--- /dev/null
+module ActiveRecord
+ # A session store backed by an Active Record class. A default class is
+ # provided, but any object duck-typing to an Active Record Session class
+ # with text +session_id+ and +data+ attributes is sufficient.
+ #
+ # The default assumes a +sessions+ tables with columns:
+ # +id+ (numeric primary key),
+ # +session_id+ (text, or longtext if your session data exceeds 65K), and
+ # +data+ (text or longtext; careful if your session data exceeds 65KB).
+ # The +session_id+ column should always be indexed for speedy lookups.
+ # Session data is marshaled to the +data+ column in Base64 format.
+ # If the data you write is larger than the column's size limit,
+ # ActionController::SessionOverflowError will be raised.
+ #
+ # You may configure the table name, primary key, and data column.
+ # For example, at the end of <tt>config/environment.rb</tt>:
+ # ActiveRecord::SessionStore::Session.table_name = 'legacy_session_table'
+ # ActiveRecord::SessionStore::Session.primary_key = 'session_id'
+ # ActiveRecord::SessionStore::Session.data_column_name = 'legacy_session_data'
+ # Note that setting the primary key to the +session_id+ frees you from
+ # having a separate +id+ column if you don't want it. However, you must
+ # set <tt>session.model.id = session.session_id</tt> by hand! A before filter
+ # on ApplicationController is a good place.
+ #
+ # Since the default class is a simple Active Record, you get timestamps
+ # for free if you add +created_at+ and +updated_at+ datetime columns to
+ # the +sessions+ table, making periodic session expiration a snap.
+ #
+ # You may provide your own session class implementation, whether a
+ # feature-packed Active Record or a bare-metal high-performance SQL
+ # store, by setting
+ # ActiveRecord::SessionStore.session_class = MySessionClass
+ # You must implement these methods:
+ # self.find_by_session_id(session_id)
+ # initialize(hash_of_session_id_and_data)
+ # attr_reader :session_id
+ # attr_accessor :data
+ # save
+ # destroy
+ #
+ # The example SqlBypass class is a generic SQL session store. You may
+ # use it as a basis for high-performance database-specific stores.
+ class SessionStore < ActionController::Session::AbstractStore
+ # The default Active Record class.
+ class Session < ActiveRecord::Base
+ ##
+ # :singleton-method:
+ # Customizable data column name. Defaults to 'data'.
+ cattr_accessor :data_column_name
+ self.data_column_name = 'data'
+
+ before_save :marshal_data!
+ before_save :raise_on_session_data_overflow!
+
+ class << self
+ def data_column_size_limit
+ @data_column_size_limit ||= columns_hash[@@data_column_name].limit
+ end
+
+ # Hook to set up sessid compatibility.
+ def find_by_session_id(session_id)
+ setup_sessid_compatibility!
+ find_by_session_id(session_id)
+ end
+
+ def marshal(data)
+ ActiveSupport::Base64.encode64(Marshal.dump(data)) if data
+ end
+
+ def unmarshal(data)
+ Marshal.load(ActiveSupport::Base64.decode64(data)) if data
+ end
+
+ def create_table!
+ connection.execute <<-end_sql
+ CREATE TABLE #{table_name} (
+ id INTEGER PRIMARY KEY,
+ #{connection.quote_column_name('session_id')} TEXT UNIQUE,
+ #{connection.quote_column_name(@@data_column_name)} TEXT(255)
+ )
+ end_sql
+ end
+
+ def drop_table!
+ connection.execute "DROP TABLE #{table_name}"
+ end
+
+ private
+ # Compatibility with tables using sessid instead of session_id.
+ def setup_sessid_compatibility!
+ # Reset column info since it may be stale.
+ reset_column_information
+ if columns_hash['sessid']
+ def self.find_by_session_id(*args)
+ find_by_sessid(*args)
+ end
+
+ define_method(:session_id) { sessid }
+ define_method(:session_id=) { |session_id| self.sessid = session_id }
+ else
+ def self.find_by_session_id(session_id)
+ find :first, :conditions => {:session_id=>session_id}
+ end
+ end
+ end
+ end
+
+ # Lazy-unmarshal session state.
