58 lines
1.5 KiB
JavaScript
58 lines
1.5 KiB
JavaScript
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"use strict";
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var DataReader = require("./DataReader");
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var utils = require("../utils");
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function ArrayReader(data) {
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DataReader.call(this, data);
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for(var i = 0; i < this.data.length; i++) {
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data[i] = data[i] & 0xFF;
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}
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}
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utils.inherits(ArrayReader, DataReader);
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/**
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* @see DataReader.byteAt
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*/
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ArrayReader.prototype.byteAt = function(i) {
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return this.data[this.zero + i];
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};
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/**
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* @see DataReader.lastIndexOfSignature
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*/
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ArrayReader.prototype.lastIndexOfSignature = function(sig) {
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var sig0 = sig.charCodeAt(0),
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sig1 = sig.charCodeAt(1),
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sig2 = sig.charCodeAt(2),
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sig3 = sig.charCodeAt(3);
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for (var i = this.length - 4; i >= 0; --i) {
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if (this.data[i] === sig0 && this.data[i + 1] === sig1 && this.data[i + 2] === sig2 && this.data[i + 3] === sig3) {
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return i - this.zero;
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}
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}
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return -1;
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};
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/**
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* @see DataReader.readAndCheckSignature
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*/
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ArrayReader.prototype.readAndCheckSignature = function (sig) {
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var sig0 = sig.charCodeAt(0),
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sig1 = sig.charCodeAt(1),
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sig2 = sig.charCodeAt(2),
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sig3 = sig.charCodeAt(3),
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data = this.readData(4);
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return sig0 === data[0] && sig1 === data[1] && sig2 === data[2] && sig3 === data[3];
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};
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/**
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* @see DataReader.readData
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*/
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ArrayReader.prototype.readData = function(size) {
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this.checkOffset(size);
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if(size === 0) {
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return [];
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}
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var result = this.data.slice(this.zero + this.index, this.zero + this.index + size);
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this.index += size;
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return result;
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};
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module.exports = ArrayReader;
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