| /* |
| * Copyright (C) 2007, Dave Watson <dwatson@mimvista.com> |
| * Copyright (C) 2009-2010, Google Inc. |
| * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com> |
| * Copyright (C) 2006, Shawn O. Pearce <spearce@spearce.org> |
| * and other copyright owners as documented in the project's IP log. |
| * |
| * This program and the accompanying materials are made available |
| * under the terms of the Eclipse Distribution License v1.0 which |
| * accompanies this distribution, is reproduced below, and is |
| * available at http://www.eclipse.org/org/documents/edl-v10.php |
| * |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or |
| * without modification, are permitted provided that the following |
| * conditions are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * - Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * - Neither the name of the Eclipse Foundation, Inc. nor the |
| * names of its contributors may be used to endorse or promote |
| * products derived from this software without specific prior |
| * written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND |
| * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, |
| * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
| * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
| * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF |
| * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| package org.eclipse.jgit.lib; |
| |
| import static org.eclipse.jgit.lib.Constants.CHARSET; |
| import static org.eclipse.jgit.lib.Constants.HEAD; |
| import static org.eclipse.jgit.lib.Constants.LOGS; |
| import static org.eclipse.jgit.lib.Constants.OBJECT_ID_STRING_LENGTH; |
| import static org.eclipse.jgit.lib.Constants.PACKED_REFS; |
| import static org.eclipse.jgit.lib.Constants.R_HEADS; |
| import static org.eclipse.jgit.lib.Constants.R_REFS; |
| import static org.eclipse.jgit.lib.Constants.R_REMOTES; |
| import static org.eclipse.jgit.lib.Constants.R_TAGS; |
| import static org.eclipse.jgit.lib.Constants.encode; |
| import static org.eclipse.jgit.lib.Ref.Storage.LOOSE; |
| import static org.eclipse.jgit.lib.Ref.Storage.NEW; |
| import static org.eclipse.jgit.lib.Ref.Storage.PACKED; |
| |
| import java.io.BufferedReader; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.FileNotFoundException; |
| import java.io.FileOutputStream; |
| import java.io.IOException; |
| import java.io.InputStreamReader; |
| import java.util.Arrays; |
| import java.util.Map; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| import org.eclipse.jgit.errors.ObjectWritingException; |
| import org.eclipse.jgit.revwalk.RevObject; |
| import org.eclipse.jgit.revwalk.RevTag; |
| import org.eclipse.jgit.revwalk.RevWalk; |
| import org.eclipse.jgit.util.FS; |
| import org.eclipse.jgit.util.IO; |
| import org.eclipse.jgit.util.RawParseUtils; |
| import org.eclipse.jgit.util.RefList; |
| import org.eclipse.jgit.util.RefMap; |
| |
| /** |
| * Traditional file system based {@link RefDatabase}. |
| * <p> |
| * This is the classical reference database representation for a Git repository. |
| * References are stored in two formats: loose, and packed. |
| * <p> |
| * Loose references are stored as individual files within the {@code refs/} |
| * directory. The file name matches the reference name and the file contents is |
| * the current {@link ObjectId} in string form. |
| * <p> |
| * Packed references are stored in a single text file named {@code packed-refs}. |
| * In the packed format, each reference is stored on its own line. This file |
| * reduces the number of files needed for large reference spaces, reducing the |
