394 lines
12 KiB
PHP
394 lines
12 KiB
PHP
<?php
|
|
/**
|
|
* Created by PhpStorm.
|
|
* User: Ashot
|
|
* Date: 3/25/15
|
|
* Time: 11:51
|
|
*/
|
|
|
|
/*
|
|
* Copyright 2007 ZXing authors
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
namespace Zxing\Common;
|
|
|
|
/**
|
|
* <p>A simple, fast array of bits, represented compactly by an array of ints internally.</p>
|
|
*
|
|
* @author Sean Owen
|
|
*/
|
|
|
|
final class BitArray {
|
|
|
|
private $bits;
|
|
private $size;
|
|
|
|
|
|
|
|
public function __construct($bits=array(),$size=0) {
|
|
|
|
if(!$bits&&!$size){
|
|
$this->$size = 0;
|
|
$this->bits = array();
|
|
}elseif($bits&&!$size){
|
|
$this->size = $bits;
|
|
$this->bits = $this->makeArray($bits);
|
|
}else{
|
|
$this->bits = $bits;
|
|
$this->size = $size;
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
public function getSize() {
|
|
return $this->size;
|
|
}
|
|
|
|
public function getSizeInBytes() {
|
|
return ($this->size + 7) / 8;
|
|
}
|
|
|
|
private function ensureCapacity($size) {
|
|
if ($size > count($this->bits) * 32) {
|
|
$newBits = $this->makeArray($size);
|
|
$newBits = arraycopy($this->bits, 0, $newBits, 0, count($this->bits));
|
|
$this->bits = $newBits;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @param $i; bit to get
|
|
* @return true iff bit i is set
|
|
*/
|
|
public function get($i) {
|
|
$key = intval($i / 32);
|
|
return intval32bits($this->bits[$key] & (1 << ($i & 0x1F))) != 0;
|
|
}
|
|
|
|
/**
|
|
* Sets bit i.
|
|
*
|
|
* @param i bit to set
|
|
*/
|
|
public function set($i) {
|
|
$this->bits[intval($i / 32)] |= 1 << ($i & 0x1F);
|
|
$this->bits[intval($i / 32)] = overflow($this->bits[intval($i / 32)]);
|
|
}
|
|
|
|
/**
|
|
* Flips bit i.
|
|
*
|
|
* @param i bit to set
|
|
*/
|
|
public function flip($i) {
|
|
$this->bits[intval($i / 32)] ^= 1 << ($i & 0x1F);
|
|
$this->bits[intval($i / 32)] = overflow32($this->bits[intval($i / 32)]);
|
|
}
|
|
|
|
/**
|
|
* @param from first bit to check
|
|
* @return index of first bit that is set, starting from the given index, or size if none are set
|
|
* at or beyond this given index
|
|
* @see #getNextUnset(int)
|
|
*/
|
|
public function getNextSet($from) {
|
|
if ($from >= $this->size) {
|
|
return $this->size;
|
|
}
|
|
$bitsOffset = intval($from / 32);
|
|
$currentBits = (int)$this->bits[$bitsOffset];
|
|
// mask off lesser bits first
|
|
$currentBits &= ~((1 << ($from & 0x1F)) - 1);
|
|
while ($currentBits == 0) {
|
|
if (++$bitsOffset == count($this->bits)) {
|
|
return $this->size;
|
|
}
|
|
$currentBits = $this->bits[$bitsOffset];
|
|
}
|
|
$result = ($bitsOffset * 32) + numberOfTrailingZeros($currentBits); //numberOfTrailingZeros
|
|
return $result > $this->size ? $this->size : $result;
|
|
}
|
|
|
|
/**
|
|
* @param from index to start looking for unset bit
|
|
* @return index of next unset bit, or {@code size} if none are unset until the end
|
|
* @see #getNextSet(int)
|
|
*/
|
|
public function getNextUnset($from) {
|
|
if ($from >= $this->size) {
|
|
return $this->size;
|
|
}
|
|
$bitsOffset = intval($from / 32);
|
|
$currentBits = ~$this->bits[$bitsOffset];
|
|
// mask off lesser bits first
|
|
$currentBits &= ~((1 << ($from & 0x1F)) - 1);
|
|
while ($currentBits == 0) {
|
|
if (++$bitsOffset == count($this->bits)) {
|
|
return $this->size;
|
|
}
|
|
$currentBits = overflow32(~$this->bits[$bitsOffset]);
|
|
}
|
|
$result = ($bitsOffset * 32) + numberOfTrailingZeros($currentBits);
|
|
return $result > $this->size ? $this->size : $result;
|
|
}
|
|
|
|
/**
|
|
* Sets a block of 32 bits, starting at bit i.
|
|
*
|
|
* @param i first bit to set
|
|
* @param newBits the new value of the next 32 bits. Note again that the least-significant bit
|
|
* corresponds to bit i, the next-least-significant to i+1, and so on.
