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node-spearhead/lib/common.js
2015-08-31 17:14:48 -04:00

313 lines
8.2 KiB
JavaScript
Executable File

/**
* Copyright (c) 2015 Joyent Inc. All rights reserved.
*/
var assert = require('assert-plus');
var util = require('util'),
format = util.format;
var errors = require('./errors'),
InternalError = errors.InternalError;
// ---- globals
var p = console.log;
var UUID_RE = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/;
// ---- support stuff
function objCopy(obj, target) {
if (target === undefined) {
target = {};
}
Object.keys(obj).forEach(function (k) {
target[k] = obj[k];
});
return target;
}
function deepObjCopy(obj) {
return JSON.parse(JSON.stringify(obj));
}
function zeroPad(n, width) {
var s = String(n);
while (s.length < width) {
s = '0' + s;
}
return s;
}
/**
* Convert a boolean or string representation into a boolean, or
* raise TypeError trying.
*
* @param value {Boolean|String} The input value to convert.
* @param default_ {Boolean} The default value is `value` is undefined.
* @param errName {String} The context to quote in the possibly
* raised TypeError.
*/
function boolFromString(value, default_, errName) {
if (value === undefined) {
return default_;
} else if (value === 'false' || value === '0') {
return false;
} else if (value === 'true' || value === '1') {
return true;
} else if (typeof (value) === 'boolean') {
return value;
} else {
var errmsg = format('invalid boolean value: %j', value);
if (errName) {
errmsg = format('invalid boolean value for %s: %j', errName, value);
}
throw new TypeError(errmsg);
}
}
/**
* given an array return a string with each element
* JSON-stringifed separated by newlines
*/
function jsonStream(arr, stream) {
stream = stream || process.stdout;
arr.forEach(function (elem) {
stream.write(JSON.stringify(elem) + '\n');
});
}
/**
* given an array of key=value pairs, break them into an object
*
* @param {Array} kvs - an array of key=value pairs
* @param {Array} valid (optional) - an array to validate pairs
*/
function kvToObj(kvs, valid) {
var o = {};
for (var i = 0; i < kvs.length; i++) {
var kv = kvs[i];
var idx = kv.indexOf('=');
if (idx === -1)
throw new errors.UsageError(format(
'invalid filter: "%s" (must be of the form "field=value")',
kv));
var k = kv.slice(0, idx);
var v = kv.slice(idx + 1);
if (valid.indexOf(k) === -1)
throw new errors.UsageError(format(
'invalid filter name: "%s" (must be one of "%s")',
k, valid.join('", "')));
o[k] = v;
}
return o;
}
/**
* return how long ago something happened
*
* @param {Date} when - a date object in the past
* @param {Date} now (optional) - a date object to compare to
* @return {String} - printable string
*/
function longAgo(when, now) {
now = now || new Date();
var seconds = Math.round((now - when) / 1000);
var times = [
seconds / 60 / 60 / 24 / 365, // years
seconds / 60 / 60 / 24 / 7, // weeks
seconds / 60 / 60 / 24, // days
seconds / 60 / 60, // hours
seconds / 60, // minutes
seconds // seconds
];
var names = ['y', 'w', 'd', 'h', 'm', 's'];
for (var i = 0; i < names.length; i++) {
var time = Math.floor(times[i]);
if (time > 0)
return util.format('%d%s', time, names[i]);
}
return '0s';
}
/**
* checks a string and returns a boolean based on if it
* is a UUID or not
*/
function isUUID(s) {
return /^([a-f\d]{8}(-[a-f\d]{4}){3}-[a-f\d]{12}?)$/i.test(s);
}
function humanDurationFromMs(ms) {
assert.number(ms, 'ms');
var sizes = [
['ms', 1000, 's'],
['s', 60, 'm'],
['m', 60, 'h'],
['h', 24, 'd']
];
if (ms === 0) {
return '0ms';
}
var bits = [];
var n = ms;
for (var i = 0; i < sizes.length; i++) {
var size = sizes[i];
var remainder = n % size[1];
if (remainder === 0) {
bits.unshift('');
} else {
bits.unshift(format('%d%s', remainder, size[0]));
}
n = Math.floor(n / size[1]);
if (n === 0) {
break;
} else if (size[2] === 'd') {
bits.unshift(format('%d%s', n, size[2]));
break;
}
}
if (bits.length > 1 && bits[bits.length - 1].slice(-2) === 'ms') {
bits.pop();
}
return bits.slice(0, 2).join('');
}
/**
* Adapted from <http://stackoverflow.com/a/18650828>
*
* @param {Number} opts.precision The number of decimal places of precision to
* include. Note: This is just clipping (i.e. floor) instead of rounding.
