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Posted to commits@harmony.apache.org by te...@apache.org on 2009/06/24 14:30:04 UTC
svn commit: r787995 - in /harmony/enhanced/classlib/trunk/modules/luni/src:
main/java/java/lang/String.java
test/api/common/org/apache/harmony/luni/tests/java/lang/String2Test.java
Author: tellison
Date: Wed Jun 24 12:30:03 2009
New Revision: 787995
URL: http://svn.apache.org/viewvc?rev=787995&view=rev
Log:
Improve performance of String.hashCode() by avoiding multiplier.
Modified:
harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/String.java
harmony/enhanced/classlib/trunk/modules/luni/src/test/api/common/org/apache/harmony/luni/tests/java/lang/String2Test.java
Modified: harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/String.java
URL: http://svn.apache.org/viewvc/harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/String.java?rev=787995&r1=787994&r2=787995&view=diff
==============================================================================
--- harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/String.java (original)
+++ harmony/enhanced/classlib/trunk/modules/luni/src/main/java/java/lang/String.java Wed Jun 24 12:30:03 2009
@@ -937,11 +937,12 @@
@Override
public int hashCode() {
if (hashCode == 0) {
- int hash = 0, multiplier = 1;
- for (int i = offset + count - 1; i >= offset; i--) {
- hash += value[i] * multiplier;
- int shifted = multiplier << 5;
- multiplier = shifted - multiplier;
+ if (count == 0) {
+ return 0;
+ }
+ int hash = 0;
+ for (int i = offset; i < count + offset; i++) {
+ hash = value[i] + ((hash << 5) - hash);
}
hashCode = hash;
}
Modified: harmony/enhanced/classlib/trunk/modules/luni/src/test/api/common/org/apache/harmony/luni/tests/java/lang/String2Test.java
URL: http://svn.apache.org/viewvc/harmony/enhanced/classlib/trunk/modules/luni/src/test/api/common/org/apache/harmony/luni/tests/java/lang/String2Test.java?rev=787995&r1=787994&r2=787995&view=diff
==============================================================================
--- harmony/enhanced/classlib/trunk/modules/luni/src/test/api/common/org/apache/harmony/luni/tests/java/lang/String2Test.java (original)
+++ harmony/enhanced/classlib/trunk/modules/luni/src/test/api/common/org/apache/harmony/luni/tests/java/lang/String2Test.java Wed Jun 24 12:30:03 2009
@@ -529,11 +529,9 @@
hwHashCode += hw1.charAt(counter) * powerOfThirtyOne;
powerOfThirtyOne *= 31;
}
- assertTrue("String did not hash to correct value--got: "
- + String.valueOf(hw1.hashCode()) + " but wanted: "
- + String.valueOf(hwHashCode), hw1.hashCode() == hwHashCode);
- assertTrue("The empty string \"\" did not hash to zero", 0 == ""
- .hashCode());
+ assertEquals("String did not hash to correct value", hwHashCode, hw1.hashCode());
+ assertEquals("The empty string \"\" did not hash to zero", 0, "".hashCode());
+ assertEquals("Calculated wrong string hashcode", -1933545242, "Harmony".hashCode());
}
/**