/**
* 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.tajo.util;
import com.google.common.annotations.VisibleForTesting;
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 sun.misc.Unsafe;
import java.io.*;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;
/**
* 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 LexicographicalComparerHolder.BEST_COMPARER.
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 java.io.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 java.io.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 java.io.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;
}
public static void writeVLong(ByteArrayOutputStream byteStream, long l) {
byte[] vLongBytes = Bytes.vlongToBytes(l);
byteStream.write(vLongBytes, 0, vLongBytes.length);
}
/**
* 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, "UTF-8");
} 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) {
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 == '\\') {
// 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("UTF-8");
} catch (UnsupportedEncodingException e) {
LOG.error("UTF-8 not supported?", e);
return null;
}
}
/**
* Converts a char array to a ascii byte array.
*
* @param chars string
* @return the byte array
*/
public static byte[] toASCIIBytes(char[] chars) {
byte[] buffer = new byte[chars.length];
for (int i = 0; i < chars.length; i++) {
buffer[i] = (byte) chars[i];
}
return buffer;
}
/**
* 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;
}
/**
* This method will get a sequence of bytes from pos -> limit,
* but will restore pos after.
* @param buf
* @return
*/
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;
}
/**
* 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
* @return the char value
*/
public static BigDecimal toBigDecimal(byte[] bytes, int offset) {
return toBigDecimal(bytes, offset, 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, 0);
byte[] tcBytes = new byte[length - SIZEOF_INT];
System.arraycopy(bytes, 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 n Long to make a VLong of.
* @return VLong as bytes array.
*/
public static byte[] vlongToBytes(long n) {
byte [] result;
int offset = 0;
if (n >= -112 && n <= 127) {
result = new byte[1];
result[offset] = (byte) n;
return result;
}
int len = -112;
if (n < 0) {
n ^= -1L; // take one's complement'
len = -120;
}
long tmp = n;
while (tmp != 0) {
tmp = tmp >> 8;
len--;
}
int size = WritableUtils.decodeVIntSize((byte)len);
result = new byte[size];
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)((n & 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 length = (byte) WritableUtils.decodeVIntSize(firstByte);
if (length == 1) {
return firstByte;
}
long i = 0;
for (int idx = 0; idx < length - 1; idx++) {
byte b = buffer[offset + 1 + idx];
i = i << 8;
i = i | (b & 0xFF);
}
return (WritableUtils.isNegativeVInt(firstByte) ? (i ^ -1L) : i);
}
/**
* Reads a zero-compressed encoded int 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 int readVInt(final byte [] buffer, final int offset)
throws IOException {
byte firstByte = buffer[offset];
int length = (byte) WritableUtils.decodeVIntSize(firstByte);
if (length == 1) {
return firstByte;
}
int i = 0;
for (int idx = 0; idx < length - 1; idx++) {
byte b = buffer[offset + 1 + idx];
i = i << 8;
i = i | (b & 0xFF);
}
return (WritableUtils.isNegativeVInt(firstByte) ? (i ^ -1) : i);
}
public static byte getVIntSize(byte[] bytes, int offset) {
byte firstByte = bytes[offset];
return (byte) WritableUtils.decodeVIntSize(firstByte);
}
/**
* @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 LexicographicalComparerHolder.BEST_COMPARER.
compareTo(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 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) {
return LexicographicalComparerHolder.BEST_COMPARER.
compareTo(buffer1, offset1, length1, buffer2, offset2, length2);
}
/**
* The number of bytes required to represent a primitive {@code long}
* value.
*/
public static final int LONG_BYTES = Long.SIZE / Byte.SIZE;
interface Comparer<T> {
abstract public int compareTo(T buffer1, int offset1, int length1,
T buffer2, int offset2, int length2);
}
@VisibleForTesting
static Comparer<byte[]> lexicographicalComparerJavaImpl() {
return LexicographicalComparerHolder.PureJavaComparer.INSTANCE;
}
/**
* Provides a lexicographical comparer implementation; either a Java
* implementation or a faster implementation based on {@link sun.misc.Unsafe}.
*
* <p>Uses reflection to gracefully fall back to the Java implementation if
* {@code Unsafe} isn't available.
*/
@VisibleForTesting
static class LexicographicalComparerHolder {
static final String UNSAFE_COMPARER_NAME =
LexicographicalComparerHolder.class.getName() + "$UnsafeComparer";
static final Comparer<byte[]> BEST_COMPARER = getBestComparer();
/**
* Returns the Unsafe-using Comparer, or falls back to the pure-Java
* implementation if unable to do so.
