DirCache.java
/*
* Copyright (C) 2008, 2010, Google Inc.
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
* Copyright (C) 2011, 2020, Matthias Sohn <matthias.sohn@sap.com> and others
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Distribution License v. 1.0 which is available at
* https://www.eclipse.org/org/documents/edl-v10.php.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
package org.eclipse.jgit.dircache;
import static java.nio.charset.StandardCharsets.ISO_8859_1;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.EOFException;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.DigestOutputStream;
import java.security.MessageDigest;
import java.text.MessageFormat;
import java.time.Instant;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import org.eclipse.jgit.errors.CorruptObjectException;
import org.eclipse.jgit.errors.IndexReadException;
import org.eclipse.jgit.errors.LockFailedException;
import org.eclipse.jgit.errors.UnmergedPathException;
import org.eclipse.jgit.events.IndexChangedEvent;
import org.eclipse.jgit.events.IndexChangedListener;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.internal.storage.file.FileSnapshot;
import org.eclipse.jgit.internal.storage.file.LockFile;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.Config.ConfigEnum;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ObjectInserter;
import org.eclipse.jgit.lib.ObjectReader;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.treewalk.FileTreeIterator;
import org.eclipse.jgit.treewalk.TreeWalk;
import org.eclipse.jgit.treewalk.TreeWalk.OperationType;
import org.eclipse.jgit.treewalk.filter.PathFilterGroup;
import org.eclipse.jgit.util.FS;
import org.eclipse.jgit.util.IO;
import org.eclipse.jgit.util.MutableInteger;
import org.eclipse.jgit.util.NB;
import org.eclipse.jgit.util.TemporaryBuffer;
import org.eclipse.jgit.util.io.SilentFileInputStream;
/**
* Support for the Git dircache (aka index file).
* <p>
* The index file keeps track of which objects are currently checked out in the
* working directory, and the last modified time of those working files. Changes
* in the working directory can be detected by comparing the modification times
* to the cached modification time within the index file.
* <p>
* Index files are also used during merges, where the merge happens within the
* index file first, and the working directory is updated as a post-merge step.
* Conflicts are stored in the index file to allow tool (and human) based
* resolutions to be easily performed.
*/
public class DirCache {
private static final byte[] SIG_DIRC = { 'D', 'I', 'R', 'C' };
private static final int EXT_TREE = 0x54524545 /* 'TREE' */;
private static final DirCacheEntry[] NO_ENTRIES = {};
private static final byte[] NO_CHECKSUM = {};
static final Comparator<DirCacheEntry> ENT_CMP = (DirCacheEntry o1,
DirCacheEntry o2) -> {
final int cr = cmp(o1, o2);
if (cr != 0)
return cr;
return o1.getStage() - o2.getStage();
};
static int cmp(DirCacheEntry a, DirCacheEntry b) {
return cmp(a.path, a.path.length, b);
}
static int cmp(byte[] aPath, int aLen, DirCacheEntry b) {
return cmp(aPath, aLen, b.path, b.path.length);
}
static int cmp(final byte[] aPath, final int aLen, final byte[] bPath,
final int bLen) {
for (int cPos = 0; cPos < aLen && cPos < bLen; cPos++) {
final int cmp = (aPath[cPos] & 0xff) - (bPath[cPos] & 0xff);
if (cmp != 0)
return cmp;
}
return aLen - bLen;
}
/**
* Create a new empty index which is never stored on disk.
*
* @return an empty cache which has no backing store file. The cache may not
* be read or written, but it may be queried and updated (in
* memory).
*/
public static DirCache newInCore() {
return new DirCache(null, null);
}
/**
* Create a new in memory index read from the contents of a tree.
*
* @param reader
* reader to access the tree objects from a repository.
* @param treeId
* tree to read. Must identify a tree, not a tree-ish.
* @return a new cache which has no backing store file, but contains the
* contents of {@code treeId}.
* @throws java.io.IOException
* one or more trees not available from the ObjectReader.
* @since 4.2
*/
public static DirCache read(ObjectReader reader, AnyObjectId treeId)
throws IOException {
DirCache d = newInCore();
DirCacheBuilder b = d.builder();
b.addTree(null, DirCacheEntry.STAGE_0, reader, treeId);
b.finish();
return d;
}
/**
* Create a new in-core index representation and read an index from disk.
