FS.java
/*
* Copyright (C) 2008, 2020 Shawn O. Pearce <spearce@spearce.org> 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.util;
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.time.Instant.EPOCH;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.file.AccessDeniedException;
import java.nio.file.FileStore;
import java.nio.file.Files;
import java.nio.file.InvalidPathException;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;
import java.nio.file.attribute.FileTime;
import java.security.AccessControlException;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.text.MessageFormat;
import java.time.Duration;
import java.time.Instant;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;
import java.util.UUID;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.eclipse.jgit.annotations.NonNull;
import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.api.errors.JGitInternalException;
import org.eclipse.jgit.errors.CommandFailedException;
import org.eclipse.jgit.errors.ConfigInvalidException;
import org.eclipse.jgit.errors.LockFailedException;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.internal.storage.file.FileSnapshot;
import org.eclipse.jgit.lib.Config;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.lib.StoredConfig;
import org.eclipse.jgit.treewalk.FileTreeIterator.FileEntry;
import org.eclipse.jgit.treewalk.FileTreeIterator.FileModeStrategy;
import org.eclipse.jgit.treewalk.WorkingTreeIterator.Entry;
import org.eclipse.jgit.util.ProcessResult.Status;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Abstraction to support various file system operations not in Java.
*/
public abstract class FS {
private static final Logger LOG = LoggerFactory.getLogger(FS.class);
/**
* An empty array of entries, suitable as a return value for
* {@link #list(File, FileModeStrategy)}.
*
* @since 5.0
*/
protected static final Entry[] NO_ENTRIES = {};
private static final Pattern VERSION = Pattern
.compile("\\s(\\d+)\\.(\\d+)\\.(\\d+)"); //$NON-NLS-1$
private volatile Boolean supportSymlinks;
/**
* This class creates FS instances. It will be overridden by a Java7 variant
* if such can be detected in {@link #detect(Boolean)}.
*
* @since 3.0
*/
public static class FSFactory {
/**
* Constructor
*/
protected FSFactory() {
// empty
}
/**
* Detect the file system
*
* @param cygwinUsed
* @return FS instance
*/
public FS detect(Boolean cygwinUsed) {
if (SystemReader.getInstance().isWindows()) {
if (cygwinUsed == null) {
cygwinUsed = Boolean.valueOf(FS_Win32_Cygwin.isCygwin());
}
if (cygwinUsed.booleanValue()) {
return new FS_Win32_Cygwin();
}
return new FS_Win32();
}
return new FS_POSIX();
}
}
/**
* Result of an executed process. The caller is responsible to close the
* contained {@link TemporaryBuffer}s
*
* @since 4.2
*/
public static class ExecutionResult {
private TemporaryBuffer stdout;
private TemporaryBuffer stderr;
private int rc;
/**
* @param stdout
* @param stderr
* @param rc
*/
public ExecutionResult(TemporaryBuffer stdout, TemporaryBuffer stderr,
int rc) {
this.stdout = stdout;
this.stderr = stderr;
this.rc = rc;
}
/**
* @return buffered standard output stream
*/
public TemporaryBuffer getStdout() {
return stdout;
}
/**
* @return buffered standard error stream
*/
public TemporaryBuffer getStderr() {
return stderr;
}
/**
* @return the return code of the process
*/
public int getRc() {
return rc;
}
}
/**
* Attributes of FileStores on this system
*
* @since 5.1.9
*/
public static final class FileStoreAttributes {
/**
* Marker to detect undefined values when reading from the config file.
*/
private static final Duration UNDEFINED_DURATION = Duration
.ofNanos(Long.MAX_VALUE);
/**
* Fallback filesystem timestamp resolution. The worst case timestamp
* resolution on FAT filesystems is 2 seconds.
* <p>
* Must be at least 1 second.
* </p>
*/
public static final Duration FALLBACK_TIMESTAMP_RESOLUTION = Duration
.ofMillis(2000);
/**
* Fallback FileStore attributes used when we can't measure the
* filesystem timestamp resolution. The last modified time granularity
* of FAT filesystems is 2 seconds.
*/
public static final FileStoreAttributes FALLBACK_FILESTORE_ATTRIBUTES = new FileStoreAttributes(
FALLBACK_TIMESTAMP_RESOLUTION);
private static final long ONE_MICROSECOND = TimeUnit.MICROSECONDS
.toNanos(1);
private static final long ONE_MILLISECOND = TimeUnit.MILLISECONDS
.toNanos(1);
private static final long ONE_SECOND = TimeUnit.SECONDS.toNanos(1);
/**
* Minimum file system timestamp resolution granularity to check, in
* nanoseconds. Should be a positive power of ten smaller than
* {@link #ONE_SECOND}. Must be strictly greater than zero, i.e.,
* minimum value is 1 nanosecond.
* <p>
* Currently set to 1 microsecond, but could also be lower still.
* </p>
*/
private static final long MINIMUM_RESOLUTION_NANOS = ONE_MICROSECOND;
private static final String JAVA_VERSION_PREFIX = System
.getProperty("java.vendor") + '|' //$NON-NLS-1$
+ System.getProperty("java.version") + '|'; //$NON-NLS-1$
private static final Duration FALLBACK_MIN_RACY_INTERVAL = Duration
.ofMillis(10);
private static final Map<FileStore, FileStoreAttributes> attributeCache = new ConcurrentHashMap<>();
private static final SimpleLruCache<Path, FileStoreAttributes> attrCacheByPath = new SimpleLruCache<>(
100, 0.2f);
private static final AtomicBoolean background = new AtomicBoolean();
private static final Map<FileStore, Lock> locks = new ConcurrentHashMap<>();
private static final AtomicInteger threadNumber = new AtomicInteger(1);
/**
* Don't use the default thread factory of the ForkJoinPool for the
* CompletableFuture; it runs without any privileges, which causes
* trouble if a SecurityManager is present.
* <p>
* Instead use normal daemon threads. They'll belong to the
* SecurityManager's thread group, or use the one of the calling thread,
* as appropriate.
* </p>
*
* @see java.util.concurrent.Executors#newCachedThreadPool()
*/
private static final Executor FUTURE_RUNNER = new ThreadPoolExecutor(0,
5, 30L, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>(),
runnable -> {
Thread t = new Thread(runnable,
"JGit-FileStoreAttributeReader-" //$NON-NLS-1$
+ threadNumber.getAndIncrement());
// Make sure these threads don't prevent application/JVM
// shutdown.
t.setDaemon(true);
return t;
});
/**
* Use a separate executor with at most one thread to synchronize
* writing to the config. We write asynchronously since the config
* itself might be on a different file system, which might otherwise
* lead to locking problems.
* <p>
* Writing the config must not use a daemon thread, otherwise we may
* leave an inconsistent state on disk when the JVM shuts down. Use a
* small keep-alive time to avoid delays on shut-down.
* </p>
*/
private static final Executor SAVE_RUNNER = new ThreadPoolExecutor(0, 1,
1L, TimeUnit.MILLISECONDS, new LinkedBlockingQueue<Runnable>(),
runnable -> {
Thread t = new Thread(runnable,
"JGit-FileStoreAttributeWriter-" //$NON-NLS-1$
+ threadNumber.getAndIncrement());
// Make sure these threads do finish
t.setDaemon(false);
return t;
});
/**
* Whether FileStore attributes should be determined asynchronously
*
* @param async
* whether FileStore attributes should be determined
* asynchronously. If false access to cached attributes may
* block for some seconds for the first call per FileStore
* @since 5.6.2
*/
public static void setBackground(boolean async) {
background.set(async);
}
/**
* Configures size and purge factor of the path-based cache for file
* system attributes. Caching of file system attributes avoids recurring
* lookup of @{code FileStore} of files which may be expensive on some
* platforms.
*
* @param maxSize
* maximum size of the cache, default is 100
* @param purgeFactor
* when the size of the map reaches maxSize the oldest
* entries will be purged to free up some space for new
* entries, {@code purgeFactor} is the fraction of
* {@code maxSize} to purge when this happens
* @since 5.1.9
*/
public static void configureAttributesPathCache(int maxSize,
float purgeFactor) {
FileStoreAttributes.attrCacheByPath.configure(maxSize, purgeFactor);
}
/**
* Get the FileStoreAttributes for the given FileStore
*
* @param path
* file residing in the FileStore to get attributes for
* @return FileStoreAttributes for the given path.