*/
static Comparer<byte[]> getBestComparer() {
try {
Class<?> theClass = Class.forName(UNSAFE_COMPARER_NAME);
// yes, UnsafeComparer does implement Comparer<byte[]>
@SuppressWarnings("unchecked")
Comparer<byte[]> comparer =
(Comparer<byte[]>) theClass.getEnumConstants()[0];
return comparer;
} catch (Throwable t) { // ensure we really catch *everything*
return lexicographicalComparerJavaImpl();
}
}
enum PureJavaComparer implements Comparer<byte[]> {
INSTANCE;
@Override
public int compareTo(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;
}
}
@VisibleForTesting
enum UnsafeComparer implements Comparer<byte[]> {
INSTANCE;
static final Unsafe theUnsafe;
/** The offset to the first element in a byte array. */
static final int BYTE_ARRAY_BASE_OFFSET;
static {
theUnsafe = (Unsafe) AccessController.doPrivileged(
new PrivilegedAction<Object>() {
@Override
public Object run() {
try {
Field f = Unsafe.class.getDeclaredField("theUnsafe");
f.setAccessible(true);
return f.get(null);
} catch (NoSuchFieldException e) {
// It doesn't matter what we throw;
// it's swallowed in getBestComparer().
throw new Error();
} catch (IllegalAccessException e) {
throw new Error();
}
}
});
BYTE_ARRAY_BASE_OFFSET = theUnsafe.arrayBaseOffset(byte[].class);
// sanity check - this should never fail
if (theUnsafe.arrayIndexScale(byte[].class) != 1) {
throw new AssertionError();
}
}
static final boolean littleEndian =
ByteOrder.nativeOrder().equals(ByteOrder.LITTLE_ENDIAN);
/**
* Returns true if x1 is less than x2, when both values are treated as
* unsigned.
*/
static boolean lessThanUnsigned(long x1, long x2) {
return (x1 + Long.MIN_VALUE) < (x2 + Long.MIN_VALUE);
}
/**
* 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 0 if equal, < 0 if left is less than right, etc.
*/
@Override
public int compareTo(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;
}
int minLength = Math.min(length1, length2);
int minWords = minLength / LONG_BYTES;
int offset1Adj = offset1 + BYTE_ARRAY_BASE_OFFSET;
int offset2Adj = offset2 + BYTE_ARRAY_BASE_OFFSET;
/*
* Compare 8 bytes at a time. Benchmarking shows comparing 8 bytes at a
* time is no slower than comparing 4 bytes at a time even on 32-bit.
* On the other hand, it is substantially faster on 64-bit.
*/
for (int i = 0; i < minWords * LONG_BYTES; i += LONG_BYTES) {
long lw = theUnsafe.getLong(buffer1, offset1Adj + (long) i);
long rw = theUnsafe.getLong(buffer2, offset2Adj + (long) i);
long diff = lw ^ rw;
if (diff != 0) {
if (!littleEndian) {
return lessThanUnsigned(lw, rw) ? -1 : 1;
}
// Use binary search
int n = 0;
int y;
int x = (int) diff;
if (x == 0) {
x = (int) (diff >>> 32);
n = 32;
}
y = x << 16;
if (y == 0) {
n += 16;
} else {
x = y;
}
y = x << 8;
if (y == 0) {
n += 8;
}
return (int) (((lw >>> n) & 0xFFL) - ((rw >>> n) & 0xFFL));
}
}
// The epilogue to cover the last (minLength % 8) elements.
for (int i = minWords * LONG_BYTES; i < minLength; i++) {
int a = (buffer1[offset1 + i] & 0xff);
int b = (buffer2[offset2 + i] & 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 LexicographicalComparerHolder.BEST_COMPARER.
compareTo(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 &&
LexicographicalComparerHolder.BEST_COMPARER.
