (method == "none")
return make_ref<std::string>(in);
else if (method == "xz")
return decompressXZ(in);
else if (method == "bzip2")
return decompressBzip2(in);
else
throw UnknownCompressionMethod(format("unknown compression method %s") % method);
}
}