/*
- * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2018, Oracle and/or its affiliates. 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.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 
 package java.lang;
 
+import jdk.internal.HotSpotIntrinsicCandidate;
 
 /**
  * A mutable sequence of characters.  This class provides an API compatible
  * with {@code StringBuffer}, but with no guarantee of synchronization.
  * This class is designed for use as a drop-in replacement for
  * {@code StringBuffer} in places where the string buffer was being
  * used by a single thread (as is generally the case).   Where possible,
  * it is recommended that this class be used in preference to
  * {@code StringBuffer} as it will be faster under most implementations.
  *
  * <p>The principal operations on a {@code StringBuilder} are the
  * {@code append} and {@code insert} methods, which are
  * overloaded so as to accept data of any type. Each effectively
  * converts a given datum to a string and then appends or inserts the
  * characters of that string to the string builder. The
  * {@code append} method always adds these characters at the end
  * of the builder; the {@code insert} method adds the characters at
  * a specified point.
  * <p>
  * For example, if {@code z} refers to a string builder object
  * whose current contents are "{@code start}", then
  * the method call {@code z.append("le")} would cause the string
  * builder to contain "{@code startle}", whereas
  * {@code z.insert(4, "le")} would alter the string builder to
  * contain "{@code starlet}".
  * <p>
  * In general, if sb refers to an instance of a {@code StringBuilder},
  * then {@code sb.append(x)} has the same effect as
  * {@code sb.insert(sb.length(), x)}.
  * <p>
  * Every string builder has a capacity. As long as the length of the
  * character sequence contained in the string builder does not exceed
  * the capacity, it is not necessary to allocate a new internal
  * buffer. If the internal buffer overflows, it is automatically made larger.
  *
  * <p>Instances of {@code StringBuilder} are not safe for
  * use by multiple threads. If such synchronization is required then it is
  * recommended that {@link java.lang.StringBuffer} be used.
  *
  * <p>Unless otherwise noted, passing a {@code null} argument to a constructor
  * or method in this class will cause a {@link NullPointerException} to be
  * thrown.
  *
+ * @apiNote
+ * {@code StringBuilder} implements {@code Comparable} but does not override
+ * {@link Object#equals equals}. Thus, the natural ordering of {@code StringBuilder}
+ * is inconsistent with equals. Care should be exercised if {@code StringBuilder}
+ * objects are used as keys in a {@code SortedMap} or elements in a {@code SortedSet}.
+ * See {@link Comparable}, {@link java.util.SortedMap SortedMap}, or
+ * {@link java.util.SortedSet SortedSet} for more information.
+ *
  * @author      Michael McCloskey
  * @see         java.lang.StringBuffer
  * @see         java.lang.String
  * @since       1.5
  */
 public final class StringBuilder
     extends AbstractStringBuilder
-    implements java.io.Serializable, CharSequence
+    implements java.io.Serializable, Comparable<StringBuilder>, CharSequence
 {
 
     /** use serialVersionUID for interoperability */
     static final long serialVersionUID = 4383685877147921099L;
 
     /**
      * Constructs a string builder with no characters in it and an
      * initial capacity of 16 characters.
      */
+    @HotSpotIntrinsicCandidate
     public StringBuilder() {
         super(16);
     }
 
     /**
      * Constructs a string builder with no characters in it and an
      * initial capacity specified by the {@code capacity} argument.
      *
      * @param      capacity  the initial capacity.
      * @throws     NegativeArraySizeException  if the {@code capacity}
      *               argument is less than {@code 0}.
      */
+    @HotSpotIntrinsicCandidate
     public StringBuilder(int capacity) {
         super(capacity);
     }
 
     /**
      * Constructs a string builder initialized to the contents of the
      * specified string. The initial capacity of the string builder is
      * {@code 16} plus the length of the string argument.
      *
      * @param   str   the initial contents of the buffer.
      */
+    @HotSpotIntrinsicCandidate
     public StringBuilder(String str) {
         super(str.length() + 16);
         append(str);
     }
 
     /**
      * Constructs a string builder that contains the same characters
      * as the specified {@code CharSequence}. The initial capacity of
      * the string builder is {@code 16} plus the length of the
      * {@code CharSequence} argument.
      *
      * @param      seq   the sequence to copy.
      */
     public StringBuilder(CharSequence seq) {
         this(seq.length() + 16);
         append(seq);
     }
 
+    /**
+     * Compares two {@code StringBuilder} instances lexicographically. This method
+     * follows the same rules for lexicographical comparison as defined in the
+     * {@linkplain java.lang.CharSequence#compare(java.lang.CharSequence,
+     * java.lang.CharSequence)  CharSequence.compare(this, another)} method.
+     *
+     * <p>
+     * For finer-grained, locale-sensitive String comparison, refer to
+     * {@link java.text.Collator}.
+     *
+     * @param another the {@code StringBuilder} to be compared with
+     *
+     * @return  the value {@code 0} if this {@code StringBuilder} contains the same
+     * character sequence as that of the argument {@code StringBuilder}; a negative integer
+     * if this {@code StringBuilder} is lexicographically less than the
+     * {@code StringBuilder} argument; or a positive integer if this {@code StringBuilder}
+     * is lexicographically greater than the {@code StringBuilder} argument.
+     *
+     * @since 11
+     */
+    @Override
+    public int compareTo(StringBuilder another) {
+        return super.compareTo(another);
+    }
+
     @Override
     public StringBuilder append(Object obj) {
         return append(String.valueOf(obj));
     }
 
     @Override
+    @HotSpotIntrinsicCandidate
     public StringBuilder append(String str) {
         super.append(str);
         return this;
     }
 
