/*
* The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
* (the "License"). You may not use this work except in compliance with the License, which is
* available at www.apache.org/licenses/LICENSE-2.0
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
* either express or implied, as more fully set forth in the License.
*
* See the NOTICE file distributed with this work for information regarding copyright ownership.
*/
package alluxio.util.io;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import javax.annotation.concurrent.ThreadSafe;
/**
* A collection of utility functions to read/write primitive values from/to a byte array.
*/
@ThreadSafe
public final class ByteIOUtils {
private ByteIOUtils() {} // prevent instantiation.
/**
* Reads a specific byte value from the input byte array at the given offset.
*
* @param buf input byte array
* @param pos offset into the byte buffer to read
* @return the byte value read
*/
public static byte readByte(byte[] buf, int pos) {
checkBoundary(buf, pos, 1);
return (byte) (buf[pos] & 0xff);
}
/**
* Reads a specific byte value from the input byte buffer at the given offset.
*
* @param buf input byte buffer
* @param pos offset into the byte buffer to read
* @return the byte value read
*/
public static byte readByte(ByteBuffer buf, int pos) {
return (byte) (buf.get(pos) & 0xff);
}
/**
* Reads a specific short byte value (2 bytes) from the input byte array at the given offset.
*
* @param buf input byte buffer
* @param pos offset into the byte buffer to read
* @return the short value read
*/
public static short readShort(byte[] buf, int pos) {
checkBoundary(buf, pos, 2);
return (short) (((short) (buf[pos] & 0xff) << 8) | ((short) (buf[pos + 1] & 0xff)));
}
/**
* Reads a specific integer byte value (4 bytes) from the input byte array at the given offset.
*
* @param buf input byte array
* @param pos offset into the byte buffer to read
* @return the int value read
*/
public static int readInt(byte[] buf, int pos) {
checkBoundary(buf, pos, 4);
return (((buf[pos++] & 0xff) << 24) | ((buf[pos++] & 0xff) << 16)
| ((buf[pos++] & 0xff) << 8) | (buf[pos] & 0xff));
}
/**
* Reads a specific integer byte value (4 bytes) from the input byte buffer at the given offset.
*
* @param buf input byte buffer
* @param pos offset into the byte buffer to read
* @return the int value read
*/
public static int readInt(ByteBuffer buf, int pos) {
return (((buf.get(pos) & 0xff) << 24) | ((buf.get(pos + 1) & 0xff) << 16)
| ((buf.get(pos + 2) & 0xff) << 8) | (buf.get(pos + 3) & 0xff));
}
/**
* Reads a specific long byte value (8 bytes) from the input byte array at the given offset.
*
* @param buf input byte buffer
* @param pos offset into the byte buffer to read
* @return the long value read
*/
public static long readLong(byte[] buf, int pos) {
checkBoundary(buf, pos, 8);
return (((long) (buf[pos++] & 0xff) << 56) | ((long) (buf[pos++] & 0xff) << 48)
| ((long) (buf[pos++] & 0xff) << 40) | ((long) (buf[pos++] & 0xff) << 32)
| ((long) (buf[pos++] & 0xff) << 24) | ((long) (buf[pos++] & 0xff) << 16)
| ((long) (buf[pos++] & 0xff) << 8) | ((long) (buf[pos] & 0xff)));
}
/**
* Writes a single byte value (1 byte) to the output byte array at the given offset.
*
* @param buf output byte buffer
* @param pos offset into the byte buffer to write
* @param v byte value to write
*/
public static void writeByte(byte[] buf, int pos, byte v) {
checkBoundary(buf, pos, 1);
buf[pos] = v;
}
/**
* Writes a single byte value (1 byte) to the output byte buffer at the given offset.
*
* @param buf output byte buffer
* @param pos offset into the byte buffer to write
* @param v byte value to write
*/
public static void writeByte(ByteBuffer buf, int pos, byte v) {
buf.put(pos, v);
}
/**
* Writes a single byte value (1 byte) to the output stream. This is equivalent of
* {@link OutputStream#write(int)}.