* <p>
* The new index will be read before it is returned to the caller. Read
* failures are reported as exceptions and therefore prevent the method from
* returning a partially populated index.
*
* @param repository
* repository containing the index to read
* @return a cache representing the contents of the specified index file (if
* it exists) or an empty cache if the file does not exist.
* @throws java.io.IOException
* the index file is present but could not be read.
* @throws org.eclipse.jgit.errors.CorruptObjectException
* the index file is using a format or extension that this
* library does not support.
*/
public static DirCache read(Repository repository)
throws CorruptObjectException, IOException {
final DirCache c = read(repository.getIndexFile(), repository.getFS());
c.repository = repository;
return c;
}
/**
* Create a new in-core index representation and read an index from disk.
* <p>
* The new index will be read before it is returned to the caller. Read
* failures are reported as exceptions and therefore prevent the method from
* returning a partially populated index.
*
* @param indexLocation
* location of the index file on disk.
* @param fs
* the file system abstraction which will be necessary to perform
* certain file system operations.
* @return a cache representing the contents of the specified index file (if
* it exists) or an empty cache if the file does not exist.
* @throws java.io.IOException
* the index file is present but could not be read.
* @throws org.eclipse.jgit.errors.CorruptObjectException
* the index file is using a format or extension that this
* library does not support.
*/
public static DirCache read(File indexLocation, FS fs)
throws CorruptObjectException, IOException {
final DirCache c = new DirCache(indexLocation, fs);
c.read();
return c;
}
/**
* Create a new in-core index representation, lock it, and read from disk.
* <p>
* The new index will be locked and then read before it is returned to the
* caller. Read failures are reported as exceptions and therefore prevent
* the method from returning a partially populated index. On read failure,
* the lock is released.
*
* @param indexLocation
* location of the index file on disk.
* @param fs
* the file system abstraction which will be necessary to perform
* certain file system operations.
* @return a cache representing the contents of the specified index file (if
* it exists) or an empty cache if the file does not exist.
* @throws java.io.IOException
* the index file is present but could not be read, or the lock
* could not be obtained.
* @throws org.eclipse.jgit.errors.CorruptObjectException
* the index file is using a format or extension that this
* library does not support.
*/
public static DirCache lock(File indexLocation, FS fs)
throws CorruptObjectException, IOException {
final DirCache c = new DirCache(indexLocation, fs);
if (!c.lock())
throw new LockFailedException(indexLocation);
try {
c.read();
} catch (IOException | RuntimeException | Error e) {
c.unlock();
throw e;
}
return c;
}
/**
* Create a new in-core index representation, lock it, and read from disk.
* <p>
* The new index will be locked and then read before it is returned to the
* caller. Read failures are reported as exceptions and therefore prevent
* the method from returning a partially populated index. On read failure,
* the lock is released.
*
* @param repository
* repository containing the index to lock and read
* @param indexChangedListener
* listener to be informed when DirCache is committed
* @return a cache representing the contents of the specified index file (if
* it exists) or an empty cache if the file does not exist.
* @throws java.io.IOException
* the index file is present but could not be read, or the lock
* could not be obtained.
* @throws org.eclipse.jgit.errors.CorruptObjectException
* the index file is using a format or extension that this
* library does not support.
* @since 2.0
*/
public static DirCache lock(final Repository repository,
final IndexChangedListener indexChangedListener)
throws CorruptObjectException, IOException {
DirCache c = lock(repository.getIndexFile(), repository.getFS(),
indexChangedListener);
c.repository = repository;
return c;
}
/**
* Create a new in-core index representation, lock it, and read from disk.
* <p>
* The new index will be locked and then read before it is returned to the
* caller. Read failures are reported as exceptions and therefore prevent
* the method from returning a partially populated index. On read failure,
* the lock is released.
*
* @param indexLocation
* location of the index file on disk.
* @param fs
* the file system abstraction which will be necessary to perform
* certain file system operations.
* @param indexChangedListener
* listener to be informed when DirCache is committed
* @return a cache representing the contents of the specified index file (if
* it exists) or an empty cache if the file does not exist.