| * overall size of a Git repository on disk. |
| */ |
| public class RefDirectory extends RefDatabase { |
| /** Magic string denoting the start of a symbolic reference file. */ |
| public static final String SYMREF = "ref: "; //$NON-NLS-1$ |
| |
| /** Magic string denoting the header of a packed-refs file. */ |
| public static final String PACKED_REFS_HEADER = "# pack-refs with:"; //$NON-NLS-1$ |
| |
| /** If in the header, denotes the file has peeled data. */ |
| public static final String PACKED_REFS_PEELED = " peeled"; //$NON-NLS-1$ |
| |
| private final Repository parent; |
| |
| private final File gitDir; |
| |
| private final File refsDir; |
| |
| private final File logsDir; |
| |
| private final File logsRefsDir; |
| |
| private final File packedRefsFile; |
| |
| /** |
| * Immutable sorted list of loose references. |
| * <p> |
| * Symbolic references in this collection are stored unresolved, that is |
| * their target appears to be a new reference with no ObjectId. These are |
| * converted into resolved references during a get operation, ensuring the |
| * live value is always returned. |
| */ |
| private final AtomicReference<RefList<LooseRef>> looseRefs = new AtomicReference<RefList<LooseRef>>(); |
| |
| /** Immutable sorted list of packed references. */ |
| private final AtomicReference<PackedRefList> packedRefs = new AtomicReference<PackedRefList>(); |
| |
| /** |
| * Number of modifications made to this database. |
| * <p> |
| * This counter is incremented when a change is made, or detected from the |
| * filesystem during a read operation. |
| */ |
| private final AtomicInteger modCnt = new AtomicInteger(); |
| |
| /** |
| * Last {@link #modCnt} that we sent to listeners. |
| * <p> |
| * This value is compared to {@link #modCnt}, and a notification is sent to |
| * the listeners only when it differs. |
| */ |
| private final AtomicInteger lastNotifiedModCnt = new AtomicInteger(); |
| |
| RefDirectory(final Repository db) { |
| parent = db; |
| gitDir = db.getDirectory(); |
| refsDir = FS.resolve(gitDir, R_REFS); |
| logsDir = FS.resolve(gitDir, LOGS); |
| logsRefsDir = FS.resolve(gitDir, LOGS + '/' + R_REFS); |
| packedRefsFile = FS.resolve(gitDir, PACKED_REFS); |
| |
| looseRefs.set(RefList.<LooseRef> emptyList()); |
| packedRefs.set(PackedRefList.NO_PACKED_REFS); |
| } |
| |
| Repository getRepository() { |
| return parent; |
| } |
| |
| public void create() throws IOException { |
| refsDir.mkdir(); |
| logsDir.mkdir(); |
| logsRefsDir.mkdir(); |
| |
| new File(refsDir, R_HEADS.substring(R_REFS.length())).mkdir(); |
| new File(refsDir, R_TAGS.substring(R_REFS.length())).mkdir(); |
| new File(logsRefsDir, R_HEADS.substring(R_REFS.length())).mkdir(); |
| } |
| |
| @Override |
| public void close() { |
| // We have no resources to close. |
| } |
| |
| void rescan() { |
| looseRefs.set(RefList.<LooseRef> emptyList()); |
| packedRefs.set(PackedRefList.NO_PACKED_REFS); |
| } |
| |
| @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; |
| } |
| |
| private RefList<LooseRef> getLooseRefs() { |
| final RefList<LooseRef> oldLoose = looseRefs.get(); |
| |
| LooseScanner scan = new LooseScanner(oldLoose); |
| scan.scan(ALL); |
| |
| RefList<LooseRef> loose; |
| if (scan.newLoose != null) { |
| loose = scan.newLoose.toRefList(); |
| if (looseRefs.compareAndSet(oldLoose, loose)) |
| modCnt.incrementAndGet(); |
| } else |
| loose = oldLoose; |
| return loose; |
| } |
| |
| @Override |
| public Ref getRef(final String needle) throws IOException { |
| final RefList<Ref> packed = getPackedRefs(); |
| Ref ref = null; |
| for (String prefix : SEARCH_PATH) { |
| ref = readRef(prefix + needle, packed); |
