| Current File : /home/tradevaly/www/node_modules/jszip/lib/utils.js |
'use strict';
var support = require('./support');
var base64 = require('./base64');
var nodejsUtils = require('./nodejsUtils');
var setImmediate = require('set-immediate-shim');
var external = require("./external");
/**
* Convert a string that pass as a "binary string": it should represent a byte
* array but may have > 255 char codes. Be sure to take only the first byte
* and returns the byte array.
* @param {String} str the string to transform.
* @return {Array|Uint8Array} the string in a binary format.
*/
function string2binary(str) {
var result = null;
if (support.uint8array) {
result = new Uint8Array(str.length);
} else {
result = new Array(str.length);
}
return stringToArrayLike(str, result);
}
/**
* Create a new blob with the given content and the given type.
* @param {String|ArrayBuffer} part the content to put in the blob. DO NOT use
* an Uint8Array because the stock browser of android 4 won't accept it (it
* will be silently converted to a string, "[object Uint8Array]").
*
* Use only ONE part to build the blob to avoid a memory leak in IE11 / Edge:
* when a large amount of Array is used to create the Blob, the amount of
* memory consumed is nearly 100 times the original data amount.
*
* @param {String} type the mime type of the blob.
* @return {Blob} the created blob.
*/
exports.newBlob = function(part, type) {
exports.checkSupport("blob");
try {
// Blob constructor
return new Blob([part], {
type: type
});
}
catch (e) {
try {
// deprecated, browser only, old way
var Builder = self.BlobBuilder || self.WebKitBlobBuilder || self.MozBlobBuilder || self.MSBlobBuilder;
var builder = new Builder();
builder.append(part);
return builder.getBlob(type);
}
catch (e) {
// well, fuck ?!
throw new Error("Bug : can't construct the Blob.");
}
}
};
/**
* The identity function.
* @param {Object} input the input.
* @return {Object} the same input.
*/
function identity(input) {
return input;
}
/**
* Fill in an array with a string.
* @param {String} str the string to use.
* @param {Array|ArrayBuffer|Uint8Array|Buffer} array the array to fill in (will be mutated).
* @return {Array|ArrayBuffer|Uint8Array|Buffer} the updated array.
*/
function stringToArrayLike(str, array) {
for (var i = 0; i < str.length; ++i) {
array[i] = str.charCodeAt(i) & 0xFF;
}
return array;
}
/**
* An helper for the function arrayLikeToString.
* This contains static information and functions that
* can be optimized by the browser JIT compiler.
*/
var arrayToStringHelper = {
/**
* Transform an array of int into a string, chunk by chunk.
* See the performances notes on arrayLikeToString.
* @param {Array|ArrayBuffer|Uint8Array|Buffer} array the array to transform.
* @param {String} type the type of the array.
* @param {Integer} chunk the chunk size.
* @return {String} the resulting string.
* @throws Error if the chunk is too big for the stack.
*/
stringifyByChunk: function(array, type, chunk) {
var result = [], k = 0, len = array.length;
// shortcut
if (len <= chunk) {
return String.fromCharCode.apply(null, array);
}
while (k < len) {
if (type === "array" || type === "nodebuffer") {
result.push(String.fromCharCode.apply(null, array.slice(k, Math.min(k + chunk, len))));
}
else {
result.push(String.fromCharCode.apply(null, array.subarray(k, Math.min(k + chunk, len))));
}
k += chunk;
}
return result.join("");
},
/**
* Call String.fromCharCode on every item in the array.
* This is the naive implementation, which generate A LOT of intermediate string.
* This should be used when everything else fail.
* @param {Array|ArrayBuffer|Uint8Array|Buffer} array the array to transform.
* @return {String} the result.
*/
stringifyByChar: function(array){
var resultStr = "";
for(var i = 0; i < array.length; i++) {
resultStr += String.fromCharCode(array[i]);
}
return resultStr;
},
applyCanBeUsed : {
/**
* true if the browser accepts to use String.fromCharCode on Uint8Array
*/
uint8array : (function () {
try {
return support.uint8array && String.fromCharCode.apply(null, new Uint8Array(1)).length === 1;
} catch (e) {
return false;
}
})(),
/**
* true if the browser accepts to use String.fromCharCode on nodejs Buffer.
*/
nodebuffer : (function () {
try {
return support.nodebuffer && String.fromCharCode.apply(null, nodejsUtils.allocBuffer(1)).length === 1;
} catch (e) {
return false;
}
})()
}
};
/**
* Transform an array-like object to a string.
* @param {Array|ArrayBuffer|Uint8Array|Buffer} array the array to transform.
* @return {String} the result.