* @throws java.io.IOException
* the index file is present but could not be read, or the lock
* could not be obtained.
* @throws org.eclipse.jgit.errors.CorruptObjectException
* the index file is using a format or extension that this
* library does not support.
*/
public static DirCache lock(final File indexLocation, final FS fs,
IndexChangedListener indexChangedListener)
throws CorruptObjectException,
IOException {
DirCache c = lock(indexLocation, fs);
c.registerIndexChangedListener(indexChangedListener);
return c;
}
/** Location of the current version of the index file. */
private final File liveFile;
/** Individual file index entries, sorted by path name. */
private DirCacheEntry[] sortedEntries;
/** Number of positions within {@link #sortedEntries} that are valid. */
private int entryCnt;
/** Cache tree for this index; null if the cache tree is not available. */
private DirCacheTree tree;
/** Our active lock (if we hold it); null if we don't have it locked. */
private LockFile myLock;
/** Keep track of whether the index has changed or not */
private FileSnapshot snapshot;
/** index checksum when index was read from disk */
private byte[] readIndexChecksum;
/** index checksum when index was written to disk */
private byte[] writeIndexChecksum;
/** listener to be informed on commit */
private IndexChangedListener indexChangedListener;
/** Repository containing this index */
private Repository repository;
/** If we read this index from disk, the original format. */
private DirCacheVersion version;
/**
* Create a new in-core index representation.
* <p>
* The new index will be empty. Callers may wish to read from the on disk
* file first with {@link #read()}.
*
* @param indexLocation
* location of the index file on disk.
* @param fs
* the file system abstraction which will be necessary to perform
* certain file system operations.
*/
public DirCache(File indexLocation, FS fs) {
liveFile = indexLocation;
clear();
}
/**
* Create a new builder to update this cache.
* <p>
* Callers should add all entries to the builder, then use
* {@link org.eclipse.jgit.dircache.DirCacheBuilder#finish()} to update this
* instance.
*
* @return a new builder instance for this cache.
*/
public DirCacheBuilder builder() {
return new DirCacheBuilder(this, entryCnt + 16);
}
/**
* Create a new editor to recreate this cache.
* <p>
* Callers should add commands to the editor, then use
* {@link org.eclipse.jgit.dircache.DirCacheEditor#finish()} to update this
* instance.
*
* @return a new builder instance for this cache.
*/
public DirCacheEditor editor() {
return new DirCacheEditor(this, entryCnt + 16);
}
DirCacheVersion getVersion() {
return version;
}
void replace(DirCacheEntry[] e, int cnt) {
sortedEntries = e;
entryCnt = cnt;
tree = null;
}
/**
* Read the index from disk, if it has changed on disk.
* <p>
* This method tries to avoid loading the index if it has not changed since
* the last time we consulted it. A missing index file will be treated as
* though it were present but had no file entries in it.
*
* @throws java.io.IOException
* the index file is present but could not be read. This
* DirCache instance may not be populated correctly.
* @throws org.eclipse.jgit.errors.CorruptObjectException
* the index file is using a format or extension that this
* library does not support.
*/
public void read() throws IOException, CorruptObjectException {
if (liveFile == null)
throw new IOException(JGitText.get().dirCacheDoesNotHaveABackingFile);
if (!liveFile.exists())
clear();
else if (snapshot == null || snapshot.isModified(liveFile)) {
try (SilentFileInputStream inStream = new SilentFileInputStream(
liveFile)) {
clear();
readFrom(inStream);
} catch (FileNotFoundException fnfe) {
if (liveFile.exists()) {
// Panic: the index file exists but we can't read it
throw new IndexReadException(
MessageFormat.format(JGitText.get().cannotReadIndex,
liveFile.getAbsolutePath(), fnfe));
}
// Someone must have deleted it between our exists test
// and actually opening the path. That's fine, its empty.
//
clear();
}
snapshot = FileSnapshot.save(liveFile);
}
}
/**
* Whether the memory state differs from the index file
*
* @return {@code true} if the memory state differs from the index file
* @throws java.io.IOException
*/
public boolean isOutdated() throws IOException {
if (liveFile == null || !liveFile.exists())
return false;
return snapshot == null || snapshot.isModified(liveFile);
}
/**
* Empty this index, removing all entries.
