MemDb

Embedded database with support of composite indices and complex document matching.

ARCHIVED

Main repostory https://github.com/wallarm/mem_db

Installation

Add this line to your application's Gemfile:

gem 'mem_db'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install mem_db

Usage

# Define how fields will be matched
fields = MemDB::Fields.new([
  MemDB::Field::Enum.new(:category),
  MemDB::Field::Enum.new(:"!category").query(:category).negative,

  MemDB::Field::Regexp.new(:text),
  MemDB::Field::Regexp.new(:"!text").query(:text).negative,

  MemDB::Field::Pattern.new(:breadcrumbs),
  MemDB::Field::Pattern.new(:"!breadcrumbs").query(:breadcrumbs).negative,
].map!(&:may_missing))

# Specify index

index = MemDB::Index.compose([
  MemDB::Index::Enum::Bucket.new(
    idx: MemDB::Idx::Itself.new(:category).default_any
  ).accept_any,
  MemDB::Index::PatternMatch::Bucket.new(
    idx: MemDB::Idx::Pattern.new(:breadcrumbs).default_any
  ).accept_any,
])

# Create database instance

db = MemDB.new(fields, index)

# Indexate

indexation = db.new_indexation

indexation.add(
  {
    category: "food",
    text: ".*fish.*",
    breadcrumbs: "*/retail/*"
  },
  :food_fish
)
indexation.add(
  {
    "!category": "food",
    text: ".*fish.*",
    breadcrumbs: "*/retail/*"
  },
  :not_food_fish
)

# Query

MemDB::Query.new({
  category: "toy",
  text: "animated fish",
  breadcrumbs: "/shops/retail/123"
}).using(database)
# => [:not_food_fish]

MemDB::Query.new({
  category: "food",
  text: "delicious fish",
  breadcrumbs: "/shops/retail/123"
}).using(database)
# => [:food_fish]

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/DmitryBochkarev/mem_db.

License

The gem is available as open source under the terms of the MIT License.