Large mutable byte array in Erlang

Question

As I am writing a simple Minecraft server application in Erlang, I am now concerned with the question of how to efficiently store and modify chunk data. For those who don\'t kno

Answer 1

Since binaries are read-only, I can think of the following approaches (assuming you expect high rate of changes):

1. Use tree-like structure with relatively small immutable binaries in the leafs. In that case, when you modify you data, you only need to re-create small leaf binary + all nodes up to the root. Assuming that changes are "local" to some position, I think, you can start with octo-tree.
2. Use "big" binaries + list of changes (that could be as simple list of functions). When you need to modify world, just add new function to the list. When someone asks for the world state, take base binary and apply all changes from the list. From time to time "squash" all changes and prepare a new baseline state binary. This could be combined with previous approach (tree with pairs of binary/changes in the leafs).
3. Move mutable world management to the external code. You can use NIFs or Ports. I think, that would be the fastest way. Also, I think it would be relatively easy to implement it. The first version of API could be as simple as world:new(X, Y, Z) -> ref(); world:get(Ref, X, Y, Z); world:set(Ref, X, Y, Z, Value);