io.github.linmoure.utils.hash.ByteUtils Maven / Gradle / Ivy
package io.github.linmoure.utils.hash;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
public final class ByteUtils {
public static final String DEFAULT_CHARSET_NAME = "utf-8";
public static final Charset DEFAULT_CHARSET = Charset
.forName(DEFAULT_CHARSET_NAME);
/**
* if it is testing,check key argument even if use binary protocol. The user
* must never change this value at all.
*/
public static boolean testing;
private ByteUtils() {
}
public static boolean isNumber(String string) {
if (string == null || string.isEmpty()) {
return false;
}
int i = 0;
if (string.charAt(0) == '-') {
if (string.length() > 1) {
i++;
} else {
return false;
}
}
for (; i < string.length(); i++) {
if (!Character.isDigit(string.charAt(i))) {
return false;
}
}
return true;
}
public static byte[] getBytes(String k) {
if (k == null || k.length() == 0) {
throw new IllegalArgumentException("Key must not be blank");
}
try {
return k.getBytes(DEFAULT_CHARSET_NAME);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
private static final int maxKeyLength = 250;
public static int normalizeCapacity(int requestedCapacity) {
switch (requestedCapacity) {
case 0:
case 1 << 0:
case 1 << 1:
case 1 << 2:
case 1 << 3:
case 1 << 4:
case 1 << 5:
case 1 << 6:
case 1 << 7:
case 1 << 8:
case 1 << 9:
case 1 << 10:
case 1 << 11:
case 1 << 12:
case 1 << 13:
case 1 << 14:
case 1 << 15:
case 1 << 16:
case 1 << 17:
case 1 << 18:
case 1 << 19:
case 1 << 21:
case 1 << 22:
case 1 << 23:
case 1 << 24:
case 1 << 25:
case 1 << 26:
case 1 << 27:
case 1 << 28:
case 1 << 29:
case 1 << 30:
case Integer.MAX_VALUE:
return requestedCapacity;
}
int newCapacity = 1;
while (newCapacity < requestedCapacity) {
newCapacity <<= 1;
if (newCapacity < 0) {
return Integer.MAX_VALUE;
}
}
return newCapacity;
}
public static final boolean stepBuffer(ByteBuffer buffer, int remaining) {
if (buffer.remaining() >= remaining) {
buffer.position(buffer.position() + remaining);
return true;
} else {
return false;
}
}
public static String getString(byte[] bytes) {
try {
return new String(bytes, DEFAULT_CHARSET_NAME);
} catch (UnsupportedEncodingException e) {
throw new RuntimeException(e);
}
}
public static void byte2hex(byte b, StringBuffer buf) {
char[] hexChars = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'A', 'B', 'C', 'D', 'E', 'F'};
int high = ((b & 0xf0) >> 4);
int low = (b & 0x0f);
buf.append(hexChars[high]);
buf.append(hexChars[low]);
}
public static void int2hex(int a, StringBuffer str) {
str.append(Integer.toHexString(a));
}
public static void short2hex(int a, StringBuffer str) {
str.append(Integer.toHexString(a));
}
public static void getBytes(long i, int index, byte[] buf) {
long q;
int r;
int pos = index;
byte sign = 0;
if (i < 0) {
sign = '-';
i = -i;
}
// Get 2 digits/iteration using longs until quotient fits into an int
while (i > Integer.MAX_VALUE) {
q = i / 100;
// really: r = i - (q * 100);
r = (int) (i - ((q << 6) + (q << 5) + (q << 2)));
i = q;
buf[--pos] = DigitOnes[r];
buf[--pos] = DigitTens[r];
}
// Get 2 digits/iteration using ints
int q2;
int i2 = (int) i;
while (i2 >= 65536) {
q2 = i2 / 100;
// really: r = i2 - (q * 100);
r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
i2 = q2;
buf[--pos] = DigitOnes[r];
buf[--pos] = DigitTens[r];
}
// Fall thru to fast mode for smaller numbers
// assert(i2 <= 65536, i2);
for (; ; ) {
q2 = (i2 * 52429) >>> (16 + 3);
r = i2 - ((q2 << 3) + (q2 << 1)); // r = i2-(q2*10) ...
buf[--pos] = digits[r];
i2 = q2;
if (i2 == 0)
break;
}
if (sign != 0) {
buf[--pos] = sign;
}
}
/**
* Places characters representing the integer i into the character array
* buf. The characters are placed into the buffer backwards starting with
* the least significant digit at the specified index (exclusive), and
* working backwards from there.
*
* Will fail if i == Integer.MIN_VALUE
*/
static void getBytes(int i, int index, byte[] buf) {
int q, r;
int pos = index;
byte sign = 0;
if (i < 0) {
sign = '-';
i = -i;
}
// Generate two digits per iteration
while (i >= 65536) {
q = i / 100;
// really: r = i - (q * 100);
r = i - ((q << 6) + (q << 5) + (q << 2));
i = q;
buf[--pos] = DigitOnes[r];
buf[--pos] = DigitTens[r];
}
// Fall thru to fast mode for smaller numbers
// assert(i <= 65536, i);
for (; ; ) {
q = (i * 52429) >>> (16 + 3);
r = i - ((q << 3) + (q << 1)); // r = i-(q*10) ...
buf[--pos] = digits[r];
i = q;
if (i == 0)
break;
}
if (sign != 0) {
buf[--pos] = sign;
}
}
/**
* All possible chars for representing a number as a String
*/
final static byte[] digits = {'0', '1', '2', '3', '4', '5', '6', '7', '8',
'9', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l',
'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y',
'z'};
final static byte[] DigitTens = {'0', '0', '0', '0', '0', '0', '0', '0',
'0', '0', '1', '1', '1', '1', '1', '1', '1', '1', '1', '1', '2',
'2', '2', '2', '2', '2', '2', '2', '2', '2', '3', '3', '3', '3',
'3', '3', '3', '3', '3', '3', '4', '4', '4', '4', '4', '4', '4',
'4', '4', '4', '5', '5', '5', '5', '5', '5', '5', '5', '5', '5',
'6', '6', '6', '6', '6', '6', '6', '6', '6', '6', '7', '7', '7',
'7', '7', '7', '7', '7', '7', '7', '8', '8', '8', '8', '8', '8',
'8', '8', '8', '8', '9', '9', '9', '9', '9', '9', '9', '9', '9',
'9',};
final static byte[] DigitOnes = {'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
'1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '0', '1', '2',
'3', '4', '5', '6', '7', '8', '9', '0', '1', '2', '3', '4', '5',
'6', '7', '8', '9', '0', '1', '2', '3', '4', '5', '6', '7', '8',
'9',};
final static int[] sizeTable = {9, 99, 999, 9999, 99999, 999999, 9999999,
99999999, 999999999, Integer.MAX_VALUE};
// Requires positive x
public static final int stringSize(int x) {
for (int i = 0; ; i++)
if (x <= sizeTable[i])
return i + 1;
}
// Requires positive x
public static final int stringSize(long x) {
long p = 10;
for (int i = 1; i < 19; i++) {
if (x < p)
return i;
p = 10 * p;
}
return 19;
}
final static int[] byte_len_array = new int[256];
static {
for (int i = Byte.MIN_VALUE; i <= Byte.MAX_VALUE; ++i) {
int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
byte_len_array[i & 0xFF] = size;
}
}
}
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