2008-02-29 Andrew John Hughes <gnu_andrew@member.fsf.org>

	* gnu/classpath/CPStringBuffer.java:
	New non-copying string buffer.
	* java/lang/AbstractStringBuffer.java:
	Add note about CPStringBuffer.

3 files changed, 1174 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 1a3ab6071..5be098042 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2008-02-29  Andrew John Hughes  <gnu_andrew@member.fsf.org>
+
+	* gnu/classpath/CPStringBuffer.java:
+	New non-copying string buffer.
+	* java/lang/AbstractStringBuffer.java:
+	Add note about CPStringBuffer.
+
 2008-02-28  Andrew John Hughes  <gnu_andrew@member.fsf.org>
 
 	* gnu/java/util/EmptyEnumeration.java:
diff --git a/gnu/classpath/CPStringBuffer.java b/gnu/classpath/CPStringBuffer.java
new file mode 100644
index 000000000..c09034423
--- /dev/null
+++ b/gnu/classpath/CPStringBuffer.java
@@ -0,0 +1,1161 @@
+/* ClasspathStringBuffer.java -- Growable strings without locking or copying
+   Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2008
+   Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath 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 for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package gnu.classpath;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+
+import java.io.Serializable;
+
+/**
+ * This class is based on java.lang.AbstractStringBuffer but
+ * without the copying of the string by toString.
+ * If you modify this, please consider also modifying that code.
+ * This code is not thread-safe; limit its use to internal use within
+ * methods.
+ */
+public final class CPStringBuffer
+  implements Serializable, CharSequence, Appendable
+{
+
+  /**
+   * Index of next available character (and thus the size of the current
+   * string contents).  Note that this has permissions set this way so that
+   * String can get the value.
+   *
+   * @serial the number of characters in the buffer
+   */
+  private int count;
+
+  /**
+   * The buffer.  Note that this has permissions set this way so that String
+   * can get the value.
+   *
+   * @serial the buffer
+   */
+  private char[] value;
+
+  /**
+   * The package-private constructor for String objects without copying.
+   */
+  private static final Constructor<String> cons;
+
+  /**
+   * The default capacity of a buffer.
+   */
+  private static final int DEFAULT_CAPACITY = 16;
+
+  static
+  {
+    try
+      {
+	cons = String.class.getDeclaredConstructor(char[].class, Integer.TYPE,
+						   Integer.TYPE, Boolean.TYPE);
+      }
+    catch (NoSuchMethodException e)
+      {
+	throw (Error) 
+	  new InternalError("Could not get no-copy String constructor").initCause(e);
+      }
+  }
+
+  /**
+   * Create a new CPStringBuffer with default capacity 16.
+   */
+  CPStringBuffer()
+  {
+    this(DEFAULT_CAPACITY);
+  }
+
+  /**
+   * Create an empty <code>StringBuffer</code> with the specified initial
+   * capacity.
+   *
+   * @param capacity the initial capacity
+   * @throws NegativeArraySizeException if capacity is negative
+   */
+  CPStringBuffer(int capacity)
+  {
+    value = new char[capacity];
+  }
+
+  /**
+   * Create a new <code>StringBuffer</code> with the characters in the
+   * specified <code>String</code>. Initial capacity will be the size of the
+   * String plus 16.
+   *
+   * @param str the <code>String</code> to convert
+   * @throws NullPointerException if str is null
+   */
+  CPStringBuffer(String str)
+  {
+    count = str.count;
+    value = new char[count + DEFAULT_CAPACITY];
+    str.getChars(0, count, value, 0);
+  }
+
+  /**
+   * Create a new <code>StringBuffer</code> with the characters in the
+   * specified <code>CharSequence</code>. Initial capacity will be the
+   * length of the sequence plus 16; if the sequence reports a length
+   * less than or equal to 0, then the initial capacity will be 16.
+   *
+   * @param seq the initializing <code>CharSequence</code>
+   * @throws NullPointerException if str is null
+   * @since 1.5
+   */
+  CPStringBuffer(CharSequence seq)
+  {
+    int len = seq.length();
+    count = len <= 0 ? 0 : len;
+    value = new char[count + DEFAULT_CAPACITY];
+    for (int i = 0; i < len; ++i)
+      value[i] = seq.charAt(i);
+  }
+
+  /**
+   * Increase the capacity of this <code>StringBuffer</code>. This will
+   * ensure that an expensive growing operation will not occur until
+   * <code>minimumCapacity</code> is reached. The buffer is grown to the
+   * larger of <code>minimumCapacity</code> and
+   * <code>capacity() * 2 + 2</code>, if it is not already large enough.
