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#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, ref<std::string> in)
{
if (method == "none")
return 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, ref<std::string> in)
{
if (method == "none")
return in;
else if (method == "xz")
return decompressXZ(*in);
else if (method == "bzip2")
return decompressBzip2(*in);
else
throw UnknownCompressionMethod(format("unknown compression method ‘%s’") % method);
}
}
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