lix/src/libstore/builtins/unpack-channel.cc

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#include "rust.hh"
#include "builtins.hh"
#include "compression.hh"
namespace nix {
void builtinUnpackChannel(const BasicDerivation & drv)
{
auto getAttr = [&](const string & name) {
auto i = drv.env.find(name);
if (i == drv.env.end()) throw Error("attribute '%s' missing", name);
return i->second;
};
Path out = getAttr("out");
auto channelName = getAttr("channelName");
auto src = getAttr("src");
createDirs(out);
auto source = sinkToSource([&](Sink & sink) {
auto decompressor =
hasSuffix(src, ".bz2") ? makeDecompressionSink("bzip2", sink) :
hasSuffix(src, ".xz") ? makeDecompressionSink("xz", sink) :
makeDecompressionSink("none", sink);
readFile(src, *decompressor);
decompressor->finish();
});
unpack_tarfile(*source, out).use()->unwrap();
auto entries = readDirectory(out);
if (entries.size() != 1)
throw Error("channel tarball '%s' contains more than one file", src);
if (rename((out + "/" + entries[0].name).c_str(), (out + "/" + channelName).c_str()) == -1)
throw SysError("renaming channel directory");
}
}