+   *
+   * @param minimumCapacity the new capacity
+   * @see #capacity()
+   */
+  public void ensureCapacity(int minimumCapacity)
+  {
+    ensureCapacity_unsynchronized(minimumCapacity);
+  }
+
+  /**
+   * Set the length of this StringBuffer. If the new length is greater than
+   * the current length, all the new characters are set to '\0'. If the new
+   * length is less than the current length, the first <code>newLength</code>
+   * characters of the old array will be preserved, and the remaining
+   * characters are truncated.
+   *
+   * @param newLength the new length
+   * @throws IndexOutOfBoundsException if the new length is negative
+   *         (while unspecified, this is a StringIndexOutOfBoundsException)
+   * @see #length()
+   */
+  public void setLength(int newLength)
+  {
+    if (newLength < 0)
+      throw new StringIndexOutOfBoundsException(newLength);
+
+    int valueLength = value.length;
+
+    /* Always call ensureCapacity_unsynchronized in order to preserve
+       copy-on-write semantics.  */
+    ensureCapacity_unsynchronized(newLength);
+
+    if (newLength < valueLength)
+      {
+        /* If the StringBuffer's value just grew, then we know that
+           value is newly allocated and the region between count and
+           newLength is filled with '\0'.  */
+	count = newLength;
+      }
+    else
+      {
+	/* The StringBuffer's value doesn't need to grow.  However,
+	   we should clear out any cruft that may exist.  */
+	while (count < newLength)
+          value[count++] = '\0';
+      }
+  }
+
+  /**
+   * Get the character at the specified index.
+   *
+   * @param index the index of the character to get, starting at 0
+   * @return the character at the specified index
+   * @throws IndexOutOfBoundsException if index is negative or &gt;= length()
+   *         (while unspecified, this is a StringIndexOutOfBoundsException)
+   */
+  public char charAt(int index)
+  {
+    if (index < 0 || index >= count)
+      throw new StringIndexOutOfBoundsException(index);
+    return value[index];
+  }
+
+  /**
+   * Get the code point at the specified index.  This is like #charAt(int),
+   * but if the character is the start of a surrogate pair, and the
+   * following character completes the pair, then the corresponding
+   * supplementary code point is returned.
+   * @param index the index of the codepoint to get, starting at 0
+   * @return the codepoint at the specified index
+   * @throws IndexOutOfBoundsException if index is negative or &gt;= length()
+   * @since 1.5
+   */
+  public int codePointAt(int index)
+  {
+    return Character.codePointAt(value, index, count);
+  }
+
+  /**
+   * Get the code point before the specified index.  This is like
+   * #codePointAt(int), but checks the characters at <code>index-1</code> and
+   * <code>index-2</code> to see if they form a supplementary code point.
+   * @param index the index just past the codepoint to get, starting at 0
+   * @return the codepoint at the specified index
+   * @throws IndexOutOfBoundsException if index is negative or &gt;= length()
+   * @since 1.5
+   */
+  public int codePointBefore(int index)
+  {
+    // Character.codePointBefore() doesn't perform this check.  We
+    // could use the CharSequence overload, but this is just as easy.
+    if (index >= count)
+      throw new IndexOutOfBoundsException();
+    return Character.codePointBefore(value, index, 1);
+  }
+
+  /**
+   * Get the specified array of characters. <code>srcOffset - srcEnd</code>
+   * characters will be copied into the array you pass in.
+   *
+   * @param srcOffset the index to start copying from (inclusive)
+   * @param srcEnd the index to stop copying from (exclusive)
+   * @param dst the array to copy into
+   * @param dstOffset the index to start copying into
+   * @throws NullPointerException if dst is null
+   * @throws IndexOutOfBoundsException if any source or target indices are
+   *         out of range (while unspecified, source problems cause a
+   *         StringIndexOutOfBoundsException, and dest problems cause an
+   *         ArrayIndexOutOfBoundsException)
+   * @see System#arraycopy(Object, int, Object, int, int)
+   */
+  public void getChars(int srcOffset, int srcEnd,
+		       char[] dst, int dstOffset)
+  {
+    if (srcOffset < 0 || srcEnd > count || srcEnd < srcOffset)
+      throw new StringIndexOutOfBoundsException();
+    VMSystem.arraycopy(value, srcOffset, dst, dstOffset, srcEnd - srcOffset);
+  }
+
+  /**
+   * Set the character at the specified index.
