Class: ActiveRecord::SessionStore::SqlBypass

Inherits:
Object
  • Object
show all
Defined in:
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 collapse

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(attributes) ⇒ SqlBypass

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 'lib/active_record/session_store.rb', line 221

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

Instance Attribute Details

#data ⇒ Object

Lazy-unmarshal session state.



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# File 'lib/active_record/session_store.rb', line 231

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

#session_id ⇒ Object (readonly)

Returns the value of attribute session_id.



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# File 'lib/active_record/session_store.rb', line 215

def session_id
  @session_id
end

Class Method Details

.connection ⇒ Object 



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# File 'lib/active_record/session_store.rb', line 181

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

.create_table! ⇒ Object 



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# File 'lib/active_record/session_store.rb', line 200

def create_table!
  @@connection.execute <<-end_sql
    CREATE TABLE #{table_name} (
      id INTEGER PRIMARY KEY,
      #{@@connection.quote_column_name(session_id_column)} TEXT UNIQUE,
      #{@@connection.quote_column_name(data_column)} TEXT
    )
  end_sql
end

.drop_table! ⇒ Object 



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# File 'lib/active_record/session_store.rb', line 210

def drop_table!
  @@connection.execute "DROP TABLE #{table_name}"
end

.find_by_session_id(session_id) ⇒ Object

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



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# File 'lib/active_record/session_store.rb', line 186

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

.marshal(data) ⇒ Object 



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# File 'lib/active_record/session_store.rb', line 192

def marshal(data)
  ActiveSupport::Base64.encode64(Marshal.dump(data)) if data
end

.unmarshal(data) ⇒ Object 



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# File 'lib/active_record/session_store.rb', line 196

def unmarshal(data)
  Marshal.load(ActiveSupport::Base64.decode64(data)) if data
end

Instance Method Details

#connection ⇒ Object

:singleton-method: Use the ActiveRecord::Base.connection by default.



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# File 'lib/active_record/session_store.rb', line 160

cattr_accessor :connection

#data_column ⇒ Object

:singleton-method: The data field defaults to ‘data’.



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# File 'lib/active_record/session_store.rb', line 177

cattr_accessor :data_column

#destroy ⇒ Object 



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# File 'lib/active_record/session_store.rb', line 269

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

#loaded? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/session_store.rb', line 242

def loaded?
  !!@data
end

#new_record? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/session_store.rb', line 226

def new_record?
  @new_record
end

#save ⇒ Object 



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# File 'lib/active_record/session_store.rb', line 246

def save
  return false if !loaded?
  marshaled_data = self.class.marshal(data)

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

#session_id_column ⇒ Object

:singleton-method: The session id field defaults to ‘session_id’.



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# File 'lib/active_record/session_store.rb', line 171

cattr_accessor :session_id_column

#table_name ⇒ Object

:singleton-method: The table name defaults to ‘sessions’.



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# File 'lib/active_record/session_store.rb', line 165

cattr_accessor :table_name