TOKYO RECORD

The purpose of this project is to provide a nice object-oriented interface to Tokyo Cabinet, a dbm-like database.

Each attribute gets mapped to 2 databases.  
The FDB database indexes the attributes by integer ids.  
The BDB databases is the mirror opposite of the FDB database in the sense the the attribute values used for hash keys while the integer ids are placed into the value position of (key, value).  This allows for fast search by value.

Below is some sample data.  It should give you an idea of what the databases "look like."
# class User < TokyoRecord
# end

User.id.fdb
(empty)

# @user = User.new
# @user.save

User.id.fdb
1 --> 1

# class User < TokyoRecord
#   attributes :name
# end
#
# @user2 = User.new
# @user2.name = 'David'
# @user2.save  # gets the next id from User.id.fdb, 2.

User.name.bdb 
"" --> 1
David --> 2 

User.name.fdb
1 --> ""
2 --> David

# Assume Post.id.fdb's next id is 100.
#
# class Post < TokyoRecord
#   attributes :title
# end
#
# @post = Post.new
# @post.title = 'Good morning.'
# @post.save  # gets the next id from Post.id.fdb, 100
#
# @post2 = Post.new
# @post2.title = 'Good evening.'
# @post2.save  # gets the next id from Post.id.fdb, 101


# class Post < TokyoRecord
#   attributes :title
#   belongs_to :user
# end

In Post.title.bdb
title --> id
"Good morning." --> 100  # We could truncate keys to the first 30 letters so that hash keys don't get unwieldly.
"Good evening." --> 101 

In Post.title.fdb
id --> title
100 --> "Good morning."
101 --> "Good evening."

# Post.new
# @post = Post.new
# @post.user = @user2
# @post.user.save

# @post2.user_id = 2
# @post2.save

# Keep in mind that two posts are pointing to the same user_id of 2.
In Post.user_id.bdb 
post.user_id --> post.id
2 --> 100
2 --> 101

# This database is needed for fast look up by the posts's id.
Post.user_id.fdb
post.id --> post.user_id
100 --> 2
101 --> 2