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6553074: String{Buffer,Builder}.indexOf(Str, int) contains unnecessary allocation
authormduigou
Thu, 29 Nov 2012 14:09:45 -0800
changeset 14686 fb59583d33b2
parent 14685 07f3bb681bfc
child 14687 1af181e94395
6553074: String{Buffer,Builder}.indexOf(Str, int) contains unnecessary allocation Summary: It is not necessary to extract the value array with toCharArray. The value array can now be used directly. Reviewed-by: alanb
jdk/src/share/classes/java/lang/AbstractStringBuilder.java file | annotate | diff | comparison | revisions
jdk/src/share/classes/java/lang/String.java file | annotate | diff | comparison | revisions 
--- a/jdk/src/share/classes/java/lang/AbstractStringBuilder.java	Thu Nov 29 14:07:47 2012 -0800
+++ b/jdk/src/share/classes/java/lang/AbstractStringBuilder.java	Thu Nov 29 14:09:45 2012 -0800
@@ -177,11 +177,10 @@
         ensureCapacityInternal(newLength);
 
         if (count < newLength) {
-            for (; count < newLength; count++)
-                value[count] = '\0';
-        } else {
-            count = newLength;
+            Arrays.fill(value, count, newLength, '\0');
         }
+
+        count = newLength;
     }
 
     /**
@@ -1308,8 +1307,7 @@
      *            {@code null}.
      */
     public int indexOf(String str, int fromIndex) {
-        return String.indexOf(value, 0, count,
-                              str.toCharArray(), 0, str.length(), fromIndex);
+        return String.indexOf(value, 0, count, str, fromIndex);
     }
 
     /**
@@ -1352,8 +1350,7 @@
      *          {@code null}.
      */
     public int lastIndexOf(String str, int fromIndex) {
-        return String.lastIndexOf(value, 0, count,
-                              str.toCharArray(), 0, str.length(), fromIndex);
+        return String.lastIndexOf(value, 0, count, str, fromIndex);
     }
 
     /**
--- a/jdk/src/share/classes/java/lang/String.java	Thu Nov 29 14:07:47 2012 -0800
+++ b/jdk/src/share/classes/java/lang/String.java	Thu Nov 29 14:09:45 2012 -0800
@@ -1706,6 +1706,24 @@
     }
 
     /**
+     * Code shared by String and AbstractStringBuilder to do searches. The
+     * source is the character array being searched, and the target
+     * is the string being searched for.
+     *
+     * @param   source       the characters being searched.
+     * @param   sourceOffset offset of the source string.
+     * @param   sourceCount  count of the source string.
+     * @param   target       the characters being searched for.
+     * @param   fromIndex    the index to begin searching from.
+     */
+    static int indexOf(char[] source, int sourceOffset, int sourceCount,
+            String target, int fromIndex) {
+        return indexOf(source, sourceOffset, sourceCount,
+                       target.value, 0, target.value.length,
+                       fromIndex);
+    }
+
+    /**
      * Code shared by String and StringBuffer to do searches. The
      * source is the character array being searched, and the target
      * is the string being searched for.
@@ -1797,6 +1815,24 @@
     }
 
     /**
+     * Code shared by String and AbstractStringBuilder to do searches. The
+     * source is the character array being searched, and the target
+     * is the string being searched for.
+     *
+     * @param   source       the characters being searched.
+     * @param   sourceOffset offset of the source string.
+     * @param   sourceCount  count of the source string.
+     * @param   target       the characters being searched for.
+     * @param   fromIndex    the index to begin searching from.
+     */
+    static int lastIndexOf(char[] source, int sourceOffset, int sourceCount,
+            String target, int fromIndex) {
+        return lastIndexOf(source, sourceOffset, sourceCount,
+                       target.value, 0, target.value.length,
+                       fromIndex);
+    }
+
+    /**
      * Code shared by String and StringBuffer to do searches. The
      * source is the character array being searched, and the target
      * is the string being searched for.
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