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

# Skip test if we can't import mmap.
mmap = import_module('mmap')

PAGESIZE = mmap.PAGESIZE

class MmapTests(unittest.TestCase):

    def setUp(self):
        if os.path.exists(TESTFN):
            os.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, 'bw+')
        try:
            # Write 2 pages worth of data to the file
            f.write(b'\0'* PAGESIZE)
            f.write(b'foo')
            f.write(b'\0'* (PAGESIZE-3) )
            f.flush()
            m = mmap.mmap(f.fileno(), 2 * PAGESIZE)
        finally:
            f.close()

        # Simple sanity checks

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

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

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

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

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

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

        m.flush()

        # Test doing a regular expression match in an mmap'ed file
        match = re.search(b'[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)
            try:
                f.seek(0, 2)
                self.assertEqual(f.tell(), 512)
            finally:
                f.close()
            self.assertEqual(m.size(), 512)

        m.close()

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

        # Ensuring that readonly mmap can't be slice assigned
        try:
            m[:] = b'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'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(b'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(b'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()
        del m, f
        self.assertEqual(open(TESTFN, "rb").read(), b'a'*mapsize,
               "Readonly memory map data file was modified")

        # Opening mmap with size too big
        import sys
        f = open(TESTFN, "r+b")
        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'):
                self.fail("Opening mmap with size+1 should raise ValueError.")
            m.close()
        f.close()
        if sys.platform.startswith('win'):
            # Repair damage from the resizing test.
            f = open(TESTFN, 'r+b')
            f.truncate(mapsize)
            f.close()

        # Opening mmap with access=ACCESS_WRITE
        f = open(TESTFN, "r+b")
        m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_WRITE)
        # Modifying write-through memory map
        m[:] = b'c'*mapsize
        self.assertEqual(m[:], b'c'*mapsize,
               "Write-through memory map memory not updated properly.")
        m.flush()
        m.close()
        f.close()
        f = open(TESTFN, 'rb')
        stuff = f.read()
        f.close()
        self.assertEqual(stuff, b'c'*mapsize,
               "Write-through me
mory map data file not updated properly.")

        # Opening mmap with access=ACCESS_COPY
        f = open(TESTFN, "r+b")
        m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_COPY)
        # Modifying copy-on-write memory map
        m[:] = b'd'*mapsize
        self.assertEqual(m[:], b'd' * mapsize,
               "Copy-on-write memory map data not written correctly.")
        m.flush()
        self.assertEqual(open(TESTFN, "rb").read(), b'c'*mapsize,
 
              "Copy-on-write test data file should not be modified.")
        # Ensuring copy-on-write maps cannot be resized
        self.assertRaises(TypeError, m.resize, 2*mapsize)
        f.close()
        del m, f

        # Ensuring invalid access parameter raises exception
        f = open(TESTFN, "r+b")
        self.assertRaises(ValueError, mmap.mmap, f.fileno(), mapsize, access=4)
        f.close()

        if os.name == "posix":
            # Try incompatible flags, prot and access parameters.
            f = open(TESTFN, "r+b")
            self.assertRaises(ValueError, mmap.mmap, f.fileno(), mapsize,
                              flags=mmap.MAP_PRIVATE,
                              prot=mmap.PROT_READ, access=mmap.ACCESS_WRITE)
            f.close()

            # Try writing with PROT_EXEC and without PROT_WRITE
            prot = mmap.PROT_READ | getattr(mmap, 'PROT_EXEC', 0)
            with open(TESTFN, "r+b") as f:
                m = mmap.mmap(f.fileno(