Mindless Labs dev blog

Haxe serializer speed

The serializing feature of Haxe can be very handy - for example using Haxe Remoting in a flash game to communicate with your server, Haxe objects are automatically serialized on the client (converted to textual form), sent over to the server, and unserialized to object form. However the speed of serializing does matter.

The serializer not only serializes the object passed to it, but also automatically follows and serializes references to other objects. As an example, if you pass the root element of a tree structure for serialization, it will follow the links to the child nodes and as a result serialize the whole tree. This is very fine, but if the objects contain cyclic references - like child nodes linking back to their parents - the serializer would run into an endless loop.

For avoiding this, the serializer has an option called useCache, which when turned on, the serializer keeps a memory of previously met objects and won't re-serialize them. Unfortunately, for technical reasons the lookup of an object in this memory takes O(n) time, n being the number of objects met while serializing, so the full serializing takes O(n^2) time.

This means that if you are keen on speed, you must not use the useCache option, and take care of serializing structures without cyclic references. And, unconvenient as it is, but sometimes you may have to consider going down to the level of (un)serializing by hand, which would enable for highly tuned speed.

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