odba
ODBA is an unintrusive Object Cache system. It adresses the crosscutting concern of object storage by disconnecting and serializing objects into storage. All disconnected connections are replaced by instances of ODBA::Stub, thus enabling transparent object-loading.
To see a graphical overview of the Library please see
ODBA supports
- transparent loading of connected objects
- index-vectors
- transactions
- transparently fetches Hash-Elements without loading the entire Hash
DESCRIPTION:
- Object Database Access - Ruby Software for ODDB.org Memory Management
- https://dev.ywesee.com/ODBA/Index
FEATURES/PROBLEMS:
- There may still be an sql bottleneck. Has to be investigated further.
- You will need postgresql installed.
- The unit test test_clean__prefetched in test/test_cache.rb fails with Ruby 3.3/3.4 sometimes but not always
- Rework the unit tests to use a test database and less flexmock
- Rebase the library on the Sequel gem instead of ydbi/ydbd_pg
Example
You may find this code and some tests which is using this (example)[https://github.com/zdavatz/odba/blob/master/test/example.rb]
require "odba/connection_pool"
class User
attr_accessor :first_name, :last_name
include ODBA::Persistable
def initialize(first_name, last_name)
@first_name = first_name
@last_name = last_name
end
def to_s
"#{@first_name} #{@last_name}"
end
end
class Example
def self.db_setup
# connect default storage manager to a relational database on
# our localhost using port 5435 with a user odba_test and an empty password
ODBA.storage.dbi = ODBA::ConnectionPool.new("DBI:Pg:dbname=odba_test;host=127.0.0.1;port=5432", "odba_test", "")
ODBA.cache.setup
end
def self.show_last_added_user
res = ODBA.storage.dbi.select_all("Select count(*) from object;").first.first
odba_id = ODBA.storage.dbi.select_one("select odba_id from object order by odba_id desc limit 1;")
puts "show_last_added_user: We have #{res} objects. Highest odba_id is #{odba_id}"
first = ODBA.storage.dbi.select_one("select odba_id, name, prefetchable, extent, content from object order by odba_id desc limit 1;")
puts " DB-content is #{first}"
puts " Fetched object for odba_id #{odba_id} is #{ODBA.cache.fetch(odba_id.first)}"
end
end
Example.db_setup
composer = User.new("Ludwig", "Van Beethoven")
composer.odba_store
Example.show_last_added_user
painter = User.new("Vincent", "Van Gogh")
painter.odba_store
scientist = User.new("Albert", "Einstein")
scientist.odba_store
Example.show_last_added_user
You will see something like
show_last_added_user: We have 2 objects. Highest odba_id is [2]
DB-content is [2, nil, false, "User", "04086f3a09557365720b3a104066697273745f6e616d6549220b4c7564776967063a0645543a0f406c6173745f6e616d6549221256616e2042656574686f76656e063b07543a15406f6462615f70657273697374656e74543a0d406f6462615f696469073a14406f6462615f6f6273657276657273303a13406f6462615f707265666574636830"]
Fetched object for odba_id [2] is Ludwig Van Beethoven
show_last_added_user: We have 4 objects. Highest odba_id is [4]
DB-content is [4, nil, false, "User", "04086f3a09557365720b3a104066697273745f6e616d6549220b416c62657274063a0645543a0f406c6173745f6e616d6549220d45696e737465696e063b07543a15406f6462615f70657273697374656e74543a0d406f6462615f696469093a14406f6462615f6f6273657276657273303a13406f6462615f707265666574636830"]
Fetched object for odba_id [4] is Albert Einstein
This example is run on each push to github via the (github action)[https://github.com/zdavatz/odba/blob/master/.github/workflows/devenv.yml]. It is based on (devenv.sh)[https://devenv.sh/], which ensures reproducability.
INSTALL:
- gem install odba
DEVELOPERS:
- Masamoi Hatakeyama
- Zeno R.R. Davatz
- Hannes Wyss (up to Version 1.0)
- Niklaus Giger (Porting to Ruby 2.x and 3.x, cleanup)
LICENSE:
- GPLv2.1