compareTo(bytes, 0, prefix.length, prefix, 0, prefix.length) == 0;
}
/**
* @param b bytes to hash
* @return Runs {@link org.apache.hadoop.io.WritableComparator#hashBytes(byte[], int)} on the
* passed in array. This method is what {@link org.apache.hadoop.io.Text} and
*/
public static int hashCode(final byte [] b) {
return hashCode(b, b.length);
}
/**
* @param b value
* @param length length of the value
* @return Runs {@link org.apache.hadoop.io.WritableComparator#hashBytes(byte[], int)} on the
* passed in array. This method is what {@link org.apache.hadoop.io.Text} and
*/
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, new byte [0]);
}
/**
* @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;
}
public static byte[][] splitPreserveAllTokens(byte[] str, char separatorChar, int[] target) {
return splitWorker(str, 0, -1, separatorChar, true, target);
}
public static byte[][] splitPreserveAllTokens(byte[] str, int offset, int length, char separatorChar, int[] target) {
return splitWorker(str, offset, length, separatorChar, true, target);
}
public static byte[][] splitPreserveAllTokens(byte[] str, char separatorChar) {
return splitWorker(str, 0, -1, separatorChar, true, null);
}
public static byte[][] splitPreserveAllTokens(byte[] str, int length, char separatorChar) {
return splitWorker(str, 0, length, separatorChar, true, null);
}
/**
* Performs the logic for the <code>split</code> and
* <code>splitPreserveAllTokens</code> methods that do not return a
* maximum array length.
*
* @param str the String to parse, may be <code>null</code>
* @param length amount of bytes to str
* @param separatorChar the ascii separate character
* @param preserveAllTokens if <code>true</code>, adjacent separators are
* @param target the projection target
* treated as empty token separators; if <code>false</code>, adjacent
* separators are treated as one separator.
* @return an array of parsed Strings, <code>null</code> if null String input
*/
private static byte[][] splitWorker(byte[] str, int offset, int length, char separatorChar, boolean preserveAllTokens, int[] target) {
// Performance tuned for 2.0 (JDK1.4)
if (str == null) {
return null;
}
int len = length;
if (len == 0) {
return new byte[1][0];
}else if(len < 0){
len = str.length - offset;
}
List list = new ArrayList();
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
int currentTarget = 0;
int currentIndex = 0;
while (i < len) {
if (str[i + offset] == separatorChar) {
if (match || preserveAllTokens) {
if (target == null) {
byte[] bytes = new byte[i - start];
System.arraycopy(str, start + offset, bytes, 0, bytes.length);
list.add(bytes);
} else if (target.length > currentTarget && currentIndex == target[currentTarget]) {
byte[] bytes = new byte[i - start];
System.arraycopy(str, start + offset, bytes, 0, bytes.length);
list.add(bytes);
currentTarget++;
} else {
list.add(null);
}
currentIndex++;
match = false;
lastMatch = true;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
if (match || (preserveAllTokens && lastMatch)) {
if (target == null) {
byte[] bytes = new byte[i - start];
System.arraycopy(str, start + offset, bytes, 0, bytes.length);
list.add(bytes);
} else if (target.length > currentTarget && currentIndex == target[currentTarget]) {
byte[] bytes = new byte[i - start];
System.arraycopy(str, start + offset, bytes, 0, bytes.length);
list.add(bytes); //str.substring(start, i));
currentTarget++;
} else {
list.add(null);
}
currentIndex++;
}
return (byte[][]) list.toArray(new byte[list.size()][]);
}
/**
* 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 zero-based index of the key, if the key is present in the array.
* Otherwise, a value -(i + 1) such that the key is between arr[i -
* 1] and arr[i] non-inclusively, where i is in [0, i], if we define
* arr[-1] = -Inf and arr[N] = Inf for an N-element array. The above
* means that this function can return 2N + 1 different values
* ranging from -(N + 1) to N - 1.
*/
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)
*/
public static byte [] incrementBytes(byte[] value, long amount)
{
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;
}
/**
* Writes a string as a fixed-size field, padded with zeros.
*/
public static void writeStringFixedSize(final DataOutput out, String s,
int size) throws IOException {
byte[] b = toBytes(s);
if (b.length > size) {
throw new IOException("Trying to write " + b.length + " bytes (" +
toStringBinary(b) + ") into a field of length " + size);
}
out.writeBytes(s);
for (int i = 0; i < size - s.length(); ++i)
out.writeByte(0);
}
/**
* Reads a fixed-size field and interprets it as a string padded with zeros.
*/
public static String readStringFixedSize(final DataInput in, int size)
throws IOException {
byte[] b = new byte[size];
in.readFully(b);
int n = b.length;
while (n > 0 && b[n - 1] == 0)
--n;
return toString(b, 0, n);
}
public static int readFully(InputStream is, byte[] buffer, int offset, int length)
throws IOException {
int nread = 0;
while (nread < length) {
int nbytes = is.read(buffer, offset + nread, length - nread);
if (nbytes < 0) {
return nread > 0 ? nread : nbytes;
}
nread += nbytes;
}
return nread;
}
/**
* Similar to readFully(). Skips bytes in a loop.
* @param in The DataInput to skip bytes from
* @param len number of bytes to skip.