| if (ref != null) { |
| ref = resolve(ref, 0, null, null, packed); |
| break; |
| } |
| } |
| fireRefsChanged(); |
| return ref; |
| } |
| |
| @Override |
| public Map<String, Ref> getRefs(String prefix) throws IOException { |
| final RefList<Ref> packed = getPackedRefs(); |
| final RefList<LooseRef> oldLoose = looseRefs.get(); |
| |
| LooseScanner scan = new LooseScanner(oldLoose); |
| scan.scan(prefix); |
| |
| RefList<LooseRef> loose; |
| if (scan.newLoose != null) { |
| loose = scan.newLoose.toRefList(); |
| if (looseRefs.compareAndSet(oldLoose, loose)) |
| modCnt.incrementAndGet(); |
| } else |
| loose = oldLoose; |
| fireRefsChanged(); |
| |
| RefList.Builder<Ref> symbolic = scan.symbolic; |
| for (int idx = 0; idx < symbolic.size();) { |
| Ref ref = symbolic.get(idx); |
| ref = resolve(ref, 0, prefix, loose, packed); |
| if (ref != null && ref.getObjectId() != null) { |
| symbolic.set(idx, ref); |
| idx++; |
| } else { |
| // A broken symbolic reference, we have to drop it from the |
| // collections the client is about to receive. Should be a |
| // rare occurrence so pay a copy penalty. |
| loose = loose.remove(idx); |
| symbolic.remove(idx); |
| } |
| } |
| |
| return new RefMap(prefix, packed, upcast(loose), symbolic.toRefList()); |
| } |
| |
| @SuppressWarnings("unchecked") |
| private RefList<Ref> upcast(RefList<? extends Ref> loose) { |
| return (RefList<Ref>) loose; |
| } |
| |
| private class LooseScanner { |
| private final RefList<LooseRef> curLoose; |
| |
| private int curIdx; |
| |
| final RefList.Builder<Ref> symbolic = new RefList.Builder<Ref>(4); |
| |
| RefList.Builder<LooseRef> newLoose; |
| |
| LooseScanner(final RefList<LooseRef> curLoose) { |
| this.curLoose = curLoose; |
| } |
| |
| 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("/")) { |
| 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 void scanTree(String prefix, File dir) { |
| final String[] entries = dir.list(LockFile.FILTER); |
| if (entries != null && 0 < entries.length) { |
| Arrays.sort(entries); |
| for (String name : entries) { |
| File e = new File(dir, name); |
| if (e.isDirectory()) |
| scanTree(prefix + name + '/', e); |
| else |
| scanOne(prefix + name); |
| } |
| } |
| } |
| |
| 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; |
| |
| RevWalk rw = new RevWalk(getRepository()); |
| RevObject obj = rw.parseAny(leaf.getObjectId()); |
| ObjectIdRef newLeaf; |
| if (obj instanceof RevTag) { |
| do { |
| obj = rw.parseAny(((RevTag) obj).getObject()); |
| } while (obj instanceof RevTag); |
| |
| newLeaf = new ObjectIdRef.PeeledTag(leaf.getStorage(), leaf |
| .getName(), leaf.getObjectId(), obj.copy()); |
| } else { |
| newLeaf = new ObjectIdRef.PeeledNonTag(leaf.getStorage(), leaf |
| .getName(), leaf.getObjectId()); |
| } |
| |
| // 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); |
| } |
| |
| private static Ref recreate(final Ref old, final ObjectIdRef leaf) { |
| if (old.isSymbolic()) { |
| Ref dst = recreate(old.getTarget(), leaf); |
| return new SymbolicRef(old.getName(), dst); |
| } |
| return leaf; |
| } |
| |
| void storedSymbolicRef(RefDirectoryUpdate u, long modified, String target) { |
| putLooseRef(newSymbolicRef(modified, u.getRef().getName(), target)); |
| fireRefsChanged(); |
| } |
| |
| public RefDirectoryUpdate newUpdate(String name, boolean detach) |
| throws IOException { |
| final RefList<Ref> packed = getPackedRefs(); |
| Ref ref = readRef(name, packed); |
| if (ref != null) |
| ref = resolve(ref, 0, null, null, packed); |
| if (ref == null) |
| ref = new ObjectIdRef.Unpeeled(NEW, name, null); |
| else if (detach && ref.isSymbolic()) |
