/**
* Copyright 2010 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.hadoop.hbase.util;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.io.RawComparator;
import org.apache.hadoop.io.WritableComparator;
import org.apache.hadoop.io.WritableUtils;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.util.Comparator;
import java.util.Iterator;
/**
* Utility class that handles byte arrays, conversions to/from other types,
* comparisons, hash code generation, manufacturing keys for HashMaps or
* HashSets, etc.
*/
public class Bytes {
private static final Log LOG = LogFactory.getLog(Bytes.class);
/**
* Size of boolean in bytes
*/
public static final int SIZEOF_BOOLEAN = Byte.SIZE / Byte.SIZE;
/**
* Size of byte in bytes
*/
public static final int SIZEOF_BYTE = SIZEOF_BOOLEAN;
/**
* Size of char in bytes
*/
public static final int SIZEOF_CHAR = Character.SIZE / Byte.SIZE;
/**
* Size of double in bytes
*/
public static final int SIZEOF_DOUBLE = Double.SIZE / Byte.SIZE;
/**
* Size of float in bytes
*/
public static final int SIZEOF_FLOAT = Float.SIZE / Byte.SIZE;
/**
* Size of int in bytes
*/
public static final int SIZEOF_INT = Integer.SIZE / Byte.SIZE;
/**
* Size of long in bytes
*/
public static final int SIZEOF_LONG = Long.SIZE / Byte.SIZE;
/**
* Size of short in bytes
*/
public static final int SIZEOF_SHORT = Short.SIZE / Byte.SIZE;
/**
* Estimate of size cost to pay beyond payload in jvm for instance of byte [].
* Estimate based on study of jhat and jprofiler numbers.
*/
// JHat says BU is 56 bytes.
// SizeOf which uses java.lang.instrument says 24 bytes. (3 longs?)
public static final int ESTIMATED_HEAP_TAX = 16;
/**
* Byte array comparator class.
*/
public static class ByteArrayComparator implements RawComparator<byte []> {
/**
* Constructor
*/
public ByteArrayComparator() {
super();
}
public int compare(byte [] left, byte [] right) {
return compareTo(left, right);
}
public int compare(byte [] b1, int s1, int l1, byte [] b2, int s2, int l2) {
return compareTo(b1, s1, l1, b2, s2, l2);
}
}
/**
* Pass this to TreeMaps where byte [] are keys.
*/
public static Comparator<byte []> BYTES_COMPARATOR =
new ByteArrayComparator();
/**
* Use comparing byte arrays, byte-by-byte
*/
public static RawComparator<byte []> BYTES_RAWCOMPARATOR =
new ByteArrayComparator();
/**
* Read byte-array written with a WritableableUtils.vint prefix.
* @param in Input to read from.
* @return byte array read off <code>in</code>
* @throws IOException e
*/
public static byte [] readByteArray(final DataInput in)
throws IOException {
int len = WritableUtils.readVInt(in);
if (len < 0) {
throw new NegativeArraySizeException(Integer.toString(len));
}
byte [] result = new byte[len];
in.readFully(result, 0, len);
return result;
}
/**
* Read byte-array written with a WritableableUtils.vint prefix.
* IOException is converted to a RuntimeException.
* @param in Input to read from.
* @return byte array read off <code>in</code>
*/
public static byte [] readByteArrayThrowsRuntime(final DataInput in) {
try {
return readByteArray(in);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Write byte-array with a WritableableUtils.vint prefix.
* @param out output stream to be written to
* @param b array to write
* @throws IOException e
*/
public static void writeByteArray(final DataOutput out, final byte [] b)
throws IOException {
if(b == null) {
WritableUtils.writeVInt(out, 0);
} else {
writeByteArray(out, b, 0, b.length);
}
}
/**
* Write byte-array to out with a vint length prefix.
* @param out output stream
* @param b array
* @param offset offset into array
* @param length length past offset
* @throws IOException e
*/
public static void writeByteArray(final DataOutput out, final byte [] b,
final int offset, final int length)
throws IOException {
WritableUtils.writeVInt(out, length);
out.write(b, offset, length);
}
/**
* Write byte-array from src to tgt with a vint length prefix.