     /**
      * Appends the specified {@code StringBuffer} to this sequence.
      * <p>
      * The characters of the {@code StringBuffer} argument are appended,
      * in order, to this sequence, increasing the
      * length of this sequence by the length of the argument.
      * If {@code sb} is {@code null}, then the four characters
      * {@code "null"} are appended to this sequence.
      * <p>
      * Let <i>n</i> be the length of this character sequence just prior to
      * execution of the {@code append} method. Then the character at index
      * <i>k</i> in the new character sequence is equal to the character at
      * index <i>k</i> in the old character sequence, if <i>k</i> is less than
      * <i>n</i>; otherwise, it is equal to the character at index <i>k-n</i>
      * in the argument {@code sb}.
      *
      * @param   sb   the {@code StringBuffer} to append.
      * @return  a reference to this object.
      */
     public StringBuilder append(StringBuffer sb) {
         super.append(sb);
         return this;
     }
 
     @Override
     public StringBuilder append(CharSequence s) {
         super.append(s);
         return this;
     }
 
     /**
      * @throws     IndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder append(CharSequence s, int start, int end) {
         super.append(s, start, end);
         return this;
     }
 
     @Override
     public StringBuilder append(char[] str) {
         super.append(str);
         return this;
     }
 
     /**
      * @throws IndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder append(char[] str, int offset, int len) {
         super.append(str, offset, len);
         return this;
     }
 
     @Override
     public StringBuilder append(boolean b) {
         super.append(b);
         return this;
     }
 
     @Override
+    @HotSpotIntrinsicCandidate
     public StringBuilder append(char c) {
         super.append(c);
         return this;
     }
 
     @Override
+    @HotSpotIntrinsicCandidate
     public StringBuilder append(int i) {
         super.append(i);
         return this;
     }
 
     @Override
     public StringBuilder append(long lng) {
         super.append(lng);
         return this;
     }
 
     @Override
     public StringBuilder append(float f) {
         super.append(f);
         return this;
     }
 
     @Override
     public StringBuilder append(double d) {
         super.append(d);
         return this;
     }
 
     /**
      * @since 1.5
      */
     @Override
     public StringBuilder appendCodePoint(int codePoint) {
         super.appendCodePoint(codePoint);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder delete(int start, int end) {
         super.delete(start, end);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder deleteCharAt(int index) {
         super.deleteCharAt(index);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder replace(int start, int end, String str) {
         super.replace(start, end, str);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int index, char[] str, int offset,
                                 int len)
     {
         super.insert(index, str, offset, len);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, Object obj) {
             super.insert(offset, obj);
             return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, String str) {
         super.insert(offset, str);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, char[] str) {
         super.insert(offset, str);
         return this;
     }
 
     /**
      * @throws IndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int dstOffset, CharSequence s) {
             super.insert(dstOffset, s);
             return this;
     }
 
     /**
      * @throws IndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int dstOffset, CharSequence s,
                                 int start, int end)
     {
         super.insert(dstOffset, s, start, end);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, boolean b) {
         super.insert(offset, b);
         return this;
     }
 
     /**
      * @throws IndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, char c) {
         super.insert(offset, c);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, int i) {
         super.insert(offset, i);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, long l) {
         super.insert(offset, l);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, float f) {
         super.insert(offset, f);
         return this;
     }
 
     /**
      * @throws StringIndexOutOfBoundsException {@inheritDoc}
      */
     @Override
     public StringBuilder insert(int offset, double d) {
         super.insert(offset, d);
         return this;
     }
 
     @Override
     public int indexOf(String str) {
         return super.indexOf(str);
     }
 
     @Override
     public int indexOf(String str, int fromIndex) {
         return super.indexOf(str, fromIndex);
     }
 
     @Override
     public int lastIndexOf(String str) {
         return super.lastIndexOf(str);
     }
 
     @Override
     public int lastIndexOf(String str, int fromIndex) {
         return super.lastIndexOf(str, fromIndex);
     }
 
     @Override
     public StringBuilder reverse() {
         super.reverse();
         return this;
     }
 
     @Override
+    @HotSpotIntrinsicCandidate
     public String toString() {
         // Create a copy, don't share the array
-        return new String(value, 0, count);
+        return isLatin1() ? StringLatin1.newString(value, 0, count)
+                          : StringUTF16.newString(value, 0, count);
     }
 
     /**
      * Save the state of the {@code StringBuilder} instance to a stream
      * (that is, serialize it).
      *
      * @serialData the number of characters currently stored in the string
      *             builder ({@code int}), followed by the characters in the
      *             string builder ({@code char[]}).   The length of the
      *             {@code char} array may be greater than the number of
      *             characters currently stored in the string builder, in which
      *             case extra characters are ignored.
      */
     private void writeObject(java.io.ObjectOutputStream s)
         throws java.io.IOException {
         s.defaultWriteObject();
         s.writeInt(count);
-        s.writeObject(value);
+        char[] val = new char[capacity()];
+        if (isLatin1()) {
+            StringLatin1.getChars(value, 0, count, val, 0);
+        } else {
+            StringUTF16.getChars(value, 0, count, val, 0);
+        }
+        s.writeObject(val);
     }
 
     /**
      * readObject is called to restore the state of the StringBuffer from
      * a stream.
      */
     private void readObject(java.io.ObjectInputStream s)
         throws java.io.IOException, ClassNotFoundException {
         s.defaultReadObject();
         count = s.readInt();
-        value = (char[]) s.readObject();
+        char[] val = (char[]) s.readObject();
+        initBytes(val, 0, val.length);
     }
 
 }