Initial revision

From-SVN: r26263

libjava/java/util/BitSet.java

@@ -0,0 +1,183 @@
+// BitSet - A vector of bits.
+
+/* Copyright (C) 1998, 1999  Cygnus Solutions
+
+   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.util;
+import java.io.Serializable;
+
+/**
+ * @author Tom Tromey <tromey@cygnus.com>
+ * @date October 23, 1998.
+ */
+
+/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
+ * hashCode algorithm taken from JDK 1.2 docs.
+ */
+
+public final class BitSet implements Cloneable, Serializable
+{
+  public void and (BitSet bs)
+    {
+      if (bs == null)
+	throw new NullPointerException ();
+      int max = Math.min(bits.length, bs.bits.length);
+      int i;
+      for (i = 0; i < max; ++i)
+	bits[i] &= bs.bits[i];
+      for ( ; i < bits.length; ++i)
+	bits[i] = 0;
+    }
+
+  public BitSet ()
+    {
+      this (64);
+    }
+
+  public BitSet (int nbits)
+    {
+      if (nbits < 0)
+	throw new NegativeArraySizeException ();
+      int length = nbits / 64;
+      if (nbits % 64 != 0)
+	++length;
+      bits = new long[length];
+    }
+
+  public void clear (int pos)
+    {
+      if (pos < 0)
+	throw new IndexOutOfBoundsException ();
+      int bit = pos % 64;
+      int offset = pos / 64;
+      ensure (offset);
+      bits[offset] &= ~ (1 << bit);
+    }
+
+  public Object clone ()
+    {
+      BitSet bs = new BitSet (bits.length * 64);
+      System.arraycopy(bits, 0, bs.bits, 0, bits.length);
+      return bs;
+    }
+
+  public boolean equals (Object obj)
+    {
+      if (! (obj instanceof BitSet))
+	return false;
+      BitSet bs = (BitSet) obj;
+      int max = Math.min(bits.length, bs.bits.length);
+      int i;
+      for (i = 0; i < max; ++i)
+	if (bits[i] != bs.bits[i])
+	  return false;
+      // If one is larger, check to make sure all extra bits are 0.
+      for (int j = i; j < bits.length; ++j)
+	if (bits[j] != 0)
+	  return false;
+      for (int j = i; j < bs.bits.length; ++j)
+	if (bs.bits[j] != 0)
+	  return false;
+      return true;
+    }
+
+  public boolean get (int pos)
+    {
+      if (pos < 0)
+	throw new IndexOutOfBoundsException ();
+
+      int bit = pos % 64;
+      int offset = pos / 64;
+
+      if (offset >= bits.length)
+	return false;
+
+      return (bits[offset] & (1 << bit)) == 0 ? false : true;
+    }
+
+  public int hashCode ()
+    {
+      long h = 1234;
+      for (int i = bits.length - 1; i >= 0; --i)
+	h ^= bits[i] * (i + 1);
+      return (int) ((h >> 32) ^ h);
+    }
+
+  public void or (BitSet bs)
+    {
+      if (bs == null)
+	throw new NullPointerException ();
+      ensure (bs.bits.length - 1);
+      int i;
+      for (i = 0; i < bs.bits.length; ++i)
+	bits[i] |= bs.bits[i];
+    }
+
+  public void set (int pos)
+    {
+      if (pos < 0)
+	throw new IndexOutOfBoundsException ();
+      int bit = pos % 64;
+      int offset = pos / 64;
+      ensure (offset);
+      bits[offset] |= 1 << bit;
+    }
+
+  public int size ()
+    {
+      return bits.length * 64;
+    }
+
+  public String toString ()
+    {
+      StringBuffer result = new StringBuffer ("{");
+      boolean first = true;
+      for (int i = 0; i < bits.length; ++i)
+	{
+	  int bit = 1;
+	  long word = bits[i];
+	  for (int j = 0; j < 64; ++j)
+	    {
+	      if ((word & bit) != 0)
+		{
+		  if (! first)
+		    result.append(", ");
+		  result.append(64 * i + j);
+		  first = false;
+		}
+	      bit <<= 1;
+	    }
+	}
+
+      return result.append("}").toString();
+    }
+
+  public void xor (BitSet bs)
+    {
+      if (bs == null)
+	throw new NullPointerException ();
+      ensure (bs.bits.length - 1);
+      int i;
+      for (i = 0; i < bs.bits.length; ++i)
+	bits[i] ^= bs.bits[i];
+    }
+
+  // Make sure the vector is big enough.
+  private final void ensure (int lastElt)
+    {
+      if (lastElt + 1 > bits.length)
+	{
+	  long[] nd = new long[lastElt + 1];
+	  System.arraycopy(bits, 0, nd, 0, bits.length);
+	  bits = nd;
+	}
+    }
+
+  // The actual bits.
+  private long[] bits;
+}