lix/src/libutil/compression.cc

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#include "compression.hh"
#include "types.hh"
#include <lzma.h>
namespace nix {
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");
lzma_action action = LZMA_RUN;
uint8_t outbuf[BUFSIZ];
string res;
strm.next_in = (uint8_t *) in.c_str();
strm.avail_in = in.size();
strm.next_out = outbuf;
strm.avail_out = sizeof(outbuf);
while (true) {
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");
}
}
}