File: //usr/lib/ruby/vendor_ruby/moneta/adapters/lmdb.rb
require 'lmdb'
require 'fileutils'
module Moneta
module Adapters
# LMDB backend
# @api public
class LMDB
include Defaults
supports :create, :increment
attr_reader :backend, :db
PUT_FLAGS = [:nooverwrite, :nodupdata, :current, :append, :appenddup]
# @param [Hash] options
# @option options [String] :dir Environment directory
# @option options [::LMDB::Environment] :backend Use existing backend instance
# @option options [String or nil] :db Database name
def initialize(options)
db = options.delete(:db)
@backend = options.delete(:backend) ||
begin
raise ArgumentError, 'Option :dir is required' unless dir = options.delete(:dir)
FileUtils.mkpath(dir)
::LMDB.new(dir, options)
end
@db = @backend.database(db, create: true)
end
# (see Proxy#key?)
def key?(key, options = {})
!@db.get(key).nil?
end
# (see Proxy#load)
def load(key, options = {})
@db.get(key)
end
# (see Proxy#store)
def store(key, value, options = {})
@db.put(key, value, Utils.only(options, *PUT_FLAGS))
value
end
# (see Proxy#delete)
def delete(key, options = {})
@backend.transaction do
if value = @db.get(key)
@db.delete(key)
value
end
end
end
# (see Proxy#clear)
def clear(options = {})
@db.clear
self
end
# (see Proxy#increment)
def increment(key, amount = 1, options = {})
@backend.transaction do
value = @db.get(key)
value = Utils.to_int(value) + amount
@db.put(key, value.to_s, Utils.only(options, *PUT_FLAGS))
value
end
end
# (see Defaults#create)
def create(key, value, options = {})
@backend.transaction do
if @db.get(key)
false
else
@db.put(key, value, Utils.only(options, *PUT_FLAGS))
true
end
end
end
# (see Proxy#close)
def close
@backend.close
nil
end
end
end
end