| ref = new ObjectIdRef.Unpeeled(LOOSE, name, ref.getObjectId()); |
| return new RefDirectoryUpdate(this, ref); |
| } |
| |
| @Override |
| public RefDirectoryRename newRename(String fromName, String toName) |
| throws IOException { |
| RefDirectoryUpdate from = newUpdate(fromName, false); |
| RefDirectoryUpdate to = newUpdate(toName, false); |
| return new RefDirectoryRename(from, to); |
| } |
| |
| void stored(RefDirectoryUpdate update, long modified) { |
| final ObjectId target = update.getNewObjectId().copy(); |
| final Ref leaf = update.getRef().getLeaf(); |
| putLooseRef(new LooseUnpeeled(modified, leaf.getName(), target)); |
| } |
| |
| private void putLooseRef(LooseRef ref) { |
| RefList<LooseRef> cList, nList; |
| do { |
| cList = looseRefs.get(); |
| nList = cList.put(ref); |
| } while (!looseRefs.compareAndSet(cList, nList)); |
| modCnt.incrementAndGet(); |
| fireRefsChanged(); |
| } |
| |
| void delete(RefDirectoryUpdate update) throws IOException { |
| Ref dst = update.getRef().getLeaf(); |
| String name = dst.getName(); |
| |
| // Write the packed-refs file using an atomic update. We might |
| // wind up reading it twice, before and after the lock, to ensure |
| // we don't miss an edit made externally. |
| final PackedRefList packed = getPackedRefs(); |
| if (packed.contains(name)) { |
| LockFile lck = new LockFile(packedRefsFile); |
| if (!lck.lock()) |
| throw new IOException("Cannot lock " + packedRefsFile); |
| try { |
| PackedRefList cur = readPackedRefs(0, 0); |
| int idx = cur.find(name); |
| if (0 <= idx) |
| commitPackedRefs(lck, cur.remove(idx), packed); |
| } finally { |
| lck.unlock(); |
| } |
| } |
| |
| RefList<LooseRef> curLoose, newLoose; |
| do { |
| curLoose = looseRefs.get(); |
| int idx = curLoose.find(name); |
| if (idx < 0) |
| break; |
| newLoose = curLoose.remove(idx); |
| } while (!looseRefs.compareAndSet(curLoose, newLoose)); |
| |
| int levels = levelsIn(name) - 2; |
| delete(logFor(name), levels); |
| if (dst.getStorage().isLoose()) { |
| update.unlock(); |
| delete(fileFor(name), levels); |
| } |
| |
| modCnt.incrementAndGet(); |
| fireRefsChanged(); |
| } |
| |
| void log(final RefUpdate update, final String msg, final boolean deref) |
| throws IOException { |
| final ObjectId oldId = update.getOldObjectId(); |
| final ObjectId newId = update.getNewObjectId(); |
| final Ref ref = update.getRef(); |
| |
| PersonIdent ident = update.getRefLogIdent(); |
| if (ident == null) |
| ident = new PersonIdent(parent); |
| else |
| ident = new PersonIdent(ident); |
| |
| final StringBuilder r = new StringBuilder(); |
| r.append(ObjectId.toString(oldId)); |
| r.append(' '); |
| r.append(ObjectId.toString(newId)); |
| r.append(' '); |
| r.append(ident.toExternalString()); |
| r.append('\t'); |
| r.append(msg); |
| r.append('\n'); |
| final byte[] rec = encode(r.toString()); |
| |
| if (deref && ref.isSymbolic()) { |
| log(ref.getName(), rec); |
| log(ref.getLeaf().getName(), rec); |
| } else { |
| log(ref.getName(), rec); |
| } |
| } |
| |
| private void log(final String refName, final byte[] rec) throws IOException { |
| final File log = logFor(refName); |
| final boolean write; |
| if (isLogAllRefUpdates() && shouldAutoCreateLog(refName)) |
| write = true; |
| else if (log.isFile()) |
| write = true; |
| else |
| write = false; |
| |
| if (write) { |
| FileOutputStream out; |
| try { |
| out = new FileOutputStream(log, true); |
| } catch (FileNotFoundException err) { |
| final File dir = log.getParentFile(); |
| if (dir.exists()) |
| throw err; |
| if (!dir.mkdirs() && !dir.isDirectory()) |
| throw new IOException("Cannot create directory " + dir); |
