github
/
jgit
mirror of https://gitee.com/github-mirror-repo/jgit.git
1
0
Fork 0
Code Issues Releases Wiki Activity
Browse Source

UnionInputStream: combines sequential InputStreams into one 

The UnionInputStream utility class combines multiple sequential
InputStreams so they appear to the caller as a single stream with
no gaps.  This can be used to concentate streams coming from multiple
independent HTTP connections (for example).

The companion unit test covers the class's full functionality.

Change-Id: I0676c7b5e082a5886bf0e8f43f9fd6c46a666228
Signed-off-by: Shawn O. Pearce <sop@google.com>
stable-0.7
Shawn O. Pearce 15 years ago committed by Shawn O. Pearce
parent
0b821817fc
commit
2ef29ed106
2 changed files with 425 additions and 0 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 217
      org.eclipse.jgit.test/tst/org/eclipse/jgit/util/io/UnionInputStreamTest.java
  2. 208
      org.eclipse.jgit/src/org/eclipse/jgit/util/io/UnionInputStream.java

217
org.eclipse.jgit.test/tst/org/eclipse/jgit/util/io/UnionInputStreamTest.java
Unescape View File

@ -0,0 +1,217 @@
/*
* Copyright (C) 2009, Google Inc.
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.eclipse.jgit.util.io;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.Arrays;
import junit.framework.TestCase;
public class UnionInputStreamTest extends TestCase {
public void testEmptyStream() throws IOException {
final UnionInputStream u = new UnionInputStream();
assertTrue(u.isEmpty());
assertEquals(-1, u.read());
assertEquals(-1, u.read(new byte[1], 0, 1));
assertEquals(0, u.available());
assertEquals(0, u.skip(1));
u.close();
}
public void testReadSingleBytes() throws IOException {
final UnionInputStream u = new UnionInputStream();
assertTrue(u.isEmpty());
u.add(new ByteArrayInputStream(new byte[] { 1, 0, 2 }));
u.add(new ByteArrayInputStream(new byte[] { 3 }));
u.add(new ByteArrayInputStream(new byte[] { 4, 5 }));
assertFalse(u.isEmpty());
assertEquals(3, u.available());
assertEquals(1, u.read());
assertEquals(0, u.read());
assertEquals(2, u.read());
assertEquals(0, u.available());
assertEquals(3, u.read());
assertEquals(0, u.available());
assertEquals(4, u.read());
assertEquals(1, u.available());
assertEquals(5, u.read());
assertEquals(0, u.available());
assertEquals(-1, u.read());
assertTrue(u.isEmpty());
u.add(new ByteArrayInputStream(new byte[] { (byte) 255 }));
assertEquals(255, u.read());
assertEquals(-1, u.read());
assertTrue(u.isEmpty());
}
public void testReadByteBlocks() throws IOException {
final UnionInputStream u = new UnionInputStream();
u.add(new ByteArrayInputStream(new byte[] { 1, 0, 2 }));
u.add(new ByteArrayInputStream(new byte[] { 3 }));
u.add(new ByteArrayInputStream(new byte[] { 4, 5 }));
final byte[] r = new byte[5];
assertEquals(5, u.read(r, 0, 5));
assertTrue(Arrays.equals(new byte[] { 1, 0, 2, 3, 4 }, r));
assertEquals(1, u.read(r, 0, 5));
assertEquals(5, r[0]);
assertEquals(-1, u.read(r, 0, 5));
}
public void testArrayConstructor() throws IOException {
final UnionInputStream u = new UnionInputStream(
new ByteArrayInputStream(new byte[] { 1, 0, 2 }),
new ByteArrayInputStream(new byte[] { 3 }),
new ByteArrayInputStream(new byte[] { 4, 5 }));
final byte[] r = new byte[5];
assertEquals(5, u.read(r, 0, 5));
assertTrue(Arrays.equals(new byte[] { 1, 0, 2, 3, 4 }, r));
assertEquals(1, u.read(r, 0, 5));
assertEquals(5, r[0]);
assertEquals(-1, u.read(r, 0, 5));
}
public void testMarkSupported() {
final UnionInputStream u = new UnionInputStream();
assertFalse(u.markSupported());
u.add(new ByteArrayInputStream(new byte[] { 1, 0, 2 }));
assertFalse(u.markSupported());
}
public void testSkip() throws IOException {
final UnionInputStream u = new UnionInputStream();
u.add(new ByteArrayInputStream(new byte[] { 1, 0, 2 }));
u.add(new ByteArrayInputStream(new byte[] { 3 }));
u.add(new ByteArrayInputStream(new byte[] { 4, 5 }));
assertEquals(0, u.skip(0));
assertEquals(4, u.skip(4));
assertEquals(4, u.read());
assertEquals(1, u.skip(5));
assertEquals(0, u.skip(5));
assertEquals(-1, u.read());
u.add(new ByteArrayInputStream(new byte[] { 20, 30 }) {
public long skip(long n) {
return 0;
}
});
assertEquals(2, u.skip(8));
assertEquals(-1, u.read());
}
public void testAutoCloseDuringRead() throws IOException {
final UnionInputStream u = new UnionInputStream();
final boolean closed[] = new boolean[2];
u.add(new ByteArrayInputStream(new byte[] { 1 }) {
public void close() {
closed[0] = true;
}
});
u.add(new ByteArrayInputStream(new byte[] { 2 }) {
public void close() {
closed[1] = true;
}
});
assertFalse(closed[0]);
assertFalse(closed[1]);
assertEquals(1, u.read());
assertFalse(closed[0]);
assertFalse(closed[1]);
assertEquals(2, u.read());
assertTrue(closed[0]);
assertFalse(closed[1]);
assertEquals(-1, u.read());
assertTrue(closed[0]);
assertTrue(closed[1]);
}
public void testCloseDuringClose() throws IOException {
final UnionInputStream u = new UnionInputStream();
final boolean closed[] = new boolean[2];
u.add(new ByteArrayInputStream(new byte[] { 1 }) {
public void close() {
closed[0] = true;
}
});
u.add(new ByteArrayInputStream(new byte[] { 2 }) {
public void close() {
closed[1] = true;
}
});
assertFalse(closed[0]);
assertFalse(closed[1]);
u.close();
assertTrue(closed[0]);
assertTrue(closed[1]);
}
public void testExceptionDuringClose() {
final UnionInputStream u = new UnionInputStream();
u.add(new ByteArrayInputStream(new byte[] { 1 }) {
public void close() throws IOException {
throw new IOException("I AM A TEST");
}
});
try {
u.close();
fail("close ignored inner stream exception");
} catch (IOException e) {
assertEquals("I AM A TEST", e.getMessage());
}
}
}

