radare2/libr/db/sdb

SDB (simple database)
=====================
author: pancake

Description
-----------

sdb is a simple key/value database with disk storage.
mcsdbd is a memcache server with disk storage based on sdb.
sdbtypes is a vala library that implements several data
   structures on top of an sdb or memcache instance.

Rips
----
disk storage based on cdb code
in memory hashtable based on wayland
linked lists from r2 api

Changes
-------
I have slightly modified the cdb code to get smaller databases
and be memory leak free.

The sdb's cdb database format is 10% smaller than the original
one. This is because keylen and valuelen are encoded in 4 bytes
using two endian-safe unsigned short values.

In a test case, a 4.3MB cdb database takes only 3.9MB after this
file format change.

Backups
-------
To make a backup of a database to move it between different boxes use the textual format:
 $ sdb my.db > my.txt
 $ gzip my.txt
 $ du -hs my.*
 my.db        3.9M
 my.txt.gz    500K

To import the database:
  $ zcat my.txt.gz | sdb my.db =