/**
* Unlock this file and abort this change.
*
* <p>The temporary file (if created) is deleted before returning.
*/
public void unlock() {
final LockFile tmp = myLock;
if (tmp != null) {
myLock = null;
tmp.unlock();
}
}
void writeTo(final OutputStream os) throws IOException {
final MessageDigest foot = Constants.newMessageDigest();
final DigestOutputStream dos = new DigestOutputStream(os, foot);
boolean extended = false;
for (int i = 0; i < entryCnt; i++) extended |= sortedEntries[i].isExtended();
// Write the header.
//
final byte[] tmp = new byte[128];
System.arraycopy(SIG_DIRC, 0, tmp, 0, SIG_DIRC.length);
NB.encodeInt32(tmp, 4, extended ? 3 : 2);
NB.encodeInt32(tmp, 8, entryCnt);
dos.write(tmp, 0, 12);
// Write the individual file entries.
final int smudge_s;
final int smudge_ns;
if (myLock != null) {
// For new files we need to smudge the index entry
// if they have been modified "now". Ideally we'd
// want the timestamp when we're done writing the index,
// so we use the current timestamp as a approximation.
myLock.createCommitSnapshot();
snapshot = myLock.getCommitSnapshot();
smudge_s = (int) (snapshot.lastModified() / 1000);
smudge_ns = ((int) (snapshot.lastModified() % 1000)) * 1000000;
} else {
// Used in unit tests only
smudge_ns = 0;
smudge_s = 0;
}
// Check if tree is non-null here since calling updateSmudgedEntries
// will automatically build it via creating a DirCacheIterator
final boolean writeTree = tree != null;
if (repository != null && entryCnt > 0) updateSmudgedEntries();
for (int i = 0; i < entryCnt; i++) {
final DirCacheEntry e = sortedEntries[i];
if (e.mightBeRacilyClean(smudge_s, smudge_ns)) e.smudgeRacilyClean();
e.write(dos);
}
if (writeTree) {
final TemporaryBuffer bb = new TemporaryBuffer.LocalFile();
tree.write(tmp, bb);
bb.close();
NB.encodeInt32(tmp, 0, EXT_TREE);
NB.encodeInt32(tmp, 4, (int) bb.length());
dos.write(tmp, 0, 8);
bb.writeTo(dos, null);
}
writeIndexChecksum = foot.digest();
os.write(writeIndexChecksum);
os.close();
}
/**
* Commit this change and release the lock.
*
* <p>If this method fails (returns false) the lock is still released.
*
* @return true if the commit was successful and the file contains the new data; false if the
* commit failed and the file remains with the old data.
* @throws IllegalStateException the lock is not held.
*/
public boolean commit() {
final LockFile tmp = myLock;
requireLocked(tmp);
myLock = null;
if (!tmp.commit()) return false;
snapshot = tmp.getCommitSnapshot();
if (indexChangedListener != null && !Arrays.equals(readIndexChecksum, writeIndexChecksum))
indexChangedListener.onIndexChanged(new IndexChangedEvent());
return true;
}
/**
* Try to establish an update lock on the cache file.
*
* @return true if the lock is now held by the caller; false if it is held by someone else.
* @throws IOException the output file could not be created. The caller does not hold the lock.
*/
public boolean lock() throws IOException {
if (liveFile == null) throw new IOException(JGitText.get().dirCacheDoesNotHaveABackingFile);
final LockFile tmp = new LockFile(liveFile, fs);
if (tmp.lock()) {
tmp.setNeedStatInformation(true);
myLock = tmp;
return true;
}
return false;
}
/**
* Write the entry records from memory to disk.
*
* <p>The cache must be locked first by calling {@link #lock()} and receiving true as the return
* value. Applications are encouraged to lock the index, then invoke {@link #read()} to ensure the
* in-memory data is current, prior to updating the in-memory entries.
*
* <p>Once written the lock is closed and must be either committed with {@link #commit()} or
* rolled back with {@link #unlock()}.
*
* @throws IOException the output file could not be created. The caller no longer holds the lock.
*/
public void write() throws IOException {
final LockFile tmp = myLock;
requireLocked(tmp);
try {
writeTo(new SafeBufferedOutputStream(tmp.getOutputStream()));
} catch (IOException err) {
tmp.unlock();
throw err;
} catch (RuntimeException err) {
tmp.unlock();
throw err;
} catch (Error err) {
tmp.unlock();
throw err;
}
}
/**
* Save the configuration as a Git text style configuration file.
*
* <p><b>Warning:</b> Although this method uses the traditional Git file locking approach to
* protect against concurrent writes of the configuration file, it does not ensure that the file
* has not been modified since the last read, which means updates performed by other objects
* accessing the same backing file may be lost.
*
* @throws IOException the file could not be written.
*/
public void save() throws IOException {
final byte[] out;
final String text = toText();
if (utf8Bom) {
final ByteArrayOutputStream bos = new ByteArrayOutputStream();
bos.write(0xEF);
bos.write(0xBB);
bos.write(0xBF);
bos.write(text.getBytes(RawParseUtils.UTF8_CHARSET.name()));
out = bos.toByteArray();
} else {
out = Constants.encode(text);
}
final LockFile lf = new LockFile(getFile(), fs);
if (!lf.lock()) throw new LockFailedException(getFile());
try {
lf.setNeedSnapshot(true);
lf.write(out);
if (!lf.commit())
throw new IOException(MessageFormat.format(JGitText.get().cannotCommitWriteTo, getFile()));
} finally {
lf.unlock();
}
snapshot = lf.getCommitSnapshot();
hash = hash(out);
// notify the listeners
fireConfigChangedEvent();
}