* @param tgt target array
* @param tgtOffset offset into target array
* @param src source array
* @param srcOffset source offset
* @param srcLength source length
* @return New offset in src array.
*/
public static int writeByteArray(final byte [] tgt, final int tgtOffset,
final byte [] src, final int srcOffset, final int srcLength) {
byte [] vint = vintToBytes(srcLength);
System.arraycopy(vint, 0, tgt, tgtOffset, vint.length);
int offset = tgtOffset + vint.length;
System.arraycopy(src, srcOffset, tgt, offset, srcLength);
return offset + srcLength;
}
/**
* Put bytes at the specified byte array position.
* @param tgtBytes the byte array
* @param tgtOffset position in the array
* @param srcBytes array to write out
* @param srcOffset source offset
* @param srcLength source length
* @return incremented offset
*/
public static int putBytes(byte[] tgtBytes, int tgtOffset, byte[] srcBytes,
int srcOffset, int srcLength) {
System.arraycopy(srcBytes, srcOffset, tgtBytes, tgtOffset, srcLength);
return tgtOffset + srcLength;
}
/**
* Write a single byte out to the specified byte array position.
* @param bytes the byte array
* @param offset position in the array
* @param b byte to write out
* @return incremented offset
*/
public static int putByte(byte[] bytes, int offset, byte b) {
bytes[offset] = b;
return offset + 1;
}
/**
* Returns a new byte array, copied from the passed ByteBuffer.
* @param bb A ByteBuffer
* @return the byte array
*/
public static byte[] toBytes(ByteBuffer bb) {
int length = bb.limit();
byte [] result = new byte[length];
System.arraycopy(bb.array(), bb.arrayOffset(), result, 0, length);
return result;
}
/**
* @param b Presumed UTF-8 encoded byte array.
* @return String made from <code>b</code>
*/
public static String toString(final byte [] b) {
if (b == null) {
return null;
}
return toString(b, 0, b.length);
}
/**
* Joins two byte arrays together using a separator.
* @param b1 The first byte array.
* @param sep The separator to use.
* @param b2 The second byte array.
*/
public static String toString(final byte [] b1,
String sep,
final byte [] b2) {
return toString(b1, 0, b1.length) + sep + toString(b2, 0, b2.length);
}
/**
* This method will convert utf8 encoded bytes into a string. If
* an UnsupportedEncodingException occurs, this method will eat it
* and return null instead.
*
* @param b Presumed UTF-8 encoded byte array.
* @param off offset into array
* @param len length of utf-8 sequence
* @return String made from <code>b</code> or null
*/
public static String toString(final byte [] b, int off, int len) {
if (b == null) {
return null;
}
if (len == 0) {
return "";
}
try {
return new String(b, off, len, HConstants.UTF8_ENCODING);
} catch (UnsupportedEncodingException e) {
LOG.error("UTF-8 not supported?", e);
return null;
}
}
/**
* Write a printable representation of a byte array.
*
* @param b byte array
* @return string
* @see #toStringBinary(byte[], int, int)
*/
public static String toStringBinary(final byte [] b) {
return toStringBinary(b, 0, b.length);
}
/**
* Write a printable representation of a byte array. Non-printable
* characters are hex escaped in the format \\x%02X, eg:
* \x00 \x05 etc
*
* @param b array to write out
* @param off offset to start at
* @param len length to write
* @return string output
*/
public static String toStringBinary(final byte [] b, int off, int len) {
StringBuilder result = new StringBuilder();
try {
String first = new String(b, off, len, "ISO-8859-1");
for (int i = 0; i < first.length() ; ++i ) {
int ch = first.charAt(i) & 0xFF;
if ( (ch >= '0' && ch <= '9')
|| (ch >= 'A' && ch <= 'Z')
|| (ch >= 'a' && ch <= 'z')
|| " `~!@#$%^&*()-_=+[]{}\\|;:'\",.<>/?".indexOf(ch) >= 0 ) {
result.append(first.charAt(i));
} else {
result.append(String.format("\\x%02X", ch));
}
}
} catch (UnsupportedEncodingException e) {
LOG.error("ISO-8859-1 not supported?", e);
}
return result.toString();
}
private static boolean isHexDigit(char c) {
return
(c >= 'A' && c <= 'F') ||
(c >= '0' && c <= '9');
}
/**
* Takes a ASCII digit in the range A-F0-9 and returns
* the corresponding integer/ordinal value.
