bulker

bulker is library that privides bulk execution functionality for paging and buffering. bulker provides Bulker::Pager and Bulker::Buffer.

Bulker::Pager gives you paging functionality to split large number of data to devided segments. When 1000,000 records in your database, and you're going to do some process for each record, Bulker::Pager will help you. It can handle large data very easily such like array with each method.

Bulker::Buffer provides simple buffer that enables implimenting bulk insert or bulk upload behavior.

Install bulker with RubyGems

$ gem install bulker

or add this to your Gemfile if you use Bundler:

$ gem "bulker"

Bulker::Pager is especially designed for ActiveRecord. For other data source, Bulker::Criteria provides interface for Bulker::Pager.

If you have large records in items table and want to process each item, then:

require 'bulker'
class Item < ActiveRecord::Base; end
Bulker::Pager.each(Item.where(:status => "selling"), 100) do
  # do some process for each item
end

This sample, Bulker::Pager fetches 100 items for each sql query, and continues fetching until all records are covered. Block that given to each method is called for each record.

When you use library other than ActiveRecord for accessing data soruce, you can use Bulker::Criteria.

require 'bulker'
data = (1..20).to_a
criteria = Bulker::Criteria.new data
criteria.define_each lambda { |values, offset, limit, block|
  values[offset..(offset + limit - 1)].each do |v|
    block.call(v)
  end
}
Bulker::Pager.each(criteria, 10) do |v|
  #  do some process
end

Wrap your data objects with Bulker::Criteria, and define behavior of each method through define_each using lambda. Then Bulker::Pager can work with the criteria.

By default, same each implementation for array as above is bundled in Bulker::Criteria as from_array.

criteria = Bulker::Criteria.from_array([1, 2, 3, 4, 5])

It's easy to understand Bulker::Buffer behavior through seeing our RSPEC.

require 'bulker'
result = []
# create buffer with size = 4
buffer = Bulker::Buffer.new(4) do |ary|
  result << ary # when buffer filled
end
(1..10).each do |i|
  buffer << i
end
buffer.flush
result.should == [
  [1, 2, 3, 4],
  [5, 6, 7, 8],
  [9, 10]
]

• Check out the latest master to make sure the feature hasn't been implemented or the bug hasn't been fixed yet.
• Check out the issue tracker to make sure someone already hasn't requested it and/or contributed it.
• Fork the project.
• Start a feature/bugfix branch.
• Commit and push until you are happy with your contribution.
• Make sure to add tests for it. This is important so I don't break it in a future version unintentionally.
• Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

bulker is released under the MIT license.

Copyright (c) 2012 daisuke sugimori.