/*
* Copyright (c) 2008, 2016, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package sun.nio.fs;
import java.nio.file.*;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.concurrent.locks.*;
import java.io.IOException;
import static sun.nio.fs.UnixNativeDispatcher.*;
/**
* Unix implementation of java.nio.file.DirectoryStream
*/
class UnixDirectoryStream
implements DirectoryStream<Path>
{
// path to directory when originally opened
private final UnixPath dir;
// directory pointer (returned by opendir)
private final long dp;
// filter (may be null)
private final DirectoryStream.Filter<? super Path> filter;
// used to coordinate closing of directory stream
private final ReentrantReadWriteLock streamLock =
new ReentrantReadWriteLock(true);
// indicates if directory stream is open (synchronize on closeLock)
private volatile boolean isClosed;
// directory iterator
private Iterator<Path> iterator;
/**
* Initializes a new instance
*/
UnixDirectoryStream(UnixPath dir, long dp, DirectoryStream.Filter<? super Path> filter) {
this.dir = dir;
this.dp = dp;
this.filter = filter;
}
protected final UnixPath directory() {
return dir;
}
protected final Lock readLock() {
return streamLock.readLock();
}
protected final Lock writeLock() {
return streamLock.writeLock();
}
protected final boolean isOpen() {
return !isClosed;
}
protected final boolean closeImpl() throws IOException {
if (!isClosed) {
isClosed = true;
try {
closedir(dp);
} catch (UnixException x) {
throw new IOException(x.errorString());
}
return true;
} else {
return false;
}
}
@Override
public void close()
throws IOException
{
writeLock().lock();
try {
closeImpl();
} finally {
writeLock().unlock();
}
}
protected final Iterator<Path> iterator(DirectoryStream<Path> ds) {
if (isClosed) {
throw new IllegalStateException("Directory stream is closed");
}
synchronized (this) {
if (iterator != null)
throw new IllegalStateException("Iterator already obtained");
iterator = new UnixDirectoryIterator();
return iterator;
}
}
@Override
public Iterator<Path> iterator() {
return iterator(this);
}
/**
* Iterator implementation
*/
private class UnixDirectoryIterator implements Iterator<Path> {
// true when at EOF
private boolean atEof;
// next entry to return
private Path nextEntry;
UnixDirectoryIterator() {
atEof = false;
}
// Return true if file name is "." or ".."
private boolean isSelfOrParent(byte[] nameAsBytes) {
if (nameAsBytes[0] == '.') {
if ((nameAsBytes.length == 1) ||
(nameAsBytes.length == 2 && nameAsBytes[1] == '.')) {
return true;
}
}
return false;
}
// Returns next entry (or null)
private Path readNextEntry() {
assert Thread.holdsLock(this);
for (;;) {
byte[] nameAsBytes = null;
// prevent close while reading
readLock().lock();
try {
if (isOpen()) {
nameAsBytes = readdir(dp);
}
} catch (UnixException x) {
IOException ioe = x.asIOException(dir);
throw new DirectoryIteratorException(ioe);
} finally {
readLock().unlock();
}
// EOF
if (nameAsBytes == null) {
atEof = true;
return null;
}
// ignore "." and ".."
if (!isSelfOrParent(nameAsBytes)) {
Path entry = dir.resolve(nameAsBytes);
// return entry if no filter or filter accepts it
try {
if (filter == null || filter.accept(entry))
return entry;
} catch (IOException ioe) {
throw new DirectoryIteratorException(ioe);
}
}
}
}
@Override
public synchronized boolean hasNext() {
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