data = {}
set_pickle_by_oid = data.__setitem__
get_pickle_by_oid = data.__getitem__

class HTML5Storage(object):
    __name__ = "HTML5Storage"
    
    def __init__(self):
        self._oid = id("new-randomish-number")
        self._to_store = {}
    
    def getName(self):
        return self.__name__
    
    def getSize(self):
        return len(`self._to_store`)
    
    def getTid(self, oid):
        return 0
    
    def history(self, oid, size=None):
        return []
    
    def isReadOnly(self):
        return False
    
    def lastTransaction(self):
        return '0'*8
    
    def __len__(self):
        return len(self._to_store)
    
    def load(self, oid, version=''):
        try:
            return get_pickle_by_oid(oid), '0'*8
        except:
            raise KeyError#raise ZODB.POSException.POSKeyError(oid)
    
    def loadBefore(self, oid, tid):
        raise NotImplementedError
    
    def loadSerial(self, oid, serial):
        return self.load(oid)
    
    def new_oid(self):
        self.oid += 1
    
    def pack(self, t, references, gc=True):
        # Packing isn't supported
        raise NotImplementedError
    
    def registerDB(self, db):
        pass
    
    def sortKey(self):
        return self.__name__
    
    def store(self, oid, serial, data, version, transaction):
        self._to_store[oid] = data
        return '0'*8
    
    def tpc_abort(self, transaction):
        self._to_store = {}
    
    def tpc_begin(self, transaction, tid=None):
        self._to_store = {}
    
    def tpc_finish(self, transaction, func = lambda tid: None):
        for oid in self._to_store:
            set_pickle_by_oid(oid, self._to_store[oid])
        self._to_store = {}
    
    def tpc_transaction(self):
        return None
    
    def tpc_vote(self, transaction):
        pass
    
def dodgy_encode(string):
    return ("x".join(map(str,map(ord, string))))

def dump_db():
    s = "ZODB|{"
    for key, value in data.items():
        s += ' '.join([`dodgy_encode(key)`, ':', `value`.replace("\\","\\\\")])
    s += "}|"
    return s.replace("'", "\"")

def load_db(val):
    for key, value in val.items():
        try:
            key = ''.join(map(chr, map(int, key.split("x"))))
        except:
            continue # irrelevant item, skip
        value = eval('"""%s"""'%value)
        data[key] = value

from ZODB.DB import DB
storage = HTML5Storage()
db = DB(storage)
conn = db.open()
root = conn.root()

import transaction
oldcommit = transaction.commit
def newcommit():
    res = oldcommit()
    print dump_db()
    return res
transaction.commit = newcommit