Skip to content

[3.13] GH-120754: Add more tests around seek + readall (GH-122103) #122215

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
hauntsaninja merged 1 commit into from
Jul 24, 2024
Merged

[3.13] GH-120754: Add more tests around seek + readall (GH-122103) #122215

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
GH-120754: Add more tests around seek + readall (GH-122103) 
In the process of speeding up readall, A number of related tests
(ex. large file tests in test_zipfile) found problems with the
change I was making. This adds I/O tests to specifically test these
cases to help ensure they don't regress and hopefully make debugging
easier.

This is part of the improvements from
https://github.com/python/cpython/pull/121593GH-issuecomment-2222261986
(cherry picked from commit 9eb7341)

Co-authored-by: Cody Maloney <cmaloney@users.noreply.github.com>
  • Loading branch information
@cmaloney @miss-islington
cmaloney authored and miss-islington committed Jul 24, 2024
commit 3ffccc7da1331d4072d92cf239d1647b6593fd67
19 changes: 19 additions & 0 deletions Lib/test/test_largefile.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -141,6 +141,9 @@ def test_truncate(self):
f.truncate(1)
self.assertEqual(f.tell(), 0) # else pointer moved
f.seek(0)
# Verify readall on a truncated file is well behaved. read()
# without a size can be unbounded, this should get just the byte
# that remains.
self.assertEqual(len(f.read()), 1) # else wasn't truncated

def test_seekable(self):
Expand All @@ -151,6 +154,22 @@ def test_seekable(self):
f.seek(pos)
self.assertTrue(f.seekable())

@bigmemtest(size=size, memuse=2, dry_run=False)
def test_seek_readall(self, _size):
# Seek which doesn't change position should readall successfully.
with self.open(TESTFN, 'rb') as f:
self.assertEqual(f.seek(0, os.SEEK_CUR), 0)
self.assertEqual(len(f.read()), size + 1)

# Seek which changes (or might change) position should readall
# successfully.
with self.open(TESTFN, 'rb') as f:
self.assertEqual(f.seek(20, os.SEEK_SET), 20)
self.assertEqual(len(f.read()), size - 19)

with self.open(TESTFN, 'rb') as f:
self.assertEqual(f.seek(-3, os.SEEK_END), size - 2)
self.assertEqual(len(f.read()), 3)

def skip_no_disk_space(path, required):
def decorator(fun):
Expand Down