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Merged to R9439. Fixed a computeFSClosure bug. The state garbage colletor basically works, Missing items: State locks, shared state and Topological sort

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This commit is contained in:
Wouter den Breejen 2007-10-10 15:55:00 +00:00
parent 7d82fd16e9
commit 16410fc714
12 changed files with 372 additions and 154 deletions
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133
src/libstore/local-store.cc
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@ -288,7 +288,7 @@ void copyPath(const Path & src, const Path & dst, PathFilter & filter)
}
static void _canonicalisePathMetaData(const Path & path)
static void _canonicalisePathMetaData(const Path & path, bool recurse)
{
checkInterrupt();
@ -337,17 +337,17 @@ static void _canonicalisePathMetaData(const Path & path)
}
if (S_ISDIR(st.st_mode)) {
if (recurse && S_ISDIR(st.st_mode)) {
Strings names = readDirectory(path);
for (Strings::iterator i = names.begin(); i != names.end(); ++i)
_canonicalisePathMetaData(path + "/" + *i);
_canonicalisePathMetaData(path + "/" + *i, true);
}
}
void canonicalisePathMetaData(const Path & path)
{
_canonicalisePathMetaData(path);
_canonicalisePathMetaData(path, true);
/* On platforms that don't have lchown(), the top-level path can't
be a symlink, since we can't change its ownership. */
@ -1118,7 +1118,7 @@ void LocalStore::exportPath(const Path & path, bool sign,
consistent metadata. */
Transaction txn(nixDB);
addTempRoot(path);
if (!isValidPath(path))
if (!isValidPathTxn(txn, path))
throw Error(format("path `%1%' is not valid") % path);
HashAndWriteSink hashAndWriteSink(sink);
@ -1418,7 +1418,7 @@ void verifyStore(bool checkContents)
}
else {
PathSet references;
queryXReferencesTxn(txn, *i, references, true, -1); //TODO
queryXReferencesTxn(txn, *i, references, true, 0); //TODO
for (PathSet::iterator j = references.begin();
j != references.end(); ++j)
{
@ -1843,6 +1843,125 @@ void LocalStore::revertToRevision(const Path & statePath, const unsigned int rev
}
typedef std::map<Hash, std::pair<Path, ino_t> > HashToPath;
static void makeWritable(const Path & path)
{
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError(format("getting attributes of path `%1%'") % path);
if (chmod(path.c_str(), st.st_mode | S_IWUSR) == -1)
throw SysError(format("changing writability of `%1%'") % path);
}
static void hashAndLink(bool dryRun, HashToPath & hashToPath,
OptimiseStats & stats, const Path & path)
{
struct stat st;
if (lstat(path.c_str(), &st))
throw SysError(format("getting attributes of path `%1%'") % path);
/* Sometimes SNAFUs can cause files in the Nix store to be
modified, in particular when running programs as root under
NixOS (example: $fontconfig/var/cache being modified). Skip
those files. */
if (S_ISREG(st.st_mode) && (st.st_mode & S_IWUSR)) {
printMsg(lvlError, format("skipping suspicious writable file `%1%'") % path);
return;
}
/* We can hard link regular files and symlinks. */
if (S_ISREG(st.st_mode) || S_ISLNK(st.st_mode)) {
/* Hash the file. Note that hashPath() returns the hash over
the NAR serialisation, which includes the execute bit on
the file. Thus, executable and non-executable files with
the same contents *won't* be linked (which is good because
otherwise the permissions would be screwed up).
Also note that if `path' is a symlink, then we're hashing
the contents of the symlink (i.e. the result of
readlink()), not the contents of the target (which may not
even exist). */
Hash hash = hashPath(htSHA256, path);
stats.totalFiles++;
printMsg(lvlDebug, format("`%1%' has hash `%2%'") % path % printHash(hash));
std::pair<Path, ino_t> prevPath = hashToPath[hash];
if (prevPath.first == "") {
hashToPath[hash] = std::pair<Path, ino_t>(path, st.st_ino);
return;
}
/* Yes! We've seen a file with the same contents. Replace
the current file with a hard link to that file. */
stats.sameContents++;
if (prevPath.second == st.st_ino) {
printMsg(lvlDebug, format("`%1%' is already linked to `%2%'") % path % prevPath.first);
return;
}
if (!dryRun) {
printMsg(lvlTalkative, format("linking `%1%' to `%2%'") % path % prevPath.first);
Path tempLink = (format("%1%.tmp-%2%-%3%")
% path % getpid() % rand()).str();
/* Make the containing directory writable, but only if
it's not the store itself (we don't want or need to
mess with its permissions). */
bool mustToggle = !isStorePath(path);
if (mustToggle) makeWritable(dirOf(path));
if (link(prevPath.first.c_str(), tempLink.c_str()) == -1)
throw SysError(format("cannot link `%1%' to `%2%'")
% tempLink % prevPath.first);
/* Atomically replace the old file with the new hard link. */
if (rename(tempLink.c_str(), path.c_str()) == -1)
throw SysError(format("cannot rename `%1%' to `%2%'")
% tempLink % path);
/* Make the directory read-only again and reset its
timestamp back to 0. */
if (mustToggle) _canonicalisePathMetaData(dirOf(path), false);
} else
printMsg(lvlTalkative, format("would link `%1%' to `%2%'") % path % prevPath.first);
stats.filesLinked++;
stats.bytesFreed += st.st_size;
}
if (S_ISDIR(st.st_mode)) {
Strings names = readDirectory(path);
for (Strings::iterator i = names.begin(); i != names.end(); ++i)
hashAndLink(dryRun, hashToPath, stats, path + "/" + *i);
}
}
void LocalStore::optimiseStore(bool dryRun, OptimiseStats & stats)
{
HashToPath hashToPath;
Paths paths;
PathSet validPaths;
nixDB.enumTable(noTxn, dbValidPaths, paths);
for (Paths::iterator i = paths.begin(); i != paths.end(); ++i) {
addTempRoot(*i);
if (!isValidPath(*i)) continue; /* path was GC'ed, probably */
startNest(nest, lvlChatty, format("hashing files in `%1%'") % *i);
hashAndLink(dryRun, hashToPath, stats, *i);
}
}
/* Upgrade from schema 1 (Nix <= 0.7) to schema 2 (Nix >= 0.8). */
static void upgradeStore07()
{
@ -1912,7 +2031,7 @@ static void upgradeStore07()
}
PathSet prevReferences;
queryXReferencesTxn(txn, path, prevReferences, true, -1);
queryXReferencesTxn(txn, path, prevReferences, true, 0);
if (prevReferences.size() > 0 && references != prevReferences)
printMsg(lvlError, format("warning: conflicting references for `%1%'") % path);