*/
public void clear() {
snapshot = null;
sortedEntries = NO_ENTRIES;
entryCnt = 0;
tree = null;
readIndexChecksum = NO_CHECKSUM;
}
private void readFrom(InputStream inStream) throws IOException,
CorruptObjectException {
final BufferedInputStream in = new BufferedInputStream(inStream);
final MessageDigest md = Constants.newMessageDigest();
// Read the index header and verify we understand it.
//
final byte[] hdr = new byte[20];
IO.readFully(in, hdr, 0, 12);
md.update(hdr, 0, 12);
if (!is_DIRC(hdr))
throw new CorruptObjectException(JGitText.get().notADIRCFile);
int versionCode = NB.decodeInt32(hdr, 4);
DirCacheVersion ver = DirCacheVersion.fromInt(versionCode);
if (ver == null) {
throw new CorruptObjectException(
MessageFormat.format(JGitText.get().unknownDIRCVersion,
Integer.valueOf(versionCode)));
}
boolean extended = false;
switch (ver) {
case DIRC_VERSION_MINIMUM:
break;
case DIRC_VERSION_EXTENDED:
case DIRC_VERSION_PATHCOMPRESS:
extended = true;
break;
default:
throw new CorruptObjectException(MessageFormat
.format(JGitText.get().unknownDIRCVersion, ver));
}
version = ver;
entryCnt = NB.decodeInt32(hdr, 8);
if (entryCnt < 0)
throw new CorruptObjectException(JGitText.get().DIRCHasTooManyEntries);
snapshot = FileSnapshot.save(liveFile);
Instant smudge = snapshot.lastModifiedInstant();
// Load the individual file entries.
//
final int infoLength = DirCacheEntry.getMaximumInfoLength(extended);
final byte[] infos = new byte[infoLength * entryCnt];
sortedEntries = new DirCacheEntry[entryCnt];
final MutableInteger infoAt = new MutableInteger();
for (int i = 0; i < entryCnt; i++) {
sortedEntries[i] = new DirCacheEntry(infos, infoAt, in, md, smudge,
version, i == 0 ? null : sortedEntries[i - 1]);
}
// After the file entries are index extensions, and then a footer.
//
for (;;) {
in.mark(21);
IO.readFully(in, hdr, 0, 20);
if (in.read() < 0) {
// No extensions present; the file ended where we expected.
//
break;
}
in.reset();
md.update(hdr, 0, 8);
IO.skipFully(in, 8);
long sz = NB.decodeUInt32(hdr, 4);
switch (NB.decodeInt32(hdr, 0)) {
case EXT_TREE: {
if (Integer.MAX_VALUE < sz) {
throw new CorruptObjectException(MessageFormat.format(
JGitText.get().DIRCExtensionIsTooLargeAt,
formatExtensionName(hdr), Long.valueOf(sz)));
}
final byte[] raw = new byte[(int) sz];
IO.readFully(in, raw, 0, raw.length);
md.update(raw, 0, raw.length);
tree = new DirCacheTree(raw, new MutableInteger(), null);
break;
}
default:
if (hdr[0] >= 'A' && hdr[0] <= 'Z') {
// The extension is optional and is here only as
// a performance optimization. Since we do not
// understand it, we can safely skip past it, after
// we include its data in our checksum.
//
skipOptionalExtension(in, md, hdr, sz);
} else {
// The extension is not an optimization and is
// _required_ to understand this index format.
// Since we did not trap it above we must abort.
