Class: Mongomatic::TransactionLock

Inherits:
Base
  • Object
show all
Defined in:
lib/mongomatic/transaction_lock.rb

Constant Summary

Constants included from TypedFields

Mongomatic::TypedFields::KNOWN_TYPES

Instance Attribute Summary

Attributes inherited from Base

#errors, #is_new, #removed

Class Method Summary collapse

Methods inherited from Base

#==, #[], #[]=, all, collection, collection_name, count, db, db=, #delete, #do_callback, do_callback, #doc, #doc=, drop, each, empty?, find, find_one, first, #has_key?, #hash_for_field, #initialize, #insert, insert, #insert!, insert!, #is_new?, #merge, #new?, #reload, #remove, #remove!, #removed?, #set_value_for_key, #to_hash, #transaction, #update, #update!, #valid?, #validate, #value_for_key

Methods included from TypedFields

included

Methods included from ActiveModelCompliancy

#destroyed?, #new_record?, #persisted?, #to_key, #to_model, #to_param

Methods included from Util

#create_array

Methods included from Modifiers

#add_to_set, #add_to_set!, #inc, #inc!, #pop_first, #pop_first!, #pop_last, #pop_last!, #pull, #pull!, #pull_all, #pull_all!, #push, #push!, #push_all, #push_all!, #set, #set!, #unset, #unset!

Constructor Details

This class inherits a constructor from Mongomatic::Base

Class Method Details

.create_indexes ⇒ Object 



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# File 'lib/mongomatic/transaction_lock.rb', line 4

def self.create_indexes
  collection.create_index("key", :unique => true, :drop_dups => true)
  collection.create_index("expire_at")
end

.remove_stale_locks ⇒ Object 



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# File 'lib/mongomatic/transaction_lock.rb', line 30

def self.remove_stale_locks
  collection.remove({:expire_at => {"$lte" => Time.now.utc}}, {:safe => true})
end

.start(key, duration, &block) ⇒ Object 



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# File 'lib/mongomatic/transaction_lock.rb', line 9

def self.start(key, duration, &block)
  lock = new(:key => key, :expire_at => Time.now.utc + duration)
  
  # we need to get a lock
  begin
    lock.insert!
  rescue Mongo::OperationFailure => e
    remove_stale_locks
    if find_one(:key => key) == nil
      return start(key, duration, &block)
    end
    raise Mongomatic::Exceptions::CannotGetTransactionLock
  end
  
  begin
    block.call
  ensure
    lock.remove
  end
end