/**
* CopyRight by Chinamobile
*
* Bytes.java
*/
package com.chinamobile.bcbsp.util;
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 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 com.chinamobile.bcbsp.Constants;
/**
* Bytes
*
* Utility class that handles byte arrays, conversions to/from other types,
* comparisons, hash code generation, manufacturing keys for HashMaps or
* HashSets, etc.
*
* @author
* @version
*/
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, Constants.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') || ch == ',' || ch == '_'
|| ch == '-' || ch == ':' || ch == ' ' || ch == '<'
|| ch == '>' || ch == '=' || ch == '/' || ch == '.') {
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(Constants.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 b1
* left operand
* @param b2
* right operand
* @param s1
* Where to start comparing in the left buffer
* @param s2
* Where to start comparing in the right buffer
* @param l1
* How much to compare from the left buffer
* @param l2
* 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[] b1, int s1, int l1, byte[] b2, int s2,
int l2) {
// Bring WritableComparator code local
int end1 = s1 + l1;
int end2 = s2 + l2;
for (int i = s1, j = s2; i < end1 && j < end2; i++, j++) {
int a = (b1[i] & 0xff);
int b = (b2[j] & 0xff);
if (a != b) {
return a - b;
}
}
return l1 - l2;
}
/**
* @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);
}
/**
* @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} 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} 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, Constants.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[] 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 };
BigInteger startBI = new BigInteger(add(prependHeader, aPadded));
BigInteger stopBI = new BigInteger(add(prependHeader, bPadded));
BigInteger diffBI = stopBI.subtract(startBI);
BigInteger splitsBI = BigInteger.valueOf(num + 1);
if (diffBI.compareTo(splitsBI) < 0) {
return null;
}
BigInteger intervalBI;
try {
intervalBI = diffBI.divide(splitsBI);
} catch (Exception e) {
LOG.error("Exception caught during division", e);
return null;
}
byte[][] result = new byte[num + 2][];
result[0] = a;
for (int i = 1; i <= num; i++) {
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);
result[i] = padded;
}
result[num + 1] = b;
return result;
}
/**
* @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;
}
}