//
throw new CorruptObjectException(MessageFormat.format(JGitText.get().DIRCExtensionNotSupportedByThisVersion
, formatExtensionName(hdr)));
}
}
}
readIndexChecksum = md.digest();
if (!Arrays.equals(readIndexChecksum, hdr)) {
throw new CorruptObjectException(JGitText.get().DIRCChecksumMismatch);
}
}
private void skipOptionalExtension(final InputStream in,
final MessageDigest md, final byte[] hdr, long sz)
throws IOException {
final byte[] b = new byte[4096];
while (0 < sz) {
int n = in.read(b, 0, (int) Math.min(b.length, sz));
if (n < 0) {
throw new EOFException(
MessageFormat.format(
JGitText.get().shortReadOfOptionalDIRCExtensionExpectedAnotherBytes,
formatExtensionName(hdr), Long.valueOf(sz)));
}
md.update(b, 0, n);
sz -= n;
}
}
private static String formatExtensionName(byte[] hdr) {
return "'" + new String(hdr, 0, 4, ISO_8859_1) + "'"; //$NON-NLS-1$ //$NON-NLS-2$
}
private static boolean is_DIRC(byte[] hdr) {
if (hdr.length < SIG_DIRC.length)
return false;
for (int i = 0; i < SIG_DIRC.length; i++)
if (hdr[i] != SIG_DIRC[i])
return false;
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 java.io.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);
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 java.io.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 (OutputStream o = tmp.getOutputStream();
OutputStream bo = new BufferedOutputStream(o)) {
writeTo(liveFile.getParentFile(), bo);
} catch (IOException | RuntimeException | Error err) {
tmp.unlock();
throw err;
}
}
void writeTo(File dir, OutputStream os) throws IOException {
final MessageDigest foot = Constants.newMessageDigest();
final DigestOutputStream dos = new DigestOutputStream(os, foot);
if (version == null && this.repository != null) {
// A new DirCache is being written.
DirCacheConfig config = repository.getConfig()
.get(DirCacheConfig::new);
version = config.getIndexVersion();
}
if (version == null
|| version == DirCacheVersion.DIRC_VERSION_MINIMUM) {
version = DirCacheVersion.DIRC_VERSION_MINIMUM;
for (int i = 0; i < entryCnt; i++) {
if (sortedEntries[i].isExtended()) {
version = DirCacheVersion.DIRC_VERSION_EXTENDED;
break;
}
}
}
// Write the header.
//
final byte[] tmp = new byte[128];
System.arraycopy(SIG_DIRC, 0, tmp, 0, SIG_DIRC.length);
NB.encodeInt32(tmp, 4, version.getVersionCode());
NB.encodeInt32(tmp, 8, entryCnt);
dos.write(tmp, 0, 12);
// Write the individual file entries.
Instant smudge;
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 = snapshot.lastModifiedInstant();
} else {
// Used in unit tests only
smudge = Instant.EPOCH;
}
// 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)) {
e.smudgeRacilyClean();
}
e.write(dos, version, i == 0 ? null : sortedEntries[i - 1]);
}
if (writeTree) {
@SuppressWarnings("resource") // Explicitly closed in try block, and
// destroyed in finally
TemporaryBuffer bb = new TemporaryBuffer.LocalFile(dir, 5 << 20);
try {
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);
} finally {
bb.destroy();
}
}
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 java.lang.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(true));
}
return true;
}
private void requireLocked(LockFile tmp) {
if (liveFile == null)
throw new IllegalStateException(JGitText.get().dirCacheIsNotLocked);
if (tmp == null)
throw new IllegalStateException(MessageFormat.format(JGitText.get().dirCacheFileIsNotLocked
, liveFile.getAbsolutePath()));
}
/**
* 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();
}
}
/**
* Locate the position a path's entry is at in the index. For details refer
* to #findEntry(byte[], int).
*
* @param path
* the path to search for.
* @return if >= 0 then the return value is the position of the entry in
* the index; pass to {@link #getEntry(int)} to obtain the entry
* information. If < 0 the entry does not exist in the index.
*/
public int findEntry(String path) {
final byte[] p = Constants.encode(path);
return findEntry(p, p.length);
}
/**
* Locate the position a path's entry is at in the index.
* <p>
* If there is at least one entry in the index for this path the position of
* the lowest stage is returned. Subsequent stages can be identified by
* testing consecutive entries until the path differs.
* <p>
* If no path matches the entry -(position+1) is returned, where position is
* the location it would have gone within the index.
*
* @param p
* the byte array starting with the path to search for.
* @param pLen
* the length of the path in bytes
* @return if >= 0 then the return value is the position of the entry in
* the index; pass to {@link #getEntry(int)} to obtain the entry
* information. If < 0 the entry does not exist in the index.
