motiejus
/
jgit
1
Fork 0
Code Releases Activity

IO: Add a method for reading lines 

Change-Id: Ib7be76aa7ac889354ad4782e2b64d4221a0e25b9
This commit is contained in:
Dave Borowitz 2015-06-29 17:26:39 -07:00
parent 469734bf87
commit dac6ae3d17
2 changed files with 185 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

116
org.eclipse.jgit.test/tst/org/eclipse/jgit/util/IOReadLineTest.java Normal file
View File

@ -0,0 +1,116 @@
/*
* Copyright (C) 2015, 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;
import static org.junit.Assert.assertEquals;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.Collection;
import org.eclipse.jgit.lib.Constants;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameter;
import org.junit.runners.Parameterized.Parameters;
@RunWith(Parameterized.class)
public class IOReadLineTest {
@Parameter(0)
public boolean buffered;
@Parameter(1)
public int sizeHint;
@SuppressWarnings("boxing")
@Parameters(name="buffered={0}, sizeHint={1}")
public static Collection<Object[]> getParameters() {
Boolean[] bv = {false, true};
Integer[] sv = {-1, 0, 1, 2, 3, 4, 64};
Collection<Object[]> params = new ArrayList<>(bv.length * sv.length);
for (boolean b : bv) {
for (Integer s : sv) {
params.add(new Object[]{b, s});
}
}
return params;
}
@Test
public void testReadLine() throws Exception {
Reader r = newReader("foo\nbar\nbaz\n");
assertEquals("foo\n", readLine(r));
assertEquals("bar\n", readLine(r));
assertEquals("baz\n", readLine(r));
assertEquals("", readLine(r));
}
@Test
public void testReadLineNoTrailingNewline() throws Exception {
Reader r = newReader("foo\nbar\nbaz");
assertEquals("foo\n", readLine(r));
assertEquals("bar\n", readLine(r));
assertEquals("baz", readLine(r));
assertEquals("", readLine(r));
}
private String readLine(Reader r) throws Exception {
return IO.readLine(r, sizeHint);
}
private Reader newReader(String in) {
Reader r = new InputStreamReader(
new ByteArrayInputStream(Constants.encode(in)));
if (buffered) {
r = new BufferedReader(r);
}
assertEquals(Boolean.valueOf(buffered),
Boolean.valueOf(r.markSupported()));
return r;
}
}

69
org.eclipse.jgit/src/org/eclipse/jgit/util/IO.java
View File

@ -51,6 +51,7 @@
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.nio.ByteBuffer;
import java.nio.channels.ReadableByteChannel;
import java.text.MessageFormat;
@ -371,6 +372,74 @@ public static List<String> readLines(final String s) {
return l;
}
/**
* Read the next line from a reader.
* <p>
* Like {@link java.io.BufferedReader#readLine()}, but only treats {@code \n}
* as end-of-line, and includes the trailing newline.
*
* @param in
* the reader to read from.
* @param sizeHint
* hint for buffer sizing; 0 or negative for default.
* @return the next line from the input, always ending in {@code \n} unless
* EOF was reached.
* @throws IOException
* there was an error reading from the stream.
*/
public static String readLine(Reader in, int sizeHint) throws IOException {
if (in.markSupported()) {
if (sizeHint <= 0) {
sizeHint = 1024;
}
StringBuilder sb = new StringBuilder(sizeHint);
char[] buf = new char[sizeHint];
while (true) {
in.mark(sizeHint);
int n = in.read(buf);
if (n < 0) {
in.reset();
return sb.toString();
}
for (int i = 0; i < n; i++) {
if (buf[i] == '\n') {
resetAndSkipFully(in, ++i);
sb.append(buf, 0, i);
return sb.toString();
}
}
if (n > 0) {
sb.append(buf, 0, n);
}
resetAndSkipFully(in, n);
}
} else {
StringBuilder buf = sizeHint > 0
? new StringBuilder(sizeHint)
: new StringBuilder();
int i;
while ((i = in.read()) != -1) {
char c = (char) i;
buf.append(c);
if (c == '\n') {
break;
}
}
return buf.toString();
}
}
private static void resetAndSkipFully(Reader fd, long toSkip) throws IOException {
fd.reset();
while (toSkip > 0) {
long r = fd.skip(toSkip);
if (r <= 0) {
throw new EOFException(JGitText.get().shortSkipOfBlock);
}
toSkip -= r;
}
}
private IO() {
// Don't create instances of a static only utility.
}