|
|
*/
|
|
public function setBulk($i, $newBits) {
|
|
$this->bits[intval($i / 32)] = $newBits;
|
|
}
|
|
|
|
/**
|
|
* Sets a range of bits.
|
|
*
|
|
* @param start start of range, inclusive.
|
|
* @param end end of range, exclusive
|
|
*/
|
|
public function setRange($start, $end) {
|
|
if ($end < $start) {
|
|
throw new \InvalidArgumentException();
|
|
}
|
|
if ($end == $start) {
|
|
return;
|
|
}
|
|
$end--; // will be easier to treat this as the last actually set bit -- inclusive
|
|
$firstInt = intval($start / 32);
|
|
$lastInt = intval($end / 32);
|
|
for ($i = $firstInt; $i <= $lastInt; $i++) {
|
|
$firstBit = $i > $firstInt ? 0 : $start & 0x1F;
|
|
$lastBit = $i < $lastInt ? 31 : $end & 0x1F;
|
|
$mask = 0;
|
|
if ($firstBit == 0 && $lastBit == 31) {
|
|
$mask = -1;
|
|
} else {
|
|
$mask = 0;
|
|
for ($j = $firstBit; $j <= $lastBit; $j++) {
|
|
$mask |= 1 << $j;
|
|
}
|
|
}
|
|
$this->bits[$i] = overflow32($this->bits[$i]|$mask);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Clears all bits (sets to false).
|
|
*/
|
|
public function clear() {
|
|
$max = count($this->bits);
|
|
for ($i = 0; $i < $max; $i++) {
|
|
$this->bits[$i] = 0;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Efficient method to check if a range of bits is set, or not set.
|
|
*
|
|
* @param start start of range, inclusive.
|
|
* @param end end of range, exclusive
|
|
* @param value if true, checks that bits in range are set, otherwise checks that they are not set
|
|
* @return true iff all bits are set or not set in range, according to value argument
|
|
* @throws InvalidArgumentException if end is less than or equal to start
|
|
*/
|
|
public function isRange($start, $end, $value) {
|
|
if ($end < $start) {
|
|
throw new \InvalidArgumentException();
|
|
}
|
|
if ($end == $start) {
|
|
return true; // empty range matches
|
|
}
|
|
$end--; // will be easier to treat this as the last actually set bit -- inclusive
|
|
$firstInt = intval($start / 32);
|
|
$lastInt = intval($end / 32);
|
|
for ($i = $firstInt; $i <= $lastInt; $i++) {
|
|
$firstBit = $i > $firstInt ? 0 : $start & 0x1F;
|
|
$lastBit = $i < $lastInt ? 31 :$end & 0x1F;
|
|
$mask = 0;
|
|
if ($firstBit == 0 && $lastBit == 31) {
|
|
$mask = -1;
|
|
} else {
|
|
$mask = 0;
|
|
for ($j = $firstBit; $j <= $lastBit; $j++) {
|
|
$mask = overflow32($mask|(1 << $j));
|
|
}
|
|
}
|
|
|
|
// Return false if we're looking for 1s and the masked bits[i] isn't all 1s (that is,
|
|
// equals the mask, or we're looking for 0s and the masked portion is not all 0s
|
|
if (($this->bits[$i] & $mask) != ($value ? $mask : 0)) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
public function appendBit($bit) {
|
|
$this->ensureCapacity($this->size + 1);
|
|
if ($bit) {
|
|
$this->bits[intval($this->size / 32)] |= 1 << ($this->size & 0x1F);
|
|
}
|
|
$this->size++;
|
|
}
|
|
|
|
/**
|
|
* Appends the least-significant bits, from value, in order from most-significant to
|
|
* least-significant. For example, appending 6 bits from 0x000001E will append the bits
|
|
* 0, 1, 1, 1, 1, 0 in that order.
|
|
*
|
|
* @param value {@code int} containing bits to append
|
|
* @param numBits bits from value to append
|
|
*/
|
|
public function appendBits($value, $numBits) {
|
|
if ($numBits < 0 || $numBits > 32) {
|
|
throw new \InvalidArgumentException("Num bits must be between 0 and 32");
|
|
}
|
|
$this->ensureCapacity($this->size + $numBits);
|
|
for ($numBitsLeft = $numBits; $numBitsLeft > 0; $numBitsLeft--) {
|
|
$this->appendBit((($value >> ($numBitsLeft - 1)) & 0x01) == 1);
|
|
}
|
|
}
|
|
|
|
public function appendBitArray($other) {
|
|
$otherSize = $other->size;
|
|
$this->ensureCapacity($this->size + $otherSize);
|
|
for ($i = 0; $i < $otherSize; $i++) {
|
|
$this->appendBit($other->get($i));
|
|
}
|
|
}
|
|
|
|
public function _xor($other) {
|
|
if (count($this->bits) != count($other->bits)) {
|
|
throw new \InvalidArgumentException("Sizes don't match");
|
|
}
|
|
for ($i = 0; $i < count($this->bits); $i++) {
|
|
// The last byte could be incomplete (i.e. not have 8 bits in
|
|
// it) but there is no problem since 0 XOR 0 == 0.
