src/core/common/BitArray.ts
/*
* 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 com.google.zxing.common {*/
/*import java.util.Arrays;*/
import IllegalArgumentException from '../IllegalArgumentException';
import Arrays from '../util/Arrays';
import Integer from '../util/Integer';
import System from '../util/System';
/**
* <p>A simple, fast array of bits, represented compactly by an array of ints internally.</p>
*
* @author Sean Owen
*/
export default class BitArray /*implements Cloneable*/ {
private size: number;
private bits: Int32Array;
// public constructor() {
// this.size = 0
// this.bits = new Int32Array(1)
// }
// public constructor(size?: number /*int*/) {
// if (undefined === size) {
// this.size = 0
// } else {
// this.size = size
// }
// this.bits = this.makeArray(size)
// }
// For testing only
public constructor(size?: number /*int*/, bits?: Int32Array) {
if (undefined === size) {
this.size = 0;
this.bits = new Int32Array(1);
} else {
this.size = size;
if (undefined === bits || null === bits) {
this.bits = BitArray.makeArray(size);
} else {
this.bits = bits;
}
}
}
public getSize(): number /*int*/ {
return this.size;
}
public getSizeInBytes(): number /*int*/ {
return Math.floor((this.size + 7) / 8);
}
private ensureCapacity(size: number /*int*/): void {
if (size > this.bits.length * 32) {
const newBits = BitArray.makeArray(size);
System.arraycopy(this.bits, 0, newBits, 0, this.bits.length);
this.bits = newBits;
}
}
/**
* @param i bit to get
* @return true iff bit i is set
*/
public get(i: number /*int*/): boolean {
return (this.bits[Math.floor(i / 32)] & (1 << (i & 0x1F))) !== 0;
}
/**
* Sets bit i.
*
* @param i bit to set
*/
public set(i: number /*int*/): void {
this.bits[Math.floor(i / 32)] |= 1 << (i & 0x1F);
}
/**
* Flips bit i.
*
* @param i bit to set
*/
public flip(i: number /*int*/): void {
this.bits[Math.floor(i / 32)] ^= 1 << (i & 0x1F);
}
/**
* @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 getNextSet(from: number /*int*/): number /*int*/ {
const size = this.size;
if (from >= size) {
return size;
}
const bits = this.bits;
let bitsOffset = Math.floor(from / 32);
let currentBits = bits[bitsOffset];
// mask off lesser bits first
currentBits &= ~((1 << (from & 0x1F)) - 1);
const length = bits.length;
while (currentBits === 0) {
if (++bitsOffset === length) {
return size;
}
currentBits = bits[bitsOffset];
}
const result = (bitsOffset * 32) + Integer.numberOfTrailingZeros(currentBits);
return result > size ? 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 getNextUnset(from: number /*int*/): number /*int*/ {
const size = this.size;
if (from >= size) {
return size;
}
const bits = this.bits;
let bitsOffset = Math.floor(from / 32);
let currentBits = ~bits[bitsOffset];
// mask off lesser bits first
currentBits &= ~((1 << (from & 0x1F)) - 1);
const length = bits.length;
while (currentBits === 0) {
if (++bitsOffset === length) {
return size;
}
currentBits = ~bits[bitsOffset];
}
const result = (bitsOffset * 32) + Integer.numberOfTrailingZeros(currentBits);
return result > size ? 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 setBulk(i: number /*int*/, newBits: number /*int*/): void {
this.bits[Math.floor(i / 32)] = newBits;
}
/**
* Sets a range of bits.
*
* @param start start of range, inclusive.
* @param end end of range, exclusive
*/
public setRange(start: number /*int*/, end: number /*int*/): void {
if (end < start || start < 0 || end > this.size) {
throw new IllegalArgumentException();
}
if (end === start) {
return;
}
end--; // will be easier to treat this as the last actually set bit -- inclusive
const firstInt = Math.floor(start / 32);
const lastInt = Math.floor(end / 32);
const bits = this.bits;
for (let i = firstInt; i <= lastInt; i++) {
const firstBit = i > firstInt ? 0 : start & 0x1F;
const lastBit = i < lastInt ? 31 : end & 0x1F;
// Ones from firstBit to lastBit, inclusive
const mask = (2 << lastBit) - (1 << firstBit);
bits[i] |= mask;
}
}
/**
* Clears all bits (sets to false).