* @since 3.4
*/
public int findEntry(byte[] p, int pLen) {
return findEntry(0, p, pLen);
}
int findEntry(int low, byte[] p, int pLen) {
int high = entryCnt;
while (low < high) {
int mid = (low + high) >>> 1;
final int cmp = cmp(p, pLen, sortedEntries[mid]);
if (cmp < 0)
high = mid;
else if (cmp == 0) {
while (mid > 0 && cmp(p, pLen, sortedEntries[mid - 1]) == 0)
mid--;
return mid;
} else
low = mid + 1;
}
return -(low + 1);
}
/**
* Determine the next index position past all entries with the same name.
* <p>
* As index entries are sorted by path name, then stage number, this method
* advances the supplied position to the first position in the index whose
* path name does not match the path name of the supplied position's entry.
*
* @param position
* entry position of the path that should be skipped.
* @return position of the next entry whose path is after the input.
*/
public int nextEntry(int position) {
DirCacheEntry last = sortedEntries[position];
int nextIdx = position + 1;
while (nextIdx < entryCnt) {
final DirCacheEntry next = sortedEntries[nextIdx];
if (cmp(last, next) != 0)
break;
last = next;
nextIdx++;
}
return nextIdx;
}
int nextEntry(byte[] p, int pLen, int nextIdx) {
while (nextIdx < entryCnt) {
final DirCacheEntry next = sortedEntries[nextIdx];
if (!DirCacheTree.peq(p, next.path, pLen))
break;
nextIdx++;
}
return nextIdx;
}
/**
* Total number of file entries stored in the index.
* <p>
* This count includes unmerged stages for a file entry if the file is
* currently conflicted in a merge. This means the total number of entries
* in the index may be up to 3 times larger than the number of files in the
* working directory.
* <p>
* Note that this value counts only <i>files</i>.
*
* @return number of entries available.
* @see #getEntry(int)
*/
public int getEntryCount() {
return entryCnt;
}
/**
* Get a specific entry.
*
* @param i
* position of the entry to get.
* @return the entry at position <code>i</code>.
*/
public DirCacheEntry getEntry(int i) {
return sortedEntries[i];
}
/**
* Get a specific entry.
*
* @param path
* the path to search for.
* @return the entry for the given <code>path</code>.
*/
public DirCacheEntry getEntry(String path) {
final int i = findEntry(path);
return i < 0 ? null : sortedEntries[i];
}
/**
* Recursively get all entries within a subtree.
*
* @param path
* the subtree path to get all entries within.
* @return all entries recursively contained within the subtree.
*/
public DirCacheEntry[] getEntriesWithin(String path) {
if (path.length() == 0) {
DirCacheEntry[] r = new DirCacheEntry[entryCnt];
System.arraycopy(sortedEntries, 0, r, 0, entryCnt);
return r;
}
if (!path.endsWith("/")) //$NON-NLS-1$
path += "/"; //$NON-NLS-1$
final byte[] p = Constants.encode(path);
final int pLen = p.length;
int eIdx = findEntry(p, pLen);
if (eIdx < 0)
eIdx = -(eIdx + 1);
final int lastIdx = nextEntry(p, pLen, eIdx);
final DirCacheEntry[] r = new DirCacheEntry[lastIdx - eIdx];
System.arraycopy(sortedEntries, eIdx, r, 0, r.length);
return r;
}
void toArray(final int i, final DirCacheEntry[] dst, final int off,
final int cnt) {
System.arraycopy(sortedEntries, i, dst, off, cnt);
}
/**
* Obtain (or build) the current cache tree structure.
* <p>
* This method can optionally recreate the cache tree, without flushing the
* tree objects themselves to disk.
*
* @param build
* if true and the cache tree is not present in the index it will
* be generated and returned to the caller.
* @return the cache tree; null if there is no current cache tree available
* and <code>build</code> was false.
*/
public DirCacheTree getCacheTree(boolean build) {
if (build) {
if (tree == null)
tree = new DirCacheTree();
tree.validate(sortedEntries, entryCnt, 0, 0);
}
return tree;
}
/**
* Write all index trees to the object store, returning the root tree.
*
* @param ow
* the writer to use when serializing to the store. The caller is
* responsible for flushing the inserter before trying to use the
* returned tree identity.
* @return identity for the root tree.
* @throws org.eclipse.jgit.errors.UnmergedPathException
* one or more paths contain higher-order stages (stage > 0),
* which cannot be stored in a tree object.
