CollationKey.java   [plain text]

// CollationKey.java - Sort key for locale-sensitive String.

/* Copyright (C) 1999, 2000  Free Software Foundation

   This file is part of libgcj.

This software is copyrighted work licensed under the terms of the
Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
details.  */

package java.text;

/**
 * @author Tom Tromey <tromey@cygnus.com>
 * @date March 25, 1999
 */
/* Written using "Java Class Libraries", 2nd edition, plus online
 * API docs for JDK 1.2 from http://www.javasoft.com.
 * Status: Believed complete and correct.
 */

public final class CollationKey implements Comparable
{
  public int compareTo (CollationKey target)
  {
    int max = Math.min(key.length, target.key.length);

    for (int i = 0; i < max; ++i)
      {
	if (key[i] != target.key[i])
	  return key[i] - target.key[i];
      }

    return key.length - target.key.length;
  }

  public int compareTo (Object o)
  {
    return compareTo ((CollationKey) o);
  }

  public boolean equals (Object obj)
  {
    if (! (obj instanceof CollationKey))
      return false;

    CollationKey ck = (CollationKey) obj;

    if (key.length != ck.key.length)
      return false;

    for (int i = 0; i < key.length; ++i)
      if (key[i] != ck.key[i])
	return false;

    return true;
  }

  public String getSourceString ()
  {
    return originalText;
  }

  public int hashCode ()
  {
    // We just follow BitSet instead of thinking up something new.
    long h = originalText.hashCode();
    for (int i = key.length - 1; i >= 0; --i)
      h ^= key[i] * (i + 1);
    return (int) ((h >> 32) ^ h);
  }

  public byte[] toByteArray ()
  {
    byte[] r = new byte[4 * key.length];
    int off = 0;
    for (int i = 0; i < key.length; ++i)
      {
	r[off++] = (byte) ((key[i] >>> 24) & 255);
	r[off++] = (byte) ((key[i] >>> 16) & 255);
	r[off++] = (byte) ((key[i] >>>  8) & 255);
	r[off++] = (byte) ((key[i]       ) & 255);
      }
    return r;
  }

  CollationKey (CollationElementIterator iter, String originalText,
		int strength)
  {
    this.originalText = originalText;

    // Compute size of required array.
    int size = 0;
    while (RuleBasedCollator.next(iter, strength)
	   != CollationElementIterator.NULLORDER)
      ++size;

    iter.reset();
    key = new int[size];
    for (int i = 0; i < size; i++)
      key[i] = RuleBasedCollator.next(iter, strength);
  }

  // Original string.
  private String originalText;

  // Collation key.
  private int[] key;
}