Class: DatastaxRails::Cql::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/datastax_rails/cql/base.rb

Overview

Base class for CQL generation

Instance Method Summary collapse

Constructor Details

#initialize(klass, *_args) ⇒ Base

Base initialize that sets the default consistency.



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# File 'lib/datastax_rails/cql/base.rb', line 6

def initialize(klass, *_args)
  @consistency = klass.default_consistency.to_s.downcase.to_sym
  @keyspace = DatastaxRails::Base.config[:keyspace]
  @values = []
end

Instance Method Details

#execute ⇒ Object

Generates the CQL and calls Cassandra to execute it. If you are using this outside of Rails, then DatastaxRails::Base.connection must have already been set up (Rails does this for you).



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# File 'lib/datastax_rails/cql/base.rb', line 25

def execute
  cql = to_cql
  puts cql if ENV['DEBUG_CQL'] == 'true'
  pp @values if ENV['DEBUG_CQL'] == 'true'
  digest = Digest::MD5.digest cql
  try_again = true
  begin
    stmt = DatastaxRails::Base.statement_cache[digest] ||= DatastaxRails::Base.connection.prepare(cql)
    if @consistency
      stmt.execute(*@values, consistency: @consistency)
    else
      stmt.execute(*@values)
    end
  rescue ::Cql::NotConnectedError
    if try_again
      Rails.logger.warn('Lost connection to Cassandra. Attempting to reconnect...')
      try_again = false
      DatastaxRails::Base.reconnect
      retry
    else
      raise
    end
  end
end

#to_cql ⇒ Object

Abstract. Should be overridden by subclasses



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# File 'lib/datastax_rails/cql/base.rb', line 18

def to_cql
  fail NotImplementedError
end

#using(consistency) ⇒ Object 



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# File 'lib/datastax_rails/cql/base.rb', line 12

def using(consistency)
  @consistency = consistency.to_s.downcase.to_sym
  self
end