* @param ch The hex digit.
* @return The converted hex value as a byte.
*/
public static byte toBinaryFromHex(byte ch) {
if ( ch >= 'A' && ch <= 'F' )
return (byte) ((byte)10 + (byte) (ch - 'A'));
// else
return (byte) (ch - '0');
}
public static byte [] toBytesBinary(String in) {
// this may be bigger than we need, but lets be safe.
byte [] b = new byte[in.length()];
int size = 0;
for (int i = 0; i < in.length(); ++i) {
char ch = in.charAt(i);
if (ch == '\\') {
// begin hex escape:
char next = in.charAt(i+1);
if (next != 'x') {
// invalid escape sequence, ignore this one.
b[size++] = (byte)ch;
continue;
}
// ok, take next 2 hex digits.
char hd1 = in.charAt(i+2);
char hd2 = in.charAt(i+3);
// they need to be A-F0-9:
if (!isHexDigit(hd1) ||
!isHexDigit(hd2)) {
// bogus escape code, ignore:
continue;
}
// turn hex ASCII digit -> number
byte d = (byte) ((toBinaryFromHex((byte)hd1) << 4) + toBinaryFromHex((byte)hd2));
b[size++] = d;
i += 3; // skip 3
} else {
b[size++] = (byte) ch;
}
}
// resize:
byte [] b2 = new byte[size];
System.arraycopy(b, 0, b2, 0, size);
return b2;
}
/**
* Converts a string to a UTF-8 byte array.
* @param s string
* @return the byte array
*/
public static byte[] toBytes(String s) {
try {
return s.getBytes(HConstants.UTF8_ENCODING);
} catch (UnsupportedEncodingException e) {
LOG.error("UTF-8 not supported?", e);
return null;
}
}
/**
* Convert a boolean to a byte array. True becomes -1
* and false becomes 0.
*
* @param b value
* @return <code>b</code> encoded in a byte array.
*/
public static byte [] toBytes(final boolean b) {
return new byte[] { b ? (byte) -1 : (byte) 0 };
}
/**
* Reverses {@link #toBytes(boolean)}
* @param b array
* @return True or false.
*/
public static boolean toBoolean(final byte [] b) {
if (b.length != 1) {
throw new IllegalArgumentException("Array has wrong size: " + b.length);
}
return b[0] != (byte) 0;
}
/**
* Convert a long value to a byte array using big-endian.
*
* @param val value to convert
* @return the byte array
*/
public static byte[] toBytes(long val) {
byte [] b = new byte[8];
for (int i = 7; i > 0; i--) {
b[i] = (byte) val;
val >>>= 8;
}
b[0] = (byte) val;
return b;
}
/**
* Converts a byte array to a long value. Reverses
* {@link #toBytes(long)}
* @param bytes array
* @return the long value
*/
public static long toLong(byte[] bytes) {
return toLong(bytes, 0, SIZEOF_LONG);
}
/**
* Converts a byte array to a long value. Assumes there will be
* {@link #SIZEOF_LONG} bytes available.
*
* @param bytes bytes
* @param offset offset
* @return the long value
*/
public static long toLong(byte[] bytes, int offset) {
return toLong(bytes, offset, SIZEOF_LONG);
}
/**
* Converts a byte array to a long value.
*
* @param bytes array of bytes
* @param offset offset into array
* @param length length of data (must be {@link #SIZEOF_LONG})
* @return the long value
* @throws IllegalArgumentException if length is not {@link #SIZEOF_LONG} or
* if there's not enough room in the array at the offset indicated.
