text: from test.test_support import verify, vereq, TESTFN
  import mmap
  import os, re
  
  PAGESIZE = mmap.PAGESIZE
  
  def test_both():
      "Test mmap module on Unix systems and Windows"
  
      # Create a file to be mmap'ed.
      if os.path.exists(TESTFN):
          os.unlink(TESTFN)
      f = open(TESTFN, 'w+')
  
      try:    # unlink TESTFN no matter what
          # 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
  
          print type(m)  # SF bug 128713:  segfaulted on Linux
          print '  Position of foo:', m.find('foo') / float(PAGESIZE), 'pages'
          vereq(m.find('foo'), PAGESIZE)
  
          print '  Length of file:', len(m) / float(PAGESIZE), 'pages'
          vereq(len(m), 2*PAGESIZE)
  
          print '  Contents of byte 0:', repr(m[0])
          vereq(m[0], '\0')
          print '  Contents of first 3 bytes:', repr(m[0:3])
          vereq(m[0:3], '\0\0\0')
  
          # Modify the file's content
          print "\n  Modifying file's content..."
          m[0] = '3'
          m[PAGESIZE +3: PAGESIZE +3+3] = 'bar'
  
          # Check that the modification worked
          print '  Contents of byte 0:', repr(m[0])
          vereq(m[0], '3')
          print '  Contents of first 3 bytes:', repr(m[0:3])
          vereq(m[0:3], '3\0\0')
          print '  Contents of second page:',  repr(m[PAGESIZE-1 : PAGESIZE + 7])
          vereq(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:
              print '  ERROR: regex match on mmap failed!'
          else:
              start, end = match.span(0)
              length = end - start
  
              print '  Regex match on mmap (page start, length of match):',
              print start / float(PAGESIZE), length
  
              vereq(start, PAGESIZE)
              vereq(end, PAGESIZE + 6)
  
          # test seeking around (try to overflow the seek implementation)
          m.seek(0,0)
          print '  Seek to zeroth byte'
          vereq(m.tell(), 0)
          m.seek(42,1)
          print '  Seek to 42nd byte'
          vereq(m.tell(), 42)
          m.seek(0,2)
          print '  Seek to last byte'
          vereq(m.tell(), len(m))
  
          print '  Try to seek to negative position...'
          try:
              m.seek(-1)
          except ValueError:
              pass
          else:
              verify(0, 'expected a ValueError but did not get it')
  
          print '  Try to seek beyond end of mmap...'
          try:
              m.seek(1,2)
          except ValueError:
              pass
          else:
              verify(0, 'expected a ValueError but did not get it')
  
          print '  Try to seek to negative position...'
          try:
              m.seek(-len(m)-1,2)
          except ValueError:
              pass
          else:
              verify(0, 'expected a ValueError but did not get it')
  
          # Try resizing map
          print '  Attempting resize()'
          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
              verify(len(m) == 512,
                      "len(m) is %d, but expecting 512" % (len(m),) )
              # Check that we can no longer seek beyond the new size.
              try:
                  m.seek(513,0)
              except ValueError:
                  pass
              else:
                  verify(0, 'Could seek beyond the new size')
  
              # Check that the underlying file is truncated too
              # (bug #728515)
              f = open(TESTFN)
              f.seek(0, 2)
              verify(f.tell() == 512, 'Underlying file not truncated')
              f.close()
              verify(m.size() == 512, 'New size not reflected in file')
  
          m.close()
  
      finally:
          try:
              f.close()
          except OSError:
              pass
          try:
              os.unlink(TESTFN)
          except OSError:
              pass
  
      # Test for "access" keyword parameter
      try:
          mapsize = 10
          print "  Creating", mapsize, "byte test data file."
          open(TESTFN, "wb").write("a"*mapsize)
          print "  Opening mmap with access=ACCESS_READ"
          f = open(TESTFN, "rb")
          m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_READ)
          verify(m[:] == 'a'*mapsize, "Readonly memory map data incorrect.")
  
          print "  Ensuring that readonly mmap can't be slice assigned."
          try:
              m[:] = 'b'*mapsize
          except TypeError:
              pass
          else:
              verify(0, "Able to write to readonly memory map")
  
          print "  Ensuring that readonly mmap can't be item assigned."
          try:
              m[0] = 'b'
          except TypeError:
              pass
          else:
              verify(0, "Able to write to readonly memory map")
  
          print "  Ensuring that readonly mmap can't be write() to."
          try:
              m.seek(0,0)
              m.write('abc')
          except TypeError:
              pass
          else:
              verify(0, "Able to write to readonly memory map")
  
          print "  Ensuring that readonly mmap can't be write_byte() to."
          try:
              m.seek(0,0)
              m.write_byte('d')
          except TypeError:
              pass
          else:
              verify(0, "Able to write to readonly memory map")
  
          print "  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:
              verify(0, "Able to resize readonly memory map")
          del m, f
          verify(open(TESTFN, "rb").read() == 'a'*mapsize,
                 "Readonly memory map data file was modified")
  
          print "  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'):
                  verify(0, "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'):
                  verify(0, "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()
  
          print "  Opening mmap with access=ACCESS_WRITE"
          f = open(TESTFN, "r+b")
          m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_WRITE)
          print "  Modifying write-through memory map."
          m[:] = 'c'*mapsize
          verify(m[:] == '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()
          verify(stuff == 'c'*mapsize,
                 "Write-through memory map data file not updated properly.")
  
