dorkbox.util.bytes.OptimizeUtilsByteArray Maven / Gradle / Ivy
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/*
* Copyright 2014 dorkbox, llc
*
* Licensed 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.
*
* Copyright (c) 2008, Nathan Sweet
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided with the distribution.
* - Neither the name of Esoteric Software nor the names of its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package dorkbox.util.bytes;
@SuppressWarnings({"Duplicates", "NumericCastThatLosesPrecision", "UnusedAssignment", "IntegerMultiplicationImplicitCastToLong", "unused"})
public
class OptimizeUtilsByteArray {
/**
* Returns the number of bytes that would be written with {@link #writeInt(byte[], int, boolean)}.
*
* @param optimizePositive
* true if you want to optimize the number of bytes needed to write the length value
*/
public static
int intLength(int value, boolean optimizePositive) {
return OptimizeUtilsByteBuf.intLength(value, optimizePositive);
}
// int
/**
* look at buffer, and see if we can read the length of the int off of it. (from the reader index)
*
* @return 0 if we could not read anything, >0 for the number of bytes for the int on the buffer
*/
@SuppressWarnings("SimplifiableIfStatement")
public static
boolean canReadInt(byte[] buffer) {
int position = 0;
return canReadInt(buffer, position);
}
/**
* FROM KRYO
*
* look at buffer, and see if we can read the length of the int off of it. (from the reader index)
*
* @param position where in the buffer to start reading
* @return 0 if we could not read anything, >0 for the number of bytes for the int on the buffer
*/
@SuppressWarnings("SimplifiableIfStatement")
public static
boolean canReadInt(final byte[] buffer, int position) {
int length = buffer.length;
if (length >= 5) {
return true;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == length) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == length) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == length) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
return position != length;
}
/**
* Reads an int from the buffer that was optimized at position 0
*
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (5
* bytes). This ultimately means that it will use fewer bytes for positive numbers.
*/
public static
int readInt(byte[] buffer, boolean optimizePositive) {
int position = 0;
return readInt(buffer, optimizePositive, position);
}
/**
* FROM KRYO
*
* Reads an int from the buffer that was optimized.
*
* @param position where in the buffer to start reading
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (5
* bytes). This ultimately means that it will use fewer bytes for positive numbers.
*/
public static
int readInt(final byte[] buffer, final boolean optimizePositive, int position) {
int b = buffer[position++];
int result = b & 0x7F;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 7;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 14;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 21;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 28;
}
}
}
}
return optimizePositive ? result : result >>> 1 ^ -(result & 1);
}
/**
* Writes the specified int to the buffer using 1 to 5 bytes, depending on the size of the number.
*
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (5
* bytes). This ultimately means that it will use fewer bytes for positive numbers.
*
* @return the number of bytes written.
*/
public static
int writeInt(byte[] buffer, int value, boolean optimizePositive) {
int position = 0;
return writeInt(buffer, value, optimizePositive, position);
}
/**
* FROM KRYO
*
* Writes the specified int to the buffer using 1 to 5 bytes, depending on the size of the number.
*
* @param position where in the buffer to start writing
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (5
* bytes). This ultimately means that it will use fewer bytes for positive numbers.
*
* @return the number of bytes written.
*/
public static
int writeInt(final byte[] buffer, int value, final boolean optimizePositive, int position) {
if (!optimizePositive) {
value = value << 1 ^ value >> 31;
}
if (value >>> 7 == 0) {
buffer[position++] = (byte) value;
return 1;
}
if (value >>> 14 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7);
return 2;
}
if (value >>> 21 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14);
return 3;
}
if (value >>> 28 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21);
return 4;
}
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21 | 0x80);
buffer[position++] = (byte) (value >>> 28);
return 5;
}
/**
* Returns 1-9 bytes that would be written with {@link #writeLong(byte[], long, boolean)}.
*
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (9
* bytes). This ultimately means that it will use fewer bytes for positive numbers.
*/
public static
int longLength(long value, boolean optimizePositive) {
return OptimizeUtilsByteBuf.longLength(value, optimizePositive);
}
// long
/**
* Reads a 1-9 byte long.
*
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (9
* bytes). This ultimately means that it will use fewer bytes for positive numbers.