*/
public static long toLong(byte[] bytes, int offset, final int length) {
if (length != SIZEOF_LONG || offset + length > bytes.length) {
throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_LONG);
}
long l = 0;
for(int i = offset; i < offset + length; i++) {
l <<= 8;
l ^= bytes[i] & 0xFF;
}
return l;
}
private static IllegalArgumentException
explainWrongLengthOrOffset(final byte[] bytes,
final int offset,
final int length,
final int expectedLength) {
String reason;
if (length != expectedLength) {
reason = "Wrong length: " + length + ", expected " + expectedLength;
} else {
reason = "offset (" + offset + ") + length (" + length + ") exceed the"
+ " capacity of the array: " + bytes.length;
}
return new IllegalArgumentException(reason);
}
/**
* Put a long value out to the specified byte array position.
* @param bytes the byte array
* @param offset position in the array
* @param val long to write out
* @return incremented offset
* @throws IllegalArgumentException if the byte array given doesn't have
* enough room at the offset specified.
*/
public static int putLong(byte[] bytes, int offset, long val) {
if (bytes.length - offset < SIZEOF_LONG) {
throw new IllegalArgumentException("Not enough room to put a long at"
+ " offset " + offset + " in a " + bytes.length + " byte array");
}
for(int i = offset + 7; i > offset; i--) {
bytes[i] = (byte) val;
val >>>= 8;
}
bytes[offset] = (byte) val;
return offset + SIZEOF_LONG;
}
/**
* Presumes float encoded as IEEE 754 floating-point "single format"
* @param bytes byte array
* @return Float made from passed byte array.
*/
public static float toFloat(byte [] bytes) {
return toFloat(bytes, 0);
}
/**
* Presumes float encoded as IEEE 754 floating-point "single format"
* @param bytes array to convert
* @param offset offset into array
* @return Float made from passed byte array.
*/
public static float toFloat(byte [] bytes, int offset) {
return Float.intBitsToFloat(toInt(bytes, offset, SIZEOF_INT));
}
/**
* @param bytes byte array
* @param offset offset to write to
* @param f float value
* @return New offset in <code>bytes</code>
*/
public static int putFloat(byte [] bytes, int offset, float f) {
return putInt(bytes, offset, Float.floatToRawIntBits(f));
}
/**
* @param f float value
* @return the float represented as byte []
*/
public static byte [] toBytes(final float f) {
// Encode it as int
return Bytes.toBytes(Float.floatToRawIntBits(f));
}
/**
* @param bytes byte array
* @return Return double made from passed bytes.
*/
public static double toDouble(final byte [] bytes) {
return toDouble(bytes, 0);
}
/**
* @param bytes byte array
* @param offset offset where double is
* @return Return double made from passed bytes.
*/
public static double toDouble(final byte [] bytes, final int offset) {
return Double.longBitsToDouble(toLong(bytes, offset, SIZEOF_LONG));
}
/**
* @param bytes byte array
* @param offset offset to write to
* @param d value
* @return New offset into array <code>bytes</code>
*/
public static int putDouble(byte [] bytes, int offset, double d) {
return putLong(bytes, offset, Double.doubleToLongBits(d));
}
/**
* Serialize a double as the IEEE 754 double format output. The resultant
* array will be 8 bytes long.
*
* @param d value
* @return the double represented as byte []
*/
public static byte [] toBytes(final double d) {
// Encode it as a long
return Bytes.toBytes(Double.doubleToRawLongBits(d));
}
/**
* Convert an int value to a byte array
* @param val value
* @return the byte array
*/
public static byte[] toBytes(int val) {
byte [] b = new byte[4];
for(int i = 3; i > 0; i--) {
b[i] = (byte) val;
val >>>= 8;
}
b[0] = (byte) val;
return b;
}
/**
* Converts a byte array to an int value
* @param bytes byte array
* @return the int value
*/
public static int toInt(byte[] bytes) {
return toInt(bytes, 0, SIZEOF_INT);
}
/**
* Converts a byte array to an int value
* @param bytes byte array
* @param offset offset into array
* @return the int value
*/
public static int toInt(byte[] bytes, int offset) {
return toInt(bytes, offset, SIZEOF_INT);
}
/**
* Converts a byte array to an int value
* @param bytes byte array
* @param offset offset into array
* @param length length of int (has to be {@link #SIZEOF_INT})
* @return the int value
* @throws IllegalArgumentException if length is not {@link #SIZEOF_INT} or
* if there's not enough room in the array at the offset indicated.