208
org.eclipse.jgit/src/org/eclipse/jgit/util/io/UnionInputStream.java
Unescape View File

@ -0,0 +1,208 @@
/*
* Copyright (C) 2009, Google Inc.
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.eclipse.jgit.util.io;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import java.util.LinkedList;
/**
* An InputStream which reads from one or more InputStreams.
* <p>
* This stream may enter into an EOF state, returning -1 from any of the read
* methods, and then later successfully read additional bytes if a new
* InputStream is added after reaching EOF.
* <p>
* Currently this stream does not support the mark/reset APIs. If mark and later
* reset functionality is needed the caller should wrap this stream with a
* {@link java.io.BufferedInputStream}.
* */
public class UnionInputStream extends InputStream {
private static final InputStream EOF = new InputStream() {
@Override
public int read() throws IOException {
return -1;
}
};
private final LinkedList<InputStream> streams = new LinkedList<InputStream>();
/** Create an empty InputStream that is currently at EOF state. */
public UnionInputStream() {
// Do nothing.
}
/**
* Create an InputStream that is a union of the individual streams.
* <p>
* As each stream reaches EOF, it will be automatically closed before bytes
* from the next stream are read.
*
* @param inputStreams
* streams to be pushed onto this stream.
*/
public UnionInputStream(InputStream... inputStreams) {
for (InputStream i : inputStreams)
add(i);
}
private InputStream head() {
return streams.isEmpty() ? EOF : streams.getFirst();
}
private void pop() throws IOException {
if (!streams.isEmpty())
streams.removeFirst().close();
}
/**
* Add the given InputStream onto the end of the stream queue.
* <p>
* When the stream reaches EOF it will be automatically closed.
*
* @param in
* the stream to add; must not be null.
*/
public void add(final InputStream in) {
streams.add(in);
}
/**
* Returns true if there are no more InputStreams in the stream queue.
* <p>
* If this method returns {@code true} then all read methods will signal EOF
* by returning -1, until another InputStream has been pushed into the queue
* with {@link #add(InputStream)}.
*
* @return true if there are no more streams to read from.
*/
public boolean isEmpty() {
return streams.isEmpty();
}
@Override
public int read() throws IOException {
for (;;) {
final InputStream in = head();
final int r = in.read();
if (0 <= r)
return r;
else if (in == EOF)
return -1;
else
pop();
}
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
int cnt = 0;
while (0 < len) {
final InputStream in = head();
final int n = in.read(b, off, len);
if (0 < n) {
cnt += n;
off += n;
len -= n;
} else if (in == EOF)
return 0 < cnt ? cnt : -1;
else
pop();
}
return cnt;
}
@Override
public int available() throws IOException {
return head().available();
}
@Override
public long skip(long len) throws IOException {
long cnt = 0;
while (0 < len) {
final InputStream in = head();
final long n = in.skip(len);
if (0 < n) {
cnt += n;
len -= n;
} else if (in == EOF) {
return cnt;
} else {
// Is this stream at EOF? We can't tell from skip alone.
// Read one byte to test for EOF, discard it if we aren't
// yet at EOF.
//
final int r = in.read();
if (r < 0) {
pop();
} else {
cnt += 1;
len -= 1;
}
}
}
return cnt;
}
@Override
public void close() throws IOException {
IOException err = null;
for (Iterator<InputStream> i = streams.iterator(); i.hasNext();) {
try {
i.next().close();
} catch (IOException closeError) {
err = closeError;
}
i.remove();
}
if (err != null)
throw err;
}
}
Write Preview
Loading…
Cancel
Save