Created
October 26, 2013 19:50
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Fun with __proto__
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| # To run: | |
| # npm install -g coffee-script | |
| # npm install usage | |
| # coffee example.coffee | |
| # Let me know if you know of a more memory efficient way that is compatible with IE | |
| _ = require 'lodash' | |
| assert = require 'assert' | |
| usage = require 'usage' | |
| class Num | |
| num: true | |
| class Str | |
| str: true | |
| # changing the class out from under an object using __proto__ - not supported in IE :( | |
| ohs = [] | |
| for i in [0..1000000] | |
| do -> | |
| n = new Num() | |
| n.__proto__ = Str.prototype | |
| assert.ok n.str | |
| ohs.push n | |
| # runs in < 1s uses 69MB of memory | |
| # changing the class out from under an object by creating a new Class per object - works everywhere but uses too much memory | |
| ohs = [] | |
| for i in [0..1000000] | |
| do -> | |
| Cons = -> | |
| Cons.prototype = _.clone Num.prototype | |
| n = new Cons() | |
| Object.keys(Cons.prototype).forEach (k) -> | |
| delete Cons.prototype[k] | |
| _.extend Cons.prototype, Str.prototype | |
| assert.ok n.str | |
| ohs.push n | |
| # runs in about 5s uses 1091MB of memory | |
| usage.lookup process.pid, (err, result) -> | |
| console.log result |
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