* TODO: round
* @param {Boolean} opts.narrow Make it as narrow as possible: short units,
* no space between value and unit, drop precision if it is all zeros.
*/
function humanSizeFromBytes(opts, bytes) {
if (bytes === undefined) {
opts = {};
bytes = opts;
}
assert.number(bytes, 'bytes');
// The number of decimal places, default 1.
assert.optionalNumber(opts.precision, 'opts.precision');
var precision = opts.precision === undefined ? 1 : opts.precision;
assert.ok(precision >= 0);
assert.optionalBool(opts.narrow, 'opts.narrow');
var sizes = ['B', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB'];
if (opts.narrow) {
sizes = ['B', 'K', 'M', 'G', 'T', 'P'];
}
var template = opts.narrow ? '%s%s' : '%s %s';
if (bytes === 0) {
return '0 B';
}
var i = Number(Math.floor(Math.log(bytes) / Math.log(1024)));
var s = String(bytes / Math.pow(1024, i));
var hasDecimal = s.indexOf('.') !== -1;
if (precision === 0) {
if (hasDecimal) {
s = s.slice(0, s.indexOf('.'));
}
} else if (opts.narrow && !hasDecimal) {
/* skip all-zero precision */
} else {
if (!hasDecimal) {
s += '.';
}
var places = s.length - s.indexOf('.') - 1;
while (places < precision) {
s += '0';
places++;
}
if (places > precision) {
s = s.slice(0, s.length - places + precision);
}
}
//var precision1 = (s.indexOf('.') === -1
// ? s + '.0' : s.slice(0, s.indexOf('.') + 2));
return format(template, s, sizes[i]);
}
function capitalize(s) {
return s[0].toUpperCase() + s.substr(1);
}
/*
* Normalize a short ID. Returns undefined if the given string isn't a valid
* short id.
*
* Short IDs:
* - UUID prefix
* - allow '-' to be elided (to support using containers IDs from
* docker)
* - support docker ID *longer* than a UUID? The curr implementation does.
*/
function normShortId(s) {
var shortIdCharsRe = /^[a-f0-9]+$/;
var shortId;
if (s.indexOf('-') === -1) {
if (!shortIdCharsRe.test(s)) {
return;
}
shortId = s.substr(0, 8) + '-'
+ s.substr(8, 4) + '-'
+ s.substr(12, 4) + '-'
+ s.substr(16, 4) + '-'
+ s.substr(20, 12);
shortId = shortId.replace(/-+$/, '');
} else {
// UUID prefix.
var shortId = '';
var chunk;
var remaining = s;
var spans = [8, 4, 4, 4, 12];
for (var i = 0; i < spans.length; i++) {
var span = spans[i];
head = remaining.slice(0, span);
remaining = remaining.slice(span + 1);
if (!shortIdCharsRe.test(head)) {
return;
}
shortId += head;
if (remaining) {
shortId += '-';
} else {
break;
}
}
}
return shortId;
}
//---- exports
module.exports = {
UUID_RE: UUID_RE,
objCopy: objCopy,
deepObjCopy: deepObjCopy,
zeroPad: zeroPad,
boolFromString: boolFromString,
jsonStream: jsonStream,
kvToObj: kvToObj,
longAgo: longAgo,
isUUID: isUUID,
humanDurationFromMs: humanDurationFromMs,
humanSizeFromBytes: humanSizeFromBytes,
capitalize: capitalize,
normShortId: normShortId
};
// vim: set softtabstop=4 shiftwidth=4: