Class: ActiveRecordViews::ChecksumCache

Inherits:
Object
  • Object
show all
Defined in:
lib/active_record_views/checksum_cache.rb

Instance Method Summary collapse

Constructor Details

#initialize(connection) ⇒ ChecksumCache

Returns a new instance of ChecksumCache.



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# File 'lib/active_record_views/checksum_cache.rb', line 3

def initialize(connection)
  @connection = connection
  init_state_table!
end

Instance Method Details

#get(name) ⇒ Object 



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# File 'lib/active_record_views/checksum_cache.rb', line 38

def get(name)
  if data = @connection.select_one("SELECT class_name, checksum, options FROM active_record_views WHERE name = #{@connection.quote name}")
    data.symbolize_keys!
    data[:options] = JSON.load(data[:options]).symbolize_keys
    data
  end
end

#init_state_table! ⇒ Object 



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# File 'lib/active_record_views/checksum_cache.rb', line 8

def init_state_table!
  table_exists = @connection.data_source_exists?('active_record_views')

  if table_exists && !@connection.column_exists?('active_record_views', 'class_name')
    @connection.begin_transaction
    in_transaction = true

    @connection.select_values('SELECT name FROM active_record_views;').each do |view_name|
      @connection.execute "DROP VIEW IF EXISTS #{view_name} CASCADE;"
    end
    @connection.execute 'DROP TABLE active_record_views;'
    table_exists = false
  end

  if table_exists && !@connection.column_exists?('active_record_views', 'options')
    @connection.execute "ALTER TABLE active_record_views ADD COLUMN options json NOT NULL DEFAULT '{}';"
  end

  if table_exists && !@connection.column_exists?('active_record_views', 'refreshed_at')
    @connection.execute "ALTER TABLE active_record_views ADD COLUMN refreshed_at timestamp;"
  end

  unless table_exists
    @connection.execute "CREATE TABLE active_record_views(name text PRIMARY KEY, class_name text NOT NULL UNIQUE, checksum text NOT NULL, options json NOT NULL DEFAULT '{}', refreshed_at timestamp);"
  end

ensure
  @connection.commit_transaction if in_transaction
end

#set(name, data) ⇒ Object 



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# File 'lib/active_record_views/checksum_cache.rb', line 46

def set(name, data)
  if data
    data.assert_valid_keys :class_name, :checksum, :options

    options = data[:options] || {}
    unless options.keys.all? { |key| key.is_a?(Symbol) }
      raise ArgumentError, 'option keys must be symbols'
    end
    options_json = JSON.dump(options)

    rows_updated = @connection.update(<<-SQL.squish)
      UPDATE active_record_views
      SET
        class_name = #{@connection.quote data[:class_name]},
        checksum = #{@connection.quote data[:checksum]},
        options = #{@connection.quote options_json}
      WHERE
        name = #{@connection.quote name}
      ;
    SQL

    if rows_updated == 0
      @connection.insert <<-SQL.squish
        INSERT INTO active_record_views (
          name,
          class_name,
          checksum,
          options
        ) VALUES (
          #{@connection.quote name},
          #{@connection.quote data[:class_name]},
          #{@connection.quote data[:checksum]},
          #{@connection.quote options_json}
        )
      SQL
    end
  else
    @connection.delete "DELETE FROM active_record_views WHERE name = #{@connection.quote name}"
  end
end