import mmap import string, os, re, sys PAGESIZE = mmap.PAGESIZE def test_both(): "Test mmap module on Unix systems and Windows" # Create an mmap'ed file f = open('foo', 'w+') # Write 2 pages worth of data to the file f.write('\0'* PAGESIZE) f.write('foo') f.write('\0'* (PAGESIZE-3) ) m = mmap.mmap(f.fileno(), 2 * PAGESIZE) f.close() # Simple sanity checks print ' Position of foo:', string.find(m, 'foo') / float(PAGESIZE), 'pages' assert string.find(m, 'foo') == PAGESIZE print ' Length of file:', len(m) / float(PAGESIZE), 'pages' assert len(m) == 2*PAGESIZE print ' Contents of byte 0:', repr(m[0]) assert m[0] == '\0' print ' Contents of first 3 bytes:', repr(m[0:3]) assert 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]) assert m[0] == '3' print ' Contents of first 3 bytes:', repr(m[0:3]) assert m[0:3] == '3\0\0' print ' Contents of second page:', m[PAGESIZE-1 : PAGESIZE + 7] assert 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 == 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 assert start == PAGESIZE assert end == PAGESIZE + 6 # test seeking around (try to overflow the seek implementation) m.seek(0,0) print ' Seek to zeroth byte' assert m.tell() == 0 m.seek(42,1) print ' Seek to 42nd byte' assert m.tell() == 42 m.seek(0,2) print ' Seek to last byte' assert m.tell() == len(m) print ' Try to seek to negative position...' try: m.seek(-1) except ValueError: pass else: assert 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: assert 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: assert 0, 'expected a ValueError but did not get it' m.close() os.unlink("foo") print ' Test passed' test_both()