Contents

module Picky

  module Backends

    class Sqlite

      class DB

        include Helpers::File

        attr_reader :cache_path, :db

        def initialize cache_path, options = {}
          @cache_path = "#{cache_path}.sqlite3"
          @empty      = options[:empty]
          @initial    = options[:initial]
        end

        def initial
          @initial && @initial.clone || {}
        end

        def empty
          @empty && @empty.clone || {}
        end

        def lazily_initialize_client
          @db ||= SQLite3::Database.new cache_path
        end

        def dump_sqlite internal
          lazily_initialize_client

          # TODO Does it make a difference if these
          #      statements are given as one to the
          #      @db.execute method?
          #

          db.execute 'drop table if exists key_value;'
          db.execute 'create table key_value (key varchar(255), value text);'
          db.execute 'create index key_idx on key_value (key);'
          db.execute 'BEGIN;'

          # Note: Internal structures need to
          #       implement each.
          #
          internal.each do |key, value|
            encoded_value = Yajl::Encoder.encode value
            db.execute 'insert into key_value values (?,?)', key.to_s, encoded_value
          end

          db.execute 'COMMIT;'
        end

        def dump internal
          create_directory cache_path
          dump_sqlite internal
        end

        def load
          lazily_initialize_client
          self
        end

        def [] key
          res = db.execute "select value from key_value where key = ? limit 1;", key.to_s
          return nil if res.empty?

          # TODO Slightly speed up by not calling Yajl for the || case?
          #
          Yajl::Parser.parse res.first.first || ""
        end

        def to_s
          "#{self.class}(#{cache_path})"
        end

      end

    end

  end

end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
picky-3.6.1	lib/picky/backends/sqlite/db.rb
picky-3.6.0	lib/picky/backends/sqlite/db.rb