*/
public static FileStoreAttributes get(Path path) {
try {
path = path.toAbsolutePath();
Path dir = Files.isDirectory(path) ? path : path.getParent();
if (dir == null) {
return FALLBACK_FILESTORE_ATTRIBUTES;
}
FileStoreAttributes cached = attrCacheByPath.get(dir);
if (cached != null) {
return cached;
}
FileStoreAttributes attrs = getFileStoreAttributes(dir);
if (attrs == null) {
// Don't cache, result might be late
return FALLBACK_FILESTORE_ATTRIBUTES;
}
attrCacheByPath.put(dir, attrs);
return attrs;
} catch (SecurityException e) {
return FALLBACK_FILESTORE_ATTRIBUTES;
}
}
private static FileStoreAttributes getFileStoreAttributes(Path dir) {
FileStore s;
try {
if (Files.exists(dir)) {
s = Files.getFileStore(dir);
FileStoreAttributes c = attributeCache.get(s);
if (c != null) {
return c;
}
if (!Files.isWritable(dir)) {
// cannot measure resolution in a read-only directory
LOG.debug(
"{}: cannot measure timestamp resolution in read-only directory {}", //$NON-NLS-1$
Thread.currentThread(), dir);
return FALLBACK_FILESTORE_ATTRIBUTES;
}
} else {
// cannot determine FileStore of an unborn directory
LOG.debug(
"{}: cannot measure timestamp resolution of unborn directory {}", //$NON-NLS-1$
Thread.currentThread(), dir);
return FALLBACK_FILESTORE_ATTRIBUTES;
}
CompletableFuture<Optional<FileStoreAttributes>> f = CompletableFuture
.supplyAsync(() -> {
Lock lock = locks.computeIfAbsent(s,
l -> new ReentrantLock());
if (!lock.tryLock()) {
LOG.debug(
"{}: couldn't get lock to measure timestamp resolution in {}", //$NON-NLS-1$
Thread.currentThread(), dir);
return Optional.empty();
}
Optional<FileStoreAttributes> attributes = Optional
.empty();
try {
// Some earlier future might have set the value
// and removed itself since we checked for the
// value above. Hence check cache again.
FileStoreAttributes c = attributeCache.get(s);
if (c != null) {
return Optional.of(c);
}
attributes = readFromConfig(s);
if (attributes.isPresent()) {
attributeCache.put(s, attributes.get());
return attributes;
}
Optional<Duration> resolution = measureFsTimestampResolution(
s, dir);
if (resolution.isPresent()) {
c = new FileStoreAttributes(
resolution.get());
attributeCache.put(s, c);
// for high timestamp resolution measure
// minimal racy interval
if (c.fsTimestampResolution
.toNanos() < 100_000_000L) {
c.minimalRacyInterval = measureMinimalRacyInterval(
dir);
}
if (LOG.isDebugEnabled()) {
LOG.debug(c.toString());
}
FileStoreAttributes newAttrs = c;
SAVE_RUNNER.execute(
() -> saveToConfig(s, newAttrs));
}
attributes = Optional.of(c);
} finally {
lock.unlock();
locks.remove(s);
}
return attributes;
}, FUTURE_RUNNER);
f = f.exceptionally(e -> {
LOG.error(e.getLocalizedMessage(), e);
return Optional.empty();
});
// even if measuring in background wait a little - if the result
// arrives, it's better than returning the large fallback
boolean runInBackground = background.get();
Optional<FileStoreAttributes> d = runInBackground ? f.get(
100, TimeUnit.MILLISECONDS) : f.get();
if (d.isPresent()) {
return d.get();
} else if (runInBackground) {
// return null until measurement is finished
return null;
}
// fall through and return fallback
} catch (IOException | InterruptedException
| ExecutionException | CancellationException e) {
LOG.error(e.getMessage(), e);
} catch (TimeoutException | SecurityException e) {
// use fallback
}
LOG.debug("{}: use fallback timestamp resolution for directory {}", //$NON-NLS-1$
Thread.currentThread(), dir);
return FALLBACK_FILESTORE_ATTRIBUTES;
}
@SuppressWarnings("boxing")
private static Duration measureMinimalRacyInterval(Path dir) {
LOG.debug("{}: start measure minimal racy interval in {}", //$NON-NLS-1$
Thread.currentThread(), dir);
int n = 0;
int failures = 0;
long racyNanos = 0;
ArrayList<Long> deltas = new ArrayList<>();
Path probe = dir.resolve(".probe-" + UUID.randomUUID()); //$NON-NLS-1$
Instant end = Instant.now().plusSeconds(3);
try {
Files.createFile(probe);
do {
n++;
write(probe, "a"); //$NON-NLS-1$
FileSnapshot snapshot = FileSnapshot.save(probe.toFile());
read(probe);
write(probe, "b"); //$NON-NLS-1$
if (!snapshot.isModified(probe.toFile())) {
deltas.add(Long.valueOf(snapshot.lastDelta()));
racyNanos = snapshot.lastRacyThreshold();
failures++;
}
} while (Instant.now().compareTo(end) < 0);
} catch (IOException e) {
LOG.error(e.getMessage(), e);
return FALLBACK_MIN_RACY_INTERVAL;
} finally {
deleteProbe(probe);
}
if (failures > 0) {
Stats stats = new Stats();
for (Long d : deltas) {
stats.add(d);
}
LOG.debug(
"delta [ns] since modification FileSnapshot failed to detect\n" //$NON-NLS-1$
+ "count, failures, racy limit [ns], delta min [ns]," //$NON-NLS-1$
+ " delta max [ns], delta avg [ns]," //$NON-NLS-1$
+ " delta stddev [ns]\n" //$NON-NLS-1$
+ "{}, {}, {}, {}, {}, {}, {}", //$NON-NLS-1$
n, failures, racyNanos, stats.min(), stats.max(),
stats.avg(), stats.stddev());
return Duration
.ofNanos(Double.valueOf(stats.max()).longValue());
}
// since no failures occurred using the measured filesystem
// timestamp resolution there is no need for minimal racy interval
LOG.debug("{}: no failures when measuring minimal racy interval", //$NON-NLS-1$
Thread.currentThread());
return Duration.ZERO;
}
private static void write(Path p, String body) throws IOException {
Path parent = p.getParent();
if (parent != null) {
FileUtils.mkdirs(parent.toFile(), true);
}
try (Writer w = new OutputStreamWriter(Files.newOutputStream(p),
UTF_8)) {
w.write(body);
}
}
private static String read(Path p) throws IOException {
byte[] body = IO.readFully(p.toFile());
return new String(body, 0, body.length, UTF_8);
}
private static Optional<Duration> measureFsTimestampResolution(
FileStore s, Path dir) {
if (LOG.isDebugEnabled()) {
LOG.debug("{}: start measure timestamp resolution {} in {}", //$NON-NLS-1$
Thread.currentThread(), s, dir);
}
Path probe = dir.resolve(".probe-" + UUID.randomUUID()); //$NON-NLS-1$
try {
Files.createFile(probe);
Duration fsResolution = getFsResolution(s, dir, probe);
Duration clockResolution = measureClockResolution();
fsResolution = fsResolution.plus(clockResolution);
if (LOG.isDebugEnabled()) {
LOG.debug(
"{}: end measure timestamp resolution {} in {}; got {}", //$NON-NLS-1$
Thread.currentThread(), s, dir, fsResolution);
}
return Optional.of(fsResolution);
} catch (SecurityException e) {
// Log it here; most likely deleteProbe() below will also run
// into a SecurityException, and then this one will be lost
// without trace.
LOG.warn(e.getLocalizedMessage(), e);
} catch (AccessDeniedException e) {
LOG.warn(e.getLocalizedMessage(), e); // see bug 548648
} catch (IOException e) {
LOG.error(e.getLocalizedMessage(), e);
} finally {
deleteProbe(probe);
}
return Optional.empty();
}
private static Duration getFsResolution(FileStore s, Path dir,
Path probe) throws IOException {
File probeFile = probe.toFile();
FileTime t1 = Files.getLastModifiedTime(probe);
Instant t1i = t1.toInstant();
FileTime t2;
Duration last = FALLBACK_TIMESTAMP_RESOLUTION;
long minScale = MINIMUM_RESOLUTION_NANOS;
long scale = ONE_SECOND;
long high = TimeUnit.MILLISECONDS.toSeconds(last.toMillis());
long low = 0;
// Try up-front at microsecond and millisecond
long[] tries = { ONE_MICROSECOND, ONE_MILLISECOND };
for (long interval : tries) {
if (interval >= ONE_MILLISECOND) {
probeFile.setLastModified(
t1i.plusNanos(interval).toEpochMilli());
} else {
Files.setLastModifiedTime(probe,
FileTime.from(t1i.plusNanos(interval)));
}
t2 = Files.getLastModifiedTime(probe);
if (t2.compareTo(t1) > 0) {
Duration diff = Duration.between(t1i, t2.toInstant());
if (!diff.isZero() && !diff.isNegative()
&& diff.compareTo(last) < 0) {
scale = interval;
high = 1;
last = diff;
break;
}
} else {
// Makes no sense going below
minScale = Math.max(minScale, interval);
}
}
// Binary search loop
while (high > low) {
long mid = (high + low) / 2;
if (mid == 0) {
// Smaller than current scale. Adjust scale.