| out = new FileOutputStream(log, true); |
| } |
| try { |
| out.write(rec); |
| } finally { |
| out.close(); |
| } |
| } |
| } |
| |
| private boolean isLogAllRefUpdates() { |
| return parent.getConfig().getCore().isLogAllRefUpdates(); |
| } |
| |
| private boolean shouldAutoCreateLog(final String refName) { |
| return refName.equals(HEAD) // |
| || refName.startsWith(R_HEADS) // |
| || refName.startsWith(R_REMOTES); |
| } |
| |
| 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; |
| } |
| |
| private PackedRefList getPackedRefs() throws IOException { |
| long size = packedRefsFile.length(); |
| long mtime = size != 0 ? packedRefsFile.lastModified() : 0; |
| |
| final PackedRefList curList = packedRefs.get(); |
| if (size == curList.lastSize && mtime == curList.lastModified) |
| return curList; |
| |
| final PackedRefList newList = readPackedRefs(size, mtime); |
| if (packedRefs.compareAndSet(curList, newList)) |
| modCnt.incrementAndGet(); |
| return newList; |
| } |
| |
| private PackedRefList readPackedRefs(long size, long mtime) |
| throws IOException { |
| final BufferedReader br; |
| try { |
| br = new BufferedReader(new InputStreamReader(new FileInputStream( |
| packedRefsFile), CHARSET)); |
| } catch (FileNotFoundException noPackedRefs) { |
| // Ignore it and leave the new list empty. |
| return PackedRefList.NO_PACKED_REFS; |
| } |
| try { |
| return new PackedRefList(parsePackedRefs(br), size, mtime); |
| } finally { |
| br.close(); |
| } |
| } |
| |
| private RefList<Ref> parsePackedRefs(final BufferedReader br) |
| throws IOException { |
| RefList.Builder<Ref> all = new RefList.Builder<Ref>(); |
| Ref last = null; |
| boolean peeled = false; |
| boolean needSort = false; |
| |
| String p; |
| while ((p = br.readLine()) != null) { |
| if (p.charAt(0) == '#') { |
| if (p.startsWith(PACKED_REFS_HEADER)) { |
| p = p.substring(PACKED_REFS_HEADER.length()); |
| peeled = p.contains(PACKED_REFS_PEELED); |
| } |
| continue; |
| } |
| |
| if (p.charAt(0) == '^') { |
| if (last == null) |
| throw new IOException("Peeled line before ref."); |
| |
| ObjectId id = ObjectId.fromString(p.substring(1)); |
| last = new ObjectIdRef.PeeledTag(PACKED, last.getName(), last |
| .getObjectId(), id); |
| all.set(all.size() - 1, last); |
| continue; |
| } |
| |
| int sp = p.indexOf(' '); |
| ObjectId id = ObjectId.fromString(p.substring(0, sp)); |
| String name = copy(p, sp + 1, p.length()); |
| ObjectIdRef cur; |
| if (peeled) |
| cur = new ObjectIdRef.PeeledNonTag(PACKED, name, id); |
| else |
| cur = new ObjectIdRef.Unpeeled(PACKED, name, id); |
| if (last != null && RefComparator.compareTo(last, cur) > 0) |
| needSort = true; |
| all.add(cur); |
| last = cur; |
| } |
| |
| if (needSort) |
| all.sort(); |
| return all.toRefList(); |
| } |
| |
| private static String copy(final String src, final int off, final int end) { |
| // Don't use substring since it could leave a reference to the much |
| // larger existing string. Force construction of a full new object. |
| return new StringBuilder(end - off).append(src, off, end).toString(); |
| } |
| |
| private void commitPackedRefs(final LockFile lck, final RefList<Ref> refs, |
| final PackedRefList oldPackedList) throws IOException { |
| new RefWriter(refs) { |
| @Override |
| protected void writeFile(String name, byte[] content) |
| throws IOException { |
| lck.setNeedStatInformation(true); |
| try { |
| lck.write(content); |
| } catch (IOException ioe) { |
| throw new ObjectWritingException("Unable to write " + name, |
| ioe); |
| } |
| try { |
| lck.waitForStatChange(); |
| } catch (InterruptedException e) { |
| lck.unlock(); |
