Re: svn commit: r772849 - /harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/AbstractStringBuilder.java

[Regis]

Regis wrote:

Tim Ellison wrote:

Doesn't this break the spec for ensureCapacity [1]?

It seems to cause a test case failure for me:

expected:<12> but was:<10>

junit.framework.AssertionFailedError: expected:<12> but was:<10>
at

org.apache.harmony.luni.tests.java.lang.StringBuilderTest.test_ensureCapacityI(StringBuilderTest.java:624)

Weird, it didn't appear in my last ran. How about the patch [1], that will not break spec and save the memory?

[1]:

Index: modules/luni/src/main/java/java/lang/AbstractStringBuilder.java
=====================================================================
--- modules/luni/src/main/java/java/lang/AbstractStringBuilder.java
+++ modules/luni/src/main/java/java/lang/AbstractStringBuilder.java
@@ -258,7 +258,8 @@ abstract class AbstractStringBuilder {
      */
     public void ensureCapacity(int min) {
         if (min > value.length) {
-            enlargeBuffer(min);
+            int twice = (value.length << 1) + 2;
+            enlargeBuffer(twice > min ? twice : min);
         }
     }

[1]

http://java.sun.com/j2se/1.5.0/docs/api/java/lang/StringBuilder.html#ensureCapacity(int)

Regards,
Tim


regi...@apache.org wrote:

Author: regisxu
Date: Fri May  8 05:54:20 2009
New Revision: 772849

URL: http://svn.apache.org/viewvc?rev=772849&view=rev
Log:
enlarge half size of buffer to reduce wasted memory

Modified:

harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/AbstractStringBuilder.java

Modified: harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/AbstractStringBuilder.java URL: http://svn.apache.org/viewvc/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/AbstractStringBuilder.java?rev=772849&r1=772848&r2=772849&view=diff ============================================================================== --- harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/AbstractStringBuilder.java (original) +++ harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/AbstractStringBuilder.java Fri May 8 05:54:20 2009

@@ -91,8 +91,8 @@
     }

private void enlargeBuffer(int min) {

-        int twice = (value.length << 1) + 2;
-        char[] newData = new char[min > twice ? min : twice];
+        int newSize = (value.length >> 1 + value.length) + 2;
+        char[] newData = new char[min > newSize ? min : newSize];
         System.arraycopy(value, 0, newData, 0, count);
         value = newData;
         shared = false;

It passed all luni tests, so I applied it to repository at r772937.

--
Best Regards,
Regis.