long newScale = scale / 10;
if (newScale < minScale) {
break;
}
high *= scale / newScale;
low *= scale / newScale;
scale = newScale;
mid = (high + low) / 2;
}
long delta = mid * scale;
if (scale >= ONE_MILLISECOND) {
probeFile.setLastModified(
t1i.plusNanos(delta).toEpochMilli());
} else {
Files.setLastModifiedTime(probe,
FileTime.from(t1i.plusNanos(delta)));
}
t2 = Files.getLastModifiedTime(probe);
int cmp = t2.compareTo(t1);
if (cmp > 0) {
high = mid;
Duration diff = Duration.between(t1i, t2.toInstant());
if (diff.isZero() || diff.isNegative()) {
LOG.warn(JGitText.get().logInconsistentFiletimeDiff,
Thread.currentThread(), s, dir, t2, t1, diff,
last);
break;
} else if (diff.compareTo(last) > 0) {
LOG.warn(JGitText.get().logLargerFiletimeDiff,
Thread.currentThread(), s, dir, diff, last);
break;
}
last = diff;
} else if (cmp < 0) {
LOG.warn(JGitText.get().logSmallerFiletime,
Thread.currentThread(), s, dir, t2, t1, last);
break;
} else {
// No discernible difference
low = mid + 1;
}
}
return last;
}
private static Duration measureClockResolution() {
Duration clockResolution = Duration.ZERO;
for (int i = 0; i < 10; i++) {
Instant t1 = Instant.now();
Instant t2 = t1;
while (t2.compareTo(t1) <= 0) {
t2 = Instant.now();
}
Duration r = Duration.between(t1, t2);
if (r.compareTo(clockResolution) > 0) {
clockResolution = r;
}
}
return clockResolution;
}
private static void deleteProbe(Path probe) {
try {
FileUtils.delete(probe.toFile(),
FileUtils.SKIP_MISSING | FileUtils.RETRY);
} catch (IOException e) {
LOG.error(e.getMessage(), e);
}
}
private static Optional<FileStoreAttributes> readFromConfig(
FileStore s) {
StoredConfig userConfig;
try {
userConfig = SystemReader.getInstance().getUserConfig();
} catch (IOException | ConfigInvalidException e) {
LOG.error(JGitText.get().readFileStoreAttributesFailed, e);
return Optional.empty();
}
String key = getConfigKey(s);
Duration resolution = Duration.ofNanos(userConfig.getTimeUnit(
ConfigConstants.CONFIG_FILESYSTEM_SECTION, key,
ConfigConstants.CONFIG_KEY_TIMESTAMP_RESOLUTION,
UNDEFINED_DURATION.toNanos(), TimeUnit.NANOSECONDS));
if (UNDEFINED_DURATION.equals(resolution)) {
return Optional.empty();
}
Duration minRacyThreshold = Duration.ofNanos(userConfig.getTimeUnit(
ConfigConstants.CONFIG_FILESYSTEM_SECTION, key,
ConfigConstants.CONFIG_KEY_MIN_RACY_THRESHOLD,
UNDEFINED_DURATION.toNanos(), TimeUnit.NANOSECONDS));
FileStoreAttributes c = new FileStoreAttributes(resolution);
if (!UNDEFINED_DURATION.equals(minRacyThreshold)) {
c.minimalRacyInterval = minRacyThreshold;
}
return Optional.of(c);
}
private static void saveToConfig(FileStore s,
FileStoreAttributes c) {
StoredConfig jgitConfig;
try {
jgitConfig = SystemReader.getInstance().getJGitConfig();
} catch (IOException | ConfigInvalidException e) {
LOG.error(JGitText.get().saveFileStoreAttributesFailed, e);
return;
}
long resolution = c.getFsTimestampResolution().toNanos();
TimeUnit resolutionUnit = getUnit(resolution);
long resolutionValue = resolutionUnit.convert(resolution,
TimeUnit.NANOSECONDS);
long minRacyThreshold = c.getMinimalRacyInterval().toNanos();
TimeUnit minRacyThresholdUnit = getUnit(minRacyThreshold);
long minRacyThresholdValue = minRacyThresholdUnit
.convert(minRacyThreshold, TimeUnit.NANOSECONDS);
final int max_retries = 5;
int retries = 0;
boolean succeeded = false;
String key = getConfigKey(s);
while (!succeeded && retries < max_retries) {
try {
jgitConfig.setString(
ConfigConstants.CONFIG_FILESYSTEM_SECTION, key,
ConfigConstants.CONFIG_KEY_TIMESTAMP_RESOLUTION,
String.format("%d %s", //$NON-NLS-1$
Long.valueOf(resolutionValue),
resolutionUnit.name().toLowerCase()));
jgitConfig.setString(
ConfigConstants.CONFIG_FILESYSTEM_SECTION, key,
ConfigConstants.CONFIG_KEY_MIN_RACY_THRESHOLD,
String.format("%d %s", //$NON-NLS-1$
Long.valueOf(minRacyThresholdValue),
minRacyThresholdUnit.name().toLowerCase()));
jgitConfig.save();
succeeded = true;
} catch (LockFailedException e) {
// race with another thread, wait a bit and try again
try {
retries++;
if (retries < max_retries) {
Thread.sleep(100);
LOG.debug("locking {} failed, retries {}/{}", //$NON-NLS-1$
jgitConfig, Integer.valueOf(retries),
Integer.valueOf(max_retries));
} else {
LOG.warn(MessageFormat.format(
JGitText.get().lockFailedRetry, jgitConfig,
Integer.valueOf(retries)));
}
} catch (InterruptedException e1) {
Thread.currentThread().interrupt();
break;
}
} catch (IOException e) {
LOG.error(MessageFormat.format(
JGitText.get().cannotSaveConfig, jgitConfig), e);
break;
}
}
}
private static String getConfigKey(FileStore s) {
String storeKey;
if (SystemReader.getInstance().isWindows()) {
Object attribute = null;
try {
attribute = s.getAttribute("volume:vsn"); //$NON-NLS-1$
} catch (IOException ignored) {
// ignore
}
if (attribute instanceof Integer) {
storeKey = attribute.toString();
} else {
storeKey = s.name();
}
} else {
storeKey = s.name();
}
return JAVA_VERSION_PREFIX + storeKey;
}
private static TimeUnit getUnit(long nanos) {
TimeUnit unit;
if (nanos < 200_000L) {
unit = TimeUnit.NANOSECONDS;
} else if (nanos < 200_000_000L) {
unit = TimeUnit.MICROSECONDS;
} else {
unit = TimeUnit.MILLISECONDS;
}
return unit;
}
private final @NonNull Duration fsTimestampResolution;
private Duration minimalRacyInterval;
/**
* @return the measured minimal interval after a file has been modified
* in which we cannot rely on lastModified to detect
* modifications
*/
public Duration getMinimalRacyInterval() {
return minimalRacyInterval;
}
/**
* @return the measured filesystem timestamp resolution
*/
@NonNull
public Duration getFsTimestampResolution() {
return fsTimestampResolution;
}
/**
* Construct a FileStoreAttributeCache entry for the given filesystem
* timestamp resolution
*
* @param fsTimestampResolution
*/
public FileStoreAttributes(
@NonNull Duration fsTimestampResolution) {
this.fsTimestampResolution = fsTimestampResolution;
this.minimalRacyInterval = Duration.ZERO;
}
@SuppressWarnings({ "nls", "boxing" })
@Override
public String toString() {
return String.format(
"FileStoreAttributes[fsTimestampResolution=%,d µs, "
+ "minimalRacyInterval=%,d µs]",
fsTimestampResolution.toNanos() / 1000,
minimalRacyInterval.toNanos() / 1000);
}
}
/** The auto-detected implementation selected for this operating system and JRE. */
public static final FS DETECTED = detect();
private static volatile FSFactory factory;
/**
* Auto-detect the appropriate file system abstraction.
*
* @return detected file system abstraction
*/
public static FS detect() {
return detect(null);
}
/**
* Whether FileStore attributes should be determined asynchronously
*
* @param asynch
* whether FileStore attributes should be determined
* asynchronously. If false access to cached attributes may block
* for some seconds for the first call per FileStore
* @since 5.1.9
* @deprecated Use {@link FileStoreAttributes#setBackground} instead
*/
@Deprecated
public static void setAsyncFileStoreAttributes(boolean asynch) {
FileStoreAttributes.setBackground(asynch);
}
/**
* Auto-detect the appropriate file system abstraction, taking into account
* the presence of a Cygwin installation on the system. Using jgit in
* combination with Cygwin requires a more elaborate (and possibly slower)
* resolution of file system paths.
