from __future__ import absolute_import

import copy

import errno

import tempfile

import types

import unittest

import silenttestrunner

from mercurial import (

    encoding,

    error,

    lock,

    vfs as vfsmod,

)

testlockname = b'testlock'

# work around http://bugs.python.org/issue1515

if types.MethodType not in copy._deepcopy_dispatch:

    def _deepcopy_method(x, memo):

        return type(x)(x.__func__, copy.deepcopy(x.__self__, memo), x.im_class)

    copy._deepcopy_dispatch[types.MethodType] = _deepcopy_method

class lockwrapper(lock.lock):

    def __init__(self, pidoffset, *args, **kwargs):

        # lock.lock.__init__() calls lock(), so the pidoffset assignment needs

        # to be earlier

        self._pidoffset = pidoffset

        super(lockwrapper, self).__init__(*args, **kwargs)

    def _getpid(self):

        return super(lockwrapper, self)._getpid() + self._pidoffset

class teststate(object):

    def __init__(self, testcase, dir, pidoffset=0):

        self._testcase = testcase

        self._acquirecalled = False

        self._releasecalled = False

        self._postreleasecalled = False

        self.vfs = vfsmod.vfs(dir, audit=False)

        self._pidoffset = pidoffset

    def makelock(self, *args, **kwargs):

        l = lockwrapper(

            self._pidoffset,

            self.vfs,

            testlockname,

            releasefn=self.releasefn,

            acquirefn=self.acquirefn,

            *args,

            **kwargs

        )

        l.postrelease.append(self.postreleasefn)

        return l

    def acquirefn(self):

        self._acquirecalled = True

    def releasefn(self):

        self._releasecalled = True

    def postreleasefn(self, success):

        self._postreleasecalled = True

    def assertacquirecalled(self, called):

        self._testcase.assertEqual(

            self._acquirecalled,

            called,

            'expected acquire to be %s but was actually %s'

            % (

                self._tocalled(called),

                self._tocalled(self._acquirecalled),

            ),

        )

    def resetacquirefn(self):

        self._acquirecalled = False

    def assertreleasecalled(self, called):

        self._testcase.assertEqual(

            self._releasecalled,

            called,

            'expected release to be %s but was actually %s'

            % (

                self._tocalled(called),

                self._tocalled(self._releasecalled),

            ),

        )

    def assertpostreleasecalled(self, called):

        self._testcase.assertEqual(

            self._postreleasecalled,

            called,

            'expected postrelease to be %s but was actually %s'

            % (

                self._tocalled(called),

                self._tocalled(self._postreleasecalled),

            ),

        )

    def assertlockexists(self, exists):

        actual = self.vfs.lexists(testlockname)

        self._testcase.assertEqual(

            actual,

            exists,

            'expected lock to %s but actually did %s'

            % (

                self._toexists(exists),

                self._toexists(actual),

            ),

        )

    def _tocalled(self, called):

        if called:

            return 'called'

        else:

            return 'not called'

    def _toexists(self, exists):

        if exists:

            return 'exist'

        else:

            return 'not exist'

class testlock(unittest.TestCase):

    def testlock(self):

        state = teststate(self, tempfile.mkdtemp(dir=encoding.getcwd()))

        lock = state.makelock()

        state.assertacquirecalled(True)

        lock.release()

        state.assertreleasecalled(True)

        state.assertpostreleasecalled(True)

        state.assertlockexists(False)

    def testrecursivelock(self):

        state = teststate(self, tempfile.mkdtemp(dir=encoding.getcwd()))

        lock = state.makelock()

        state.assertacquirecalled(True)

        state.resetacquirefn()

        lock.lock()

        # recursive lock should not call acquirefn again

        state.assertacquirecalled(False)

        lock.release()  # brings lock refcount down from 2 to 1

        state.assertreleasecalled(False)

        state.assertpostreleasecalled(False)

        state.assertlockexists(True)

        lock.release()  # releases the lock

        state.assertreleasecalled(True)

        state.assertpostreleasecalled(True)

        state.assertlockexists(False)

    def testlockfork(self):

        state = teststate(self, tempfile.mkdtemp(dir=encoding.getcwd()))

        lock = state.makelock()

        state.assertacquirecalled(True)

        # fake a fork

        forklock = copy.copy(lock)

        forklock._pidoffset = 1

        forklock.release()

        state.assertreleasecalled(False)

        state.assertpostreleasecalled(False)

        state.assertlockexists(True)

        # release the actual lock

        lock.release()

        state.assertreleasecalled(True)

        state.assertpostreleasecalled(True)

        state.assertlockexists(False)

    def testfrequentlockunlock(self):

        """This tests whether lock acquisition fails as expected, even if

        (1) lock can't be acquired (makelock fails by EEXIST), and

        (2) locker info can't be read in (readlock fails by ENOENT) while

        retrying 5 times.

        """

        d = tempfile.mkdtemp(dir=encoding.getcwd())

        state = teststate(self, d)

        def emulatefrequentlock(*args):

            raise OSError(errno.EEXIST, "File exists")

        def emulatefrequentunlock(*args):

            raise OSError(errno.ENOENT, "No such file or directory")

        state.vfs.makelock = emulatefrequentlock

        state.vfs.readlock = emulatefrequentunlock

        try:

            state.makelock(timeout=0)

            self.fail("unexpected lock acquisition")

        except error.LockHeld as why:

            self.assertTrue(why.errno == errno.ETIMEDOUT)

            self.assertTrue(why.locker == b"")

            state.assertlockexists(False)

if __name__ == '__main__':

    silenttestrunner.main(__name__)