*/
public static int toInt(byte[] bytes, int offset, final int length) {
if (length != SIZEOF_INT || offset + length > bytes.length) {
throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_INT);
}
int n = 0;
for(int i = offset; i < (offset + length); i++) {
n <<= 8;
n ^= bytes[i] & 0xFF;
}
return n;
}
/**
* Put an int value out to the specified byte array position.
* @param bytes the byte array
* @param offset position in the array
* @param val int to write out
* @return incremented offset
* @throws IllegalArgumentException if the byte array given doesn't have
* enough room at the offset specified.
*/
public static int putInt(byte[] bytes, int offset, int val) {
if (bytes.length - offset < SIZEOF_INT) {
throw new IllegalArgumentException("Not enough room to put an int at"
+ " offset " + offset + " in a " + bytes.length + " byte array");
}
for(int i= offset + 3; i > offset; i--) {
bytes[i] = (byte) val;
val >>>= 8;
}
bytes[offset] = (byte) val;
return offset + SIZEOF_INT;
}
/**
* Convert a short value to a byte array of {@link #SIZEOF_SHORT} bytes long.
* @param val value
* @return the byte array
*/
public static byte[] toBytes(short val) {
byte[] b = new byte[SIZEOF_SHORT];
b[1] = (byte) val;
val >>= 8;
b[0] = (byte) val;
return b;
}
/**
* Converts a byte array to a short value
* @param bytes byte array
* @return the short value
*/
public static short toShort(byte[] bytes) {
return toShort(bytes, 0, SIZEOF_SHORT);
}
/**
* Converts a byte array to a short value
* @param bytes byte array
* @param offset offset into array
* @return the short value
*/
public static short toShort(byte[] bytes, int offset) {
return toShort(bytes, offset, SIZEOF_SHORT);
}
/**
* Converts a byte array to a short value
* @param bytes byte array
* @param offset offset into array
* @param length length, has to be {@link #SIZEOF_SHORT}
* @return the short value
* @throws IllegalArgumentException if length is not {@link #SIZEOF_SHORT}
* or if there's not enough room in the array at the offset indicated.
*/
public static short toShort(byte[] bytes, int offset, final int length) {
if (length != SIZEOF_SHORT || offset + length > bytes.length) {
throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_SHORT);
}
short n = 0;
n ^= bytes[offset] & 0xFF;
n <<= 8;
n ^= bytes[offset+1] & 0xFF;
return n;
}
/**
* Put a short value out to the specified byte array position.
* @param bytes the byte array
* @param offset position in the array
* @param val short to write out
* @return incremented offset
* @throws IllegalArgumentException if the byte array given doesn't have
* enough room at the offset specified.
*/
public static int putShort(byte[] bytes, int offset, short val) {
if (bytes.length - offset < SIZEOF_SHORT) {
throw new IllegalArgumentException("Not enough room to put a short at"
+ " offset " + offset + " in a " + bytes.length + " byte array");
}
bytes[offset+1] = (byte) val;
val >>= 8;
bytes[offset] = (byte) val;
return offset + SIZEOF_SHORT;
}
/**
* @param vint Integer to make a vint of.
* @return Vint as bytes array.
*/
public static byte [] vintToBytes(final long vint) {
long i = vint;
int size = WritableUtils.getVIntSize(i);
byte [] result = new byte[size];
int offset = 0;
if (i >= -112 && i <= 127) {
result[offset] = (byte) i;
return result;
}
int len = -112;
if (i < 0) {
i ^= -1L; // take one's complement'
len = -120;
}
long tmp = i;
while (tmp != 0) {
tmp = tmp >> 8;
len--;
}
result[offset++] = (byte) len;
len = (len < -120) ? -(len + 120) : -(len + 112);
for (int idx = len; idx != 0; idx--) {
int shiftbits = (idx - 1) * 8;
long mask = 0xFFL << shiftbits;
result[offset++] = (byte)((i & mask) >> shiftbits);
}
return result;
}
/**
* @param buffer buffer to convert
* @return vint bytes as an integer.
