SERIALIZATION

Serialization (a.k.a. "save and restore")
=========================================

[All occurences of the word "filename" in the sequel are replaced
 by the value of the '-r' parameter.]

There are three fundamental pieces of persistent data that need to be
saved to and restored from disk:

1. The world:

   The world data comprises the block type and block
   metadata for each block in the world. This is implemented
   in serializer.*; the data is stored in filename.{dat,idx}
   and consists simply of a flat, DEFLATE-compressed dump of
   all the block data of all loaded chunks. (The index file
   contains the offsets of each chunk for quick random access.)

2. World metadata:

   Meta data comprises the following information:

   - Map randomness generator seed
   - Game time of day
   - Default initial spawn position
   - Saplings, signs
   - Spawn items and chest content (read "chests, furnaces, dispensers")

   The data is stored in filename.meta, but THE FORMAT IS NOT FIXED YET.

3. Per-player data:

   Per-player data comprises the following information:

   - Position and orientation
   - Health
   - Inventory

   The data is stored in filename.player.HASH, where HASH is replaced
   by the SHA1 hash of the UTF-8 representation of the player's nickname.

   THE FORMAT IS NOT YET FIXED.