+   *
+   * @param index the index of the character to set starting at 0
+   * @param ch the value to set that character to
+   * @throws IndexOutOfBoundsException if index is negative or &gt;= length()
+   *         (while unspecified, this is a StringIndexOutOfBoundsException)
+   */
+  public void setCharAt(int index, char ch)
+  {
+    if (index < 0 || index >= count)
+      throw new StringIndexOutOfBoundsException(index);
+    // Call ensureCapacity to enforce copy-on-write.
+    ensureCapacity_unsynchronized(count);
+    value[index] = ch;
+  }
+
+  /**
+   * Append the <code>String</code> value of the argument to this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param obj the <code>Object</code> to convert and append
+   * @return this <code>StringBuffer</code>
+   * @see String#valueOf(Object)
+   * @see #append(String)
+   */
+  public CPStringBuffer append(Object obj)
+  {
+    return append(String.valueOf(obj));
+  }
+
+  /**
+   * Append the <code>String</code> to this <code>StringBuffer</code>. If
+   * str is null, the String "null" is appended.
+   *
+   * @param str the <code>String</code> to append
+   * @return this <code>StringBuffer</code>
+   */
+  public CPStringBuffer append(String str)
+  {
+    if (str == null)
+      str = "null";
+    int len = str.count;
+    ensureCapacity_unsynchronized(count + len);
+    str.getChars(0, len, value, count);
+    count += len;
+    return this;
+  }
+
+  /**
+   * Append the <code>StringBuilder</code> value of the argument to this
+   * <code>StringBuilder</code>. This behaves the same as
+   * <code>append((Object) stringBuffer)</code>, except it is more efficient.
+   *
+   * @param stringBuffer the <code>StringBuilder</code> to convert and append
+   * @return this <code>StringBuilder</code>
+   * @see #append(Object)
+   */
+  public CPStringBuffer append(StringBuffer stringBuffer)
+  {
+    if (stringBuffer == null)
+      return append("null");
+    synchronized (stringBuffer)
+      {
+	int len = stringBuffer.count;
+	ensureCapacity(count + len);
+	VMSystem.arraycopy(stringBuffer.value, 0, value, count, len);
+	count += len;
+      }
+    return this;
+  }
+
+  /**
+   * Append the <code>char</code> array to this <code>StringBuffer</code>.
+   * This is similar (but more efficient) than
+   * <code>append(new String(data))</code>, except in the case of null.
+   *
+   * @param data the <code>char[]</code> to append
+   * @return this <code>StringBuffer</code>
+   * @throws NullPointerException if <code>str</code> is <code>null</code>
+   * @see #append(char[], int, int)
+   */
+  public CPStringBuffer append(char[] data)
+  {
+    return append(data, 0, data.length);
+  }
+
+  /**
+   * Append part of the <code>char</code> array to this
+   * <code>StringBuffer</code>. This is similar (but more efficient) than
+   * <code>append(new String(data, offset, count))</code>, except in the case
+   * of null.
+   *
+   * @param data the <code>char[]</code> to append
+   * @param offset the start location in <code>str</code>
+   * @param count the number of characters to get from <code>str</code>
+   * @return this <code>StringBuffer</code>
+   * @throws NullPointerException if <code>str</code> is <code>null</code>
+   * @throws IndexOutOfBoundsException if offset or count is out of range
+   *         (while unspecified, this is a StringIndexOutOfBoundsException)
+   */
+  public CPStringBuffer append(char[] data, int offset, int count)
+  {
+    if (offset < 0 || count < 0 || offset > data.length - count)
+      throw new StringIndexOutOfBoundsException();
+    ensureCapacity_unsynchronized(this.count + count);
+    VMSystem.arraycopy(data, offset, value, this.count, count);
+    this.count += count;
+    return this;
+  }
+
+  /**
+   * Append the <code>String</code> value of the argument to this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param bool the <code>boolean</code> to convert and append
+   * @return this <code>StringBuffer</code>
+   * @see String#valueOf(boolean)
+   */
+  public CPStringBuffer append(boolean bool)
+  {
+    return append(bool ? "true" : "false");
+  }
+
+  /**
+   * Append the <code>char</code> to this <code>StringBuffer</code>.
+   *
+   * @param ch the <code>char</code> to append
+   * @return this <code>StringBuffer</code>
+   */
+  public CPStringBuffer append(char ch)
+  {
+    ensureCapacity_unsynchronized(count + 1);
+    value[count++] = ch;
+    return this;
+  }
+
+  /**
+   * Append the characters in the <code>CharSequence</code> to this
+   * buffer.
+   *
+   * @param seq the <code>CharSequence</code> providing the characters
+   * @return this <code>StringBuffer</code>
+   * @since 1.5
+   */
+  public CPStringBuffer append(CharSequence seq)
+  {
+    return append(seq, 0, seq.length());
+  }
+
+  /**
+   * Append some characters from the <code>CharSequence</code> to this
+   * buffer.  If the argument is null, the four characters "null" are
+   * appended.