*/
public static long bytesToVint(final byte [] buffer) {
int offset = 0;
byte firstByte = buffer[offset++];
int len = WritableUtils.decodeVIntSize(firstByte);
if (len == 1) {
return firstByte;
}
long i = 0;
for (int idx = 0; idx < len-1; idx++) {
byte b = buffer[offset++];
i = i << 8;
i = i | (b & 0xFF);
}
return (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
}
/**
* Reads a zero-compressed encoded long from input stream and returns it.
* @param buffer Binary array
* @param offset Offset into array at which vint begins.
* @throws java.io.IOException e
* @return deserialized long from stream.
*/
public static long readVLong(final byte [] buffer, final int offset)
throws IOException {
byte firstByte = buffer[offset];
int len = WritableUtils.decodeVIntSize(firstByte);
if (len == 1) {
return firstByte;
}
long i = 0;
for (int idx = 0; idx < len-1; idx++) {
byte b = buffer[offset + 1 + idx];
i = i << 8;
i = i | (b & 0xFF);
}
return (WritableUtils.isNegativeVInt(firstByte) ? ~i : i);
}
/**
* @param left left operand
* @param right right operand
* @return 0 if equal, < 0 if left is less than right, etc.
*/
public static int compareTo(final byte [] left, final byte [] right) {
return compareTo(left, 0, left.length, right, 0, right.length);
}
/**
* Lexographically compare two arrays.
*
* @param buffer1 left operand
* @param buffer2 right operand
* @param offset1 Where to start comparing in the left buffer
* @param offset2 Where to start comparing in the right buffer
* @param length1 How much to compare from the left buffer
* @param length2 How much to compare from the right buffer
* @return 0 if equal, < 0 if left is less than right, etc.
*/
public static int compareTo(byte[] buffer1, int offset1, int length1,
byte[] buffer2, int offset2, int length2) {
// Bring WritableComparator code local
int end1 = offset1 + length1;
int end2 = offset2 + length2;
for (int i = offset1, j = offset2; i < end1 && j < end2; i++, j++) {
int a = (buffer1[i] & 0xff);
int b = (buffer2[j] & 0xff);
if (a != b) {
return a - b;
}
}
return length1 - length2;
}
/**
* @param left left operand
* @param right right operand
* @return True if equal
*/
public static boolean equals(final byte [] left, final byte [] right) {
// Could use Arrays.equals?
//noinspection SimplifiableConditionalExpression
if (left == null && right == null) {
return true;
}
return (left == null || right == null || (left.length != right.length)
? false : compareTo(left, right) == 0);
}
/**
* Return true if the byte array on the right is a prefix of the byte
* array on the left.
*/
public static boolean startsWith(byte[] bytes, byte[] prefix) {
return bytes != null && prefix != null &&
bytes.length >= prefix.length &&
compareTo(bytes, 0, prefix.length, prefix, 0, prefix.length) == 0;
}
/**
* @param b bytes to hash
* @return Runs {@link WritableComparator#hashBytes(byte[], int)} on the
* passed in array. This method is what {@link org.apache.hadoop.io.Text} and
* {@link ImmutableBytesWritable} use calculating hash code.
*/
public static int hashCode(final byte [] b) {
return hashCode(b, b.length);
}
/**
* @param b value
* @param length length of the value
* @return Runs {@link WritableComparator#hashBytes(byte[], int)} on the
* passed in array. This method is what {@link org.apache.hadoop.io.Text} and
* {@link ImmutableBytesWritable} use calculating hash code.
*/
public static int hashCode(final byte [] b, final int length) {
return WritableComparator.hashBytes(b, length);
}
/**
* @param b bytes to hash
* @return A hash of <code>b</code> as an Integer that can be used as key in
* Maps.
*/
public static Integer mapKey(final byte [] b) {
return hashCode(b);
}
/**
* @param b bytes to hash
* @param length length to hash
* @return A hash of <code>b</code> as an Integer that can be used as key in
* Maps.
*/
public static Integer mapKey(final byte [] b, final int length) {
return hashCode(b, length);
}
/**
* @param a lower half
* @param b upper half
* @return New array that has a in lower half and b in upper half.