| throw new ObjectWritingException("Interrupted writing " |
| + name); |
| } |
| if (!lck.commit()) |
| throw new ObjectWritingException("Unable to write " + name); |
| |
| packedRefs.compareAndSet(oldPackedList, new PackedRefList(refs, |
| content.length, lck.getCommitLastModified())); |
| } |
| }.writePackedRefs(); |
| } |
| |
| 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); |
| if (looseRefs.compareAndSet(curList, curList.add(idx, n))) |
| modCnt.incrementAndGet(); |
| return n; |
| } |
| |
| private LooseRef scanRef(LooseRef ref, String name) throws IOException { |
| final File path = fileFor(name); |
| final long modified = path.lastModified(); |
| |
| if (ref != null) { |
| if (ref.getLastModified() == modified) |
| return ref; |
| name = ref.getName(); |
| } else if (modified == 0) |
| return null; |
| |
| final byte[] buf; |
| try { |
| buf = IO.readFully(path, 4096); |
| } catch (FileNotFoundException noFile) { |
| return null; // doesn't exist; not a reference. |
| } |
| |
| int n = buf.length; |
| if (n == 0) |
| return null; // empty file; not a reference. |
| |
| if (isSymRef(buf, n)) { |
| // trim trailing whitespace |
| while (0 < n && Character.isWhitespace(buf[n - 1])) |
| n--; |
| if (n < 6) { |
| String content = RawParseUtils.decode(buf, 0, n); |
| throw new IOException("Not a ref: " + name + ": " + content); |
| } |
| final String target = RawParseUtils.decode(buf, 5, n); |
| return newSymbolicRef(modified, name, target); |
| } |
| |
| if (n < OBJECT_ID_STRING_LENGTH) |
| return null; // impossibly short object identifier; not a reference. |
| |
| final ObjectId id; |
| try { |
| id = ObjectId.fromString(buf, 0); |
| } catch (IllegalArgumentException notRef) { |
| while (0 < n && Character.isWhitespace(buf[n - 1])) |
| n--; |
| String content = RawParseUtils.decode(buf, 0, n); |
| throw new IOException("Not a ref: " + name + ": " + content); |
| } |
| return new LooseUnpeeled(modified, name, id); |
| } |
| |
| private static boolean isSymRef(final byte[] buf, int n) { |
| if (n < 6) |
| return false; |
| return /**/buf[0] == 'r' // |
| && buf[1] == 'e' // |
| && buf[2] == 'f' // |
| && buf[3] == ':' // |
| && buf[4] == ' '; |
| } |
| |
| /** If the parent should fire listeners, fires them. */ |
| private void fireRefsChanged() { |
| final int last = lastNotifiedModCnt.get(); |
| final int curr = modCnt.get(); |
| if (last != curr && lastNotifiedModCnt.compareAndSet(last, curr)) |
| parent.fireRefsChanged(); |
| } |
| |
| /** |
| * Create a reference update to write a temporary reference. |
| * |
| * @return an update for a new temporary reference. |
| * @throws IOException |
| * a temporary name cannot be allocated. |
| */ |
| RefDirectoryUpdate newTemporaryUpdate() throws IOException { |
| File tmp = File.createTempFile("renamed_", "_ref", refsDir); |
| String name = Constants.R_REFS + tmp.getName(); |
| Ref ref = new ObjectIdRef.Unpeeled(NEW, name, null); |
| return new RefDirectoryUpdate(this, ref); |
| } |
| |
| /** |
| * Locate the file on disk for a single reference name. |
| * |
| * @param name |
| * name of the ref, relative to the Git repository top level |
| * directory (so typically starts with refs/). |
| * @return the loose file location. |
| */ |
| File fileFor(String name) { |
| if (name.startsWith(R_REFS)) { |
| name = name.substring(R_REFS.length()); |
| return new File(refsDir, name); |
| } |
| return new File(gitDir, name); |
| } |
| |
| /** |
| * Locate the log file on disk for a single reference name. |
| * |
| * @param name |
| * name of the ref, relative to the Git repository top level |
| * directory (so typically starts with refs/). |
| * @return the log file location. |
