ZodbFile

import os
import shutil
from tempfile import mkstemp

import transaction
from ZODB import FileStorage, DB
from ZODB.broken import find_global
from ZODB.serialize import referencesf
from persistent.list import PersistentList


class ZodbFile(object):
    def __init__(self, filename):
        self._filename = filename
        fh, self._tempname = mkstemp(prefix="MyPrefix_", suffix=".fs")
        os.close(fh)
        if filename != "":
            shutil.copyfile(self._filename, self._tempname)
        self._zodb_storage = FileStorage.FileStorage(self._tempname)
        self._zodb_db = DB(self._zodb_storage)
        self._zodb_connection = self._zodb_db.open()
        self._zodb_root = self._zodb_connection.root()
        self._bootstrap()


    def close(self):
        """ close db connection and remove temporary db files """
        transaction.abort()
        self._zodb_connection.close()
        self._zodb_root = None
        # cleanup db files in TMP dir
        for fn in (self._tempname,
                   "%s.index" % self._tempname,
                   "%s.index_tmp" % self._tempname,
                   "%s.lock" % self._tempname,
                   "%s.old" % self._tempname,
                   "%s.pack" % self._tempname,
                   "%s.tmp" % self._tempname):
            try:
               os.unlink(fn)
            except OSError:
                pass


    def dbRoot(self):
        """ return zodb root """
        return self._zodb_root


    def save(self):
        """ save temporary db to original filename """
        self.saveAs(self._filename)


    def saveAs(self, filename):
        """ save temporary db to given filename """
        transaction.commit()
        self._zodb_storage.pack(time(), referencesf)
        shutil.copyfile(self._tempname, filename)
        self._filename = filename


    def _bootstrap(self):
        """ setup internal structure of ZODB """
        root = self._zodb_root
        # do your db initialization and schema migration stuff here...