ring-jdbc-single-session

change from jdbc-ring-session

A Clojure library for sginle session for ervery user JDBC backed Ring sessions.

Usage

Use the ring-jdbc-single-session.core/jdbc-store function to create a new store. The function accepts a clojure.java.jdbc datasource definition:

(ns db.core
  (:require [ring-jdbc-single-session.core :refer [jdbc-store]]))

(def db
  {:subprotocol "postgresql"
   :subname "session"
   :user "admin"
   :password "admin"})

(def key-fn :users-id)

(def store (jdbc-store key-fn db))

database configuration

The session will be stored as a byte array serialized using nippy. The table formats are shown below.

PostgeSQL:

CREATE TABLE single_session_store
(
  session_id character varying(36) NOT NULL,
  idle_timeout bigint,
  absolute_timeout bigint,
  value bytea,
  id character varying NOT NULL,
  CONSTRAINT single_session_store_pkey PRIMARY KEY (session_id),
  CONSTRAINT single_session_store_id_unique UNIQUE (id)
)

Oracle:

;; TODO

MySQL:

;;TODO

H2:

;;TODO

session store initialization

The jdbc-store function accepts an optional map with the keys called :table, :serializer and :deserializer. The :table defaults to :session_store, while the :serializer and :deserializer keys are used to specify how the session data should be serialized and deserialized for the specific database. The library will attempt to figure out the appropriate serializer/deserializer based on the connection type. MySQL, PostgeSQL and Oracle BLOB formats are supported out of the box.

(jdbc-store db {:table :sessions})

custom serialization

The serializer function accepts the session map and returns the serialized value that will be inserted in the table, eg:

(defn serialize-postgres [value]
  (nippy/freeze value))

The deserializer function receives the session value in the database and returns the deserialized session, eg:

(defn deserialize-postgres [value]
  (when value
    (nippy/thaw value)))

stale session cleanup

A cleaner thread is provided in the ring-jdbc-single-session.cleaner for removing expired sessions from the database. The idle_timeout and absolute_timeout keys are expected to be populated by the ring-session-timeout library. These keys are used by the cleaner to remove stale sessions. The cleaner can be started and stopped as follows:

(ns db.core
  (:require [ring-jdbc-single-session.cleaner :refer [start-cleaner stop-cleaner]))

(start-cleaner db)

(stop-cleaner session-cleaner)

The start-cleaner function accepts an optional map with the :interval-secs key that defaults to 60. This is the number of seconds to sleep between runs.

(start-cleaner {:interval-secs 120})

License

Copyright © 2015 zzwu

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.