Class: OCI8EnhancedAutoRecover

Inherits:
OCI8
  • Object
show all
Defined in:
lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb

Overview

The OCI8AutoRecover class enhances the OCI8 driver with auto-recover and reset functionality. If a call to #exec fails, and autocommit is turned on (ie., we’re not in the middle of a longer transaction), it will automatically reconnect and try again. If autocommit is turned off, this would be dangerous (as the earlier part of the implied transaction may have failed silently if the connection died) – so instead the connection is marked as dead, to be reconnected on it’s next use.

Constant Summary collapse

LOST_CONNECTION_ERROR_CODES =

ORA-00028: your session has been killed ORA-01012: not logged on ORA-03113: end-of-file on communication channel ORA-03114: not connected to ORACLE ORA-03135: connection lost contact

[ 28, 1012, 3113, 3114, 3135 ]
@@auto_retry = 
false

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config, factory) ⇒ OCI8EnhancedAutoRecover

Returns a new instance of OCI8EnhancedAutoRecover.



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# File 'lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb', line 287

def initialize(config, factory)
  @active = true
  @config = config
  @factory = factory
  @connection  = @factory.new_connection @config
  super @connection
end

Instance Attribute Details

#active ⇒ Object Also known as: active?

Returns the value of attribute active.



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# File 'lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb', line 278

def active
  @active
end

Instance Method Details

#describe(name) ⇒ Object 



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# File 'lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb', line 346

def describe(name)
  @connection.describe(name)
end

#exec(sql, *bindvars, &block) ⇒ Object

Adds auto-recovery functionality.

See: www.jiubao.org/ruby-oci8/api.en.html#label-11



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# File 'lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb', line 329

def exec(sql, *bindvars, &block)
  should_retry = self.class.auto_retry? && autocommit?

  begin
    @connection.exec(sql, *bindvars, &block)
  rescue OCIException => e
    raise unless LOST_CONNECTION_ERROR_CODES.include?(e.code)
    @active = false
    raise unless should_retry
    should_retry = false
    reset! rescue nil
    retry
  end
end

#ping ⇒ Object

Checks connection, returns true if active. Note that ping actively checks the connection, while #active? simply returns the last known state.



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# File 'lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb', line 298

def ping
  @connection.exec("select 1 from dual") { |r| nil }
  @active = true
rescue
  @active = false
  raise
end

#reset! ⇒ Object

Resets connection, by logging off and creating a new connection.



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# File 'lib/active_record/connection_adapters/oracle_enhanced_oci_connection.rb', line 307

def reset!
  logoff rescue nil
  begin
    @connection = @factory.new_connection @config
    __setobj__ @connection
    @active = true
  rescue
    @active = false
    raise
  end
end