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Aliyun Open Services SDK for Java Copyright (C) Alibaba Cloud Computing All rights reserved. 版权所有 （C）阿里云计算有限公司 http://www.aliyun.com
package com.aliyun.openservices.ots.utils;
import com.aliyun.openservices.ots.internal.OTSConsts;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.ByteBuffer;
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;
public static class WritableUtils {
public static int readVInt(DataInput stream) throws IOException {
return (int) readVLong(stream);
}
public static long readVLong(DataInput stream) throws IOException {
byte firstByte = stream.readByte();
int len = decodeVIntSize(firstByte);
if (len == 1) {
return firstByte;
}
long i = 0;
for (int idx = 0; idx < len - 1; idx++) {
byte b = stream.readByte();
i = i << 8;
i = i | (b & 0xFF);
}
return (isNegativeVInt(firstByte) ? (i ^ -1L) : i);
}
public static int decodeVIntSize(byte value) {
if (value >= -112) {
return 1;
} else if (value < -120) {
return -119 - value;
}
return -111 - value;
}
public static boolean isNegativeVInt(byte value) {
return value < -120 || (value >= -112 && value < 0);
}
public static boolean writeVInt(byte value) {
return value < -120 || (value >= -112 && value < 0);
}
public static void writeVInt(DataOutput stream, int i) throws IOException {
writeVLong(stream, i);
}
public static void writeVLong(DataOutput stream, long i) throws IOException {
if (i >= -112 && i <= 127) {
stream.writeByte((byte) i);
return;
}
int len = -112;
if (i < 0) {
i ^= -1L; // take one's complement'
len = -120;
}
long tmp = i;
while (tmp != 0) {
tmp = tmp >> 8;
len--;
}
stream.writeByte((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;
stream.writeByte((byte) ((i & mask) >> shiftbits));
}
}
public static int getVIntSize(long i) {
if (i >= -112 && i <= 127) {
return 1;
}
if (i < 0) {
i ^= -1L; // take one's complement'
}
// find the number of bytes with non-leading zeros
int dataBits = Long.SIZE - Long.numberOfLeadingZeros(i);
// find the number of data bytes + length byte
return (dataBits + 7) / 8 + 1;
}
}
/**
* Read byte-array written with a WritableableUtils.vint prefix.
*
* @param in Input to read from.
* @return byte array read off in
* @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 in
*/
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 b
*/
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.
* @return String b1+sep+b2 value
*/
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 b 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, OTSConsts.DEFAULT_ENCODING);
} catch (UnsupportedEncodingException e) {
LOG.error("UTF-8 not supported?", e);
return null;
}
}
public static byte[] copyBytes(final byte[] bytes, int offset, int length) {
if (offset + length > bytes.length) {
throw explainWrongLengthOrOffset(bytes, offset, length, length);
}
byte[] result = new byte[length];
System.arraycopy(bytes, offset, result, 0, length);
return result;
}
/**
* 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) {
if (b == null)
return "null";
return toStringBinary(b, 0, b.length);
}
/**
* Converts the given byte buffer, from its array offset to its limit, to
* a string. The position and the mark are ignored.
*
* @param buf a byte buffer
* @return a string representation of the buffer's binary contents
*/
public static String toStringBinary(ByteBuffer buf) {
if (buf == null)
return "null";
return toStringBinary(buf.array(), buf.arrayOffset(), buf.limit());
}
/**
* 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 == '\\' && in.length() > i + 1 && in.charAt(i + 1) == 'x') {
// 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(OTSConsts.DEFAULT_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 b 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;
}
public static boolean toBoolean(final byte[] bytes, int offset, int length) {
if (length != SIZEOF_BOOLEAN || offset + length > bytes.length) {
throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_BOOLEAN);
}
return bytes[offset] != (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 bytes
*/
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 bytes
*/
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;
}
/**
* This method will get a sequence of bytes from pos ,
* but will restore pos after.
*
* @param buf
* @return byte array
*/
public static byte[] getBytes(ByteBuffer buf) {
int savedPos = buf.position();
byte[] newBytes = new byte[buf.remaining()];
buf.get(newBytes);
buf.position(savedPos);
return newBytes;
}
/**
* 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;
}
public static byte toByte(byte[] bytes, int offset, int length) {
if (length != SIZEOF_BYTE || offset + length > bytes.length) {
throw explainWrongLengthOrOffset(bytes, offset, length, SIZEOF_BYTE);
}
return bytes[offset];
}
/**
* Convert a BigDecimal value to a byte array
*
* @param val
* @return the byte array
*/
public static byte[] toBytes(BigDecimal val) {
byte[] valueBytes = val.unscaledValue().toByteArray();
byte[] result = new byte[valueBytes.length + SIZEOF_INT];
int offset = putInt(result, 0, val.scale());
putBytes(result, offset, valueBytes, 0, valueBytes.length);
return result;
}
/**
* Converts a byte array to a BigDecimal
*
* @param bytes
* @return the char value
*/
public static BigDecimal toBigDecimal(byte[] bytes) {
return toBigDecimal(bytes, 0, bytes.length);
}
/**
* Converts a byte array to a BigDecimal value
*
* @param bytes
* @param offset
* @param length
* @return the char value
*/
public static BigDecimal toBigDecimal(byte[] bytes, int offset, final int length) {
if (bytes == null || length < SIZEOF_INT + 1 ||
(offset + length > bytes.length)) {
return null;
}
int scale = toInt(bytes, offset);
byte[] tcBytes = new byte[length - SIZEOF_INT];
System.arraycopy(bytes, offset + SIZEOF_INT, tcBytes, 0, length - SIZEOF_INT);
return new BigDecimal(new BigInteger(tcBytes), scale);
}
/**
* Put a BigDecimal value out to the specified byte array position.
