private Ref readRef(String name, RefList<Ref> packed) throws IOException {
final RefList<LooseRef> curList = looseRefs.get();
final int idx = curList.find(name);
if (0 <= idx) {
final LooseRef o = curList.get(idx);
final LooseRef n = scanRef(o, name);
if (n == null) {
if (looseRefs.compareAndSet(curList, curList.remove(idx))) modCnt.incrementAndGet();
return packed.get(name);
}
if (o == n) return n;
if (looseRefs.compareAndSet(curList, curList.set(idx, n))) modCnt.incrementAndGet();
return n;
}
final LooseRef n = scanRef(null, name);
if (n == null) return packed.get(name);
// check whether the found new ref is the an additional ref. These refs
// should not go into looseRefs
for (int i = 0; i < additionalRefsNames.length; i++)
if (name.equals(additionalRefsNames[i])) return n;
if (looseRefs.compareAndSet(curList, curList.add(idx, n))) modCnt.incrementAndGet();
return n;
}
void scan(String prefix) {
if (ALL.equals(prefix)) {
scanOne(HEAD);
scanTree(R_REFS, refsDir);
// If any entries remain, they are deleted, drop them.
if (newLoose == null && curIdx < curLoose.size()) newLoose = curLoose.copy(curIdx);
} else if (prefix.startsWith(R_REFS) && prefix.endsWith("/")) { // $NON-NLS-1$
curIdx = -(curLoose.find(prefix) + 1);
File dir = new File(refsDir, prefix.substring(R_REFS.length()));
scanTree(prefix, dir);
// Skip over entries still within the prefix; these have
// been removed from the directory.
while (curIdx < curLoose.size()) {
if (!curLoose.get(curIdx).getName().startsWith(prefix)) break;
if (newLoose == null) newLoose = curLoose.copy(curIdx);
curIdx++;
}
// Keep any entries outside of the prefix space, we
// do not know anything about their status.
if (newLoose != null) {
while (curIdx < curLoose.size()) newLoose.add(curLoose.get(curIdx++));
}
}
}
private Ref resolve(
final Ref ref, int depth, String prefix, RefList<LooseRef> loose, RefList<Ref> packed)
throws IOException {
if (ref.isSymbolic()) {
Ref dst = ref.getTarget();
if (MAX_SYMBOLIC_REF_DEPTH <= depth) return null; // claim it doesn't exist
// If the cached value can be assumed to be current due to a
// recent scan of the loose directory, use it.
if (loose != null && dst.getName().startsWith(prefix)) {
int idx;
if (0 <= (idx = loose.find(dst.getName()))) dst = loose.get(idx);
else if (0 <= (idx = packed.find(dst.getName()))) dst = packed.get(idx);
else return ref;
} else {
dst = readRef(dst.getName(), packed);
if (dst == null) return ref;
}
dst = resolve(dst, depth + 1, prefix, loose, packed);
if (dst == null) return null;
return new SymbolicRef(ref.getName(), dst);
}
return ref;
}
@Override
public boolean isNameConflicting(String name) throws IOException {
RefList<Ref> packed = getPackedRefs();
RefList<LooseRef> loose = getLooseRefs();
// Cannot be nested within an existing reference.
int lastSlash = name.lastIndexOf('/');
while (0 < lastSlash) {
String needle = name.substring(0, lastSlash);
if (loose.contains(needle) || packed.contains(needle)) return true;
lastSlash = name.lastIndexOf('/', lastSlash - 1);
}
// Cannot be the container of an existing reference.
String prefix = name + '/';
int idx;
idx = -(packed.find(prefix) + 1);
if (idx < packed.size() && packed.get(idx).getName().startsWith(prefix)) return true;
idx = -(loose.find(prefix) + 1);
if (idx < loose.size() && loose.get(idx).getName().startsWith(prefix)) return true;
return false;
}
/**
* Adds a set of refs to the set of packed-refs. Only non-symbolic refs are added. If a ref with
* the given name already existed in packed-refs it is updated with the new value. Each loose ref
* which was added to the packed-ref file is deleted. If a given ref can't be locked it will not
* be added to the pack file.
*
* @param refs the refs to be added. Must be fully qualified.