| */ |
| File logFor(String name) { |
| if (name.startsWith(R_REFS)) { |
| name = name.substring(R_REFS.length()); |
| return new File(logsRefsDir, name); |
| } |
| return new File(logsDir, name); |
| } |
| |
| static int levelsIn(final String name) { |
| int count = 0; |
| for (int p = name.indexOf('/'); p >= 0; p = name.indexOf('/', p + 1)) |
| count++; |
| return count; |
| } |
| |
| static void delete(final File file, final int depth) throws IOException { |
| if (!file.delete() && file.isFile()) |
| throw new IOException("File cannot be deleted: " + file); |
| |
| File dir = file.getParentFile(); |
| for (int i = 0; i < depth; ++i) { |
| if (!dir.delete()) |
| break; // ignore problem here |
| dir = dir.getParentFile(); |
| } |
| } |
| |
| private static class PackedRefList extends RefList<Ref> { |
| static final PackedRefList NO_PACKED_REFS = new PackedRefList(RefList |
| .emptyList(), 0, 0); |
| |
| /** Last length of the packed-refs file when we read it. */ |
| final long lastSize; |
| |
| /** Last modified time of the packed-refs file when we read it. */ |
| final long lastModified; |
| |
| PackedRefList(RefList<Ref> src, long size, long mtime) { |
| super(src); |
| lastSize = size; |
| lastModified = mtime; |
| } |
| } |
| |
| private static LooseSymbolicRef newSymbolicRef(long lastModified, |
| String name, String target) { |
| Ref dst = new ObjectIdRef.Unpeeled(NEW, target, null); |
| return new LooseSymbolicRef(lastModified, name, dst); |
| } |
| |
| private static interface LooseRef extends Ref { |
| long getLastModified(); |
| |
| LooseRef peel(ObjectIdRef newLeaf); |
| } |
| |
| private final static class LoosePeeledTag extends ObjectIdRef.PeeledTag |
| implements LooseRef { |
| private final long lastModified; |
| |
| LoosePeeledTag(long mtime, String refName, ObjectId id, ObjectId p) { |
| super(LOOSE, refName, id, p); |
| this.lastModified = mtime; |
| } |
| |
| public long getLastModified() { |
| return lastModified; |
| } |
| |
| public LooseRef peel(ObjectIdRef newLeaf) { |
| return this; |
| } |
| } |
| |
| private final static class LooseNonTag extends ObjectIdRef.PeeledNonTag |
| implements LooseRef { |
| private final long lastModified; |
| |
| LooseNonTag(long mtime, String refName, ObjectId id) { |
| super(LOOSE, refName, id); |
| this.lastModified = mtime; |
| } |
| |
| public long getLastModified() { |
| return lastModified; |
| } |
| |
| public LooseRef peel(ObjectIdRef newLeaf) { |
| return this; |
| } |
| } |
| |
| private final static class LooseUnpeeled extends ObjectIdRef.Unpeeled |
| implements LooseRef { |
| private final long lastModified; |
| |
| LooseUnpeeled(long mtime, String refName, ObjectId id) { |
| super(LOOSE, refName, id); |
| this.lastModified = mtime; |
| } |
| |
| public long getLastModified() { |
| return lastModified; |
| } |
| |
| public LooseRef peel(ObjectIdRef newLeaf) { |
| if (newLeaf.getPeeledObjectId() != null) |
| return new LoosePeeledTag(lastModified, getName(), |
| getObjectId(), newLeaf.getPeeledObjectId()); |
| else |
| return new LooseNonTag(lastModified, getName(), getObjectId()); |
| } |
| } |
| |
| private final static class LooseSymbolicRef extends SymbolicRef implements |
| LooseRef { |
| private final long lastModified; |
| |
| LooseSymbolicRef(long mtime, String refName, Ref target) { |
| super(refName, target); |
| this.lastModified = mtime; |
| } |
| |
| public long getLastModified() { |
| return lastModified; |
| } |
| |
| public LooseRef peel(ObjectIdRef newLeaf) { |
| // We should never try to peel the symbolic references. |
| throw new UnsupportedOperationException(); |
| } |
| } |
| } |