* @throws java.lang.IllegalStateException
* one or more paths contain an invalid mode which should never
* appear in a tree object.
* @throws java.io.IOException
* an unexpected error occurred writing to the object store.
*/
public ObjectId writeTree(ObjectInserter ow)
throws UnmergedPathException, IOException {
return getCacheTree(true).writeTree(sortedEntries, 0, 0, ow);
}
/**
* Tells whether this index contains unmerged paths.
*
* @return {@code true} if this index contains unmerged paths. Means: at
* least one entry is of a stage different from 0. {@code false}
* will be returned if all entries are of stage 0.
*/
public boolean hasUnmergedPaths() {
for (int i = 0; i < entryCnt; i++) {
if (sortedEntries[i].getStage() > 0) {
return true;
}
}
return false;
}
private void registerIndexChangedListener(IndexChangedListener listener) {
this.indexChangedListener = listener;
}
/**
* Update any smudged entries with information from the working tree.
*
* @throws IOException
*/
private void updateSmudgedEntries() throws IOException {
List<String> paths = new ArrayList<>(128);
try (TreeWalk walk = new TreeWalk(repository)) {
walk.setOperationType(OperationType.CHECKIN_OP);
for (int i = 0; i < entryCnt; i++)
if (sortedEntries[i].isSmudged())
paths.add(sortedEntries[i].getPathString());
if (paths.isEmpty())
return;
walk.setFilter(PathFilterGroup.createFromStrings(paths));
DirCacheIterator iIter = new DirCacheIterator(this);
FileTreeIterator fIter = new FileTreeIterator(repository);
walk.addTree(iIter);
walk.addTree(fIter);
fIter.setDirCacheIterator(walk, 0);
walk.setRecursive(true);
while (walk.next()) {
iIter = walk.getTree(0, DirCacheIterator.class);
if (iIter == null)
continue;
fIter = walk.getTree(1, FileTreeIterator.class);
if (fIter == null)
continue;
DirCacheEntry entry = iIter.getDirCacheEntry();
if (entry.isSmudged() && iIter.idEqual(fIter)) {
entry.setLength(fIter.getEntryLength());
entry.setLastModified(fIter.getEntryLastModifiedInstant());
}
}
}
}
enum DirCacheVersion implements ConfigEnum {
/** Minimum index version on-disk format that we support. */
DIRC_VERSION_MINIMUM(2),
/** Version 3 supports extended flags. */
DIRC_VERSION_EXTENDED(3),
/**
* Version 4 adds very simple "path compression": it strips out the
* common prefix between the last entry written and the current entry.
* Instead of writing two entries with paths "foo/bar/baz/a.txt" and
* "foo/bar/baz/b.txt" it only writes "b.txt" for the second entry.
* <p>
* It is also <em>not</em> padded.
* </p>
*/
DIRC_VERSION_PATHCOMPRESS(4);
private final int version;
private DirCacheVersion(int versionCode) {
this.version = versionCode;
}
public int getVersionCode() {
return version;
}
@Override
public String toConfigValue() {
return Integer.toString(version);
}
@Override
public boolean matchConfigValue(String in) {
try {
return version == Integer.parseInt(in);
} catch (NumberFormatException e) {
return false;
}
}
public static DirCacheVersion fromInt(int val) {
for (DirCacheVersion v : DirCacheVersion.values()) {
if (val == v.getVersionCode()) {
return v;
}
}
return null;
}
}
private static class DirCacheConfig {
private final DirCacheVersion indexVersion;
public DirCacheConfig(Config cfg) {
boolean manyFiles = cfg.getBoolean(
ConfigConstants.CONFIG_FEATURE_SECTION,
ConfigConstants.CONFIG_KEY_MANYFILES, false);
indexVersion = cfg.getEnum(DirCacheVersion.values(),
ConfigConstants.CONFIG_INDEX_SECTION, null,
ConfigConstants.CONFIG_KEY_VERSION,
manyFiles ? DirCacheVersion.DIRC_VERSION_PATHCOMPRESS
: DirCacheVersion.DIRC_VERSION_EXTENDED);
}
public DirCacheVersion getIndexVersion() {
return indexVersion;
}
}
}