*/
function arrayLikeToString(array) {
// Performances notes :
// --------------------
// String.fromCharCode.apply(null, array) is the fastest, see
// see http://jsperf.com/converting-a-uint8array-to-a-string/2
// but the stack is limited (and we can get huge arrays !).
//
// result += String.fromCharCode(array[i]); generate too many strings !
//
// This code is inspired by http://jsperf.com/arraybuffer-to-string-apply-performance/2
// TODO : we now have workers that split the work. Do we still need that ?
var chunk = 65536,
type = exports.getTypeOf(array),
canUseApply = true;
if (type === "uint8array") {
canUseApply = arrayToStringHelper.applyCanBeUsed.uint8array;
} else if (type === "nodebuffer") {
canUseApply = arrayToStringHelper.applyCanBeUsed.nodebuffer;
}
if (canUseApply) {
while (chunk > 1) {
try {
return arrayToStringHelper.stringifyByChunk(array, type, chunk);
} catch (e) {
chunk = Math.floor(chunk / 2);
}
}
}
// no apply or chunk error : slow and painful algorithm
// default browser on android 4.*
return arrayToStringHelper.stringifyByChar(array);
}
exports.applyFromCharCode = arrayLikeToString;
/**
* Copy the data from an array-like to an other array-like.
* @param {Array|ArrayBuffer|Uint8Array|Buffer} arrayFrom the origin array.
* @param {Array|ArrayBuffer|Uint8Array|Buffer} arrayTo the destination array which will be mutated.
* @return {Array|ArrayBuffer|Uint8Array|Buffer} the updated destination array.
*/
function arrayLikeToArrayLike(arrayFrom, arrayTo) {
for (var i = 0; i < arrayFrom.length; i++) {
arrayTo[i] = arrayFrom[i];
}
return arrayTo;
}
// a matrix containing functions to transform everything into everything.
var transform = {};
// string to ?
transform["string"] = {
"string": identity,
"array": function(input) {
return stringToArrayLike(input, new Array(input.length));
},
"arraybuffer": function(input) {
return transform["string"]["uint8array"](input).buffer;
},
"uint8array": function(input) {
return stringToArrayLike(input, new Uint8Array(input.length));
},
"nodebuffer": function(input) {
return stringToArrayLike(input, nodejsUtils.allocBuffer(input.length));
}
};
// array to ?
transform["array"] = {
"string": arrayLikeToString,
"array": identity,
"arraybuffer": function(input) {
return (new Uint8Array(input)).buffer;
},
"uint8array": function(input) {
return new Uint8Array(input);
},
"nodebuffer": function(input) {
return nodejsUtils.newBufferFrom(input);
}
};
// arraybuffer to ?
transform["arraybuffer"] = {
"string": function(input) {
return arrayLikeToString(new Uint8Array(input));
},
"array": function(input) {
return arrayLikeToArrayLike(new Uint8Array(input), new Array(input.byteLength));
},
"arraybuffer": identity,
"uint8array": function(input) {
return new Uint8Array(input);
},
"nodebuffer": function(input) {
return nodejsUtils.newBufferFrom(new Uint8Array(input));
}
};
// uint8array to ?
transform["uint8array"] = {
"string": arrayLikeToString,
"array": function(input) {
return arrayLikeToArrayLike(input, new Array(input.length));
},
"arraybuffer": function(input) {
return input.buffer;
},
"uint8array": identity,
"nodebuffer": function(input) {
return nodejsUtils.newBufferFrom(input);
}
};
// nodebuffer to ?
transform["nodebuffer"] = {
"string": arrayLikeToString,
"array": function(input) {
return arrayLikeToArrayLike(input, new Array(input.length));
},
"arraybuffer": function(input) {
return transform["nodebuffer"]["uint8array"](input).buffer;
},
"uint8array": function(input) {
return arrayLikeToArrayLike(input, new Uint8Array(input.length));
},
"nodebuffer": identity
};
/**
* Transform an input into any type.
* The supported output type are : string, array, uint8array, arraybuffer, nodebuffer.
* If no output type is specified, the unmodified input will be returned.
* @param {String} outputType the output type.
* @param {String|Array|ArrayBuffer|Uint8Array|Buffer} input the input to convert.
* @throws {Error} an Error if the browser doesn't support the requested output type.
*/
exports.transformTo = function(outputType, input) {
if (!input) {
// undefined, null, etc
// an empty string won't harm.
input = "";
}
if (!outputType) {
return input;
}
exports.checkSupport(outputType);
var inputType = exports.getTypeOf(input);
var result = transform[inputType][outputType](input);
return result;
};
/**
* Return the type of the input.
