38 lines
719 B
JavaScript
38 lines
719 B
JavaScript
function BitBuffer () {
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this.buffer = []
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this.length = 0
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}
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BitBuffer.prototype = {
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get: function (index) {
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const bufIndex = Math.floor(index / 8)
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return ((this.buffer[bufIndex] >>> (7 - index % 8)) & 1) === 1
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},
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put: function (num, length) {
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for (let i = 0; i < length; i++) {
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this.putBit(((num >>> (length - i - 1)) & 1) === 1)
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}
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},
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getLengthInBits: function () {
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return this.length
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},
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putBit: function (bit) {
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const bufIndex = Math.floor(this.length / 8)
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if (this.buffer.length <= bufIndex) {
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this.buffer.push(0)
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}
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if (bit) {
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this.buffer[bufIndex] |= (0x80 >>> (this.length % 8))
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}
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this.length++
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}
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}
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module.exports = BitBuffer
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