Contents

# rubocop:disable Metrics/MethodLength
# rubocop:disable Style/IfUnlessModifier

# private
module Simple::SQL::Connection
  def self.active_record_connection
    ActiveRecordConnection
  end

  def self.pg_connection(connection)
    PgConnection.new(connection)
  end

  class PgConnection
    extend Forwardable
    delegate %w(exec_params exec escape wait_for_notify) => :@raw_connection

    def initialize(raw_connection)
      @raw_connection = raw_connection
      @tx_nesting_level = 0
    end

    private

    def transaction(&_block)
      # Notes: by using "ensure" (as opposed to rescue) we are rolling back
      # both when an exception was raised and when a value was thrown. This
      # also means we have to track whether or not to rollback. i.e. do roll
      # back when we yielded to &block but not otherwise.
      #
      # Also the transaction support is a bit limited: you cannot rollback.
      # Rolling back from inside a nested transaction would require SAVEPOINT
      # support; without the code is simpler at least :)

      if @tx_nesting_level == 0
        exec "BEGIN"
        tx_started = true
      end

      @tx_nesting_level += 1

      return_value = yield

      # Only commit if we started a transaction here.
      if tx_started
        exec "COMMIT"
        tx_committed = true
      end

      return_value
    ensure
      @tx_nesting_level -= 1
      if tx_started && !tx_committed
        exec "ROLLBACK"
      end
    end
  end

  module ActiveRecordConnection
    extend self

    extend Forwardable
    delegate %w(exec_params exec escape wait_for_notify) => :raw_connection
    delegate [:transaction] => :connection

    def raw_connection
      connection.raw_connection
    end

    def connection
      ActiveRecord::Base.connection
    end
  end
end

Version data entries

5 entries across 5 versions & 1 rubygems

Version	Path
simple-sql-0.3.7	lib/simple/sql/connection.rb
simple-sql-0.3.6	lib/simple/sql/connection.rb
simple-sql-0.3.5	lib/simple/sql/connection.rb
simple-sql-0.3.4	lib/simple/sql/connection.rb
simple-sql-0.3.3	lib/simple/sql/connection.rb