/*
* JBoss, Home of Professional Open Source.
*
* Copyright 2011 Red Hat, Inc. and/or its affiliates, and individual
* contributors as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.xnio;
/**
* General bit-affecting utility methods.
*
* @author <a href="mailto:david.lloyd@redhat.com">David M. Lloyd</a>
*/
public final class Bits {
private Bits() {}
//--- Bit mask methods
/**
* Get an integer bit mask consisting of 1 bits in the given range. The returned {@code int}
* will have bits {@code low} through {@code high} set, and all other bits clear.
*
* @param low the low bit value
* @param high the high bit value
* @return the bit mask
*/
public static int intBitMask(int low, int high) {
assert low >= 0;
assert low <= high;
assert high < 32;
return (high == 31 ? 0 : (1 << high + 1)) - (1 << low);
}
/**
* Get a long bit mask consisting of 1 bits in the given range. The returned {@code long}
* will have bits {@code low} through {@code high} set, and all other bits clear.
*
* @param low the low bit value
* @param high the high bit value
* @return the bit mask
*/
public static long longBitMask(int low, int high) {
assert low >= 0;
assert low <= high;
assert high < 64;
return (high == 63 ? 0L : (1L << (long) high + 1L)) - (1L << (long) low);
}
//--- Flags methods
/**
* Determine if any of the {@code flags} in the given {@code var} are set.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if any of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean anyAreSet(int var, int flags) {
return (var & flags) != 0;
}
/**
* Determine if all of the {@code flags} in the given {@code var} are set.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if all of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean allAreSet(int var, int flags) {
return (var & flags) == flags;
}
/**
* Determine if any of the {@code flags} in the given {@code var} are clear.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if not all of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean anyAreClear(int var, int flags) {
return (var & flags) != flags;
}
/**
* Determine if all of the {@code flags} in the given {@code var} are clear.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if none of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean allAreClear(int var, int flags) {
return (var & flags) == 0;
}
/**
* Determine if any of the {@code flags} in the given {@code var} are set.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if any of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean anyAreSet(long var, long flags) {
return (var & flags) != 0;
}
/**
* Determine if all of the {@code flags} in the given {@code var} are set.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if all of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean allAreSet(long var, long flags) {
return (var & flags) == flags;
}
/**
* Determine if any of the {@code flags} in the given {@code var} are clear.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if not all of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean anyAreClear(long var, long flags) {
return (var & flags) != flags;
}
/**
* Determine if all of the {@code flags} in the given {@code var} are clear.
*
* @param var the value to test
* @param flags the flags to test for
* @return {@code true} if none of {@code flags} are in {@code var}, {@code false} otherwise
*/
public static boolean allAreClear(long var, long flags) {
return (var & flags) == 0;
}
//--- Signed/unsigned methods
/**
* Convert a signed value to unsigned.
*
* @param v the signed byte
* @return the unsigned byte, as an int
*/
public static int unsigned(byte v) {
return v & 0xff;
}
/**
* Convert a signed value to unsigned.
*
* @param v the signed short
* @return the unsigned short, as an int
*/
public static int unsigned(short v) {
return v & 0xffff;
}
/**
* Convert a signed value to unsigned.
*
* @param v the signed int
* @return the unsigned int, as a long
*/
public static long unsigned(int v) {
return v & 0xffffffffL;
}
//--- Byte array read methods
/**
* Get a 16-bit signed little-endian short value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed short value
*/
public static short shortFromBytesLE(byte[] b, int off) {
return (short) (b[off + 1] << 8 | b[off] & 0xff);
}
/**
* Get a 16-bit signed big-endian short value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed short value
*/
public static short shortFromBytesBE(byte[] b, int off) {
return (short) (b[off] << 8 | b[off + 1] & 0xff);
}
/**
* Get a 16-bit signed little-endian char value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed char value
*/
public static char charFromBytesLE(byte[] b, int off) {
return (char) (b[off + 1] << 8 | b[off] & 0xff);
}
/**
* Get a 16-bit signed big-endian char value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed char value
*/
public static char charFromBytesBE(byte[] b, int off) {
return (char) (b[off] << 8 | b[off + 1] & 0xff);
}
/**
* Get a 24-bit signed little-endian int value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed medium value as an int
*/
public static int mediumFromBytesLE(byte[] b, int off) {
return (b[off + 2] & 0xff) << 16 | (b[off + 1] & 0xff) << 8 | b[off] & 0xff;
}
/**
* Get a 24-bit signed big-endian int value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed medium value as an int
*/
public static int mediumFromBytesBE(byte[] b, int off) {
return (b[off] & 0xff) << 16 | (b[off + 1] & 0xff) << 8 | b[off + 2] & 0xff;
}
/**
* Get a 32-bit signed little-endian int value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed int value
*/
public static int intFromBytesLE(byte[] b, int off) {
return b[off + 3] << 24 | (b[off + 2] & 0xff) << 16 | (b[off + 1] & 0xff) << 8 | b[off] & 0xff;
}
/**
* Get a 32-bit signed big-endian int value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed int value
*/
public static int intFromBytesBE(byte[] b, int off) {
return b[off] << 24 | (b[off + 1] & 0xff) << 16 | (b[off + 2] & 0xff) << 8 | b[off + 3] & 0xff;
}
/**
* Get a 64-bit signed little-endian long value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed long value
*/
public static long longFromBytesLE(byte[] b, int off) {
return (b[off + 7] & 0xffL) << 56L | (b[off + 6] & 0xffL) << 48L | (b[off + 5] & 0xffL) << 40L | (b[off + 4] & 0xffL) << 32L | (b[off + 3] & 0xffL) << 24L | (b[off + 2] & 0xffL) << 16L | (b[off + 1] & 0xffL) << 8L | b[off] & 0xffL;
}
/**
* Get a 64-bit signed big-endian long value from a byte array.
*
* @param b the byte array
* @param off the offset in the array
* @return the signed long value
*/
public static long longFromBytesBE(byte[] b, int off) {
return (b[off] & 0xffL) << 56L | (b[off + 1] & 0xffL) << 48L | (b[off + 2] & 0xffL) << 40L | (b[off + 3] & 0xffL) << 32L | (b[off + 4] & 0xffL) << 24L | (b[off + 5] & 0xffL) << 16L | (b[off + 6] & 0xffL) << 8L | b[off + 7] & 0xffL;
}
}