+   *
+   * @param seq the <code>CharSequence</code> providing the characters
+   * @param start the starting index
+   * @param end one past the final index
+   * @return this <code>StringBuffer</code>
+   * @since 1.5
+   */
+  public CPStringBuffer append(CharSequence seq, int start, int end)
+  {
+    if (seq == null)
+      return append("null");
+    if (end - start > 0)
+      {
+	ensureCapacity_unsynchronized(count + end - start);
+	for (; start < end; ++start)
+	  value[count++] = seq.charAt(start);
+      }
+    return this;
+  }
+
+  /**
+   * Append the <code>String</code> value of the argument to this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param inum the <code>int</code> to convert and append
+   * @return this <code>StringBuffer</code>
+   * @see String#valueOf(int)
+   */
+  // This is native in libgcj, for efficiency.
+  public CPStringBuffer append(int inum)
+  {
+    return append(String.valueOf(inum));
+  }
+
+  /**
+   * Append the <code>String</code> value of the argument to this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param lnum the <code>long</code> to convert and append
+   * @return this <code>StringBuffer</code>
+   * @see String#valueOf(long)
+   */
+  public CPStringBuffer append(long lnum)
+  {
+    return append(Long.toString(lnum, 10));
+  }
+
+  /**
+   * Append the <code>String</code> value of the argument to this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param fnum the <code>float</code> to convert and append
+   * @return this <code>StringBuffer</code>
+   * @see String#valueOf(float)
+   */
+  public CPStringBuffer append(float fnum)
+  {
+    return append(Float.toString(fnum));
+  }
+
+  /**
+   * Append the <code>String</code> value of the argument to this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param dnum the <code>double</code> to convert and append
+   * @return this <code>StringBuffer</code>
+   * @see String#valueOf(double)
+   */
+  public CPStringBuffer append(double dnum)
+  {
+    return append(Double.toString(dnum));
+  }
+
+  /**
+   * Append the code point to this <code>StringBuffer</code>.
+   * This is like #append(char), but will append two characters
+   * if a supplementary code point is given.
+   *
+   * @param code the code point to append
+   * @return this <code>StringBuffer</code>
+   * @see Character#toChars(int, char[], int)
+   * @since 1.5
+   */
+  public CPStringBuffer appendCodePoint(int code)
+  {
+    int len = Character.charCount(code);
+    ensureCapacity_unsynchronized(count + len);
+    Character.toChars(code, value, count);
+    count += len;
+    return this;
+  }
+
+  /**
+   * Delete characters from this <code>StringBuffer</code>.
+   * <code>delete(10, 12)</code> will delete 10 and 11, but not 12. It is
+   * harmless for end to be larger than length().
+   *
+   * @param start the first character to delete
+   * @param end the index after the last character to delete
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if start or end are out of bounds
+   * @since 1.2
+   */
+  public CPStringBuffer delete(int start, int end)
+  {
+    if (start < 0 || start > count || start > end)
+      throw new StringIndexOutOfBoundsException(start);
+    if (end > count)
+      end = count;
+    ensureCapacity_unsynchronized(count);
+    if (count - end != 0)
+      VMSystem.arraycopy(value, end, value, start, count - end);
+    count -= end - start;
+    return this;
+  }
+
+  /**
+   * Delete a character from this <code>StringBuffer</code>.
+   *
+   * @param index the index of the character to delete
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if index is out of bounds
+   * @since 1.2
+   */
+  public CPStringBuffer deleteCharAt(int index)
+  {
+    return delete(index, index + 1);
+  }
+
+  /**
+   * Replace characters between index <code>start</code> (inclusive) and
+   * <code>end</code> (exclusive) with <code>str</code>. If <code>end</code>
+   * is larger than the size of this StringBuffer, all characters after
+   * <code>start</code> are replaced.
+   *
+   * @param start the beginning index of characters to delete (inclusive)
+   * @param end the ending index of characters to delete (exclusive)
+   * @param str the new <code>String</code> to insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if start or end are out of bounds
+   * @throws NullPointerException if str is null
+   * @since 1.2
+   */
+  public CPStringBuffer replace(int start, int end, String str)
+  {
+    if (start < 0 || start > count || start > end)
+      throw new StringIndexOutOfBoundsException(start);
+
+    int len = str.count;
+    // Calculate the difference in 'count' after the replace.