+ def data
+ @data ||= self.class.unmarshal(read_attribute(@@data_column_name)) || {}
+ end
+
+ attr_writer :data
+
+ # Has the session been loaded yet?
+ def loaded?
+ !!@data
+ end
+
+ private
+ def marshal_data!
+ return false if !loaded?
+ write_attribute(@@data_column_name, self.class.marshal(self.data))
+ end
+
+ # Ensures that the data about to be stored in the database is not
+ # larger than the data storage column. Raises
+ # ActionController::SessionOverflowError.
+ def raise_on_session_data_overflow!
+ return false if !loaded?
+ limit = self.class.data_column_size_limit
+ if loaded? and limit and read_attribute(@@data_column_name).size > limit
+ raise ActionController::SessionOverflowError
+ end
+ end
+ end
+
+ # 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.
+ class SqlBypass
+ ##
+ # :singleton-method:
+ # Use the ActiveRecord::Base.connection by default.
+ cattr_accessor :connection
+
+ ##
+ # :singleton-method:
+ # The table name defaults to 'sessions'.
+ cattr_accessor :table_name
+ @@table_name = 'sessions'
+
+ ##
+ # :singleton-method:
+ # The session id field defaults to 'session_id'.
+ cattr_accessor :session_id_column
+ @@session_id_column = 'session_id'
+
+ ##
+ # :singleton-method:
+ # The data field defaults to 'data'.
+ cattr_accessor :data_column
+ @@data_column = 'data'
+
+ class << self
+ def connection
+ @@connection ||= ActiveRecord::Base.connection
+ end
+
+ # Look up a session by id and unmarshal its data if found.
+ 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
+
+ def marshal(data)
+ ActiveSupport::Base64.encode64(Marshal.dump(data)) if data
+ end
+
+ def unmarshal(data)
+ Marshal.load(ActiveSupport::Base64.decode64(data)) if data
+ end
+
+ 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
+
+ def drop_table!
+ @@connection.execute "DROP TABLE #{table_name}"
+ end
+ end
+
+ attr_reader :session_id
+ attr_writer :data
+
+ # 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.
+ def initialize(attributes)
+ @session_id, @data, @marshaled_data = attributes[:session_id], attributes[:data], attributes[:marshaled_data]
+ @new_record = @marshaled_data.nil?
+ end
+
+ def new_record?
+ @new_record
+ end
+
+ # Lazy-unmarshal session state.
+ def data
+ unless @data
+ if @marshaled_data
+ @data, @marshaled_data = self.class.unmarshal(@marshaled_data) || {}, nil
+ else
+ @data = {}
+ end
+ end
+ @data
+ end
+
+ def loaded?
+ !!@data
+ end
+
+ 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
+
+ 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
+ end
+
+ # The class used for session storage. Defaults to
+ # ActiveRecord::SessionStore::Session
+ cattr_accessor :session_class
+ self.session_class = Session
+
+ SESSION_RECORD_KEY = 'rack.session.record'.freeze
+
+ private
+ def get_session(env, sid)
+ Base.silence do
+ sid ||= generate_sid
+ session = find_session(sid)
+ env[SESSION_RECORD_KEY] = session
+ [sid, session.data]
+ end
+ end
+
+ def set_session(env, sid, session_data)
+ Base.silence do
+ record = env[SESSION_RECORD_KEY] ||= find_session(sid)
+ record.data = session_data
+ return false unless record.save
+
+ session_data = record.data
+ if session_data && session_data.respond_to?(:each_value)
+ session_data.each_value do |obj|
+ obj.clear_association_cache if obj.respond_to?(:clear_association_cache)
+ end
+ end
+ end
+
+ return true
+ end
+
+ def find_session(id)
+ @@session_class.find_by_session_id(id) ||
+ @@session_class.new(:session_id => id, :data => {})
+ end
+ end
+end
projects / feedcatcher.git / blobdiff