*
* @param out output stream
* @param v byte value to write
*/
public static void writeByte(OutputStream out, byte v) throws IOException {
out.write(v);
}
/**
* Writes a specific short value (2 bytes) to the output byte buffer at the given offset.
*
* @param buf output byte buffer
* @param pos offset into the byte buffer to write
* @param v short value to write
*/
public static void writeShort(byte[] buf, int pos, short v) {
checkBoundary(buf, pos, 2);
buf[pos++] = (byte) (0xff & (v >> 8));
buf[pos] = (byte) (0xff & v);
}
/**
* Writes a specific short value (2 bytes) to the output stream.
*
* @param out output stream
* @param v short value to write
*/
public static void writeShort(OutputStream out, short v) throws IOException {
out.write((byte) (0xff & (v >> 8)));
out.write((byte) (0xff & v));
}
/**
* Writes a specific integer value (4 bytes) to the output byte array at the given offset.
*
* @param buf output byte array
* @param pos offset into the byte buffer to write
* @param v int value to write
*/
public static void writeInt(byte[] buf, int pos, int v) {
checkBoundary(buf, pos, 4);
buf[pos++] = (byte) (0xff & (v >> 24));
buf[pos++] = (byte) (0xff & (v >> 16));
buf[pos++] = (byte) (0xff & (v >> 8));
buf[pos] = (byte) (0xff & v);
}
/**
* Writes a specific integer value (4 bytes) to the output byte buffer at the given offset.
*
* @param buf output byte buffer
* @param pos offset into the byte buffer to write
* @param v int value to write
*/
public static void writeInt(ByteBuffer buf, int pos, int v) {
buf.put(pos++, (byte) (0xff & (v >> 24)));
buf.put(pos++, (byte) (0xff & (v >> 16)));
buf.put(pos++, (byte) (0xff & (v >> 8)));
buf.put(pos, (byte) (0xff & v));
}
/**
* Writes a specific integer value (4 bytes) to the output stream.
*
* @param out output stream
* @param v integer value to write
*/
public static void writeInt(OutputStream out, int v) throws IOException {
out.write((byte) (0xff & (v >> 24)));
out.write((byte) (0xff & (v >> 16)));
out.write((byte) (0xff & (v >> 8)));
out.write((byte) (0xff & v));
}
/**
* Writes a specific long value (8 bytes) to the output byte array at the given offset.
*
* @param buf output byte array
* @param pos offset into the byte buffer to write
* @param v long value to write
*/
public static void writeLong(byte[] buf, int pos, long v) {
checkBoundary(buf, pos, 8);
buf[pos++] = (byte) (0xff & (v >> 56));
buf[pos++] = (byte) (0xff & (v >> 48));
buf[pos++] = (byte) (0xff & (v >> 40));
buf[pos++] = (byte) (0xff & (v >> 32));
buf[pos++] = (byte) (0xff & (v >> 24));
buf[pos++] = (byte) (0xff & (v >> 16));
buf[pos++] = (byte) (0xff & (v >> 8));
buf[pos] = (byte) (0xff & v);
}
/**
* Writes a specific long value (8 bytes) to the output stream.
*
* @param out output stream
* @param v long value to write
*/
public static void writeLong(OutputStream out, long v) throws IOException {
out.write((byte) (0xff & (v >> 56)));
out.write((byte) (0xff & (v >> 48)));
out.write((byte) (0xff & (v >> 40)));
out.write((byte) (0xff & (v >> 32)));
out.write((byte) (0xff & (v >> 24)));
out.write((byte) (0xff & (v >> 16)));
out.write((byte) (0xff & (v >> 8)));
out.write((byte) (0xff & v));
}
/**
* Ensures that the given buffer contains at least the given number of bytes after the given
* offset.
*
* @param buf input byte array
* @param pos position in the byte array to start writing
* @param len length of data to write from the given position
*/
private static void checkBoundary(byte[] buf, int pos, int len) {
if (pos + len > buf.length) {
throw new ArrayIndexOutOfBoundsException();
}
}
}