from 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) ) 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') 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 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() del m, f verify(open(TESTFN).read() == '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.") finally: try: os.unlink(TESTFN) except OSError: pass print ' Test passed' test_both()