*
* @param bytes the byte array
* @param offset position in the array
* @param val BigDecimal to write out
* @return incremented offset
*/
public static int putBigDecimal(byte[] bytes, int offset, BigDecimal val) {
if (bytes == null) {
return offset;
}
byte[] valueBytes = val.unscaledValue().toByteArray();
byte[] result = new byte[valueBytes.length + SIZEOF_INT];
offset = putInt(result, offset, val.scale());
return putBytes(result, offset, valueBytes, 0, valueBytes.length);
}
/**
* @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.
* @return deserialized long from stream.
* @throws java.io.IOException e
*/
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 int 相等时返回0，left小于right时返回负值
*/
public static int compareTo(final byte[] left, final byte[] right) {
return compareByteArrayInLexOrder(left, 0, left.length, right, 0, right.length);
}
/**
* Lexicographically 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 相等时返回0，left小于right时返回负值
*/
public static int compareTo(byte[] buffer1, int offset1, int length1,
byte[] buffer2, int offset2, int length2) {
return compareByteArrayInLexOrder(buffer1, offset1, length1, buffer2, offset2, length2);
}
public static int compareByteArrayInLexOrder(byte[] buffer1, int offset1, int length1,
byte[] buffer2, int offset2, int length2) {
// Short circuit equal case
if (buffer1 == buffer2 &&
offset1 == offset2 &&
length1 == length2) {
return 0;
}
// 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 == right) return true;
if (left == null || right == null) return false;
if (left.length != right.length) return false;
if (left.length == 0) return true;
// Since we're often comparing adjacent sorted data,
// it's usual to have equal arrays except for the very last byte
// so check that first
if (left[left.length - 1] != right[right.length - 1]) return false;
return compareTo(left, right) == 0;
}
public static boolean equals(final byte[] left, int leftOffset, int leftLen,
final byte[] right, int rightOffset, int rightLen) {
// short circuit case
if (left == right &&
leftOffset == rightOffset &&
leftLen == rightLen) {
return true;
}
// different lengths fast check
if (leftLen != rightLen) {
return false;
}
if (leftLen == 0) {
return true;
}
// Since we're often comparing adjacent sorted data,
// it's usual to have equal arrays except for the very last byte
// so check that first
if (left[leftOffset + leftLen - 1] != right[rightOffset + rightLen - 1]) return false;
return compareByteArrayInLexOrder(left, leftOffset, leftLen, right, rightOffset, rightLen) == 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 &&
compareByteArrayInLexOrder(bytes, 0, prefix.length, prefix, 0, prefix.length) == 0;
}
public static int hashCode(final byte[] b) {
return hashCode(b, b.length);
}
public static int hashCode(final byte[] b, final int length) {
return hashBytes(b, length);
}
/**
* Compute hash for binary data.
*/
public static int hashBytes(byte[] bytes, int offset, int length) {
int hash = 1;
for (int i = offset; i < offset + length; i++)
hash = (31 * hash) + (int) bytes[i];
return hash;
}
/**
* Compute hash for binary data.
*/
public static int hashBytes(byte[] bytes, int length) {
return hashBytes(bytes, 0, length);
}
/**
* @param bytes array to hash
* @param offset offset to start from
* @param length length to hash
*/
public static int hashCode(byte[] bytes, int offset, int length) {
int hash = 1;
for (int i = offset; i < offset + length; i++)
hash = (31 * hash) + (int) bytes[i];
return hash;
}
/**
* 参考规范： http://tools.ietf.org/html/rfc3629
*/
public static int stringtoUTF8Bytes(String str, byte[] buffer) {
int index = 0;
for (int i = 0; i < str.length(); i++) {
char strChar = str.charAt(i);
if ((strChar & 0xFF80) == 0) {
// (00000000 00000000 - 00000000 01111111) -> 0xxxxxxx
buffer[index++] = (byte) (strChar & 0x00FF);
} else if ((strChar & 0xF800) == 0) {
// (00000000 10000000 - 00000111 11111111) -> 110xxxxx 10xxxxxx
buffer[index++] = (byte) ((strChar >> 6) | 0x00c0);
buffer[index++] = (byte) ((strChar & 0x003F) | 0x0080);
} else {
// (00001000 00000000 - 11111111 11111111) -> 1110xxxx 10xxxxxx 10xxxxxx
buffer[index++] = (byte) ((strChar >> 12) | 0x00e0);
buffer[index++] = (byte) (((strChar >> 6) & 0x003F) | 0x0080);
buffer[index++] = (byte) ((strChar & 0x003F) | 0x0080);
}
}
return index;
}
}
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