*/
public clear(): void {
const max = this.bits.length;
const bits = this.bits;
for (let i = 0; i < max; i++) {
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 IllegalArgumentException if end is less than start or the range is not contained in the array
*/
public isRange(start: number /*int*/, end: number /*int*/, value: boolean): boolean {
if (end < start || start < 0 || end > this.size) {
throw new IllegalArgumentException();
}
if (end === start) {
return true; // empty range matches
}
end--; // will be easier to treat this as the last actually set bit -- inclusive
const firstInt = Math.floor(start / 32);
const lastInt = Math.floor(end / 32);
const bits = this.bits;
for (let i = firstInt; i <= lastInt; i++) {
const firstBit = i > firstInt ? 0 : start & 0x1F;
const lastBit = i < lastInt ? 31 : end & 0x1F;
// Ones from firstBit to lastBit, inclusive
const mask = (2 << lastBit) - (1 << firstBit) & 0xFFFFFFFF;
// TYPESCRIPTPORT: & 0xFFFFFFFF added to discard anything after 32 bits, as ES has 53 bits
// Return false if we're looking for 1s and the masked bits[i] isn't all 1s (is: that,
// equals the mask, or we're looking for 0s and the masked portion is not all 0s
if ((bits[i] & mask) !== (value ? mask : 0)) {
return false;
}
}
return true;
}
public appendBit(bit: boolean): void {
this.ensureCapacity(this.size + 1);
if (bit) {
this.bits[Math.floor(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 appendBits(value: number /*int*/, numBits: number /*int*/): void {
if (numBits < 0 || numBits > 32) {
throw new IllegalArgumentException('Num bits must be between 0 and 32');
}
this.ensureCapacity(this.size + numBits);
// const appendBit = this.appendBit;
for (let numBitsLeft = numBits; numBitsLeft > 0; numBitsLeft--) {
this.appendBit(((value >> (numBitsLeft - 1)) & 0x01) === 1);
}
}
public appendBitArray(other: BitArray): void {
const otherSize = other.size;
this.ensureCapacity(this.size + otherSize);
// const appendBit = this.appendBit;
for (let i = 0; i < otherSize; i++) {
this.appendBit(other.get(i));
}
}
public xor(other: BitArray): void {
if (this.size !== other.size) {
throw new IllegalArgumentException('Sizes don\'t match');
}
const bits = this.bits;
for (let i = 0, length = bits.length; i < length; i++) {
// The last int could be incomplete (i.e. not have 32 bits in
// it) but there is no problem since 0 XOR 0 == 0.
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 toBytes(bitOffset: number /*int*/, array: Uint8Array, offset: number /*int*/, numBytes: number /*int*/): void {
for (let i = 0; i < numBytes; i++) {
let theByte = 0;
for (let j = 0; j < 8; j++) {
if (this.get(bitOffset)) {
theByte |= 1 << (7 - j);
}
bitOffset++;
}
array[offset + i] = /*(byte)*/ theByte;
}
}
/**
* @return underlying array of ints. The first element holds the first 32 bits, and the least
* significant bit is bit 0.
*/
public getBitArray(): Int32Array {
return this.bits;
}
/**
* Reverses all bits in the array.
*/
public reverse(): void {
const newBits = new Int32Array(this.bits.length);
// reverse all int's first
const len = Math.floor((this.size - 1) / 32);
const oldBitsLen = len + 1;
const bits = this.bits;
for (let i = 0; i < oldBitsLen; i++) {
let x = bits[i];
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[len - i] = /*(int)*/ x;
}
// now correct the int's if the bit size isn't a multiple of 32
if (this.size !== oldBitsLen * 32) {
const leftOffset = oldBitsLen * 32 - this.size;
let currentInt = newBits[0] >>> leftOffset;
for (let i = 1; i < oldBitsLen; i++) {
const nextInt = newBits[i];
currentInt |= nextInt << (32 - leftOffset);
newBits[i - 1] = currentInt;
currentInt = nextInt >>> leftOffset;
}
newBits[oldBitsLen - 1] = currentInt;
}
this.bits = newBits;
}
private static makeArray(size: number /*int*/): Int32Array {
return new Int32Array(Math.floor((size + 31) / 32));
}
/*@Override*/
public equals(o: any): boolean {
if (!(o instanceof BitArray)) {
return false;
}
const other = <BitArray>o;
return this.size === other.size && Arrays.equals(this.bits, other.bits);
}
/*@Override*/
public hashCode(): number /*int*/ {
return 31 * this.size + Arrays.hashCode(this.bits);
}
/*@Override*/
public toString(): string {
let result = '';
for (let i = 0, size = this.size; i < size; i++) {
if ((i & 0x07) === 0) {
result += ' ';
}
result += this.get(i) ? 'X' : '.';
}
return result;
}
/*@Override*/
public clone(): BitArray {
return new BitArray(this.size, this.bits.slice());
}
/**
* converts to boolean array.
*/
public toArray(): Array<boolean> {
let result = [];
for (let i = 0, size = this.size; i < size; i++) {
result.push(this.get(i));
}
return result;
}
}