|
|
$this->bits[$i] ^= $other->bits[$i];
|
|
}
|
|
}
|
|
|
|
/**
|
|
*
|
|
* @param bitOffset first bit to start writing
|
|
* @param array array to write into. Bytes are written most-significant byte first. This is the opposite
|
|
* of the internal representation, which is exposed by {@link #getBitArray()}
|
|
* @param offset position in array to start writing
|
|
* @param numBytes how many bytes to write
|
|
*/
|
|
public function toBytes($bitOffset, &$array, $offset, $numBytes) {
|
|
for ($i = 0; $i < $numBytes; $i++) {
|
|
$theByte = 0;
|
|
for ($j = 0; $j < 8; $j++) {
|
|
if ($this->get($bitOffset)) {
|
|
$theByte |= 1 << (7 - $j);
|
|
}
|
|
$bitOffset++;
|
|
}
|
|
$array[(int)($offset + $i)] = $theByte;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @return underlying array of ints. The first element holds the first 32 bits, and the least
|
|
* significant bit is bit 0.
|
|
*/
|
|
public function getBitArray() {
|
|
return $this->bits;
|
|
}
|
|
|
|
/**
|
|
* Reverses all bits in the array.
|
|
*/
|
|
public function reverse() {
|
|
$newBits = array();
|
|
// reverse all int's first
|
|
$len = (($this->size-1) / 32);
|
|
$oldBitsLen = $len + 1;
|
|
for ($i = 0; $i < $oldBitsLen; $i++) {
|
|
$x = $this->bits[$i];/*
|
|
$x = (($x >> 1) & 0x55555555L) | (($x & 0x55555555L) << 1);
|
|
$x = (($x >> 2) & 0x33333333L) | (($x & 0x33333333L) << 2);
|
|
$x = (($x >> 4) & 0x0f0f0f0fL) | (($x & 0x0f0f0f0fL) << 4);
|
|
$x = (($x >> 8) & 0x00ff00ffL) | (($x & 0x00ff00ffL) << 8);
|
|
$x = (($x >> 16) & 0x0000ffffL) | (($x & 0x0000ffffL) << 16);*/
|
|
$x = (($x >> 1) & 0x55555555) | (($x & 0x55555555) << 1);
|
|
$x = (($x >> 2) & 0x33333333) | (($x & 0x33333333) << 2);
|
|
$x = (($x >> 4) & 0x0f0f0f0f) | (($x & 0x0f0f0f0f) << 4);
|
|
$x = (($x >> 8) & 0x00ff00ff) | (($x & 0x00ff00ff) << 8);
|
|
$x = (($x >> 16) & 0x0000ffff) | (($x & 0x0000ffff) << 16);
|
|
$newBits[(int)$len - $i] = (int) $x;
|
|
}
|
|
// now correct the int's if the bit size isn't a multiple of 32
|
|
if ($this->size != $oldBitsLen * 32) {
|
|
$leftOffset = $oldBitsLen * 32 - $this->size;
|
|
$mask = 1;
|
|
for ($i = 0; $i < 31 - $leftOffset; $i++) {
|
|
$mask = ($mask << 1) | 1;
|
|
}
|
|
$currentInt = ($newBits[0] >> $leftOffset) & $mask;
|
|
for ($i = 1; $i < $oldBitsLen; $i++) {
|
|
$nextInt = $newBits[$i];
|
|
$currentInt |= $nextInt << (32 - $leftOffset);
|
|
$newBits[intval($i) - 1] = $currentInt;
|
|
$currentInt = ($nextInt >> $leftOffset) & $mask;
|
|
}
|
|
$newBits[intval($oldBitsLen) - 1] = $currentInt;
|
|
}
|
|
$bits = $newBits;
|
|
}
|
|
|
|
private static function makeArray($size) {
|
|
return array();
|
|
}
|
|
|
|
// @Override
|
|
public function equals($o) {
|
|
if (!($o instanceof BitArray)) {
|
|
return false;
|
|
}
|
|
$other = $o;
|
|
return $this->size == $other->size && $this->bits===$other->bits;
|
|
}
|
|
|
|
//@Override
|
|
public function hashCode() {
|
|
return 31 * $this->size +hashCode($this->bits);
|
|
}
|
|
|
|
// @Override
|
|
public function toString() {
|
|
$result = '';
|
|
for ($i = 0; $i < $this->size; $i++) {
|
|
if (($i & 0x07) == 0) {
|
|
$result.=' ';
|
|
}
|
|
$result.= ($this->get($i) ? 'X' : '.');
|
|
}
|
|
return (string) $result;
|
|
}
|
|
|
|
// @Override
|
|
public function _clone() {
|
|
return new BitArray($this->bits, $this->size);
|
|
}
|
|
|
|
} |