redis_sessions.py, thanks Niphlod

VERSION

@@ -1 +1 @@
-Version 2.1.0 (2012-10-08 22:09:18) dev
+Version 2.1.0 (2012-10-09 14:36:06) dev

gluon/contrib/redis_session.py

@@ -0,0 +1,198 @@
+"""
+Developed by niphlod@gmail.com
+"""
+
+import redis
+from redis.exceptions import ConnectionError
+from gluon import current
+from gluon.storage import Storage
+import cPickle as pickle
+import time
+import re
+import logging
+import thread
+
+logger = logging.getLogger("web2py.session.redis")
+
+locker = thread.allocate_lock()
+
+def RedisSession(*args, **vars):
+    """
+    Usage example: put in models
+
+    sessiondb = RedisSession('localhost:6379',db=0, debug=True)
+    session.connect(request, response, db = sessiondb)
+
+    Simple slip-in storage for session
+    """
+
+    locker.acquire()
+    try:
+        if not hasattr(RedisSession, 'redis_instance'):
+            RedisSession.redis_instance = RedisClient(*args, **vars)
+    finally:
+        locker.release()
+    return RedisSession.redis_instance
+
+
+class RedisClient(object):
+
+    meta_storage = {}
+    MAX_RETRIES = 5
+    RETRIES = 0
+
+    def __init__(self, server='localhost:6379', db=None, debug=False, session_expiry=False):
+        """session_expiry can be an integer, in seconds, to set the default expiration
+           of sessions. The corresponding record will be deleted from the redis instance,
+           and there's virtually no need to run sessions2trash.py
+        """
+        self.server = server
+        self.db = db or 0
+        host,port = (self.server.split(':')+['6379'])[:2]
+        port = int(port)
+        self.debug = debug
+        if current and current.request:
+            self.app = current.request.application
+        else:
+            self.app = ''
+        self.r_server = redis.Redis(host=host, port=port, db=self.db)
+        self.tablename = None
+        self.session_expiry = session_expiry
+
+    def get(self, what, default):
+        return self.tablename
+
+    def Field(self, fieldname, type='string', length=None, default=None,
+              required=False,requires=None):
+        return None
+
+    def define_table(self,tablename,*fields,**args):
+        if not self.tablename:
+            self.tablename = MockTable(self, self.r_server, tablename, self.session_expiry)
+        return self.tablename
+
+    def __getitem__(self, key):
+        return self.tablename
+
+    def __call__(self, where=''):
+        q = self.tablename.query
+        return q
+
+    def commit(self):
+        #this is only called by session2trash.py
+        pass
+
+class MockTable(object):
+
+    def __init__(self, db, r_server, tablename, session_expiry):
+        self.db = db
+        self.r_server = r_server
+        self.tablename = tablename
+        #set the namespace for sessions of this app
+        self.keyprefix = 'w2p:sess:%s' % tablename.replace('web2py_session_', '')
+        #fast auto-increment id (needed for session handling)
+        self.serial = "%s:serial" % self.keyprefix
+        #index of all the session keys of this app
+        self.id_idx = "%s:id_idx" % self.keyprefix
+        #remember the session_expiry setting
+        self.session_expiry = session_expiry
+
+    def getserial(self):
+        #return an auto-increment id
+        return "%s" % self.r_server.incr(self.serial, 1)
+
+    def __getattr__(self, key):
+        if key == 'id':
+            #return a fake query. We need to query it just by id for normal operations
+            self.query = MockQuery(field='id', db=self.r_server, prefix=self.keyprefix, session_expiry=self.session_expiry)
+            return self.query
+        elif key == '_db':
+            #needed because of the calls in sessions2trash.py and globals.py
+            return self.db
+
+    def insert(self, **kwargs):
+        #usually kwargs would be a Storage with several keys:
+        #'locked', 'client_ip','created_datetime','modified_datetime'
+        #'unique_key', 'session_data'
+        #retrieve a new key
+        newid = self.getserial()
+        key = "%s:%s" % (self.keyprefix, newid)
+        #add it to the index
+        self.r_server.sadd(self.id_idx, key)
+        #set a hash key with the Storage
+        self.r_server.hmset(key, kwargs)
+        if self.session_expiry:
+            self.r_server.expire(key, self.session_expiry)
+        return newid
+
+class MockQuery(object):
+    """a fake Query object that supports querying by id
+       and listing all keys. No other operation is supported 
+    """
+    def __init__(self, field=None, db=None, prefix=None, session_expiry=False):
+        self.field = field
+        self.value = None
+        self.db = db
+        self.keyprefix = prefix
+        self.op = None
+        self.session_expiry = session_expiry
+
+    def __eq__(self, value, op='eq'):
+        self.value = value
+        self.op = op
+
+    def __gt__(self, value, op='ge'):
+        self.value = value
+        self.op = op
+
+    def select(self):
+        if self.op == 'eq' and self.field == 'id' and self.value:
+            #means that someone wants to retrieve the key self.value
+            rtn = self.db.hgetall("%s:%s" % (self.keyprefix, self.value))
+            if rtn == dict():
+                #return an empty resultset for non existing key
+                return []
+            else:
+                return [Storage(rtn)]
+        elif self.op == 'ge' and self.field == 'id' and self.value == 0:
+            #means that someone wants the complete list
+            rtn = []
+            id_idx = "%s:id_idx" % self.keyprefix
+            #find all session keys of this app
+            allkeys = self.db.smembers(id_idx)
+            for sess in allkeys:
+                val = self.db.hgetall(sess)
+                if val == dict():
+                    if self.session_expiry:
+                        #clean up the idx, because the key expired
+                        self.db.srem(id_idx, sess)
+                        continue
+                    else:
+                        continue
+                val = Storage(val)
+                #add a delete_record method (necessary for sessions2trash.py)
+                val.delete_record = RecordDeleter(self.db, sess, self.keyprefix)
+                rtn.append(val)
+            return rtn
+        else:
+            raise Exception("Operation not supported")
+
+    def update(self, **kwargs):
+        #means that the session has been found and needs an update
+        if self.op == 'eq' and self.field == 'id' and self.value:
+            return self.db.hmset("%s:%s" % (self.keyprefix, self.value), kwargs)
+
+class RecordDeleter(object):
+    """Dumb record deleter to support sessions2trash.py"""
+    
+    def __init__(self, db, key, keyprefix):
+        self.db, self.key, self.keyprefix = db, key, keyprefix
+        
+    def __call__(self):
+        id_idx = "%s:id_idx" % self.keyprefix
+        #remove from the index
+        self.db.srem(id_idx, self.key)
+        #remove the key itself
+        self.db.delete(self.key)
+        
+    

