from test.test_support import (TESTFN, run_unittest, import_module, unlink,
                               requires, _2G, _4G)
import unittest
import os, re, itertools, socket, sys

mmap = import_module('mmap')

PAGESIZE = mmap.PAGESIZE

class MmapTests(unittest.TestCase):

    def setUp(self):
        if os.path.exists(TESTFN):
            unlink(TESTFN)

    def tearDown(self):
        try:
            os.unlink(TESTFN)
        except OSError:
            pass

    def test_basic(self):
        # Test mmap module on Unix systems and Windows

        # Create a file to be mmap'ed.
        f = open(TESTFN, 'w+')
        try:
            # Write 2 pages worth of data to the file
            f.write('\0'* PAGESIZE)
            f.write('foo')
            f.write('\0'* (PAGESIZE-3) )
            f.flush()
            m = mmap.mmap(f.fileno(), 2 * PAGESIZE)
            f.close()

            # Simple sanity checks

            tp = str(type(m))  # SF bug 128713:  segfaulted on Linux
            self.assertEqual(m.find('foo'), PAGESIZE)

            self.assertEqual(len(m), 2*PAGESIZE)

            self.assertEqual(m[0], '\0')
            self.assertEqual(m[0:3], '\0\0\0')

            # Shouldn't crash on boundary (Issue #5292)
            self.assertRaises(IndexError, m.__getitem__, len(m))
            self.assertRaises(IndexError, m.__setitem__, len(m), '\0')

            # Modify the file's content
            m[0] = '3'
            m[PAGESIZE +3: PAGESIZE +3+3] = 'bar'

            # Check that the modification worked
            self.assertEqual(m[0], '3')
            self.assertEqual(m[0:3], '3\0\0')
            self.assertEqual(m[PAGESIZE-1 : PAGESIZE + 7], '\0foobar\0')

            m.flush()

            # Test doing a regular expression match in an mmap'ed file
            match = re.search('[A-Za-z]+', m)
            if match is None:
                self.fail('regex match on mmap failed!')
            else:
                start, end = match.span(0)
                length = end - start

                self.assertEqual(start, PAGESIZE)
                self.assertEqual(end, PAGESIZE + 6)

            # test seeking around (try to overflow the seek implementation)
            m.seek(0,0)
            self.assertEqual(m.tell(), 0)
            m.seek(42,1)
            self.assertEqual(m.tell(), 42)
            m.seek(0,2)
            self.assertEqual(m.tell(), len(m))

            # Try to seek to negative position...
            self.assertRaises(ValueError, m.seek, -1)

            # Try to seek beyond end of mmap...
            self.assertRaises(ValueError, m.seek, 1, 2)

            # Try to seek to negative position...
            self.assertRaises(ValueError, m.seek, -len(m)-1, 2)

            # Try resizing map
            try:
                m.resize(512)
            except SystemError:
                # resize() not supported
                # No messages are printed, since the output of this test suite
                # would then be different across platforms.
                pass
            else:
                # resize() is supported
                self.assertEqual(len(m), 512)
                # Check that we can no longer seek beyond the new size.
                self.assertRaises(ValueError, m.seek, 513, 0)

                # Check that the underlying file is truncated too
                # (bug #728515)
                f = open(TESTFN)
                f.seek(0, 2)
                self.assertEqual(f.tell(), 512)
                f.close()
                self.assertEqual(m.size(), 512)

            m.close()

        finally:
            try:
                f.close()
            except OSError:
                pass

    def test_access_parameter(self):
        # Test for "access" keyword parameter
        mapsize = 10
        with open(TESTFN, "wb") as f:
            f.write("a"*mapsize)
        f = open(TESTFN, "rb")
        m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_READ)
        self.assertEqual(m[:], 'a'*mapsize, "Readonly memory map data incorrect.")

        # Ensuring that readonly mmap can't be slice assigned
        try:
            m[:] = 'b'*mapsize
        except TypeError:
            pass
        else:
            self.fail("Able to write to readonly memory map")

        # Ensuring that readonly mmap can't be item assigned
        try:
            m[0] = 'b'
        except TypeError:
            pass
        else:
            self.fail("Able to write to readonly memory map")

        # Ensuring that readonly mmap can't be write() to
        try:
            m.seek(0,0)
            m.write('abc')
        except TypeError:
            pass
        else:
            self.fail("Able to write to readonly memory map")

        # Ensuring that readonly mmap can't be write_byte() to
        try:
            m.seek(0,0)
            m.write_byte('d')
        except TypeError:
            pass
        else:
            self.fail("Able to write to readonly memory map")

        # Ensuring that readonly mmap can't be resized
        try:
            m.resize(2*mapsize)
        except SystemError:   # resize is not universally supported
            pass
        except TypeError:
            pass
        else:
            self.fail("Able to resize readonly memory map")
        f.close()
        m.close()
        del m, f
        with open(TESTFN, "rb") as f:
            self.assertEqual(f.read(), 'a'*mapsize,
                "Readonly memory map data file was modified")

        # Opening mmap with size too big
        import sys
        f = open(TESTFN, "r+b")
        try:
            try:
                m = mmap.mmap(f.fileno(), mapsize+1)
            except ValueError:
                # we do not expect a ValueError on Windows
                # CAUTION:  This also changes the size of the file on disk, and
                # later tests assume that the length hasn't changed.  We need to
                # repair that.
                if sys.platform.startswith('win'):
                    self.fail("Opening mmap with size+1 should work on Windows.")
            else:
                # we expect a ValueError on Unix, but not on Windows
                if not sys.platform.startswith('win'):