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/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* 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. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.internal.util;
import java.nio.ByteBuffer;
/**
* Provides utilities for converting from byte[] to primitive values.
*
* @author bakera
*/
public class Bytes {
/**
* Inserts the integer value into the array at the requested offset.
*
* @param val the value
* @param buf the array
* @param off the offset
*/
public static void putInt(int val, byte[] buf, int off) {
assert off + 4 <= buf.length;
buf[off ] = int0(val);
buf[off + 1] = int1(val);
buf[off + 2] = int2(val);
buf[off + 3] = int3(val);
}
/**
* Inserts the long value into the array at the requested offset.
*
* @param val the value
* @param buf the array
* @param off the offset
*/
public static void putLong(long val, byte[] buf, int off) {
assert off + 4 <= buf.length;
buf[off ] = long0(val);
buf[off + 1] = long1(val);
buf[off + 2] = long2(val);
buf[off + 3] = long3(val);
buf[off + 4] = long4(val);
buf[off + 5] = long5(val);
buf[off + 6] = long6(val);
buf[off + 7] = long7(val);
}
/**
* Extracts the protobuf varint from the buffer.
*
* @param buf the buffer
* @return the varint
*/
public static int getVarInt(ByteBuffer buf) {
byte b;
int val;
// unrolled! :-)
b = buf.get(); val = (b & 0x7f); if ((b & 0x80) == 0) return val;
b = buf.get(); val |= (b & 0x7f) << 7; if ((b & 0x80) == 0) return val;
b = buf.get(); val |= (b & 0x7f) << 14; if ((b & 0x80) == 0) return val;
b = buf.get(); val |= (b & 0x7f) << 21; if ((b & 0x80) == 0) return val;
b = buf.get(); val |= (b & 0x7f) << 28;
return val;
}
/**
* Extracts the protbuf varint from the array.
* @param buf the array
* @param off the offset
* @return the varint
*/
public static int getVarInt(byte[] buf, int off) {
byte b;
int val;
// unrolled! :-)
b = buf[off++]; val = (b & 0x7f); if ((b & 0x80) == 0) return val;
b = buf[off++]; val |= (b & 0x7f) << 7; if ((b & 0x80) == 0) return val;
b = buf[off++]; val |= (b & 0x7f) << 14; if ((b & 0x80) == 0) return val;
b = buf[off++]; val |= (b & 0x7f) << 21; if ((b & 0x80) == 0) return val;
b = buf[off++]; val |= (b & 0x7f) << 28;
return val;
}
/**
* Inserts the protobuf varint into the buffer at the current position.
*
* @param val the value
* @param buf the buffer
* @return the buffer
*/
public static ByteBuffer putVarInt(int val, ByteBuffer buf) {
assert val >= 0;
// protobuf-style varint encoding
// set the MSB as continuation bit for each byte except the last byte
// pack the bytes in reverse order
// packed size is (bits / 7) + 1
while ((val & ~0x7f) != 0) {
buf.put((byte) ((val & 0x7f) | 0x80));
val >>= 7;
}
return buf.put((byte) val);
}
/**
* Inserts the protobuf varint into the array at the requested offset.
*
* @param val the value
* @param buf the array
* @param off the offset
* @return the updated offset
*/
public static int putVarInt(int val, byte[] buf, int off) {
assert val >= 0;
// protobuf-style varint encoding
// set the MSB as continuation bit for each byte except the last byte
// TODO see if unrolling is faster
while (val > 0x7f) {
buf[off++] = (byte) ((val & 0x7f) | 0x80);
val >>= 7;
}
buf[off++] = (byte) val;
return off;
}
/**
* Returns the bytes required to store a protobuf varint.
*
* @param val the value
* @return the varint size
*/
public static int sizeofVarInt(int val) {
assert val >= 0;
if (val < (1 << 7)) {
return 1;
} else if (val < (1 << 14)) {
return 2;
} else if (val < (1 << 21)) {
return 3;
} else if (val < (1 << 28)) {
return 4;
}
return 5;
}
/**
* Creates a short value from two bytes.
*
* @param b0 the first byte
* @param b1 the second byte
* @return the value
*/
public static short toShort(byte b0, byte b1) {
return (short) ((b0 << 8) | (b1 & 0xff));
}
/**
* Creates a char value from two bytes.
*
* @param b0 the first byte
* @param b1 the second byte
* @return the value
*/
public static char toChar(byte b0, byte b1) {
return (char) ((b0 << 8) | (b1 & 0xff));
}
/**
* Creates an unsigned short from two bytes.
*
* @param b0 the first byte
* @param b1 the second byte
* @return the value
*/
public static int toUnsignedShort(byte b0, byte b1) {
return ((b0 & 0xff) << 8) | (b1 & 0xff);
}
/**
* Creates an integer from four bytes.
*
* @param b0 the first byte
* @param b1 the second byte
* @param b2 the third byte
* @param b3 the fourth byte
* @return the value
*/
public static int toInt(byte b0, byte b1, byte b2, byte b3) {
return (b0 << 24)
| ((b1 & 0xff) << 16)
| ((b2 & 0xff) << 8)
| (b3 & 0xff);
}
/**
* Creates a long from eight bytes.
*
* @param b0 the first byte
* @param b1 the second byte
* @param b2 the third byte
* @param b3 the fourth byte
* @param b4 the fifth byte
* @param b5 the sixth byte
* @param b6 the seventh byte
* @param b7 the eighth byte
* @return the value
*/
public static long toLong(byte b0, byte b1, byte b2, byte b3, byte b4, byte b5, byte b6, byte b7) {
return ((long) b0 << 56)
| (((long) b1 & 0xff) << 48)
| (((long) b2 & 0xff) << 40)
| (((long) b3 & 0xff) << 32)
| (((long) b4 & 0xff) << 24)
| (((long) b5 & 0xff) << 16)
| (((long) b6 & 0xff) << 8)
| ((long) b7 & 0xff);
}
public static byte char0(char value) { return (byte) (value >> 8); }
public static byte char1(char value) { return (byte) value; }
public static byte short0(short value) { return (byte) (value >> 8); }
public static byte short1(short value) { return (byte) value; }
public static byte int0(int value) { return (byte) (value >> 24); }
public static byte int1(int value) { return (byte) (value >> 16); }
public static byte int2(int value) { return (byte) (value >> 8); }
public static byte int3(int value) { return (byte) value; }
public static byte long0(long value) { return (byte) (value >> 56); }
public static byte long1(long value) { return (byte) (value >> 48); }
public static byte long2(long value) { return (byte) (value >> 40); }
public static byte long3(long value) { return (byte) (value >> 32); }
public static byte long4(long value) { return (byte) (value >> 24); }
public static byte long5(long value) { return (byte) (value >> 16); }
public static byte long6(long value) { return (byte) (value >> 8); }
public static byte long7(long value) { return (byte) value; }
}