+    int delta = len - (end > count ? count : end) + start;
+    ensureCapacity_unsynchronized(count + delta);
+
+    if (delta != 0 && end < count)
+      VMSystem.arraycopy(value, end, value, end + delta, count - end);
+
+    str.getChars(0, len, value, start);
+    count += delta;
+    return this;
+  }
+
+  /**
+   * Insert a subarray of the <code>char[]</code> argument into this
+   * <code>StringBuffer</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param str the <code>char[]</code> to insert
+   * @param str_offset the index in <code>str</code> to start inserting from
+   * @param len the number of characters to insert
+   * @return this <code>StringBuffer</code>
+   * @throws NullPointerException if <code>str</code> is <code>null</code>
+   * @throws StringIndexOutOfBoundsException if any index is out of bounds
+   * @since 1.2
+   */
+  public CPStringBuffer insert(int offset, char[] str, int str_offset, int len)
+  {
+    if (offset < 0 || offset > count || len < 0
+        || str_offset < 0 || str_offset > str.length - len)
+      throw new StringIndexOutOfBoundsException();
+    ensureCapacity_unsynchronized(count + len);
+    VMSystem.arraycopy(value, offset, value, offset + len, count - offset);
+    VMSystem.arraycopy(str, str_offset, value, offset, len);
+    count += len;
+    return this;
+  }
+
+  /**
+   * Insert the <code>String</code> value of the argument into this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param obj the <code>Object</code> to convert and insert
+   * @return this <code>StringBuffer</code>
+   * @exception StringIndexOutOfBoundsException if offset is out of bounds
+   * @see String#valueOf(Object)
+   */
+  public CPStringBuffer insert(int offset, Object obj)
+  {
+    return insert(offset, obj == null ? "null" : obj.toString());
+  }
+
+  /**
+   * Insert the <code>String</code> argument into this
+   * <code>StringBuffer</code>. If str is null, the String "null" is used
+   * instead.
+   *
+   * @param offset the place to insert in this buffer
+   * @param str the <code>String</code> to insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   */
+  public CPStringBuffer insert(int offset, String str)
+  {
+    if (offset < 0 || offset > count)
+      throw new StringIndexOutOfBoundsException(offset);
+    if (str == null)
+      str = "null";
+    int len = str.count;
+    ensureCapacity_unsynchronized(count + len);
+    VMSystem.arraycopy(value, offset, value, offset + len, count - offset);
+    str.getChars(0, len, value, offset);
+    count += len;
+    return this;
+  }
+
+  /**
+   * Insert the <code>CharSequence</code> argument into this
+   * <code>StringBuffer</code>.  If the sequence is null, the String
+   * "null" is used instead.
+   *
+   * @param offset the place to insert in this buffer
+   * @param sequence the <code>CharSequence</code> to insert
+   * @return this <code>StringBuffer</code>
+   * @throws IndexOutOfBoundsException if offset is out of bounds
+   * @since 1.5
+   */
+  public CPStringBuffer insert(int offset, CharSequence sequence)
+  {
+    if (sequence == null)
+      sequence = "null";
+    return insert(offset, sequence, 0, sequence.length());
+  }
+
+  /**
+   * Insert a subsequence of the <code>CharSequence</code> argument into this
+   * <code>StringBuffer</code>.  If the sequence is null, the String
+   * "null" is used instead.