* @throws IOException if it could not skip requested number of bytes
* for any reason (including EOF)
*/
public static void skipFully(DataInput in, int len) throws IOException {
int amt = len;
while (amt > 0) {
long ret = in.skipBytes(amt);
if (ret == 0) {
// skip may return 0 even if we're not at EOF. Luckily, we can
// use the read() method to figure out if we're at the end.
int b = in.readByte();
if (b == -1) {
throw new EOFException( "Premature EOF from inputStream after " +
"skipping " + (len - amt) + " byte(s).");
}
ret = 1;
}
amt -= ret;
}
}
/**
* Parses the byte array argument as if it was an int value and returns the
* result. Throws NumberFormatException if the byte array does not represent an
* int quantity.
*
* @return int the value represented by the argument
* @throws NumberFormatException if the argument could not be parsed as an int quantity.
*/
public static int parseInt(byte[] bytes, int start, int length) {
return parseInt(bytes, start, length, 10);
}
/**
* Parses the byte array argument as if it was an int value and returns the
* result. Throws NumberFormatException if the byte array does not represent an
* int quantity. The second argument specifies the radix to use when parsing
* the value.
*
* @param radix the base to use for conversion.
* @return the value represented by the argument
* @throws NumberFormatException if the argument could not be parsed as an int quantity.
*/
public static int parseInt(byte[] bytes, int start, int length, int radix) {
if (bytes == null) {
throw new NumberFormatException("String is null");
}
if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX) {
throw new NumberFormatException("Invalid radix: " + radix);
}
if (length == 0) {
throw new NumberFormatException("Empty byte array!");
}
int offset = start;
boolean negative = bytes[start] == '-';
if (negative || bytes[start] == '+') {
offset++;
if (length == 1) {
throw new NumberFormatException(new String(bytes, start,
length));
}
}
return parse(bytes, start, length, offset, radix, negative);
}
/**
* @param bytes
* @param start
* @param length
* @param radix the base to use for conversion.
* @param offset the starting position after the sign (if exists)
* @param radix the base to use for conversion.
* @param negative whether the number is negative.
* @return the value represented by the argument
* @throws NumberFormatException if the argument could not be parsed as an int quantity.
*/
private static int parse(byte[] bytes, int start, int length, int offset,
int radix, boolean negative) {
byte separator = '.';
int max = Integer.MIN_VALUE / radix;
int result = 0, end = start + length;
while (offset < end) {
int digit = digit(bytes[offset++], radix);
if (digit == -1) {
if (bytes[offset - 1] == separator) {
// We allow decimals and will return a truncated integer in that case.
// Therefore we won't throw an exception here (checking the fractional
// part happens below.)
break;
}
throw new NumberFormatException(new String(bytes, start,
length));
}
if (max > result) {
throw new NumberFormatException(new String(bytes, start,
length));
}
int next = result * radix - digit;
if (next > result) {
throw new NumberFormatException(new String(bytes, start,
length));
}
result = next;
}
// This is the case when we've encountered a decimal separator. The fractional
// part will not change the number, but we will verify that the fractional part
// is well formed.
while (offset < end) {
int digit = digit(bytes[offset++], radix);
if (digit == -1) {
throw new NumberFormatException(new String(bytes, start,
length));
}
}
if (!negative) {
result = -result;
if (result < 0) {
throw new NumberFormatException(new String(bytes, start,
length));
}
}
return result;
}
/**
* Returns the digit represented by character b.
*
* @param b The ascii code of the character
* @param radix The radix
* @return -1 if it's invalid
*/
private static int digit(int b, int radix) {
int r = -1;
if (b >= '0' && b <= '9') {
r = b - '0';
} else if (b >= 'A' && b <= 'Z') {
r = b - 'A' + 10;
} else if (b >= 'a' && b <= 'z') {
r = b - 'a' + 10;
}
if (r >= radix) {
r = -1;
}
return r;
}
/**
* Returns the digit represented by character b, radix is 10
*
* @param b The ascii code of the character
* @return -1 if it's invalid
*/
private static boolean isDigit(int b) {
return (b >= '0' && b <= '9');
}
private static final int maxExponent = 511; /* Largest possible base 10 exponent. Any
* exponent larger than this will already
* produce underflow or overflow, so there's
* no need to worry about additional digits.
*/
public static final double powersOf10[] = { /* Table giving binary powers of 10. Entry */
10., /* is 10^2^i. Used to convert decimal */
100., /* exponents into floating-point numbers. */
1.0e4,
1.0e8,
1.0e16,
1.0e32,
1.0e64,
1.0e128,
1.0e256
};
/**
* Parses the byte array argument as if it was a double value and returns the
* result. Throws NumberFormatException if the byte array does not represent a
* double value.
