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.
This commit is contained in:
Eelco Dolstra 2016-05-04 13:36:54 +02:00
parent b6c768fb6a
commit 538a64e8c3
15 changed files with 235 additions and 338 deletions

View file

@ -901,6 +901,40 @@ void LocalStore::invalidatePath(State & state, const Path & path)
}
void LocalStore::addToStore(const ValidPathInfo & info, const std::string & nar, bool repair)
{
addTempRoot(info.path);
if (repair || !isValidPath(info.path)) {
PathLocks outputLock;
/* Lock the output path. But don't lock if we're being called
from a build hook (whose parent process already acquired a
lock on this path). */
Strings locksHeld = tokenizeString<Strings>(getEnv("NIX_HELD_LOCKS"));
if (find(locksHeld.begin(), locksHeld.end(), info.path) == locksHeld.end())
outputLock.lockPaths({info.path});
if (repair || !isValidPath(info.path)) {
deletePath(info.path);
StringSource source(nar);
restorePath(info.path, source);
canonicalisePathMetaData(info.path, -1);
optimisePath(info.path); // FIXME: combine with hashPath()
registerValidPath(info);
}
outputLock.setDeletion(true);
}
}
Path LocalStore::addToStoreFromDump(const string & dump, const string & name,
bool recursive, HashType hashAlgo, bool repair)
{
@ -1016,69 +1050,6 @@ Path LocalStore::addTextToStore(const string & name, const string & s,
}
struct HashAndWriteSink : Sink
{
Sink & writeSink;
HashSink hashSink;
HashAndWriteSink(Sink & writeSink) : writeSink(writeSink), hashSink(htSHA256)
{
}
virtual void operator () (const unsigned char * data, size_t len)
{
writeSink(data, len);
hashSink(data, len);
}
Hash currentHash()
{
return hashSink.currentHash().first;
}
};
void LocalStore::exportPath(const Path & path, Sink & sink)
{
assertStorePath(path);
printMsg(lvlTalkative, format("exporting path %1%") % path);
auto info = queryPathInfo(path);
HashAndWriteSink hashAndWriteSink(sink);
dumpPath(path, hashAndWriteSink);
/* 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 = hashAndWriteSink.currentHash();
if (hash != info->narHash && info->narHash != Hash(info->narHash.type))
throw Error(format("hash of path %1% has changed from %2% to %3%!") % path
% printHash(info->narHash) % printHash(hash));
hashAndWriteSink << exportMagic << path << info->references << info->deriver;
hashAndWriteSink << 0; // backwards compatibility
}
struct HashAndReadSource : Source
{
Source & readSource;
HashSink hashSink;
bool hashing;
HashAndReadSource(Source & readSource) : readSource(readSource), hashSink(htSHA256)
{
hashing = true;
}
size_t read(unsigned char * data, size_t len)
{
size_t n = readSource.read(data, len);
if (hashing) hashSink(data, n);
return n;
}
};
/* Create a temporary directory in the store that won't be
garbage-collected. */
Path LocalStore::createTempDirInStore()
@ -1095,103 +1066,6 @@ Path LocalStore::createTempDirInStore()
}
Path LocalStore::importPath(Source & source)
{
HashAndReadSource hashAndReadSource(source);
/* We don't yet know what store path this archive contains (the
store path follows the archive data proper), and besides, we
don't know yet whether the signature is valid. */
Path tmpDir = createTempDirInStore();
AutoDelete delTmp(tmpDir);
Path unpacked = tmpDir + "/unpacked";
restorePath(unpacked, hashAndReadSource);
uint32_t magic = readInt(hashAndReadSource);
if (magic != exportMagic)
throw Error("Nix archive cannot be imported; wrong format");
Path dstPath = readStorePath(hashAndReadSource);
printMsg(lvlTalkative, format("importing path %1%") % dstPath);
PathSet references = readStorePaths<PathSet>(hashAndReadSource);
Path deriver = readString(hashAndReadSource);
if (deriver != "") assertStorePath(deriver);
Hash hash = hashAndReadSource.hashSink.finish().first;
hashAndReadSource.hashing = false;
bool haveSignature = readInt(hashAndReadSource) == 1;
if (haveSignature)
// Ignore legacy signature.
readString(hashAndReadSource);
/* Do the actual import. */
/* !!! way too much code duplication with addTextToStore() etc. */
addTempRoot(dstPath);
if (!isValidPath(dstPath)) {
PathLocks outputLock;
/* Lock the output path. But don't lock if we're being called
from a build hook (whose parent process already acquired a
lock on this path). */
Strings locksHeld = tokenizeString<Strings>(getEnv("NIX_HELD_LOCKS"));
if (find(locksHeld.begin(), locksHeld.end(), dstPath) == locksHeld.end())
outputLock.lockPaths(singleton<PathSet, Path>(dstPath));
if (!isValidPath(dstPath)) {
deletePath(dstPath);
if (rename(unpacked.c_str(), dstPath.c_str()) == -1)
throw SysError(format("cannot move %1% to %2%")
% unpacked % dstPath);
canonicalisePathMetaData(dstPath, -1);
/* !!! if we were clever, we could prevent the hashPath()
here. */
HashResult hash = hashPath(htSHA256, dstPath);
optimisePath(dstPath); // FIXME: combine with hashPath()
ValidPathInfo info;
info.path = dstPath;
info.narHash = hash.first;
info.narSize = hash.second;
info.references = references;
info.deriver = deriver != "" && isValidPath(deriver) ? deriver : "";
registerValidPath(info);
}
outputLock.setDeletion(true);
}
return dstPath;
}
Paths LocalStore::importPaths(Source & source,
std::shared_ptr<FSAccessor> accessor)
{
Paths res;
while (true) {
unsigned long long n = readLongLong(source);
if (n == 0) break;
if (n != 1) throw Error("input doesn't look like something created by nix-store --export");
res.push_back(importPath(source));
}
return res;
}
void LocalStore::invalidatePathChecked(const Path & path)
{
assertStorePath(path);