+   *
+   * @param offset the place to insert in this buffer
+   * @param sequence the <code>CharSequence</code> to insert
+   * @param start the starting index of the subsequence
+   * @param end one past the ending index of the subsequence
+   * @return this <code>StringBuffer</code>
+   * @throws IndexOutOfBoundsException if offset, start,
+   * or end are out of bounds
+   * @since 1.5
+   */
+  public CPStringBuffer insert(int offset, CharSequence sequence, int start, int end)
+  {
+    if (sequence == null)
+      sequence = "null";
+    if (start < 0 || end < 0 || start > end || end > sequence.length())
+      throw new IndexOutOfBoundsException();
+    int len = end - start;
+    ensureCapacity_unsynchronized(count + len);
+    VMSystem.arraycopy(value, offset, value, offset + len, count - offset);
+    for (int i = start; i < end; ++i)
+      value[offset++] = sequence.charAt(i);
+    count += len;
+    return this;
+  }
+
+  /**
+   * Insert the <code>char[]</code> argument into this
+   * <code>StringBuffer</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param data the <code>char[]</code> to insert
+   * @return this <code>StringBuffer</code>
+   * @throws NullPointerException if <code>data</code> is <code>null</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   * @see #insert(int, char[], int, int)
+   */
+  public CPStringBuffer insert(int offset, char[] data)
+  {
+    return insert(offset, data, 0, data.length);
+  }
+
+  /**
+   * Insert the <code>String</code> value of the argument into this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param bool the <code>boolean</code> to convert and insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   * @see String#valueOf(boolean)
+   */
+  public CPStringBuffer insert(int offset, boolean bool)
+  {
+    return insert(offset, bool ? "true" : "false");
+  }
+
+  /**
+   * Insert the <code>char</code> argument into this <code>StringBuffer</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param ch the <code>char</code> to insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   */
+  public CPStringBuffer insert(int offset, char ch)
+  {
+    if (offset < 0 || offset > count)
+      throw new StringIndexOutOfBoundsException(offset);
+    ensureCapacity_unsynchronized(count + 1);
+    VMSystem.arraycopy(value, offset, value, offset + 1, count - offset);
+    value[offset] = ch;
+    count++;
+    return this;
+  }
+
+  /**
+   * Insert the <code>String</code> value of the argument into this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param inum the <code>int</code> to convert and insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   * @see String#valueOf(int)
+   */
+  public CPStringBuffer insert(int offset, int inum)
+  {
+    return insert(offset, String.valueOf(inum));
+  }
+
+  /**
+   * Insert the <code>String</code> value of the argument into this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param lnum the <code>long</code> to convert and insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   * @see String#valueOf(long)
+   */
+  public CPStringBuffer insert(int offset, long lnum)
+  {
+    return insert(offset, Long.toString(lnum, 10));
+  }
+
+  /**
+   * Insert the <code>String</code> value of the argument into this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param fnum the <code>float</code> to convert and insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   * @see String#valueOf(float)
+   */
+  public CPStringBuffer insert(int offset, float fnum)
+  {
+    return insert(offset, Float.toString(fnum));
+  }
+
+  /**
+   * Insert the <code>String</code> value of the argument into this
+   * <code>StringBuffer</code>. Uses <code>String.valueOf()</code> to convert
+   * to <code>String</code>.
+   *
+   * @param offset the place to insert in this buffer
+   * @param dnum the <code>double</code> to convert and insert
+   * @return this <code>StringBuffer</code>
+   * @throws StringIndexOutOfBoundsException if offset is out of bounds
+   * @see String#valueOf(double)
+   */
+  public CPStringBuffer insert(int offset, double dnum)
+  {
+    return insert(offset, Double.toString(dnum));
+  }
+
+  /**
+   * Finds the first instance of a substring in this StringBuilder.
+   *
+   * @param str String to find
+   * @return location (base 0) of the String, or -1 if not found
+   * @throws NullPointerException if str is null
+   * @see #indexOf(String, int)
+   */
+  public int indexOf(String str)
+  {
+    return indexOf(str, 0);
+  }
+
+  /**
+   * Finds the first instance of a String in this StringBuffer, starting at
+   * a given index.  If starting index is less than 0, the search starts at
+   * the beginning of this String.  If the starting index is greater than the
+   * length of this String, or the substring is not found, -1 is returned.
+   *
+   * @param str String to find
+   * @param fromIndex index to start the search
+   * @return location (base 0) of the String, or -1 if not found
+   * @throws NullPointerException if str is null
+   * @since 1.4
+   */
+  public int indexOf(String str, int fromIndex)
+  {
+    if (fromIndex < 0)
+      fromIndex = 0;
+    int limit = count - str.count;
+    for ( ; fromIndex <= limit; fromIndex++)
+      if (regionMatches(fromIndex, str))
+        return fromIndex;
+    return -1;
+  }
+
+  /**
+   * Finds the last instance of a substring in this StringBuffer.
+   *
+   * @param str String to find
+   * @return location (base 0) of the String, or -1 if not found
+   * @throws NullPointerException if str is null
+   * @see #lastIndexOf(String, int)
+   * @since 1.4
+   */
+  public int lastIndexOf(String str)
+  {
+    return lastIndexOf(str, count - str.count);
+  }
+
+  /**
+   * Finds the last instance of a String in this StringBuffer, starting at a
+   * given index.  If starting index is greater than the maximum valid index,
+   * then the search begins at the end of this String.  If the starting index
+   * is less than zero, or the substring is not found, -1 is returned.
+   *
+   * @param str String to find
+   * @param fromIndex index to start the search
+   * @return location (base 0) of the String, or -1 if not found
+   * @throws NullPointerException if str is null
+   * @since 1.4
+   */
+  public int lastIndexOf(String str, int fromIndex)
+  {
+    fromIndex = Math.min(fromIndex, count - str.count);
+    for ( ; fromIndex >= 0; fromIndex--)
+      if (regionMatches(fromIndex, str))
+        return fromIndex;
+    return -1;
+  }
+
+  /**
+   * Reverse the characters in this StringBuffer. The same sequence of
+   * characters exists, but in the reverse index ordering.
