import gdbm

import unittest

import os

from test.test_support import verbose, TESTFN, run_unittest, unlink

filename = TESTFN

class TestGdbm(unittest.TestCase):

    def setUp(self):

        self.g = None

    def tearDown(self):

        if self.g is not None:

            self.g.close()

        unlink(filename)

    def test_key_methods(self):

        self.g = gdbm.open(filename, 'c')

        self.assertEqual(self.g.keys(), [])

        self.g['a'] = 'b'

        self.g['12345678910'] = '019237410982340912840198242'

        key_set = set(self.g.keys())

        self.assertEqual(key_set, frozenset(['a', '12345678910']))

        self.assert_(self.g.has_key('a'))

        key = self.g.firstkey()

        while key:

            self.assert_(key in key_set)

            key_set.remove(key)

            key = self.g.nextkey(key)

        self.assertRaises(KeyError, lambda: self.g['xxx'])

    def test_error_conditions(self):

        # Try to open a non-existent database.

        unlink(filename)

        self.assertRaises(gdbm.error, gdbm.open, filename, 'r')

        # Try to access a closed database.

        self.g = gdbm.open(filename, 'c')

        self.g.close()

        self.assertRaises(gdbm.error, lambda: self.g['a'])

        # try pass an invalid open flag

        self.assertRaises(gdbm.error, lambda: gdbm.open(filename, 'rx').close())

    def test_flags(self):

        # Test the flag parameter open() by trying all supported flag modes.

        all = set(gdbm.open_flags)

        # Test standard flags (presumably "crwn").

        modes = all - set('fsu')

        for mode in modes:

            self.g = gdbm.open(filename, mode)

            self.g.close()

        # Test additional flags (presumably "fsu").

        flags = all - set('crwn')

        for mode in modes:

            for flag in flags:

                self.g = gdbm.open(filename, mode + flag)

                self.g.close()

    def test_reorganize(self):

        self.g = gdbm.open(filename, 'c')

        size0 = os.path.getsize(filename)

        self.g['x'] = 'x' * 10000

        size1 = os.path.getsize(filename)

        self.assert_(size0 < size1)

        del self.g['x']

        # 'size' is supposed to be the same even after deleting an entry.

        self.assertEqual(os.path.getsize(filename), size1)

        self.g.reorganize()

        size2 = os.path.getsize(filename)

        self.assert_(size1 > size2 >= size0)

def test_main():

    run_unittest(TestGdbm)

if __name__ == '__main__':

    test_main()