Tokyo Cabinet is a library of routines for managing a database. The database is a simple data file containing records, each is a pair of a key and a value. Every key and value is serial bytes with variable length. Both binary data and character string can be used as a key and a value. There is neither concept of data tables nor data types. Records are organized in hash table, B+ tree, or fixed-length array.

User Defined Functions (UDF’s) via Lua

As of mid ‘08, Hirabayashi-san embedded Lua into Tokyo Cabinet’s runtime to allow for easy extensibility of the database. There is a common set of Lua API’s built in, which allow you to interact with the underlying data, execute your extensions remotely, or even on a timer. This allows us to build additional functionality on top of the Tokyo Cabinet database with Lua!

A few examples you will find in this repository:

• Simple echo application
• Implemention of sets operations (like Redis) on top of TC
• Example of executing Map-Reduce jobs on data within TC
• TTL / Expire functionality (like memcached)
• and many others…

Please do fork the repo and add your recipes to the list!

• Lua API: tokyocabinet.sourceforge.net/tyrantdoc/#luaext
• Announcement blog post: alpha.mixi.co.jp/blog/?p=236

Installing Tokyo Cabinet with Lua

  yum install lua lua-devel

  git clone git://github.com/etrepum/tokyo-cabinet.git
  git clone git://github.com/etrepum/tokyo-tyrant.git

  (or get latest files from sourceforge: http://sourceforge.net/projects/tokyocabinet/files/)

  cd tokyo-cabinet
  ./configure --enable-lua
  make && make install

  cd tokyo-tyrant
  ./configure
  make && make install

  gem install rufus-tokyo

Source: openwferu.rubyforge.org/tokyo.html

Invoking Lua extensions via the HTTP interface

It is possible to invoke custom Lua functions via direct HTTP calls. For example, using the echo-command example, we can invoke the function via:

  $ curl -i -X POST -H “X-TT-XNAME: echo” http://localhost:1978/foo -d “bar”

  HTTP/1.1 200 OK
  Content-Type: application/octet-stream
  Content-Length: 7

  foo:bar