+   *
+   * @return this <code>StringBuffer</code>
+   */
+  public CPStringBuffer reverse()
+  {
+    // Call ensureCapacity to enforce copy-on-write.
+    ensureCapacity_unsynchronized(count);
+    for (int i = count >> 1, j = count - i; --i >= 0; ++j)
+      {
+        char c = value[i];
+        value[i] = value[j];
+        value[j] = c;
+      }
+    return this;
+  }
+
+  /**
+   * This may reduce the amount of memory used by the StringBuffer,
+   * by resizing the internal array to remove unused space.  However,
+   * this method is not required to resize, so this behavior cannot
+   * be relied upon.
+   * @since 1.5
+   */
+  public void trimToSize()
+  {
+    int wouldSave = value.length - count;
+    // Some random heuristics: if we save less than 20 characters, who
+    // cares.
+    if (wouldSave < 20)
+      return;
+    // If we save more than 200 characters, shrink.
+    // If we save more than 1/4 of the buffer, shrink.
+    if (wouldSave > 200 || wouldSave * 4 > value.length)
+      {
+	char[] newValue = new char[count];
+	VMSystem.arraycopy(value, 0, newValue, 0, count);
+	value = newValue;
+      }
+  }
+
+  /**
+   * Return the number of code points between two indices in the
+   * <code>StringBuffer</code>.  An unpaired surrogate counts as a
+   * code point for this purpose.  Characters outside the indicated
+   * range are not examined, even if the range ends in the middle of a
+   * surrogate pair.
+   *
+   * @param start the starting index
+   * @param end one past the ending index
+   * @return the number of code points
+   * @since 1.5
+   */
+  public int codePointCount(int start, int end)
+  {
+    if (start < 0 || end >= count || start > end)
+      throw new StringIndexOutOfBoundsException();
+
+    int count = 0;
+    while (start < end)
+      {
+	char base = value[start];
+	if (base < Character.MIN_HIGH_SURROGATE
+	    || base > Character.MAX_HIGH_SURROGATE
+	    || start == end
+	    || start == count
+	    || value[start + 1] < Character.MIN_LOW_SURROGATE
+	    || value[start + 1] > Character.MAX_LOW_SURROGATE)
+	  {
+	    // Nothing.
+	  }
+	else
+	  {
+	    // Surrogate pair.
+	    ++start;
+	  }
+	++start;
+	++count;
+      }
+    return count;
+  }
+
+  /**
+   * Starting at the given index, this counts forward by the indicated
+   * number of code points, and then returns the resulting index.  An
+   * unpaired surrogate counts as a single code point for this
+   * purpose.
+   *
+   * @param start the starting index
+   * @param codePoints the number of code points
+   * @return the resulting index
+   * @since 1.5
+   */
+  public int offsetByCodePoints(int start, int codePoints)
+  {
+    while (codePoints > 0)
+      {
+	char base = value[start];
+	if (base < Character.MIN_HIGH_SURROGATE
+	    || base > Character.MAX_HIGH_SURROGATE
+	    || start == count
+	    || value[start + 1] < Character.MIN_LOW_SURROGATE
+	    || value[start + 1] > Character.MAX_LOW_SURROGATE)
+	  {
+	    // Nothing.
+	  }
+	else
+	  {
+	    // Surrogate pair.
+	    ++start;
+	  }
+	++start;
+	--codePoints;
+      }
+    return start;
+  }
+
+  /**
+   * Increase the capacity of this <code>StringBuilder</code>. This will
+   * ensure that an expensive growing operation will not occur until
+   * <code>minimumCapacity</code> is reached. The buffer is grown to the
+   * larger of <code>minimumCapacity</code> and
+   * <code>capacity() * 2 + 2</code>, if it is not already large enough.
+   *
+   * @param minimumCapacity the new capacity
+   * @see #capacity()
+   */
+  protected void ensureCapacity_unsynchronized(int minimumCapacity)
+  {
+    if (minimumCapacity > value.length)
+      {
+        int max = value.length * 2 + 2;
+        minimumCapacity = (minimumCapacity < max ? max : minimumCapacity);
+        char[] nb = new char[minimumCapacity];
+        VMSystem.arraycopy(value, 0, nb, 0, count);
+        value = nb;
+      }
+  }
+
+  /**
+   * Predicate which determines if a substring of this matches another String
+   * starting at a specified offset for each String and continuing for a
+   * specified length. This is more efficient than creating a String to call
+   * indexOf on.