          print "  Opening mmap with access=ACCESS_COPY"
          f = open(TESTFN, "r+b")
          m = mmap.mmap(f.fileno(), mapsize, access=mmap.ACCESS_COPY)
          print "  Modifying copy-on-write memory map."
          m[:] = 'd'*mapsize
          verify(m[:] == 'd' * mapsize,
                 "Copy-on-write memory map data not written correctly.")
          m.flush()
          verify(open(TESTFN, "rb").read() == 'c'*mapsize,
                 "Copy-on-write test data file should not be modified.")
          try:
              print "  Ensuring copy-on-write maps cannot be resized."
              m.resize(2*mapsize)
          except TypeError:
              pass
          else:
              verify(0, "Copy-on-write mmap resize did not raise exception.")
          del m, f
          try:
              print "  Ensuring invalid access parameter raises exception."
              f = open(TESTFN, "r+b")
              m = mmap.mmap(f.fileno(), mapsize, access=4)
          except ValueError:
              pass
          else:
              verify(0, "Invalid access code should have raised exception.")
  
          if os.name == "posix":
              # Try incompatible flags, prot and access parameters.
              f = open(TESTFN, "r+b")
              try:
                  m = mmap.mmap(f.fileno(), mapsize, flags=mmap.MAP_PRIVATE,
                                prot=mmap.PROT_READ, access=mmap.ACCESS_WRITE)
              except ValueError:
                  pass
              else:
                  verify(0, "Incompatible parameters should raise ValueError.")
              f.close()
      finally:
          try:
              os.unlink(TESTFN)
          except OSError:
              pass
  
      print '  Try opening a bad file descriptor...'
      try:
          mmap.mmap(-2, 4096)
      except mmap.error:
          pass
      else:
          verify(0, 'expected a mmap.error but did not get it')
  
      # Do a tougher .find() test.  SF bug 515943 pointed out that, in 2.2,
      # searching for data with embedded \0 bytes didn't work.
      f = open(TESTFN, 'w+')
  
      try:    # unlink TESTFN no matter what
          data = 'aabaac\x00deef\x00\x00aa\x00'
          n = len(data)
          f.write(data)
          f.flush()
          m = mmap.mmap(f.fileno(), n)
          f.close()
  
          for start in range(n+1):
              for finish in range(start, n+1):
                  slice = data[start : finish]
                  vereq(m.find(slice), data.find(slice))
                  vereq(m.find(slice + 'x'), -1)
          m.close()
  
      finally:
          os.unlink(TESTFN)
  
      # make sure a double close doesn't crash on Solaris (Bug# 665913)
      f = open(TESTFN, 'w+')
  
      try:    # unlink TESTFN no matter what
          f.write(2**16 * 'a') # Arbitrary character
          f.close()
  
          f = open(TESTFN)
          mf = mmap.mmap(f.fileno(), 2**16, access=mmap.ACCESS_READ)
          mf.close()
          mf.close()
          f.close()
  
      finally:
          os.unlink(TESTFN)
  
      # test mapping of entire file by passing 0 for map length
      if hasattr(os, "stat"):
          print "  Ensuring that passing 0 as map length sets map size to current file size."
          f = open(TESTFN, "w+")
  
          try:
              f.write(2**16 * 'm') # Arbitrary character
              f.close()
  
              f = open(TESTFN, "rb+")
              mf = mmap.mmap(f.fileno(), 0)
              verify(len(mf) == 2**16, "Map size should equal file size.")
              vereq(mf.read(2**16), 2**16 * "m")
              mf.close()
              f.close()
  
          finally:
              os.unlink(TESTFN)
  
      # test mapping of entire file by passing 0 for map length
      if hasattr(os, "stat"):
          print "  Ensuring that passing 0 as map length sets map size to current file size."
          f = open(TESTFN, "w+")
          try:
              f.write(2**16 * 'm') # Arbitrary character
              f.close()
  
              f = open(TESTFN, "rb+")
              mf = mmap.mmap(f.fileno(), 0)
              verify(len(mf) == 2**16, "Map size should equal file size.")
              vereq(mf.read(2**16), 2**16 * "m")
              mf.close()
              f.close()
  
          finally:
              os.unlink(TESTFN)
  
      # make move works everywhere (64-bit format problem earlier)
      f = open(TESTFN, 'w+')
  
      try:    # unlink TESTFN no matter what
          f.write("ABCDEabcde") # Arbitrary character
          f.flush()
  
          mf = mmap.mmap(f.fileno(), 10)
          mf.move(5, 0, 5)
          verify(mf[:] == "ABCDEABCDE", "Map move should have duplicated front 5")
          mf.close()
          f.close()
  
      finally:
          os.unlink(TESTFN)
  
  def test_anon():
      print "  anonymous mmap.mmap(-1, PAGESIZE)..."
      m = mmap.mmap(-1, PAGESIZE)
      for x in xrange(PAGESIZE):
          verify(m[x] == '\0', "anonymously mmap'ed contents should be zero")
  
      for x in xrange(PAGESIZE):
          m[x] = ch = chr(x & 255)
          vereq(m[x], ch)
  
  test_both()
  test_anon()
  print ' Test passed'
  