*
* @param cygwinUsed
* <ul>
* <li><code>Boolean.TRUE</code> to assume that Cygwin is used in
* combination with jgit</li>
* <li><code>Boolean.FALSE</code> to assume that Cygwin is
* <b>not</b> used with jgit</li>
* <li><code>null</code> to auto-detect whether a Cygwin
* installation is present on the system and in this case assume
* that Cygwin is used</li>
* </ul>
*
* Note: this parameter is only relevant on Windows.
* @return detected file system abstraction
*/
public static FS detect(Boolean cygwinUsed) {
if (factory == null) {
factory = new FS.FSFactory();
}
return factory.detect(cygwinUsed);
}
/**
* Get cached FileStore attributes, if not yet available measure them using
* a probe file under the given directory.
*
* @param dir
* the directory under which the probe file will be created to
* measure the timer resolution.
* @return measured filesystem timestamp resolution
* @since 5.1.9
*/
public static FileStoreAttributes getFileStoreAttributes(
@NonNull Path dir) {
return FileStoreAttributes.get(dir);
}
private volatile Holder<File> userHome;
private volatile Holder<File> gitSystemConfig;
/**
* Constructs a file system abstraction.
*/
protected FS() {
// Do nothing by default.
}
/**
* Initialize this FS using another's current settings.
*
* @param src
* the source FS to copy from.
*/
protected FS(FS src) {
userHome = src.userHome;
gitSystemConfig = src.gitSystemConfig;
}
/**
* Create a new instance of the same type of FS.
*
* @return a new instance of the same type of FS.
*/
public abstract FS newInstance();
/**
* Does this operating system and JRE support the execute flag on files?
*
* @return true if this implementation can provide reasonably accurate
* executable bit information; false otherwise.
*/
public abstract boolean supportsExecute();
/**
* Does this file system support atomic file creation via
* java.io.File#createNewFile()? In certain environments (e.g. on NFS) it is
* not guaranteed that when two file system clients run createNewFile() in
* parallel only one will succeed. In such cases both clients may think they
* created a new file.
*
* @return true if this implementation support atomic creation of new Files
* by {@link java.io.File#createNewFile()}
* @since 4.5
*/
public boolean supportsAtomicCreateNewFile() {
return true;
}
/**
* Does this operating system and JRE supports symbolic links. The
* capability to handle symbolic links is detected at runtime.
*
* @return true if symbolic links may be used
* @since 3.0
*/
public boolean supportsSymlinks() {
if (supportSymlinks == null) {
detectSymlinkSupport();
}
return Boolean.TRUE.equals(supportSymlinks);
}
private void detectSymlinkSupport() {
File tempFile = null;
try {
tempFile = File.createTempFile("tempsymlinktarget", ""); //$NON-NLS-1$ //$NON-NLS-2$
File linkName = new File(tempFile.getParentFile(), "tempsymlink"); //$NON-NLS-1$
createSymLink(linkName, tempFile.getPath());
supportSymlinks = Boolean.TRUE;
linkName.delete();
} catch (IOException | UnsupportedOperationException | SecurityException
| InternalError e) {
supportSymlinks = Boolean.FALSE;
} finally {
if (tempFile != null) {
try {
FileUtils.delete(tempFile);
} catch (IOException e) {
LOG.error(JGitText.get().cannotDeleteFile, tempFile);
}
}
}
}
/**
* Is this file system case sensitive
*
* @return true if this implementation is case sensitive
*/
public abstract boolean isCaseSensitive();
/**
* Determine if the file is executable (or not).
* <p>
* Not all platforms and JREs support executable flags on files. If the
* feature is unsupported this method will always return false.
* <p>
* <em>If the platform supports symbolic links and <code>f</code> is a symbolic link
* this method returns false, rather than the state of the executable flags
* on the target file.</em>
*
* @param f
* abstract path to test.
* @return true if the file is believed to be executable by the user.
*/
public abstract boolean canExecute(File f);
/**
* Set a file to be executable by the user.
* <p>
* Not all platforms and JREs support executable flags on files. If the
* feature is unsupported this method will always return false and no
* changes will be made to the file specified.
*
* @param f
* path to modify the executable status of.
* @param canExec
* true to enable execution; false to disable it.
* @return true if the change succeeded; false otherwise.
*/
public abstract boolean setExecute(File f, boolean canExec);
/**
* Get the last modified time of a file system object. If the OS/JRE support
* symbolic links, the modification time of the link is returned, rather
* than that of the link target.
*
* @param f
* a {@link java.io.File} object.
* @return last modified time of f
* @throws java.io.IOException
* @since 3.0
* @deprecated use {@link #lastModifiedInstant(Path)} instead
*/
@Deprecated
public long lastModified(File f) throws IOException {
return FileUtils.lastModified(f);
}
/**
* Get the last modified time of a file system object. If the OS/JRE support
* symbolic links, the modification time of the link is returned, rather
* than that of the link target.
*
* @param p
* a {@link Path} object.
* @return last modified time of p
* @since 5.1.9
*/
public Instant lastModifiedInstant(Path p) {
return FileUtils.lastModifiedInstant(p);
}
/**
* Get the last modified time of a file system object. If the OS/JRE support
* symbolic links, the modification time of the link is returned, rather
* than that of the link target.
*
* @param f
* a {@link File} object.
* @return last modified time of p
* @since 5.1.9
*/
public Instant lastModifiedInstant(File f) {
return FileUtils.lastModifiedInstant(f.toPath());
}
/**
* Set the last modified time of a file system object.
* <p>
* For symlinks it sets the modified time of the link target.
*
* @param f
* a {@link java.io.File} object.
* @param time
* last modified time
* @throws java.io.IOException
* @since 3.0
* @deprecated use {@link #setLastModified(Path, Instant)} instead
*/
@Deprecated
public void setLastModified(File f, long time) throws IOException {
FileUtils.setLastModified(f, time);
}
/**
* Set the last modified time of a file system object.
* <p>
* For symlinks it sets the modified time of the link target.
*
* @param p
* a {@link Path} object.
* @param time
* last modified time
* @throws java.io.IOException
* @since 5.1.9
*/
public void setLastModified(Path p, Instant time) throws IOException {
FileUtils.setLastModified(p, time);
}
/**
* Get the length of a file or link, If the OS/JRE supports symbolic links
* it's the length of the link, else the length of the target.
*
* @param path
* a {@link java.io.File} object.
* @return length of a file
* @throws java.io.IOException
* @since 3.0
*/
public long length(File path) throws IOException {
return FileUtils.getLength(path);
}
/**
* Delete a file. Throws an exception if delete fails.
*
* @param f
* a {@link java.io.File} object.
* @throws java.io.IOException
* this may be a Java7 subclass with detailed information
* @since 3.3
*/
public void delete(File f) throws IOException {
FileUtils.delete(f);
}
/**
* Resolve this file to its actual path name that the JRE can use.
* <p>
* This method can be relatively expensive. Computing a translation may
* require forking an external process per path name translated. Callers
* should try to minimize the number of translations necessary by caching
* the results.
* <p>
* Not all platforms and JREs require path name translation. Currently only
* Cygwin on Win32 require translation for Cygwin based paths.
*
* @param dir
* directory relative to which the path name is.
* @param name
* path name to translate.
* @return the translated path. <code>new File(dir,name)</code> if this
* platform does not require path name translation.
*/
public File resolve(File dir, String name) {
File abspn = new File(name);
if (abspn.isAbsolute())
return abspn;
return new File(dir, name);
}
/**
* Determine the user's home directory (location where preferences are).
* <p>
* This method can be expensive on the first invocation if path name
* translation is required. Subsequent invocations return a cached result.
* <p>
* Not all platforms and JREs require path name translation. Currently only
* Cygwin on Win32 requires translation of the Cygwin HOME directory.
*
* @return the user's home directory; null if the user does not have one.
*/
public File userHome() {
Holder<File> p = userHome;
if (p == null) {
p = new Holder<>(safeUserHomeImpl());
userHome = p;
}
return p.value;
}
private File safeUserHomeImpl() {
File home;
try {
home = userHomeImpl();
if (home != null) {
home.toPath();
return home;
}
} catch (RuntimeException e) {
LOG.error(JGitText.get().exceptionWhileFindingUserHome, e);
}
home = defaultUserHomeImpl();
if (home != null) {
try {
home.toPath();
return home;
} catch (InvalidPathException e) {
LOG.error(MessageFormat
.format(JGitText.get().invalidHomeDirectory, home), e);
}
}
return null;
}
/**
* Set the user's home directory location.
*
* @param path
* the location of the user's preferences; null if there is no
* home directory for the current user.
* @return {@code this}.
*/
public FS setUserHome(File path) {
userHome = new Holder<>(path);
return this;
}
/**
* Does this file system have problems with atomic renames?
*
* @return true if the caller should retry a failed rename of a lock file.
