Class: PgLock::Locket

Inherits:
Object
  • Object
show all
Defined in:
lib/pg_lock/locket.rb

Overview

Holds the logic to aquire a lock and parse if locking was successful

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(connection, lock_args) ⇒ Locket

Returns a new instance of Locket.



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# File 'lib/pg_lock/locket.rb', line 5

def initialize(connection, lock_args)
  self.connection = connection
  self.args       = lock_args
end

Instance Attribute Details

#args ⇒ Object

Returns the value of attribute args.



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# File 'lib/pg_lock/locket.rb', line 4

def args
  @args
end

#connection ⇒ Object

Returns the value of attribute connection.



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# File 'lib/pg_lock/locket.rb', line 4

def connection
  @connection
end

Instance Method Details

#active? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pg_lock/locket.rb', line 26

def active?
  connection.exec(<<-eos, args).getvalue(0,0) == "t"
    SELECT granted
    FROM pg_locks
    WHERE locktype = 'advisory' AND
     pid = pg_backend_pid() AND
     mode = 'ExclusiveLock' AND
     classid = $1 AND
     objid = $2
  eos
end

#aquired? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pg_lock/locket.rb', line 20

def aquired?
  @lock[0]["pg_try_advisory_lock"] == "t"
rescue
  false
end

#lock ⇒ Object 



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# File 'lib/pg_lock/locket.rb', line 10

def lock
  @lock = connection.exec("select pg_try_advisory_lock($1,$2)", args)
  return aquired?
end

#unlock ⇒ Object 



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# File 'lib/pg_lock/locket.rb', line 15

def unlock
  connection.exec("select pg_advisory_unlock($1,$2)", args)
  @lock = false
end