scripts/sessions2trash.py

@@ -94,11 +94,11 @@ class SessionSetDb(SessionSet):
         """Return list of SessionDb instances for existing sessions."""
         sessions = []
         tablename = 'web2py_session'
-        if request.application:
-            tablename = 'web2py_session_' + request.application
-        if tablename in db:
-            for row in db(db[tablename].id > 0).select():
-                sessions.append(SessionDb(row))
+        from gluon import current
+        (record_id_name, table, record_id, unique_key) = \
+            current.response._dbtable_and_field
+        for row in table._db(table.id > 0).select():
+            sessions.append(SessionDb(row))
         return sessions
 
 
@@ -121,8 +121,11 @@ class SessionDb(object):
         self.row = row
 
     def delete(self):
+        from gluon import current
+        (record_id_name, table, record_id, unique_key) = \
+            current.response._dbtable_and_field
         self.row.delete_record()
-        db.commit()
+        table._db.commit()
 
     def get(self):
         session = Storage()
@@ -130,7 +133,13 @@ class SessionDb(object):
         return session
 
     def last_visit_default(self):
-        return self.row.modified_datetime
+        if isinstance(self.row.modified_datetime, datetime.datetime):
+            return self.row.modified_datetime
+        else:
+            try:
+                return datetime.datetime.strptime(self.row.modified_datetime, '%Y-%m-%d %H:%M:%S.%f')
+            except:
+                print 'failed to retrieve last modified time (value: %s)' % self.row.modified_datetime
 
     def __str__(self):
         return self.row.unique_key