*/
public abstract boolean retryFailedLockFileCommit();
/**
* Return all the attributes of a file, without following symbolic links.
*
* @param file
* @return {@link BasicFileAttributes} of the file
* @throws IOException in case of any I/O errors accessing the file
*
* @since 4.5.6
*/
public BasicFileAttributes fileAttributes(File file) throws IOException {
return FileUtils.fileAttributes(file);
}
/**
* Determine the user's home directory (location where preferences are).
*
* @return the user's home directory; null if the user does not have one.
*/
protected File userHomeImpl() {
return defaultUserHomeImpl();
}
private File defaultUserHomeImpl() {
String home = AccessController.doPrivileged(
(PrivilegedAction<String>) () -> System.getProperty("user.home") //$NON-NLS-1$
);
if (home == null || home.length() == 0)
return null;
return new File(home).getAbsoluteFile();
}
/**
* Searches the given path to see if it contains one of the given files.
* Returns the first it finds which is executable. Returns null if not found
* or if path is null.
*
* @param path
* List of paths to search separated by File.pathSeparator
* @param lookFor
* Files to search for in the given path
* @return the first match found, or null
* @since 3.0
*/
protected static File searchPath(String path, String... lookFor) {
if (path == null) {
return null;
}
for (String p : path.split(File.pathSeparator)) {
for (String command : lookFor) {
File file = new File(p, command);
try {
if (file.isFile() && file.canExecute()) {
return file.getAbsoluteFile();
}
} catch (SecurityException e) {
LOG.warn(MessageFormat.format(
JGitText.get().skipNotAccessiblePath,
file.getPath()));
}
}
}
return null;
}
/**
* Execute a command and return a single line of output as a String
*
* @param dir
* Working directory for the command
* @param command
* as component array
* @param encoding
* to be used to parse the command's output
* @return the one-line output of the command or {@code null} if there is
* none
* @throws org.eclipse.jgit.errors.CommandFailedException
* thrown when the command failed (return code was non-zero)
*/
@Nullable
protected static String readPipe(File dir, String[] command,
String encoding) throws CommandFailedException {
return readPipe(dir, command, encoding, null);
}
/**
* Execute a command and return a single line of output as a String
*
* @param dir
* Working directory for the command
* @param command
* as component array
* @param encoding
* to be used to parse the command's output
* @param env
* Map of environment variables to be merged with those of the
* current process
* @return the one-line output of the command or {@code null} if there is
* none
* @throws org.eclipse.jgit.errors.CommandFailedException
* thrown when the command failed (return code was non-zero)
* @since 4.0
*/
@Nullable
protected static String readPipe(File dir, String[] command,
String encoding, Map<String, String> env)
throws CommandFailedException {
boolean debug = LOG.isDebugEnabled();
try {
if (debug) {
LOG.debug("readpipe " + Arrays.asList(command) + "," //$NON-NLS-1$ //$NON-NLS-2$
+ dir);
}
ProcessBuilder pb = new ProcessBuilder(command);
pb.directory(dir);
if (env != null) {
pb.environment().putAll(env);
}
Process p;
try {
p = pb.start();
} catch (IOException e) {
// Process failed to start
throw new CommandFailedException(-1, e.getMessage(), e);
}
p.getOutputStream().close();
GobblerThread gobbler = new GobblerThread(p, command, dir);
gobbler.start();
String r = null;
try (BufferedReader lineRead = new BufferedReader(
new InputStreamReader(p.getInputStream(), encoding))) {
r = lineRead.readLine();
if (debug) {
LOG.debug("readpipe may return '" + r + "'"); //$NON-NLS-1$ //$NON-NLS-2$
LOG.debug("remaining output:\n"); //$NON-NLS-1$
String l;
while ((l = lineRead.readLine()) != null) {
LOG.debug(l);
}
}
}
for (;;) {
try {
int rc = p.waitFor();
gobbler.join();
if (rc == 0 && !gobbler.fail.get()) {
return r;
}
if (debug) {
LOG.debug("readpipe rc=" + rc); //$NON-NLS-1$
}
throw new CommandFailedException(rc,
gobbler.errorMessage.get(),
gobbler.exception.get());
} catch (InterruptedException ie) {
// Stop bothering me, I have a zombie to reap.
}
}
} catch (IOException e) {
LOG.error("Caught exception in FS.readPipe()", e); //$NON-NLS-1$
} catch (AccessControlException e) {
LOG.warn(MessageFormat.format(
JGitText.get().readPipeIsNotAllowedRequiredPermission,
command, dir, e.getPermission()));
} catch (SecurityException e) {
LOG.warn(MessageFormat.format(JGitText.get().readPipeIsNotAllowed,
command, dir));
}
if (debug) {
LOG.debug("readpipe returns null"); //$NON-NLS-1$
}
return null;
}
private static class GobblerThread extends Thread {
/* The process has 5 seconds to exit after closing stderr */
private static final int PROCESS_EXIT_TIMEOUT = 5;
private final Process p;
private final String desc;
private final String dir;
final AtomicBoolean fail = new AtomicBoolean();
final AtomicReference<String> errorMessage = new AtomicReference<>();
final AtomicReference<Throwable> exception = new AtomicReference<>();
GobblerThread(Process p, String[] command, File dir) {
this.p = p;
this.desc = Arrays.toString(command);
this.dir = Objects.toString(dir);
}
@Override
public void run() {
StringBuilder err = new StringBuilder();
try (InputStream is = p.getErrorStream()) {
int ch;
while ((ch = is.read()) != -1) {
err.append((char) ch);
}
} catch (IOException e) {
if (waitForProcessCompletion(e) && p.exitValue() != 0) {
setError(e, e.getMessage(), p.exitValue());
fail.set(true);
} else {
// ignore. command terminated faster and stream was just closed
// or the process didn't terminate within timeout
}
} finally {
if (waitForProcessCompletion(null) && err.length() > 0) {
setError(null, err.toString(), p.exitValue());
if (p.exitValue() != 0) {
fail.set(true);
}
}
}
}
@SuppressWarnings("boxing")
private boolean waitForProcessCompletion(IOException originalError) {
try {
if (!p.waitFor(PROCESS_EXIT_TIMEOUT, TimeUnit.SECONDS)) {
setError(originalError, MessageFormat.format(
JGitText.get().commandClosedStderrButDidntExit,
desc, PROCESS_EXIT_TIMEOUT), -1);
fail.set(true);
return false;
}
} catch (InterruptedException e) {
setError(originalError, MessageFormat.format(
JGitText.get().threadInterruptedWhileRunning, desc), -1);
fail.set(true);
return false;
}
return true;
}
private void setError(IOException e, String message, int exitCode) {
exception.set(e);
errorMessage.set(MessageFormat.format(
JGitText.get().exceptionCaughtDuringExecutionOfCommand,
desc, dir, Integer.valueOf(exitCode), message));
}
}
/**
* Discover the path to the Git executable.
*
* @return the path to the Git executable or {@code null} if it cannot be
* determined.
* @since 4.0
*/
protected abstract File discoverGitExe();
/**
* Discover the path to the system-wide Git configuration file
*
* @return the path to the system-wide Git configuration file or
* {@code null} if it cannot be determined.
* @since 4.0
*/
protected File discoverGitSystemConfig() {
File gitExe = discoverGitExe();
if (gitExe == null) {
return null;
}
// Bug 480782: Check if the discovered git executable is JGit CLI
String v;
try {
v = readPipe(gitExe.getParentFile(),
new String[] { gitExe.getPath(), "--version" }, //$NON-NLS-1$
SystemReader.getInstance().getDefaultCharset().name());
} catch (CommandFailedException e) {
LOG.warn(e.getMessage());
return null;
}
if (StringUtils.isEmptyOrNull(v)
|| (v != null && v.startsWith("jgit"))) { //$NON-NLS-1$
return null;
}
if (parseVersion(v) < makeVersion(2, 8, 0)) {
// --show-origin was introduced in git 2.8.0. For older git: trick
// it into printing the path to the config file by using "echo" as
// the editor.