*/
public static byte [] add(final byte [] a, final byte [] b) {
return add(a, b, HConstants.EMPTY_BYTE_ARRAY);
}
/**
* @param a first third
* @param b second third
* @param c third third
* @return New array made from a, b and c
*/
public static byte [] add(final byte [] a, final byte [] b, final byte [] c) {
byte [] result = new byte[a.length + b.length + c.length];
System.arraycopy(a, 0, result, 0, a.length);
System.arraycopy(b, 0, result, a.length, b.length);
System.arraycopy(c, 0, result, a.length + b.length, c.length);
return result;
}
/**
* @param a array
* @param length amount of bytes to grab
* @return First <code>length</code> bytes from <code>a</code>
*/
public static byte [] head(final byte [] a, final int length) {
if (a.length < length) {
return null;
}
byte [] result = new byte[length];
System.arraycopy(a, 0, result, 0, length);
return result;
}
/**
* @param a array
* @param length amount of bytes to snarf
* @return Last <code>length</code> bytes from <code>a</code>
*/
public static byte [] tail(final byte [] a, final int length) {
if (a.length < length) {
return null;
}
byte [] result = new byte[length];
System.arraycopy(a, a.length - length, result, 0, length);
return result;
}
/**
* @param a array
* @param length new array size
* @return Value in <code>a</code> plus <code>length</code> prepended 0 bytes
*/
public static byte [] padHead(final byte [] a, final int length) {
byte [] padding = new byte[length];
for (int i = 0; i < length; i++) {
padding[i] = 0;
}
return add(padding,a);
}
/**
* @param a array
* @param length new array size
* @return Value in <code>a</code> plus <code>length</code> appended 0 bytes
*/
public static byte [] padTail(final byte [] a, final int length) {
byte [] padding = new byte[length];
for (int i = 0; i < length; i++) {
padding[i] = 0;
}
return add(a,padding);
}
/**
* Split passed range. Expensive operation relatively. Uses BigInteger math.
* Useful splitting ranges for MapReduce jobs.
* @param a Beginning of range
* @param b End of range
* @param num Number of times to split range. Pass 1 if you want to split
* the range in two; i.e. one split.
* @return Array of dividing values
*/
public static byte [][] split(final byte [] a, final byte [] b, final int num) {
byte[][] ret = new byte[num+2][];
int i = 0;
Iterable<byte[]> iter = iterateOnSplits(a, b, num);
if (iter == null) return null;
for (byte[] elem : iter) {
ret[i++] = elem;
}
return ret;
}
/**
* Iterate over keys within the passed inclusive range.
*/
public static Iterable<byte[]> iterateOnSplits(
final byte[] a, final byte[]b, final int num)
{
byte [] aPadded;
byte [] bPadded;
if (a.length < b.length) {
aPadded = padTail(a, b.length - a.length);
bPadded = b;
} else if (b.length < a.length) {
aPadded = a;
bPadded = padTail(b, a.length - b.length);
} else {
aPadded = a;
bPadded = b;
}
if (compareTo(aPadded,bPadded) >= 0) {
throw new IllegalArgumentException("b <= a");
}
if (num <= 0) {
throw new IllegalArgumentException("num cannot be < 0");
}
byte [] prependHeader = {1, 0};
final BigInteger startBI = new BigInteger(add(prependHeader, aPadded));
final BigInteger stopBI = new BigInteger(add(prependHeader, bPadded));
final BigInteger diffBI = stopBI.subtract(startBI);
final BigInteger splitsBI = BigInteger.valueOf(num + 1);
if(diffBI.compareTo(splitsBI) < 0) {
return null;
}
final BigInteger intervalBI;
try {
intervalBI = diffBI.divide(splitsBI);
} catch(Exception e) {
LOG.error("Exception caught during division", e);
return null;
}
final Iterator<byte[]> iterator = new Iterator<byte[]>() {
private int i = -1;
@Override
public boolean hasNext() {
return i < num+1;
}
@Override
public byte[] next() {
i++;
if (i == 0) return a;
if (i == num + 1) return b;
BigInteger curBI = startBI.add(intervalBI.multiply(BigInteger.valueOf(i)));
byte [] padded = curBI.toByteArray();
if (padded[1] == 0)
padded = tail(padded, padded.length - 2);
else
padded = tail(padded, padded.length - 1);
return padded;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
};
return new Iterable<byte[]>() {
@Override
public Iterator<byte[]> iterator() {
return iterator;
}
};
}
/**
* @param t operands
* @return Array of byte arrays made from passed array of Text
*/
public static byte [][] toByteArrays(final String [] t) {
byte [][] result = new byte[t.length][];
for (int i = 0; i < t.length; i++) {
result[i] = Bytes.toBytes(t[i]);
}
return result;
}
/**
* @param column operand
* @return A byte array of a byte array where first and only entry is
* <code>column</code>
*/
public static byte [][] toByteArrays(final String column) {
return toByteArrays(toBytes(column));
}
/**
* @param column operand
* @return A byte array of a byte array where first and only entry is
* <code>column</code>
*/
public static byte [][] toByteArrays(final byte [] column) {
byte [][] result = new byte[1][];
result[0] = column;
return result;
}
/**
* Binary search for keys in indexes.