+   *
+   * @param toffset index to start comparison at for this String
+   * @param other non-null String to compare to region of this
+   * @return true if regions match, false otherwise
+   * @see #indexOf(String, int)
+   * @see #lastIndexOf(String, int)
+   * @see String#regionMatches(boolean, int, String, int, int)
+   */
+  private boolean regionMatches(int toffset, String other)
+  {
+    int len = other.count;
+    int index = other.offset;
+    while (--len >= 0)
+      if (value[toffset++] != other.value[index++])
+        return false;
+    return true;
+  }
+
+  /**
+   * Get the length of the <code>String</code> this <code>StringBuilder</code>
+   * would create. Not to be confused with the <em>capacity</em> of the
+   * <code>StringBuilder</code>.
+   *
+   * @return the length of this <code>StringBuilder</code>
+   * @see #capacity()
+   * @see #setLength(int)
+   */
+  public int length()
+  {
+    return count;
+  }
+
+  /**
+   * Creates a substring of this StringBuilder, starting at a specified index
+   * and ending at one character before a specified index. This is implemented
+   * the same as <code>substring(beginIndex, endIndex)</code>, to satisfy
+   * the CharSequence interface.
+   *
+   * @param beginIndex index to start at (inclusive, base 0)
+   * @param endIndex index to end at (exclusive)
+   * @return new String which is a substring of this StringBuilder
+   * @throws IndexOutOfBoundsException if beginIndex or endIndex is out of
+   *         bounds
+   * @see #substring(int, int)
+   */
+  public CharSequence subSequence(int beginIndex, int endIndex)
+  {
+    return substring(beginIndex, endIndex);
+  }
+
+  /**
+   * Creates a substring of this StringBuilder, starting at a specified index
+   * and ending at one character before a specified index.
+   *
+   * @param beginIndex index to start at (inclusive, base 0)
+   * @param endIndex index to end at (exclusive)
+   * @return new String which is a substring of this StringBuilder
+   * @throws StringIndexOutOfBoundsException if beginIndex or endIndex is out
+   *         of bounds
+   */
+  public String substring(int beginIndex, int endIndex)
+  {
+    int len = endIndex - beginIndex;
+    if (beginIndex < 0 || endIndex > count || endIndex < beginIndex)
+      throw new StringIndexOutOfBoundsException();
+    if (len == 0)
+      return "";
+    try
+      {
+	return cons.newInstance(value, beginIndex, len, true);
+      }
+    catch (InstantiationException e)
+      {
+	throw (Error) 
+	  new InternalError("Could not instantiate no-copy String constructor").initCause(e);
+      }
+    catch (IllegalAccessException e)
+      {
+	throw (Error) 
+	  new InternalError("Could not access no-copy String constructor").initCause(e);
+      }
+    catch (InvocationTargetException e)
+      {
+	throw (Error) 
+	  new InternalError("Error calling no-copy String constructor").initCause(e);
+      }
+  }
+
+  /**
+   * Convert this <code>StringBuilder</code> to a <code>String</code>. The
+   * String is composed of the characters currently in this StringBuilder. Note
+   * that the result is not a copy, so future modifications to this buffer
+   * do affect the String.
+   *
+   * @return the characters in this StringBuilder
+   */
+  public String toString()
+  {
+    try
+      {
+	return cons.newInstance(value, 0, count, true);
+      }
+    catch (InstantiationException e)
+      {
+	throw (Error) 
+	  new InternalError("Could not instantiate no-copy String constructor").initCause(e);
+      }
+    catch (IllegalAccessException e)
+      {
+	throw (Error) 
+	  new InternalError("Could not access no-copy String constructor").initCause(e);
+      }
+    catch (InvocationTargetException e)
+      {
+	throw (Error) 
+	  new InternalError("Error calling no-copy String constructor").initCause(e);
+      }
+  }
+
+}
diff --git a/java/lang/AbstractStringBuffer.java b/java/lang/AbstractStringBuffer.java
index 77f028c60..04ec8113e 100644
--- a/java/lang/AbstractStringBuffer.java
+++ b/java/lang/AbstractStringBuffer.java
@@ -40,6 +40,12 @@ package java.lang;
 
 import java.io.Serializable;
 
+/**
+ * This class is based on gnu.classpath.ClasspathStringBuffer but
+ * is package-private to java.lang so it can be used as the basis
+ * for StringBuffer and StringBuilder.
+ * If you modify this, please consider also modifying that code.
+ */
 abstract class AbstractStringBuffer
   implements Serializable, CharSequence, Appendable
 {