Map<String, String> env = new HashMap<>();
env.put("GIT_EDITOR", "echo"); //$NON-NLS-1$ //$NON-NLS-2$
String w;
try {
// This command prints the path even if it doesn't exist
w = readPipe(gitExe.getParentFile(),
new String[] { gitExe.getPath(), "config", "--system", //$NON-NLS-1$ //$NON-NLS-2$
"--edit" }, //$NON-NLS-1$
SystemReader.getInstance().getDefaultCharset().name(),
env);
} catch (CommandFailedException e) {
LOG.warn(e.getMessage());
return null;
}
if (StringUtils.isEmptyOrNull(w)) {
return null;
}
return new File(w);
}
String w;
try {
w = readPipe(gitExe.getParentFile(),
new String[] { gitExe.getPath(), "config", "--system", //$NON-NLS-1$ //$NON-NLS-2$
"--show-origin", "--list", "-z" }, //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
SystemReader.getInstance().getDefaultCharset().name());
} catch (CommandFailedException e) {
// This command fails if the system config doesn't exist
if (LOG.isDebugEnabled()) {
LOG.debug(e.getMessage());
}
return null;
}
if (w == null) {
return null;
}
// We get NUL-terminated items; the first one will be a file name,
// prefixed by "file:". (Using -z is crucial, otherwise git quotes file
// names with special characters.)
int nul = w.indexOf(0);
if (nul <= 0) {
return null;
}
w = w.substring(0, nul);
int colon = w.indexOf(':');
if (colon < 0) {
return null;
}
w = w.substring(colon + 1);
return w.isEmpty() ? null : new File(w);
}
private long parseVersion(String version) {
Matcher m = VERSION.matcher(version);
if (m.find()) {
try {
return makeVersion(
Integer.parseInt(m.group(1)),
Integer.parseInt(m.group(2)),
Integer.parseInt(m.group(3)));
} catch (NumberFormatException e) {
// Ignore
}
}
return -1;
}
private long makeVersion(int major, int minor, int patch) {
return ((major * 10_000L) + minor) * 10_000L + patch;
}
/**
* Get the currently used path to the system-wide Git configuration file.
*
* @return the currently used path to the system-wide Git configuration file
* or {@code null} if none has been set.
* @since 4.0
*/
public File getGitSystemConfig() {
if (gitSystemConfig == null) {
gitSystemConfig = new Holder<>(discoverGitSystemConfig());
}
return gitSystemConfig.value;
}
/**
* Set the path to the system-wide Git configuration file to use.
*
* @param configFile
* the path to the config file.
* @return {@code this}
* @since 4.0
*/
public FS setGitSystemConfig(File configFile) {
gitSystemConfig = new Holder<>(configFile);
return this;
}
/**
* Get the parent directory of this file's parent directory
*
* @param grandchild
* a {@link java.io.File} object.
* @return the parent directory of this file's parent directory or
* {@code null} in case there's no grandparent directory
* @since 4.0
*/
protected static File resolveGrandparentFile(File grandchild) {
if (grandchild != null) {
File parent = grandchild.getParentFile();
if (parent != null)
return parent.getParentFile();
}
return null;
}
/**
* Check if a file is a symbolic link and read it
*
* @param path
* a {@link java.io.File} object.
* @return target of link or null
* @throws java.io.IOException
* @since 3.0
*/
public String readSymLink(File path) throws IOException {
return FileUtils.readSymLink(path);
}
/**
* Whether the path is a symbolic link (and we support these).
*
* @param path
* a {@link java.io.File} object.
* @return true if the path is a symbolic link (and we support these)
* @throws java.io.IOException
* @since 3.0
*/
public boolean isSymLink(File path) throws IOException {
return FileUtils.isSymlink(path);
}
/**
* Tests if the path exists, in case of a symbolic link, true even if the
* target does not exist
*
* @param path
* a {@link java.io.File} object.
* @return true if path exists
* @since 3.0
*/
public boolean exists(File path) {
return FileUtils.exists(path);
}
/**
* Check if path is a directory. If the OS/JRE supports symbolic links and
* path is a symbolic link to a directory, this method returns false.
*
* @param path
* a {@link java.io.File} object.
* @return true if file is a directory,
* @since 3.0
*/
public boolean isDirectory(File path) {
return FileUtils.isDirectory(path);
}
/**
* Examine if path represents a regular file. If the OS/JRE supports
* symbolic links the test returns false if path represents a symbolic link.
*
* @param path
* a {@link java.io.File} object.
* @return true if path represents a regular file
* @since 3.0
*/
public boolean isFile(File path) {
return FileUtils.isFile(path);
}
/**
* Whether path is hidden, either starts with . on unix or has the hidden
* attribute in windows
*
* @param path
* a {@link java.io.File} object.
* @return true if path is hidden, either starts with . on unix or has the
* hidden attribute in windows
* @throws java.io.IOException
* @since 3.0
*/
public boolean isHidden(File path) throws IOException {
return FileUtils.isHidden(path);
}
/**
* Set the hidden attribute for file whose name starts with a period.
*
* @param path
* a {@link java.io.File} object.
* @param hidden
* whether to set the file hidden
* @throws java.io.IOException
* @since 3.0
*/
public void setHidden(File path, boolean hidden) throws IOException {
FileUtils.setHidden(path, hidden);
}
/**
* Create a symbolic link
*
* @param path
* a {@link java.io.File} object.
* @param target
* target path of the symlink
* @throws java.io.IOException
* @since 3.0
*/
public void createSymLink(File path, String target) throws IOException {
FileUtils.createSymLink(path, target);
}
/**
* Create a new file. See {@link java.io.File#createNewFile()}. Subclasses
* of this class may take care to provide a safe implementation for this
* even if {@link #supportsAtomicCreateNewFile()} is <code>false</code>
*
* @param path
* the file to be created
* @return <code>true</code> if the file was created, <code>false</code> if
* the file already existed
* @throws java.io.IOException
* @deprecated use {@link #createNewFileAtomic(File)} instead
* @since 4.5
*/
@Deprecated
public boolean createNewFile(File path) throws IOException {
return path.createNewFile();
}
/**
* A token representing a file created by
* {@link #createNewFileAtomic(File)}. The token must be retained until the
* file has been deleted in order to guarantee that the unique file was
* created atomically. As soon as the file is no longer needed the lock
* token must be closed.
*
* @since 4.7
*/
public static class LockToken implements Closeable {
private boolean isCreated;
private Optional<Path> link;
LockToken(boolean isCreated, Optional<Path> link) {
this.isCreated = isCreated;
this.link = link;
}
/**
* @return {@code true} if the file was created successfully
*/
public boolean isCreated() {
return isCreated;
}
@Override
public void close() {
if (!link.isPresent()) {
return;
}
Path p = link.get();
if (!Files.exists(p)) {
return;
}
try {
Files.delete(p);
} catch (IOException e) {
LOG.error(MessageFormat
.format(JGitText.get().closeLockTokenFailed, this), e);
}
}
@Override
public String toString() {
return "LockToken [lockCreated=" + isCreated + //$NON-NLS-1$
", link=" //$NON-NLS-1$
+ (link.isPresent() ? link.get().getFileName() + "]" //$NON-NLS-1$
: "<null>]"); //$NON-NLS-1$
}
}
/**
* Create a new file. See {@link java.io.File#createNewFile()}. Subclasses
* of this class may take care to provide a safe implementation for this
* even if {@link #supportsAtomicCreateNewFile()} is <code>false</code>
*
* @param path
* the file to be created
* @return LockToken this token must be closed after the created file was
* deleted
* @throws IOException
* @since 4.7
*/
public LockToken createNewFileAtomic(File path) throws IOException {
return new LockToken(path.createNewFile(), Optional.empty());
}
/**
* See
* {@link org.eclipse.jgit.util.FileUtils#relativizePath(String, String, String, boolean)}.
*
* @param base
* The path against which <code>other</code> should be
* relativized.
* @param other
* The path that will be made relative to <code>base</code>.
* @return A relative path that, when resolved against <code>base</code>,
* will yield the original <code>other</code>.
* @see FileUtils#relativizePath(String, String, String, boolean)
* @since 3.7
*/
public String relativize(String base, String other) {
return FileUtils.relativizePath(base, other, File.separator, this.isCaseSensitive());
}
/**
* Enumerates children of a directory.
*
* @param directory
* to get the children of
* @param fileModeStrategy
* to use to calculate the git mode of a child
* @return an array of entries for the children
*
* @since 5.0
*/
public Entry[] list(File directory, FileModeStrategy fileModeStrategy) {
File[] all = directory.listFiles();
if (all == null) {
return NO_ENTRIES;
}
Entry[] result = new Entry[all.length];
for (int i = 0; i < result.length; i++) {
result[i] = new FileEntry(all[i], this, fileModeStrategy);
}
return result;
}
/**
* Checks whether the given hook is defined for the given repository, then
* runs it with the given arguments.
* <p>
* The hook's standard output and error streams will be redirected to
* <code>System.out</code> and <code>System.err</code> respectively. The
* hook will have no stdin.
* </p>
*
* @param repository
* The repository for which a hook should be run.
* @param hookName
* The name of the hook to be executed.
* @param args
* Arguments to pass to this hook. Cannot be <code>null</code>,
* but can be an empty array.
* @return The ProcessResult describing this hook's execution.
* @throws org.eclipse.jgit.api.errors.JGitInternalException
* if we fail to run the hook somehow. Causes may include an
* interrupted process or I/O errors.
