src/java.base/share/classes/java/lang/StringBuffer.java

rev 13124 : [mq]: XXXXXXX-ASB-shared-value

@@ -98,16 +98,10 @@
  public final class StringBuffer
     extends AbstractStringBuilder
     implements java.io.Serializable, CharSequence
 {
 
-    /**
-     * A cache of the last value returned by toString. Cleared
-     * whenever the StringBuffer is modified.
-     */
-    private transient String toStringCache;
-
     /** use serialVersionUID from JDK 1.0.2 for interoperability */
     static final long serialVersionUID = 3388685877147921107L;
 
     /**
      * Constructs a string buffer with no characters in it and an

@@ -190,11 +184,10 @@
      * @throws IndexOutOfBoundsException {@inheritDoc}
      * @see        #length()
      */
     @Override
     public synchronized void setLength(int newLength) {
-        toStringCache = null;
         super.setLength(newLength);
     }
 
     /**
      * @throws IndexOutOfBoundsException {@inheritDoc}

@@ -255,25 +248,22 @@
      * @throws IndexOutOfBoundsException {@inheritDoc}
      * @see        #length()
      */
     @Override
     public synchronized void setCharAt(int index, char ch) {
-        toStringCache = null;
         super.setCharAt(index, ch);
     }
 
     @Override
     public synchronized StringBuffer append(Object obj) {
-        toStringCache = null;
         super.append(String.valueOf(obj));
         return this;
     }
 
     @Override
     @HotSpotIntrinsicCandidate
     public synchronized StringBuffer append(String str) {
-        toStringCache = null;
         super.append(str);
         return this;
     }
 
     /**

@@ -299,21 +289,19 @@
      * @param   sb   the {@code StringBuffer} to append.
      * @return  a reference to this object.
      * @since 1.4
      */
     public synchronized StringBuffer append(StringBuffer sb) {
-        toStringCache = null;
         super.append(sb);
         return this;
     }
 
     /**
      * @since 1.8
      */
     @Override
     synchronized StringBuffer append(AbstractStringBuilder asb) {
-        toStringCache = null;
         super.append(asb);
         return this;
     }
 
     /**

@@ -337,11 +325,10 @@
      * @return  a reference to this object.
      * @since 1.5
      */
     @Override
     public synchronized StringBuffer append(CharSequence s) {
-        toStringCache = null;
         super.append(s);
         return this;
     }
 
     /**

@@ -349,115 +336,102 @@
      * @since      1.5
      */
     @Override
     public synchronized StringBuffer append(CharSequence s, int start, int end)
     {
-        toStringCache = null;
         super.append(s, start, end);
         return this;
     }
 
     @Override
     public synchronized StringBuffer append(char[] str) {
-        toStringCache = null;
         super.append(str);
         return this;
     }
 
     /**
      * @throws IndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public synchronized StringBuffer append(char[] str, int offset, int len) {
-        toStringCache = null;
         super.append(str, offset, len);
         return this;
     }
 
     @Override
     public synchronized StringBuffer append(boolean b) {
-        toStringCache = null;
         super.append(b);
         return this;
     }
 
     @Override
     @HotSpotIntrinsicCandidate
     public synchronized StringBuffer append(char c) {
-        toStringCache = null;
         super.append(c);
         return this;
     }
 
     @Override
     @HotSpotIntrinsicCandidate
     public synchronized StringBuffer append(int i) {
-        toStringCache = null;
         super.append(i);
         return this;
     }
 
     /**
      * @since 1.5
      */
     @Override
     public synchronized StringBuffer appendCodePoint(int codePoint) {
-        toStringCache = null;
         super.appendCodePoint(codePoint);
         return this;
     }
 
     @Override
     public synchronized StringBuffer append(long lng) {
-        toStringCache = null;
         super.append(lng);
         return this;
     }
 
     @Override
     public synchronized StringBuffer append(float f) {
-        toStringCache = null;
         super.append(f);
         return this;
     }
 
     @Override
     public synchronized StringBuffer append(double d) {
-        toStringCache = null;
         super.append(d);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      * @since      1.2
      */
     @Override
     public synchronized StringBuffer delete(int start, int end) {
-        toStringCache = null;
         super.delete(start, end);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      * @since      1.2
      */
     @Override
     public synchronized StringBuffer deleteCharAt(int index) {
-        toStringCache = null;
         super.deleteCharAt(index);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      * @since      1.2
      */
     @Override
     public synchronized StringBuffer replace(int start, int end, String str) {
-        toStringCache = null;
         super.replace(start, end, str);
         return this;
     }
 