* @param arr array of byte arrays to search for
* @param key the key you want to find
* @param offset the offset in the key you want to find
* @param length the length of the key
* @param comparator a comparator to compare.
* @return index of key
*/
public static int binarySearch(byte [][]arr, byte []key, int offset,
int length, RawComparator<byte []> comparator) {
int low = 0;
int high = arr.length - 1;
while (low <= high) {
int mid = (low+high) >>> 1;
// we have to compare in this order, because the comparator order
// has special logic when the 'left side' is a special key.
int cmp = comparator.compare(key, offset, length,
arr[mid], 0, arr[mid].length);
// key lives above the midpoint
if (cmp > 0)
low = mid + 1;
// key lives below the midpoint
else if (cmp < 0)
high = mid - 1;
// BAM. how often does this really happen?
else
return mid;
}
return - (low+1);
}
/**
* Bytewise binary increment/deincrement of long contained in byte array
* on given amount.
*
* @param value - array of bytes containing long (length <= SIZEOF_LONG)
* @param amount value will be incremented on (deincremented if negative)
* @return array of bytes containing incremented long (length == SIZEOF_LONG)
* @throws IOException - if value.length > SIZEOF_LONG
*/
public static byte [] incrementBytes(byte[] value, long amount)
throws IOException {
byte[] val = value;
if (val.length < SIZEOF_LONG) {
// Hopefully this doesn't happen too often.
byte [] newvalue;
if (val[0] < 0) {
newvalue = new byte[]{-1, -1, -1, -1, -1, -1, -1, -1};
} else {
newvalue = new byte[SIZEOF_LONG];
}
System.arraycopy(val, 0, newvalue, newvalue.length - val.length,
val.length);
val = newvalue;
} else if (val.length > SIZEOF_LONG) {
throw new IllegalArgumentException("Increment Bytes - value too big: " +
val.length);
}
if(amount == 0) return val;
if(val[0] < 0){
return binaryIncrementNeg(val, amount);
}
return binaryIncrementPos(val, amount);
}
/* increment/deincrement for positive value */
private static byte [] binaryIncrementPos(byte [] value, long amount) {
long amo = amount;
int sign = 1;
if (amount < 0) {
amo = -amount;
sign = -1;
}
for(int i=0;i<value.length;i++) {
int cur = ((int)amo % 256) * sign;
amo = (amo >> 8);
int val = value[value.length-i-1] & 0x0ff;
int total = val + cur;
if(total > 255) {
amo += sign;
total %= 256;
} else if (total < 0) {
amo -= sign;
}
value[value.length-i-1] = (byte)total;
if (amo == 0) return value;
}
return value;
}
/* increment/deincrement for negative value */
private static byte [] binaryIncrementNeg(byte [] value, long amount) {
long amo = amount;
int sign = 1;
if (amount < 0) {
amo = -amount;
sign = -1;
}
for(int i=0;i<value.length;i++) {
int cur = ((int)amo % 256) * sign;
amo = (amo >> 8);
int val = ((~value[value.length-i-1]) & 0x0ff) + 1;
int total = cur - val;
if(total >= 0) {
amo += sign;
} else if (total < -256) {
amo -= sign;
total %= 256;
}
value[value.length-i-1] = (byte)total;
if (amo == 0) return value;
}
return value;
}
}