* The type will be in a format valid for JSZip.utils.transformTo : string, array, uint8array, arraybuffer.
* @param {Object} input the input to identify.
* @return {String} the (lowercase) type of the input.
*/
exports.getTypeOf = function(input) {
if (typeof input === "string") {
return "string";
}
if (Object.prototype.toString.call(input) === "[object Array]") {
return "array";
}
if (support.nodebuffer && nodejsUtils.isBuffer(input)) {
return "nodebuffer";
}
if (support.uint8array && input instanceof Uint8Array) {
return "uint8array";
}
if (support.arraybuffer && input instanceof ArrayBuffer) {
return "arraybuffer";
}
};
/**
* Throw an exception if the type is not supported.
* @param {String} type the type to check.
* @throws {Error} an Error if the browser doesn't support the requested type.
*/
exports.checkSupport = function(type) {
var supported = support[type.toLowerCase()];
if (!supported) {
throw new Error(type + " is not supported by this platform");
}
};
exports.MAX_VALUE_16BITS = 65535;
exports.MAX_VALUE_32BITS = -1; // well, "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF" is parsed as -1
/**
* Prettify a string read as binary.
* @param {string} str the string to prettify.
* @return {string} a pretty string.
*/
exports.pretty = function(str) {
var res = '',
code, i;
for (i = 0; i < (str || "").length; i++) {
code = str.charCodeAt(i);
res += '\\x' + (code < 16 ? "0" : "") + code.toString(16).toUpperCase();
}
return res;
};
/**
* Defer the call of a function.
* @param {Function} callback the function to call asynchronously.
* @param {Array} args the arguments to give to the callback.
*/
exports.delay = function(callback, args, self) {
setImmediate(function () {
callback.apply(self || null, args || []);
});
};
/**
* Extends a prototype with an other, without calling a constructor with
* side effects. Inspired by nodejs' `utils.inherits`
* @param {Function} ctor the constructor to augment
* @param {Function} superCtor the parent constructor to use
*/
exports.inherits = function (ctor, superCtor) {
var Obj = function() {};
Obj.prototype = superCtor.prototype;
ctor.prototype = new Obj();
};
/**
* Merge the objects passed as parameters into a new one.
* @private
* @param {...Object} var_args All objects to merge.
* @return {Object} a new object with the data of the others.
*/
exports.extend = function() {
var result = {}, i, attr;
for (i = 0; i < arguments.length; i++) { // arguments is not enumerable in some browsers
for (attr in arguments[i]) {
if (arguments[i].hasOwnProperty(attr) && typeof result[attr] === "undefined") {
result[attr] = arguments[i][attr];
}
}
}
return result;
};
/**
* Transform arbitrary content into a Promise.
* @param {String} name a name for the content being processed.
* @param {Object} inputData the content to process.
* @param {Boolean} isBinary true if the content is not an unicode string
* @param {Boolean} isOptimizedBinaryString true if the string content only has one byte per character.
* @param {Boolean} isBase64 true if the string content is encoded with base64.
* @return {Promise} a promise in a format usable by JSZip.
*/
exports.prepareContent = function(name, inputData, isBinary, isOptimizedBinaryString, isBase64) {
// if inputData is already a promise, this flatten it.
var promise = external.Promise.resolve(inputData).then(function(data) {
var isBlob = support.blob && (data instanceof Blob || ['[object File]', '[object Blob]'].indexOf(Object.prototype.toString.call(data)) !== -1);
if (isBlob && typeof FileReader !== "undefined") {
return new external.Promise(function (resolve, reject) {
var reader = new FileReader();
reader.onload = function(e) {
resolve(e.target.result);
};
reader.onerror = function(e) {
reject(e.target.error);
};
reader.readAsArrayBuffer(data);
});
} else {
return data;
}
});
return promise.then(function(data) {
var dataType = exports.getTypeOf(data);
if (!dataType) {
return external.Promise.reject(
new Error("Can't read the data of '" + name + "'. Is it " +
"in a supported JavaScript type (String, Blob, ArrayBuffer, etc) ?")
);
}
// special case : it's way easier to work with Uint8Array than with ArrayBuffer
if (dataType === "arraybuffer") {
data = exports.transformTo("uint8array", data);
} else if (dataType === "string") {
if (isBase64) {
data = base64.decode(data);
}
else if (isBinary) {
// optimizedBinaryString === true means that the file has already been filtered with a 0xFF mask
if (isOptimizedBinaryString !== true) {
// this is a string, not in a base64 format.
// Be sure that this is a correct "binary string"
data = string2binary(data);
}
}
}
return data;
});
};