stan/jdk-24
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

6952330: Fix for 6933217 broke contract of StringBuffer.ensureCapacity

Browse Source 
Make sure to grow with size => size * 2 + 2

Reviewed-by: dholmes, chegar, ohair
This commit is contained in:
Martin Buchholz 2010-05-13 21:56:13 -07:00
parent 0f4df9f618
commit 3927da83d0
2 changed files with 86 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
jdk/src/share/classes/java/lang/AbstractStringBuilder.java
View File

@ -117,7 +117,7 @@ abstract class AbstractStringBuilder implements Appendable, CharSequence {
* size check or synchronization.
*/
void expandCapacity(int minimumCapacity) {
int newCapacity = value.length * 2;
int newCapacity = value.length * 2 + 2;
if (newCapacity - minimumCapacity < 0)
newCapacity = minimumCapacity;
if (newCapacity < 0) {

85
jdk/test/java/lang/StringBuffer/Capacity.java Normal file
View File

@ -0,0 +1,85 @@
/*
* Copyright 2010 Google Inc. 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.
*
* 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* @test
* @bug 6952330
* @summary Test StringBuffer/StringBuilder capacity handling.
*/
import java.util.Random;
public class Capacity {
void test(String[] args) throws Throwable {
Random rnd = new Random();
int[] sizes = { 0, 1, rnd.nextInt(10), rnd.nextInt(1000) };
for (int size : sizes) {
equal(16, new StringBuffer().capacity());
equal(16, new StringBuilder().capacity());
StringBuffer buff = new StringBuffer(size);
StringBuilder bild = new StringBuilder(size);
equal(size, buff.capacity());
equal(size, bild.capacity());
buff.ensureCapacity(size);
bild.ensureCapacity(size);
equal(size, buff.capacity());
equal(size, bild.capacity());
buff.ensureCapacity(size+1);
bild.ensureCapacity(size+1);
equal(size*2+2, buff.capacity());
equal(size*2+2, bild.capacity());
size = buff.capacity();
buff.ensureCapacity(size*2+1);
bild.ensureCapacity(size*2+1);
equal(size*2+2, buff.capacity());
equal(size*2+2, bild.capacity());
size = buff.capacity();
int newSize = size * 2 + 3;
buff.ensureCapacity(newSize);
bild.ensureCapacity(newSize);
equal(newSize, buff.capacity());
equal(newSize, bild.capacity());
buff.ensureCapacity(0);
bild.ensureCapacity(0);
equal(newSize, buff.capacity());
equal(newSize, bild.capacity());
}
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
new Capacity().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
}