*/
public static
long readLong(byte[] buffer, boolean optimizePositive) {
int position = 0;
return readLong(buffer, optimizePositive, position);
}
/**
* FROM KRYO
*
* Reads a 1-9 byte long.
*
* @param position where in the buffer to start reading
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (9
* bytes). This ultimately means that it will use fewer bytes for positive numbers.
*/
public static
long readLong(final byte[] buffer, final boolean optimizePositive, int position) {
int b = buffer[position++];
long result = b & 0x7F;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 7;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 14;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (b & 0x7F) << 21;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long) (b & 0x7F) << 28;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long) (b & 0x7F) << 35;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long) (b & 0x7F) << 42;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long) (b & 0x7F) << 49;
if ((b & 0x80) != 0) {
b = buffer[position++];
result |= (long) b << 56;
}
}
}
}
}
}
}
}
if (!optimizePositive) {
result = result >>> 1 ^ -(result & 1);
}
return result;
}
/**
* Writes a 1-9 byte long.
*
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (9
* bytes).
*
* @return the number of bytes written.
*/
public static
int writeLong(byte[] buffer, long value, boolean optimizePositive) {
int position = 0;
return writeLong(buffer, value, optimizePositive, position);
}
/**
* FROM KRYO
*
* Writes a 1-9 byte long.
*
* @param position where in the buffer to start writing
* @param optimizePositive
* If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be inefficient (9
* bytes).
*
* @return the number of bytes written.
*/
public static
int writeLong(final byte[] buffer, long value, final boolean optimizePositive, int position) {
if (!optimizePositive) {
value = value << 1 ^ value >> 63;
}
if (value >>> 7 == 0) {
buffer[position++] = (byte) value;
return 1;
}
if (value >>> 14 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7);
return 2;
}
if (value >>> 21 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14);
return 3;
}
if (value >>> 28 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21);
return 4;
}
if (value >>> 35 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21 | 0x80);
buffer[position++] = (byte) (value >>> 28);
return 5;
}
if (value >>> 42 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21 | 0x80);
buffer[position++] = (byte) (value >>> 28 | 0x80);
buffer[position++] = (byte) (value >>> 35);
return 6;
}
if (value >>> 49 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21 | 0x80);
buffer[position++] = (byte) (value >>> 28 | 0x80);
buffer[position++] = (byte) (value >>> 35 | 0x80);
buffer[position++] = (byte) (value >>> 42);
return 7;
}
if (value >>> 56 == 0) {
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21 | 0x80);
buffer[position++] = (byte) (value >>> 28 | 0x80);
buffer[position++] = (byte) (value >>> 35 | 0x80);
buffer[position++] = (byte) (value >>> 42 | 0x80);
buffer[position++] = (byte) (value >>> 49);
return 8;
}
buffer[position++] = (byte) (value & 0x7F | 0x80);
buffer[position++] = (byte) (value >>> 7 | 0x80);
buffer[position++] = (byte) (value >>> 14 | 0x80);
buffer[position++] = (byte) (value >>> 21 | 0x80);
buffer[position++] = (byte) (value >>> 28 | 0x80);
buffer[position++] = (byte) (value >>> 35 | 0x80);
buffer[position++] = (byte) (value >>> 42 | 0x80);
buffer[position++] = (byte) (value >>> 49 | 0x80);
buffer[position++] = (byte) (value >>> 56);
return 9;
}
/**
* look at buffer, and see if we can read the length of the long off of it (from the reader index).
*
* @return 0 if we could not read anything, >0 for the number of bytes for the long on the buffer
*/
public static
boolean canReadLong(byte[] buffer) {
int position = 0;
return canReadLong(buffer, position);
}
/**
* FROM KRYO
*
* look at buffer, and see if we can read the length of the long off of it (from the reader index).
*
* @param position where in the buffer to start reading
* @return 0 if we could not read anything, >0 for the number of bytes for the long on the buffer
*/
private static
boolean canReadLong(final byte[] buffer, int position) {
int limit = buffer.length;
if (limit >= 9) {
return true;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == limit) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == limit) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == limit) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == limit) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == limit) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == limit) {
return false;
}
if ((buffer[position++] & 0x80) == 0) {
return true;
}
if (position == limit) {
return false;
}
//noinspection SimplifiableIfStatement
if ((buffer[position++] & 0x80) == 0) {
return true;
}
return position != limit;
}
private
OptimizeUtilsByteArray() {
}
}