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@kjk kjk/filesize.js
Created Nov 29, 2019

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human-readable file size in JavaScript (made with https://codeeval.dev)
// https://raw.githubusercontent.com/avoidwork/filesize.js/master/src/filesize.js
/**
* filesize
*
* @method filesize
* @param {Mixed} arg String, Int or Float to transform
* @param {Object} descriptor [Optional] Flags
* @return {String} Readable file size String
*/
function filesize (arg, descriptor = {}) {
let result = [],
val = 0,
e, base, bits, ceil, full, fullforms, locale, localeOptions, neg, num, output, round, unix, separator, spacer, standard, symbols;
if (isNaN(arg)) {
throw new TypeError("Invalid number");
}
bits = descriptor.bits === true;
unix = descriptor.unix === true;
base = descriptor.base || 2;
round = descriptor.round !== void 0 ? descriptor.round : unix ? 1 : 2;
locale = descriptor.locale !== void 0 ? descriptor.locale : "";
localeOptions = descriptor.localeOptions || {};
separator = descriptor.separator !== void 0 ? descriptor.separator : "";
spacer = descriptor.spacer !== void 0 ? descriptor.spacer : unix ? "" : " ";
symbols = descriptor.symbols || {};
standard = base === 2 ? descriptor.standard || "jedec" : "jedec";
output = descriptor.output || "string";
full = descriptor.fullform === true;
fullforms = descriptor.fullforms instanceof Array ? descriptor.fullforms : [];
e = descriptor.exponent !== void 0 ? descriptor.exponent : -1;
num = Number(arg);
neg = num < 0;
ceil = base > 2 ? 1000 : 1024;
// Flipping a negative number to determine the size
if (neg) {
num = -num;
}
// Determining the exponent
if (e === -1 || isNaN(e)) {
e = Math.floor(Math.log(num) / Math.log(ceil));
if (e < 0) {
e = 0;
}
}
// Exceeding supported length, time to reduce & multiply
if (e > 8) {
e = 8;
}
if (output === "exponent") {
return e;
}
// Zero is now a special case because bytes divide by 1
if (num === 0) {
result[0] = 0;
result[1] = unix ? "" : symbol[standard][bits ? "bits" : "bytes"][e];
} else {
val = num / (base === 2 ? Math.pow(2, e * 10) : Math.pow(1000, e));
if (bits) {
val = val * 8;
if (val >= ceil && e < 8) {
val = val / ceil;
e++;
}
}
result[0] = Number(val.toFixed(e > 0 ? round : 0));
if (result[0] === ceil && e < 8 && descriptor.exponent === void 0) {
result[0] = 1;
e++;
}
result[1] = base === 10 && e === 1 ? bits ? "kb" : "kB" : symbol[standard][bits ? "bits" : "bytes"][e];
if (unix) {
result[1] = standard === "jedec" ? result[1].charAt(0) : e > 0 ? result[1].replace(/B$/, "") : result[1];
if (b.test(result[1])) {
result[0] = Math.floor(result[0]);
result[1] = "";
}
}
}
// Decorating a 'diff'
if (neg) {
result[0] = -result[0];
}
// Applying custom symbol
result[1] = symbols[result[1]] || result[1];
if (locale === true) {
result[0] = result[0].toLocaleString();
} else if (locale.length > 0) {
result[0] = result[0].toLocaleString(locale, localeOptions);
} else if (separator.length > 0) {
result[0] = result[0].toString().replace(".", separator);
}
// Returning Array, Object, or String (default)
if (output === "array") {
return result;
}
if (full) {
result[1] = fullforms[e] ? fullforms[e] : fullform[standard][e] + (bits ? "bit" : "byte") + (result[0] === 1 ? "" : "s");
}
if (output === "object") {
return {value: result[0], symbol: result[1]};
}
return result.join(spacer);
}
// Partial application for functional programming
filesize.partial = opt => arg => filesize(arg, opt);
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