GT2/GT2-Android/node_modules/probe-image-size/lib/common.js

84 lines
1.8 KiB
JavaScript

'use strict';
var Transform = require('stream').Transform;
var streamParser = require('stream-parser');
var inherits = require('util').inherits;
function ParserStream() {
Transform.call(this, { readableObjectMode: true });
}
inherits(ParserStream, Transform);
streamParser(ParserStream.prototype);
exports.ParserStream = ParserStream;
exports.sliceEq = function (src, start, dest) {
for (var i = start, j = 0; j < dest.length;) {
if (src[i++] !== dest[j++]) return false;
}
return true;
};
exports.str2arr = function (str, format) {
var arr = [], i = 0;
if (format && format === 'hex') {
while (i < str.length) {
arr.push(parseInt(str.slice(i, i + 2), 16));
i += 2;
}
} else {
for (; i < str.length; i++) {
/* eslint-disable no-bitwise */
arr.push(str.charCodeAt(i) & 0xFF);
}
}
return arr;
};
exports.readUInt16LE = function (data, offset) {
return data[offset] | (data[offset + 1] << 8);
};
exports.readUInt16BE = function (data, offset) {
return data[offset + 1] | (data[offset] << 8);
};
exports.readUInt32LE = function (data, offset) {
return data[offset] |
(data[offset + 1] << 8) |
(data[offset + 2] << 16) |
(data[offset + 3] * 0x1000000);
};
exports.readUInt32BE = function (data, offset) {
return data[offset + 3] |
(data[offset + 2] << 8) |
(data[offset + 1] << 16) |
(data[offset] * 0x1000000);
};
function ProbeError(message, code, statusCode) {
Error.call(this);
Error.captureStackTrace(this, this.constructor);
this.name = this.constructor.name;
this.message = message;
if (code) this.code = code;
if (statusCode) this.statusCode = statusCode;
}
// Inherit from Error
require('inherits')(ProbeError, Error);
exports.ProbeError = ProbeError;