     /**

@@ -493,41 +467,37 @@
      */
     @Override
     public synchronized StringBuffer insert(int index, char[] str, int offset,
                                             int len)
     {
-        toStringCache = null;
         super.insert(index, str, offset, len);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public synchronized StringBuffer insert(int offset, Object obj) {
-        toStringCache = null;
         super.insert(offset, String.valueOf(obj));
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public synchronized StringBuffer insert(int offset, String str) {
-        toStringCache = null;
         super.insert(offset, str);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public synchronized StringBuffer insert(int offset, char[] str) {
-        toStringCache = null;
         super.insert(offset, str);
         return this;
     }
 
     /**

@@ -536,11 +506,10 @@
      */
     @Override
     public StringBuffer insert(int dstOffset, CharSequence s) {
         // Note, synchronization achieved via invocations of other StringBuffer methods
         // after narrowing of s to specific type
-        // Ditto for toStringCache clearing
         super.insert(dstOffset, s);
         return this;
     }
 
     /**

@@ -549,11 +518,10 @@
      */
     @Override
     public synchronized StringBuffer insert(int dstOffset, CharSequence s,
             int start, int end)
     {
-        toStringCache = null;
         super.insert(dstOffset, s, start, end);
         return this;
     }
 
     /**

@@ -561,21 +529,19 @@
      */
     @Override
     public  StringBuffer insert(int offset, boolean b) {
         // Note, synchronization achieved via invocation of StringBuffer insert(int, String)
         // after conversion of b to String by super class method
-        // Ditto for toStringCache clearing
         super.insert(offset, b);
         return this;
     }
 
     /**
      * @throws IndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public synchronized StringBuffer insert(int offset, char c) {
-        toStringCache = null;
         super.insert(offset, c);
         return this;
     }
 
     /**

@@ -583,11 +549,10 @@
      */
     @Override
     public StringBuffer insert(int offset, int i) {
         // Note, synchronization achieved via invocation of StringBuffer insert(int, String)
         // after conversion of i to String by super class method
-        // Ditto for toStringCache clearing
         super.insert(offset, i);
         return this;
     }
 
     /**

@@ -595,11 +560,10 @@
      */
     @Override
     public StringBuffer insert(int offset, long l) {
         // Note, synchronization achieved via invocation of StringBuffer insert(int, String)
         // after conversion of l to String by super class method
-        // Ditto for toStringCache clearing
         super.insert(offset, l);
         return this;
     }
 
     /**

@@ -607,11 +571,10 @@
      */
     @Override
     public StringBuffer insert(int offset, float f) {
         // Note, synchronization achieved via invocation of StringBuffer insert(int, String)
         // after conversion of f to String by super class method
-        // Ditto for toStringCache clearing
         super.insert(offset, f);
         return this;
     }
 
     /**

@@ -619,11 +582,10 @@
      */
     @Override
     public StringBuffer insert(int offset, double d) {
         // Note, synchronization achieved via invocation of StringBuffer insert(int, String)
         // after conversion of d to String by super class method
-        // Ditto for toStringCache clearing
         super.insert(offset, d);
         return this;
     }
 
     /**

@@ -663,24 +625,26 @@
     /**
      * @since   1.0.2
      */
     @Override
     public synchronized StringBuffer reverse() {
-        toStringCache = null;
         super.reverse();
         return this;
     }
 
     @Override
     @HotSpotIntrinsicCandidate
     public synchronized String toString() {
-        if (toStringCache == null) {
-            return toStringCache =
-                    isLatin1() ? StringLatin1.newString(value, 0, count)
-                               : StringUTF16.newString(value, 0, count);
+        final byte[] value = this.value;
+        if (isLatin1()) {
+            if ((count << coder) < value.length) {
+                return StringLatin1.newString(value, 0, count);
+            }
+            shared = true;
+            return new String(value, String.LATIN1);
         }
-        return new String(toStringCache);
+        return StringUTF16.newString(value, 0, count);
     }
 
     /**
      * Serializable fields for StringBuffer.
      *

@@ -726,10 +690,11 @@
         throws java.io.IOException, ClassNotFoundException {
         java.io.ObjectInputStream.GetField fields = s.readFields();
         char[] val = (char[])fields.get("value", null);
         initBytes(val, 0, val.length);
         count = fields.get("count", 0);
+        shared = false;
     }
 
     synchronized void getBytes(byte dst[], int dstBegin, byte coder) {
         super.getBytes(dst, dstBegin, coder);
     }