*
* @return double, the value represented by the argument
* @throws NumberFormatException if the argument could not be parsed as a double
*/
public static double parseDouble(byte[] bytes, int start, int length) {
if (bytes == null) {
throw new NumberFormatException("String is null");
}
if (length == 0) {
throw new NumberFormatException("Empty byte array!");
}
/*
* Strip off leading blanks
*/
int offset = start;
int end = start + length;
while (offset < end && bytes[offset] == ' ') {
offset++;
}
if (offset == end) {
throw new NumberFormatException("blank byte array!");
}
/*
* check for a sign.
*/
boolean sign = false;
if (bytes[offset] == '-') {
sign = true;
offset++;
} else if (bytes[offset] == '+') {
offset++;
}
if (offset == end) {
throw new NumberFormatException("the byte array only has a sign!");
}
/*
* Count the number of digits in the mantissa (including the decimal
* point), and also locate the decimal point.
*/
int mantSize = 0; /* Number of digits in mantissa. */
int decicalOffset = -1; /* Number of mantissa digits BEFORE decimal point. */
for (; offset < end; offset++) {
if (!isDigit(bytes[offset])) {
if ((bytes[offset] != '.') || (decicalOffset >= 0)) {
break;
}
decicalOffset = mantSize;
}
mantSize++;
}
int exponentOffset = offset; /* Temporarily holds location of exponent in bytes. */
/*
* Now suck up the digits in the mantissa. Use two integers to
* collect 9 digits each (this is faster than using floating-point).
* If the mantissa has more than 18 digits, ignore the extras, since
* they can't affect the value anyway.
*/
offset -= mantSize;
if (decicalOffset < 0) {
decicalOffset = mantSize;
} else {
mantSize -= 1; /* One of the digits was the decimal point. */
}
int fracExponent; /* Exponent that derives from the fractional
* part. Under normal circumstatnces, it is
* the negative of the number of digits in F.
* However, if I is very long, the last digits
* of I get dropped (otherwise a long I with a
* large negative exponent could cause an
* unnecessary overflow on I alone). In this
* case, fracExp is incremented one for each
* dropped digit. */
if (mantSize > 18) {
fracExponent = decicalOffset - 18;
mantSize = 18;
} else {
fracExponent = decicalOffset - mantSize;
}
if (mantSize == 0) {
return 0.0;
}
int frac1 = 0;
for (; mantSize > 9; mantSize--) {
int b = bytes[offset];
offset++;
if (b == '.') {
b = bytes[offset];
offset++;
}
frac1 = 10 * frac1 + (b - '0');
}
int frac2 = 0;
for (; mantSize > 0; mantSize--) {
int b = bytes[offset];
offset++;
if (b == '.') {
b = bytes[offset];
offset++;
}
frac2 = 10 * frac2 + (b - '0');
}
double fraction = (1.0e9 * frac1) + frac2;
/*
* Skim off the exponent.
*/
int exponent = 0; /* Exponent read from "EX" field. */
offset = exponentOffset;
boolean expSign = false;
if (offset < end) {
if ((bytes[offset] != 'E') && (bytes[offset] != 'e')) {
throw new NumberFormatException(new String(bytes, start,
length));
}
// (bytes[offset] == 'E') || (bytes[offset] == 'e')
offset++;
if (bytes[offset] == '-') {
expSign = true;
offset++;
} else if (bytes[offset] == '+') {
offset++;
}
for (; offset < end; offset++) {
if (isDigit(bytes[offset])) {
exponent = exponent * 10 + (bytes[offset] - '0');
} else {
throw new NumberFormatException(new String(bytes, start,
length));
}
}
}
exponent = expSign ? (fracExponent - exponent) : (fracExponent + exponent);
/*
* Generate a floating-point number that represents the exponent.
* Do this by processing the exponent one bit at a time to combine
* many powers of 2 of 10. Then combine the exponent with the
* fraction.
*/
if (exponent < 0) {
expSign = true;
exponent = -exponent;
} else {
expSign = false;
}
if (exponent > maxExponent) {
throw new NumberFormatException(new String(bytes, start,
length));
}
double dblExp = 1.0;
for (int i = 0; exponent != 0; exponent >>= 1, i++) {
if ((exponent & 01) == 01) {
dblExp *= powersOf10[i];
}
}
fraction = (expSign) ? (fraction / dblExp) : (fraction * dblExp);
return sign ? (-fraction) : fraction;
}
}