Class: ActiveRecord::SessionStore::SqlBypass

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

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

and unmarshaling data is

Marshal.load(::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'

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from ClassMethods

create_table!, drop_table!, marshal, unmarshal

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/sql_bypass.rb', line 77

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

Class Attribute Details

.connection ⇒ Object 



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# File 'lib/active_record/session_store/sql_bypass.rb', line 51

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

.connection_pool ⇒ Object 



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# File 'lib/active_record/session_store/sql_bypass.rb', line 55

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

Instance Attribute Details

#data ⇒ Object

Lazy-unmarshal session state.



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# File 'lib/active_record/session_store/sql_bypass.rb', line 90

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

#new_record ⇒ Object (readonly) Also known as: new_record?

Returns the value of attribute new_record.



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# File 'lib/active_record/session_store/sql_bypass.rb', line 69

def new_record
  @new_record
end

#session_id ⇒ Object (readonly)

Returns the value of attribute session_id.



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# File 'lib/active_record/session_store/sql_bypass.rb', line 69

def session_id
  @session_id
end

Class Method Details

.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/sql_bypass.rb', line 60

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

Instance Method Details

#data_column ⇒ Object

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



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# File 'lib/active_record/session_store/sql_bypass.rb', line 39

cattr_accessor :data_column

#destroy ⇒ Object 



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# File 'lib/active_record/session_store/sql_bypass.rb', line 129

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.to_s)}
  end_sql
end

#loaded? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/session_store/sql_bypass.rb', line 101

def loaded?
  @data
end

#persisted? ⇒ Boolean

Returns true if the record is persisted, i.e. it’s not a new record

Returns:

  • (Boolean) 


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# File 'lib/active_record/session_store/sql_bypass.rb', line 85

def persisted?
  !@new_record
end

#save ⇒ Object 



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# File 'lib/active_record/session_store/sql_bypass.rb', line 105

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

#session_id_column ⇒ Object

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



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# File 'lib/active_record/session_store/sql_bypass.rb', line 33

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/sql_bypass.rb', line 27

cattr_accessor :table_name