cpython/Lib/test/test_mmap.py

391 lines
13 KiB
Python

from test.test_support import TESTFN, run_unittest
import mmap
import unittest
import os, re
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('foo'), PAGESIZE)
self.assertEqual(len(m), 2*PAGESIZE)
self.assertEqual(m[0], 0)
self.assertEqual(m[0:3], b'\0\0\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('[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")
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 memory 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)
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()
def test_bad_file_desc(self):
# Try opening a bad file descriptor...
self.assertRaises(mmap.error, mmap.mmap, -2, 4096)
def test_tougher_find(self):
# 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, 'wb+')
data = b'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]
self.assertEqual(m.find(slice), data.find(slice))
self.assertEqual(m.find(slice + b'x'), -1)
m.close()
def test_double_close(self):
# make sure a double close doesn't crash on Solaris (Bug# 665913)
f = open(TESTFN, 'wb+')
f.write(2**16 * b'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()
def test_entire_file(self):
# test mapping of entire file by passing 0 for map length
if hasattr(os, "stat"):
f = open(TESTFN, "wb+")
f.write(2**16 * b'm') # Arbitrary character
f.close()
f = open(TESTFN, "rb+")
mf = mmap.mmap(f.fileno(), 0)
self.assertEqual(len(mf), 2**16, "Map size should equal file size.")
self.assertEqual(mf.read(2**16), 2**16 * b"m")
mf.close()
f.close()
def test_move(self):
# make move works everywhere (64-bit format problem earlier)
f = open(TESTFN, 'wb+')
f.write(b"ABCDEabcde") # Arbitrary character
f.flush()
mf = mmap.mmap(f.fileno(), 10)
mf.move(5, 0, 5)
self.assertEqual(mf[:], b"ABCDEABCDE", "Map move should have duplicated front 5")
mf.close()
f.close()
def test_anonymous(self):
# anonymous mmap.mmap(-1, PAGE)
m = mmap.mmap(-1, PAGESIZE)
for x in range(PAGESIZE):
self.assertEqual(m[x], 0,
"anonymously mmap'ed contents should be zero")
for x in range(PAGESIZE):
b = x & 0xff
m[x] = b
self.assertEqual(m[x], b)
def test_extended_getslice(self):
# Test extended slicing by comparing with list slicing.
s = bytes(reversed(range(256)))
m = mmap.mmap(-1, len(s))
m[:] = s
self.assertEqual(m[:], s)
indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
for start in indices:
for stop in indices:
# Skip step 0 (invalid)
for step in indices[1:]:
self.assertEqual(m[start:stop:step],
s[start:stop:step])
def test_extended_set_del_slice(self):
# Test extended slicing by comparing with list slicing.
s = bytes(reversed(range(256)))
m = mmap.mmap(-1, len(s))
indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
for start in indices:
for stop in indices:
# Skip invalid step 0
for step in indices[1:]:
m[:] = s
self.assertEqual(m[:], s)
L = list(s)
# Make sure we have a slice of exactly the right length,
# but with different data.
data = L[start:stop:step]
data = bytes(reversed(data))
L[start:stop:step] = data
m[start:stop:step] = data
self.assertEquals(m[:], bytes(L))
def make_mmap_file (self, f, halfsize):
# Write 2 pages worth of data to the file
f.write (b'\0' * halfsize)
f.write (b'foo')
f.write (b'\0' * (halfsize - 3))
f.flush ()
return mmap.mmap (f.fileno(), 0)
def test_offset (self):
f = open (TESTFN, 'w+b')
try: # unlink TESTFN no matter what
halfsize = mmap.ALLOCATIONGRANULARITY
m = self.make_mmap_file (f, halfsize)
m.close ()
f.close ()
mapsize = halfsize * 2
# Try invalid offset
f = open(TESTFN, "r+b")
for offset in [-2, -1, None]:
try:
m = mmap.mmap(f.fileno(), mapsize, offset=offset)
self.assertEqual(0, 1)
except (ValueError, TypeError, OverflowError):
pass
else:
self.assertEqual(0, 0)
f.close()
# Try valid offset, hopefully 8192 works on all OSes
f = open(TESTFN, "r+b")
m = mmap.mmap(f.fileno(), mapsize - halfsize, offset=halfsize)
self.assertEqual(m[0:3], b'foo')
f.close()
m.close()
finally:
f.close()
try:
os.unlink(TESTFN)
except OSError:
pass
def test_main():
run_unittest(MmapTests)
if __name__ == '__main__':
test_main()