Java HashCommon.nextPowerOfTwo方法代码示例

import it.unimi.dsi.fastutil.HashCommon; //导入方法依赖的package包/类
public boolean trimToSize(final int n) {
  final int l = HashCommon.nextPowerOfTwo((int) Math.ceil(n / _loadFactor));
  if (this.hashIndexSetProperties.n <= l)
    return true;
  try {
    rehash(l);
  } catch (OutOfMemoryError cantDoIt) {
    return false;
  }
  return true;
}
 

import it.unimi.dsi.fastutil.HashCommon; //导入方法依赖的package包/类
/** Creates a {@code ReorderingBlockingQueue} with the given fixed
    * capacity.
    *
    * @param capacity the capacity of this queue (will be rounded to the next power of two).
    */
public ReorderingBlockingQueue(final int capacity) {
	if (capacity <= 0) throw new IllegalArgumentException();
	a = new Object[HashCommon.nextPowerOfTwo(capacity)];
	mask = a.length - 1;
	lock = new ReentrantLock(false);
	nextObjectReady = lock.newCondition();
	newSpaceAvailable = lock.newCondition();
}
 

import it.unimi.dsi.fastutil.HashCommon; //导入方法依赖的package包/类
/** Rehashes this map if the table is too large.
 * 
 * <P>Let <var>N</var> be the smallest table size that can hold
 * <code>max(n,{@link #size()})</code> entries, still satisfying the load factor. If the current
 * table size is smaller than or equal to <var>N</var>, this method does
 * nothing. Otherwise, it rehashes this map in a table of size
 * <var>N</var>.
 *
 * <P>This method is useful when reusing maps.  {@linkplain #clear() Clearing a
 * map} leaves the table size untouched. If you are reusing a map
 * many times, you can call this method with a typical
 * size to avoid keeping around a very large table just
 * because of a few large transient maps.
 *
 * @param n the threshold for the trimming.
 * @return true if there was enough memory to trim the map.
 * @see #trim()
 */
public boolean trim( final int n ) {
 final int l = HashCommon.nextPowerOfTwo( (int)Math.ceil( n / f ) );
 if ( l >= n || size > maxFill( l, f ) ) return true;
 try {
  rehash( l );
 }
 catch( OutOfMemoryError cantDoIt ) { return false; }
 return true;
}