Class: ActiveRecord::SessionStore::SqlBypass

Inherits:
Object
  • Object
show all
Extended by:
ClassMethods
Defined in:
activerecord/lib/active_record/session_store.rb

Overview

A barebones session store which duck-types with the default session store but bypasses Active Record and issues SQL directly. This is an example session model class meant as a basis for your own classes.

The database connection, table name, and session id and data columns are configurable class attributes. Marshaling and unmarshaling are implemented as class methods that you may override. By default, marshaling data is

ActiveSupport::Base64.encode64(Marshal.dump(data))

and unmarshaling data is

Marshal.load(ActiveSupport::Base64.decode64(data))

This marshaling behavior is intended to store the widest range of binary session data in a text column. For higher performance, store in a blob column instead and forgo the Base64 encoding.

Constant Summary

@@table_name = 
'sessions'
@@session_id_column = 
'session_id'
@@data_column = 
'data'

Instance Attribute Summary (collapse)

Class Method Summary (collapse)

Instance Method Summary (collapse)

Methods included from ClassMethods

create_table!, drop_table!, marshal, unmarshal

Constructor Details

- (SqlBypass) initialize(attributes)

Look for normal and marshaled data, self.find_by_session_id's way of telling us to postpone unmarshaling until the data is requested. We need to handle a normal data attribute in case of a new record.



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# File 'activerecord/lib/active_record/session_store.rb', line 229

def initialize(attributes)
  @session_id     = attributes[:session_id]
  @data           = attributes[:data]
  @marshaled_data = attributes[:marshaled_data]
  @new_record     = @marshaled_data.nil?
end

Instance Attribute Details

- (Object) data

Lazy-unmarshal session state.



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# File 'activerecord/lib/active_record/session_store.rb', line 237

def data
  unless @data
    if @marshaled_data
      @data, @marshaled_data = self.class.unmarshal(@marshaled_data) || {}, nil
    else
      @data = {}
    end
  end
  @data
end

- (Object) new_record (readonly) Also known as: new_record?

Returns the value of attribute new_record



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# File 'activerecord/lib/active_record/session_store.rb', line 221

def new_record
  @new_record
end

- (Object) session_id (readonly)

Returns the value of attribute session_id



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# File 'activerecord/lib/active_record/session_store.rb', line 221

def session_id
  @session_id
end

Class Method Details

+ (Object) connection 



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# File 'activerecord/lib/active_record/session_store.rb', line 209

def connection
  @@connection ||= ActiveRecord::Base.connection
end

+ (Object) find_by_session_id(session_id)

Look up a session by id and unmarshal its data if found.



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# File 'activerecord/lib/active_record/session_store.rb', line 214

def find_by_session_id(session_id)
  if record = connection.select_one("SELECT * FROM #{@@table_name} WHERE #{@@session_id_column}=#{connection.quote(session_id)}")
    new(:session_id => session_id, :marshaled_data => record['data'])
  end
end

Instance Method Details

- (Object) destroy 



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# File 'activerecord/lib/active_record/session_store.rb', line 276

def destroy
  return if @new_record

  connect = connection
  connect.delete <<-end_sql, 'Destroy session'
    DELETE FROM #{table_name}
    WHERE #{connect.quote_column_name(session_id_column)}=#{connect.quote(session_id)}
  end_sql
end

- (Boolean) loaded?

Returns:

  • (Boolean) 


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# File 'activerecord/lib/active_record/session_store.rb', line 248

def loaded?
  @data
end

- (Object) save 



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# File 'activerecord/lib/active_record/session_store.rb', line 252

def save
  return false unless loaded?
  marshaled_data = self.class.marshal(data)
  connect        = connection

  if @new_record
    @new_record = false
    connect.update <<-end_sql, 'Create session'
      INSERT INTO #{table_name} (
        #{connect.quote_column_name(session_id_column)},
        #{connect.quote_column_name(data_column)} )
      VALUES (
        #{connect.quote(session_id)},
        #{connect.quote(marshaled_data)} )
    end_sql
  else
    connect.update <<-end_sql, 'Update session'
      UPDATE #{table_name}
      SET #{connect.quote_column_name(data_column)}=#{connect.quote(marshaled_data)}
      WHERE #{connect.quote_column_name(session_id_column)}=#{connect.quote(session_id)}
    end_sql
  end
end