Class: DataObjects::NestedTransaction

Inherits:
Transaction
  • Object
show all
Defined in:
lib/dm-nested-transactions.rb

Constant Summary collapse

HOST =

The host name. Note, this relies on the host name being configured and resolvable using DNS

"#{Socket::gethostbyname(Socket::gethostname)[0]}" rescue "localhost"
@@counter = 
0

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(uri, connection, adapter) ⇒ NestedTransaction

Creates a NestedTransaction bound to an existing connection



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# File 'lib/dm-nested-transactions.rb', line 64

def initialize(uri, connection, adapter)
  @adapter    = adapter
  @connection = connection
  @id = Digest::SHA256.hexdigest("#{HOST}:#{$$}:#{Time.now.to_f}:nested:#{@@counter += 1}")[0..10]
end

Instance Attribute Details

#connection ⇒ Object (readonly)

The connection object for this transaction - must have already had a transaction begun on it



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# File 'lib/dm-nested-transactions.rb', line 52

def connection
  @connection
end

#id ⇒ Object (readonly)

A unique ID for this transaction



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# File 'lib/dm-nested-transactions.rb', line 54

def id
  @id
end

Class Method Details

.create_for_uri(uri, connection, adapter) ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 56

def self.create_for_uri(uri, connection, adapter)
  uri = uri.is_a?(String) ? URI::parse(uri) : uri
  DataObjects::NestedTransaction.new(uri, connection, adapter)
end

Instance Method Details

#begin ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 90

def begin
  connection.create_command(begin_statement.call(@id)).execute_non_query
end

#begin_statement ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 70

def begin_statement
  lambda{ |id| "SAVEPOINT \"#{id}\"" }
end

#close ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 87

def close
end

#commit ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 94

def commit
  statement = commit_statement
  if statement
    connection.create_command(commit_statement.call(@id)).execute_non_query
  end
end

#commit_statement ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 74

def commit_statement
  case @adapter.class.name
  when /oracle/i
    nil
  else
    lambda{ |id| "RELEASE SAVEPOINT \"#{id}\"" }
  end
end

#rollback ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 101

def rollback
  connection.create_command(rollback_statement.call(@id)).execute_non_query
end

#rollback_statement ⇒ Object 



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# File 'lib/dm-nested-transactions.rb', line 83

def rollback_statement
  lambda{ |id| "ROLLBACK TO SAVEPOINT \"#{id}\"" }
end