nix-super/src/libstore/export-import.cc
2020-09-30 00:41:18 +00:00

100 lines
3 KiB
C++

#include "serialise.hh"
#include "store-api.hh"
#include "archive.hh"
#include "worker-protocol.hh"
#include <algorithm>
namespace nix {
void Store::exportPaths(const StorePathSet & paths, Sink & sink)
{
auto sorted = topoSortPaths(paths);
std::reverse(sorted.begin(), sorted.end());
std::string doneLabel("paths exported");
//logger->incExpected(doneLabel, sorted.size());
for (auto & path : sorted) {
//Activity act(*logger, lvlInfo, format("exporting path '%s'") % path);
sink << 1;
exportPath(path, sink);
//logger->incProgress(doneLabel);
}
sink << 0;
}
void Store::exportPath(const StorePath & path, Sink & sink)
{
auto info = queryPathInfo(path);
HashSink hashSink(htSHA256);
TeeSink teeSink(sink, hashSink);
narFromPath(path, teeSink);
/* Refuse to export paths that have changed. This prevents
filesystem corruption from spreading to other machines.
Don't complain if the stored hash is zero (unknown). */
Hash hash = hashSink.currentHash().first;
if (hash != info->narHash && info->narHash != Hash(info->narHash.type))
throw Error("hash of path '%s' has changed from '%s' to '%s'!",
printStorePath(path), info->narHash.to_string(Base32, true), hash.to_string(Base32, true));
teeSink
<< exportMagic
<< printStorePath(path);
worker_proto::write(*this, teeSink, info->references);
teeSink
<< (info->deriver ? printStorePath(*info->deriver) : "")
<< 0;
}
StorePaths Store::importPaths(Source & source, CheckSigsFlag checkSigs)
{
StorePaths res;
while (true) {
auto n = readNum<uint64_t>(source);
if (n == 0) break;
if (n != 1) throw Error("input doesn't look like something created by 'nix-store --export'");
/* Extract the NAR from the source. */
StringSink saved;
TeeSource tee { source, saved };
ParseSink ether;
parseDump(ether, tee);
uint32_t magic = readInt(source);
if (magic != exportMagic)
throw Error("Nix archive cannot be imported; wrong format");
auto path = parseStorePath(readString(source));
//Activity act(*logger, lvlInfo, format("importing path '%s'") % info.path);
auto references = worker_proto::read(*this, source, Phantom<StorePathSet> {});
auto deriver = readString(source);
auto narHash = hashString(htSHA256, *saved.s);
ValidPathInfo info { path, narHash };
if (deriver != "")
info.deriver = parseStorePath(deriver);
info.references = references;
info.narSize = saved.s->size();
// Ignore optional legacy signature.
if (readInt(source) == 1)
readString(source);
// Can't use underlying source, which would have been exhausted
auto source = StringSource { *saved.s };
addToStore(info, source, NoRepair, checkSigs);
res.push_back(info.path);
}
return res;
}
}