* @since 4.0
*/
public ProcessResult runHookIfPresent(Repository repository,
String hookName, String[] args) throws JGitInternalException {
return runHookIfPresent(repository, hookName, args, System.out,
System.err, null);
}
/**
* Checks whether the given hook is defined for the given repository, then
* runs it with the given arguments.
*
* @param repository
* The repository for which a hook should be run.
* @param hookName
* The name of the hook to be executed.
* @param args
* Arguments to pass to this hook. Cannot be <code>null</code>,
* but can be an empty array.
* @param outRedirect
* A print stream on which to redirect the hook's stdout. Can be
* <code>null</code>, in which case the hook's standard output
* will be lost.
* @param errRedirect
* A print stream on which to redirect the hook's stderr. Can be
* <code>null</code>, in which case the hook's standard error
* will be lost.
* @param stdinArgs
* A string to pass on to the standard input of the hook. May be
* <code>null</code>.
* @return The ProcessResult describing this hook's execution.
* @throws org.eclipse.jgit.api.errors.JGitInternalException
* if we fail to run the hook somehow. Causes may include an
* interrupted process or I/O errors.
* @since 5.11
*/
public ProcessResult runHookIfPresent(Repository repository,
String hookName, String[] args, OutputStream outRedirect,
OutputStream errRedirect, String stdinArgs)
throws JGitInternalException {
return new ProcessResult(Status.NOT_SUPPORTED);
}
/**
* See
* {@link #runHookIfPresent(Repository, String, String[], OutputStream, OutputStream, String)}
* . Should only be called by FS supporting shell scripts execution.
*
* @param repository
* The repository for which a hook should be run.
* @param hookName
* The name of the hook to be executed.
* @param args
* Arguments to pass to this hook. Cannot be <code>null</code>,
* but can be an empty array.
* @param outRedirect
* A print stream on which to redirect the hook's stdout. Can be
* <code>null</code>, in which case the hook's standard output
* will be lost.
* @param errRedirect
* A print stream on which to redirect the hook's stderr. Can be
* <code>null</code>, in which case the hook's standard error
* will be lost.
* @param stdinArgs
* A string to pass on to the standard input of the hook. May be
* <code>null</code>.
* @return The ProcessResult describing this hook's execution.
* @throws org.eclipse.jgit.api.errors.JGitInternalException
* if we fail to run the hook somehow. Causes may include an
* interrupted process or I/O errors.
* @since 5.11
*/
protected ProcessResult internalRunHookIfPresent(Repository repository,
String hookName, String[] args, OutputStream outRedirect,
OutputStream errRedirect, String stdinArgs)
throws JGitInternalException {
File hookFile = findHook(repository, hookName);
if (hookFile == null || hookName == null) {
return new ProcessResult(Status.NOT_PRESENT);
}
File runDirectory = getRunDirectory(repository, hookName);
if (runDirectory == null) {
return new ProcessResult(Status.NOT_PRESENT);
}
String cmd = hookFile.getAbsolutePath();
ProcessBuilder hookProcess = runInShell(shellQuote(cmd), args);
hookProcess.directory(runDirectory.getAbsoluteFile());
Map<String, String> environment = hookProcess.environment();
environment.put(Constants.GIT_DIR_KEY,
repository.getDirectory().getAbsolutePath());
if (!repository.isBare()) {
environment.put(Constants.GIT_WORK_TREE_KEY,
repository.getWorkTree().getAbsolutePath());
}
try {
return new ProcessResult(runProcess(hookProcess, outRedirect,
errRedirect, stdinArgs), Status.OK);
} catch (IOException e) {
throw new JGitInternalException(MessageFormat.format(
JGitText.get().exceptionCaughtDuringExecutionOfHook,
hookName), e);
} catch (InterruptedException e) {
throw new JGitInternalException(MessageFormat.format(
JGitText.get().exceptionHookExecutionInterrupted,
hookName), e);
}
}
/**
* Quote a string (such as a file system path obtained from a Java
* {@link File} or {@link Path} object) such that it can be passed as first
* argument to {@link #runInShell(String, String[])}.
* <p>
* This default implementation returns the string unchanged.
* </p>
*
* @param cmd
* the String to quote
* @return the quoted string
*/
String shellQuote(String cmd) {
return cmd;
}
/**
* Tries to find a hook matching the given one in the given repository.
*
* @param repository
* The repository within which to find a hook.
* @param hookName
* The name of the hook we're trying to find.
* @return The {@link java.io.File} containing this particular hook if it
* exists in the given repository, <code>null</code> otherwise.
* @since 4.0
*/
public File findHook(Repository repository, String hookName) {
if (hookName == null) {
return null;
}
File hookDir = getHooksDirectory(repository);
if (hookDir == null) {
return null;
}
File hookFile = new File(hookDir, hookName);
if (hookFile.isAbsolute()) {
if (!hookFile.exists() || (FS.DETECTED.supportsExecute()
&& !FS.DETECTED.canExecute(hookFile))) {
return null;
}
} else {
try {
File runDirectory = getRunDirectory(repository, hookName);
if (runDirectory == null) {
return null;
}
Path hookPath = runDirectory.getAbsoluteFile().toPath()
.resolve(hookFile.toPath());
FS fs = repository.getFS();
if (fs == null) {
fs = FS.DETECTED;
}
if (!Files.exists(hookPath) || (fs.supportsExecute()
&& !fs.canExecute(hookPath.toFile()))) {
return null;
}
hookFile = hookPath.toFile();
} catch (InvalidPathException e) {
LOG.warn(MessageFormat.format(JGitText.get().invalidHooksPath,
hookFile));
return null;
}
}
return hookFile;
}
private File getRunDirectory(Repository repository,
@NonNull String hookName) {
if (repository.isBare()) {
return repository.getDirectory();
}
switch (hookName) {
case "pre-receive": //$NON-NLS-1$
case "update": //$NON-NLS-1$
case "post-receive": //$NON-NLS-1$
case "post-update": //$NON-NLS-1$
case "push-to-checkout": //$NON-NLS-1$
return repository.getDirectory();
default:
return repository.getWorkTree();
}
}
private File getHooksDirectory(Repository repository) {
Config config = repository.getConfig();
String hooksDir = config.getString(ConfigConstants.CONFIG_CORE_SECTION,
null, ConfigConstants.CONFIG_KEY_HOOKS_PATH);
if (hooksDir != null) {
return new File(hooksDir);
}
File dir = repository.getDirectory();
return dir == null ? null : new File(dir, Constants.HOOKS);
}
/**
* Runs the given process until termination, clearing its stdout and stderr
* streams on-the-fly.
*
* @param processBuilder
* The process builder configured for this process.
* @param outRedirect
* A OutputStream on which to redirect the processes stdout. Can
* be <code>null</code>, in which case the processes standard
* output will be lost.
* @param errRedirect
* A OutputStream on which to redirect the processes stderr. Can
* be <code>null</code>, in which case the processes standard
* error will be lost.
* @param stdinArgs
* A string to pass on to the standard input of the hook. Can be
* <code>null</code>.
* @return the exit value of this process.
* @throws java.io.IOException
* if an I/O error occurs while executing this process.
* @throws java.lang.InterruptedException
* if the current thread is interrupted while waiting for the
* process to end.
* @since 4.2
*/
public int runProcess(ProcessBuilder processBuilder,
OutputStream outRedirect, OutputStream errRedirect, String stdinArgs)
throws IOException, InterruptedException {
InputStream in = (stdinArgs == null) ? null : new ByteArrayInputStream(
stdinArgs.getBytes(UTF_8));
return runProcess(processBuilder, outRedirect, errRedirect, in);
}
/**
* Runs the given process until termination, clearing its stdout and stderr
* streams on-the-fly.
*
* @param processBuilder
* The process builder configured for this process.
* @param outRedirect
* An OutputStream on which to redirect the processes stdout. Can
* be <code>null</code>, in which case the processes standard
* output will be lost.
* @param errRedirect
* An OutputStream on which to redirect the processes stderr. Can
* be <code>null</code>, in which case the processes standard
* error will be lost.
* @param inRedirect
* An InputStream from which to redirect the processes stdin. Can
* be <code>null</code>, in which case the process doesn't get
* any data over stdin. It is assumed that the whole InputStream
* will be consumed by the process. The method will close the
* inputstream after all bytes are read.
* @return the return code of this process.
* @throws java.io.IOException
* if an I/O error occurs while executing this process.
* @throws java.lang.InterruptedException
* if the current thread is interrupted while waiting for the
* process to end.
