radare2/shlr/sdb

SDB (string database)

sdb is a simple string key/value database based on djb's cdb disk storage and supports JSON and arrays introspection.

mcsdbd is a memcache server with disk storage based on sdb. It is distributed as a standalone binary and a library.

There's also the sdbtypes: a vala library that implements several data structures on top of an sdb or a memcache instance.

Author

pancake pancake@nopcode.org

Contains

• namespaces (multiple sdb paths)
• atomic database sync (never corrupted)
• bindings for vala, luvit, newlisp and nodejs
• commandline frontend for sdb databases
• memcache client and server with sdb backend
• arrays support (syntax sugar)
• json parser/getter (js0n.c)

Rips

• disk storage based on cdb code
• memory hashtable based on wayland code
• linked lists from r2 api

Changes

I have modified cdb code a little to create smaller databases and be memory leak free in order to use it from a library.

The sdb's cdb database format is 10% smaller than the original one. This is because keylen and valuelen are encoded in 4 bytes: 1 for the key length and 3 for the value length.

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

Usage example

Let's create a database!

$ sdb d hello=world
$ sdb d hello
world

Using arrays (>=0.6):

$ sdb - '[]list=1,2' '[0]list' '[0]list=foo' '[]list' '[+1]list=bar'
1
foo
2

Let's play with json:

$ sdb d g='{"foo":1,"bar":{"cow":3}}'
$ sdb d g:bar.cow
3
$ sdb - user='{"id":123}' user:id=99 user:id
99

Using the commandline without any disk database:

$ sdb - foo=bar foo a=3 +a -a
bar
4
3

$ sdb -
foo=bar
foo
bar
a=3
+a
4
-a
3

Remove the database

$ rm -f d