* @throws IOException
*/
public void pack(List<String> refs) throws IOException {
if (refs.size() == 0) return;
FS fs = parent.getFS();
// Lock the packed refs file and read the content
LockFile lck = new LockFile(packedRefsFile);
if (!lck.lock())
throw new IOException(MessageFormat.format(JGitText.get().cannotLock, packedRefsFile));
try {
final PackedRefList packed = getPackedRefs();
RefList<Ref> cur = readPackedRefs();
// Iterate over all refs to be packed
for (String refName : refs) {
Ref ref = readRef(refName, cur);
if (ref.isSymbolic()) continue; // can't pack symbolic refs
// Add/Update it to packed-refs
int idx = cur.find(refName);
if (idx >= 0) cur = cur.set(idx, peeledPackedRef(ref));
else cur = cur.add(idx, peeledPackedRef(ref));
}
// The new content for packed-refs is collected. Persist it.
commitPackedRefs(lck, cur, packed);
// Now delete the loose refs which are now packed
for (String refName : refs) {
// Lock the loose ref
File refFile = fileFor(refName);
if (!fs.exists(refFile)) continue;
LockFile rLck = new LockFile(refFile);
if (!rLck.lock()) continue;
try {
LooseRef currentLooseRef = scanRef(null, refName);
if (currentLooseRef == null || currentLooseRef.isSymbolic()) continue;
Ref packedRef = cur.get(refName);
ObjectId clr_oid = currentLooseRef.getObjectId();
if (clr_oid != null && clr_oid.equals(packedRef.getObjectId())) {
RefList<LooseRef> curLoose, newLoose;
do {
curLoose = looseRefs.get();
int idx = curLoose.find(refName);
if (idx < 0) break;
newLoose = curLoose.remove(idx);
} while (!looseRefs.compareAndSet(curLoose, newLoose));
int levels = levelsIn(refName) - 2;
delete(refFile, levels, rLck);
}
} finally {
rLck.unlock();
}
}
// Don't fire refsChanged. The refs have not change, only their
// storage.
} finally {
lck.unlock();
}
}
private Ref resolve(Ref ref, int depth, RefList<Ref> loose) throws IOException {
if (!ref.isSymbolic()) return ref;
Ref dst = ref.getTarget();
if (MAX_SYMBOLIC_REF_DEPTH <= depth) return null; // claim it doesn't exist
dst = loose.get(dst.getName());
if (dst == null) return ref;
dst = resolve(dst, depth + 1, loose);
if (dst == null) return null;
return new SymbolicRef(ref.getName(), dst);
}
@Override
public boolean isNameConflicting(String refName) throws IOException {
RefList<DhtRef> all = readRefs().ids;
// Cannot be nested within an existing reference.
int lastSlash = refName.lastIndexOf('/');
while (0 < lastSlash) {
String needle = refName.substring(0, lastSlash);
if (all.contains(needle)) return true;
lastSlash = refName.lastIndexOf('/', lastSlash - 1);
}
// Cannot be the container of an existing reference.
String prefix = refName + '/';
int idx = -(all.find(prefix) + 1);
if (idx < all.size() && all.get(idx).getName().startsWith(prefix)) return true;
return false;
}
private void scanOne(String name) {
LooseRef cur;
if (curIdx < curLoose.size()) {
do {
cur = curLoose.get(curIdx);
int cmp = RefComparator.compareTo(cur, name);
if (cmp < 0) {
// Reference is not loose anymore, its been deleted.
// Skip the name in the new result list.
if (newLoose == null) newLoose = curLoose.copy(curIdx);
curIdx++;
cur = null;
continue;
}
if (cmp > 0) // Newly discovered loose reference.
cur = null;
break;
} while (curIdx < curLoose.size());
} else cur = null; // Newly discovered loose reference.
LooseRef n;
try {
n = scanRef(cur, name);
} catch (IOException notValid) {
n = null;
}
if (n != null) {
if (cur != n && newLoose == null) newLoose = curLoose.copy(curIdx);
if (newLoose != null) newLoose.add(n);
if (n.isSymbolic()) symbolic.add(n);
} else if (cur != null) {
// Tragically, this file is no longer a loose reference.
// Kill our cached entry of it.
if (newLoose == null) newLoose = curLoose.copy(curIdx);
}
if (cur != null) curIdx++;
}
@Override
public Ref peel(final Ref ref) throws IOException {
final Ref leaf = ref.getLeaf();
if (leaf.isPeeled() || leaf.getObjectId() == null) return ref;
ObjectIdRef newLeaf = doPeel(leaf);
// Try to remember this peeling in the cache, so we don't have to do
// it again in the future, but only if the reference is unchanged.
if (leaf.getStorage().isLoose()) {
RefList<LooseRef> curList = looseRefs.get();
int idx = curList.find(leaf.getName());
if (0 <= idx && curList.get(idx) == leaf) {
LooseRef asPeeled = ((LooseRef) leaf).peel(newLeaf);
RefList<LooseRef> newList = curList.set(idx, asPeeled);
looseRefs.compareAndSet(curList, newList);
}
}
return recreate(ref, newLeaf);
}
/**
* Find a reference by name.
*
* @param name full name of the reference.
* @return the reference, if it exists, otherwise null.
*/
public Ref get(String name) {
return ids.get(name);
}