* @since 4.2
*/
public int runProcess(ProcessBuilder processBuilder,
OutputStream outRedirect, OutputStream errRedirect,
InputStream inRedirect) throws IOException,
InterruptedException {
ExecutorService executor = Executors.newFixedThreadPool(2);
Process process = null;
// We'll record the first I/O exception that occurs, but keep on trying
// to dispose of our open streams and file handles
IOException ioException = null;
try {
process = processBuilder.start();
executor.execute(
new StreamGobbler(process.getErrorStream(), errRedirect));
executor.execute(
new StreamGobbler(process.getInputStream(), outRedirect));
@SuppressWarnings("resource") // Closed in the finally block
OutputStream outputStream = process.getOutputStream();
try {
if (inRedirect != null) {
new StreamGobbler(inRedirect, outputStream).copy();
}
} finally {
try {
outputStream.close();
} catch (IOException e) {
// When the process exits before consuming the input, the OutputStream
// is replaced with the null output stream. This null output stream
// throws IOException for all write calls. When StreamGobbler fails to
// flush the buffer because of this, this close call tries to flush it
// again. This causes another IOException. Since we ignore the
// IOException in StreamGobbler, we also ignore the exception here.
}
}
return process.waitFor();
} catch (IOException e) {
ioException = e;
} finally {
shutdownAndAwaitTermination(executor);
if (process != null) {
try {
process.waitFor();
} catch (InterruptedException e) {
// Thrown by the outer try.
// Swallow this one to carry on our cleanup, and clear the
// interrupted flag (processes throw the exception without
// clearing the flag).
Thread.interrupted();
}
// A process doesn't clean its own resources even when destroyed
// Explicitly try and close all three streams, preserving the
// outer I/O exception if any.
if (inRedirect != null) {
inRedirect.close();
}
try {
process.getErrorStream().close();
} catch (IOException e) {
ioException = ioException != null ? ioException : e;
}
try {
process.getInputStream().close();
} catch (IOException e) {
ioException = ioException != null ? ioException : e;
}
try {
process.getOutputStream().close();
} catch (IOException e) {
ioException = ioException != null ? ioException : e;
}
process.destroy();
}
}
// We can only be here if the outer try threw an IOException.
throw ioException;
}
/**
* Shuts down an {@link ExecutorService} in two phases, first by calling
* {@link ExecutorService#shutdown() shutdown} to reject incoming tasks, and
* then calling {@link ExecutorService#shutdownNow() shutdownNow}, if
* necessary, to cancel any lingering tasks. Returns true if the pool has
* been properly shutdown, false otherwise.
* <p>
*
* @param pool
* the pool to shutdown
* @return <code>true</code> if the pool has been properly shutdown,
* <code>false</code> otherwise.
*/
private static boolean shutdownAndAwaitTermination(ExecutorService pool) {
boolean hasShutdown = true;
pool.shutdown(); // Disable new tasks from being submitted
try {
// Wait a while for existing tasks to terminate
if (!pool.awaitTermination(60, TimeUnit.SECONDS)) {
pool.shutdownNow(); // Cancel currently executing tasks
// Wait a while for tasks to respond to being canceled
if (!pool.awaitTermination(60, TimeUnit.SECONDS))
hasShutdown = false;
}
} catch (InterruptedException ie) {
// (Re-)Cancel if current thread also interrupted
pool.shutdownNow();
// Preserve interrupt status
Thread.currentThread().interrupt();
hasShutdown = false;
}
return hasShutdown;
}
/**
* Initialize a ProcessBuilder to run a command using the system shell.
*
* @param cmd
* command to execute. This string should originate from the
* end-user, and thus is platform specific.
* @param args
* arguments to pass to command. These should be protected from
* shell evaluation.
* @return a partially completed process builder. Caller should finish
* populating directory, environment, and then start the process.
*/
public abstract ProcessBuilder runInShell(String cmd, String[] args);
/**
* Execute a command defined by a {@link java.lang.ProcessBuilder}.
*
* @param pb
* The command to be executed
* @param in
* The standard input stream passed to the process
* @return The result of the executed command
* @throws java.lang.InterruptedException
* @throws java.io.IOException
* @since 4.2
*/
public ExecutionResult execute(ProcessBuilder pb, InputStream in)
throws IOException, InterruptedException {
try (TemporaryBuffer stdout = new TemporaryBuffer.LocalFile(null);
TemporaryBuffer stderr = new TemporaryBuffer.Heap(1024,
1024 * 1024)) {
int rc = runProcess(pb, stdout, stderr, in);
return new ExecutionResult(stdout, stderr, rc);
}
}
private static class Holder<V> {
final V value;
Holder(V value) {
this.value = value;
}
}
/**
* File attributes we typically care for.
*
* @since 3.3
*/
public static class Attributes {
/**
* @return true if this are the attributes of a directory
*/
public boolean isDirectory() {
return isDirectory;
}
/**
* @return true if this are the attributes of an executable file
*/
public boolean isExecutable() {
return isExecutable;
}
/**
* @return true if this are the attributes of a symbolic link
*/
public boolean isSymbolicLink() {
return isSymbolicLink;
}
/**
* @return true if this are the attributes of a regular file
*/
public boolean isRegularFile() {
return isRegularFile;
}
/**
* @return the time when the file was created
*/
public long getCreationTime() {
return creationTime;
}
/**
* @return the time (milliseconds since 1970-01-01) when this object was
* last modified
* @deprecated use getLastModifiedInstant instead
*/
@Deprecated
public long getLastModifiedTime() {
return lastModifiedInstant.toEpochMilli();
}
/**
* @return the time when this object was last modified
* @since 5.1.9
*/
public Instant getLastModifiedInstant() {
return lastModifiedInstant;
}
private final boolean isDirectory;
private final boolean isSymbolicLink;
private final boolean isRegularFile;
private final long creationTime;
private final Instant lastModifiedInstant;
private final boolean isExecutable;
private final File file;
private final boolean exists;
/**
* file length
*/
protected long length = -1;
final FS fs;
Attributes(FS fs, File file, boolean exists, boolean isDirectory,
boolean isExecutable, boolean isSymbolicLink,
boolean isRegularFile, long creationTime,
Instant lastModifiedInstant, long length) {
this.fs = fs;
this.file = file;
this.exists = exists;
this.isDirectory = isDirectory;
this.isExecutable = isExecutable;
this.isSymbolicLink = isSymbolicLink;
this.isRegularFile = isRegularFile;
this.creationTime = creationTime;
this.lastModifiedInstant = lastModifiedInstant;
this.length = length;
}
/**
* Constructor when there are issues with reading. All attributes except
* given will be set to the default values.
*
* @param fs
* @param path
*/
public Attributes(File path, FS fs) {
this(fs, path, false, false, false, false, false, 0L, EPOCH, 0L);
}
/**
* @return length of this file object
*/
public long getLength() {
if (length == -1)
return length = file.length();
return length;
}
/**
* @return the filename
*/
public String getName() {
return file.getName();
}
/**
* @return the file the attributes apply to
*/
public File getFile() {
return file;
}
boolean exists() {
return exists;
}
}
/**
* Get the file attributes we care for.
*
* @param path
* a {@link java.io.File} object.
* @return the file attributes we care for.
* @since 3.3
*/
public Attributes getAttributes(File path) {
boolean isDirectory = isDirectory(path);
boolean isFile = !isDirectory && path.isFile();
assert path.exists() == isDirectory || isFile;
boolean exists = isDirectory || isFile;
boolean canExecute = exists && !isDirectory && canExecute(path);
boolean isSymlink = false;
Instant lastModified = exists ? lastModifiedInstant(path) : EPOCH;
long createTime = 0L;
return new Attributes(this, path, exists, isDirectory, canExecute,
isSymlink, isFile, createTime, lastModified, -1);
}
/**
* Normalize the unicode path to composed form.
*
* @param file
* a {@link java.io.File} object.
* @return NFC-format File
* @since 3.3
*/
public File normalize(File file) {
return file;
}
/**
* Normalize the unicode path to composed form.
*
* @param name
* path name
* @return NFC-format string
* @since 3.3
*/
public String normalize(String name) {
return name;
}
/**
* This runnable will consume an input stream's content into an output
* stream as soon as it gets available.
* <p>
* Typically used to empty processes' standard output and error, preventing
* them to choke.
* </p>
* <p>
* <b>Note</b> that a {@link StreamGobbler} will never close either of its
* streams.
* </p>
*/
private static class StreamGobbler implements Runnable {
private InputStream in;
private OutputStream out;
public StreamGobbler(InputStream stream, OutputStream output) {
this.in = stream;
this.out = output;
}
@Override
public void run() {
try {
copy();
} catch (IOException e) {
// Do nothing on read failure; leave streams open.
}
}
void copy() throws IOException {
boolean writeFailure = false;
byte[] buffer = new byte[4096];
int readBytes;
while ((readBytes = in.read(buffer)) != -1) {
// Do not try to write again after a failure, but keep
// reading as long as possible to prevent the input stream
// from choking.
if (!writeFailure && out != null) {
try {
out.write(buffer, 0, readBytes);
out.flush();
} catch (IOException e) {
writeFailure = true;
}
}
}
}
}
}