def test_simple_read_success(caplog):
caplog.set_level(logging.INFO)
texts = TwoPhaserStageTexts()
with TwoPhaserStageFiles(texts) as stage_files:
stage_files.prepare_files({WhichFiles.PRIMARY})
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.primary) == f.name
assert texts.primary == f.read()
def test_recovery_notemporary_noprimary_havebackup_writing(caplog):
caplog.set_level(logging.INFO)
texts = TwoPhaserStageTexts()
with TwoPhaserStageFiles(texts) as stage_files:
# No Temporary, No Primary, Have Backup, Writing
# --> preserve Backup but otherwise a normal commit
stage_files.prepare_files({WhichFiles.BACKUP})
with two_phase_open(stage_files.primary, 'w') as f:
assert str(stage_files.temporary) == f.name
f.write(texts.primary)
assert stage_files.primary.exists()
assert stage_files.backup.exists()
assert not stage_files.temporary.exists()
assert not stage_files.probe.exists()
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.primary) == f.name
assert texts.primary == f.read()
assert texts.backup == stage_files.backup.read_text()
def test_recovery_notemporary_noprimary_havebackup_reading(caplog):
caplog.set_level(logging.INFO)
texts = TwoPhaserStageTexts()
with TwoPhaserStageFiles(texts) as stage_files:
# No Temporary, No Primary, Have Backup, Reading
# --> read from the Backup
stage_files.prepare_files({WhichFiles.BACKUP})
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.backup) == f.name
assert texts.backup == f.read()
assert not stage_files.primary.exists()
assert stage_files.backup.exists()
assert not stage_files.temporary.exists()
def test_recovery_havetemporary_haveprimary_nobackup(caplog):
caplog.set_level(logging.INFO)
texts = TwoPhaserStageTexts()
with TwoPhaserStageFiles(texts) as stage_files:
# Have Temporary, Have Primary, No Backup --> no recovery (rollback)
stage_files.prepare_files({WhichFiles.TEMPORARY, WhichFiles.PRIMARY})
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.primary) == f.name
assert texts.primary == f.read()
assert stage_files.primary.exists()
assert not stage_files.backup.exists()
assert not stage_files.temporary.exists()
assert not stage_files.probe.exists()
def test_recovery_havetemporary_noprimary_havebackup(caplog):
caplog.set_level(logging.INFO)
texts = TwoPhaserStageTexts()
with TwoPhaserStageFiles(texts) as stage_files:
# Have Temporary, No Primary, Have Backup
# --> recover (commit)
stage_files.prepare_files({WhichFiles.TEMPORARY, WhichFiles.BACKUP})
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.primary) == f.name
assert texts.temporary == f.read()
assert stage_files.primary.exists()
assert stage_files.backup.exists()
assert not stage_files.temporary.exists()
assert not stage_files.probe.exists()
def test_simple_write_read_success(caplog):
caplog.set_level(logging.INFO)
texts = TwoPhaserStageTexts()
with TwoPhaserStageFiles(texts) as stage_files:
# First write: primary exists, backup does not
with two_phase_open(stage_files.primary, 'w') as f:
assert str(stage_files.temporary) == f.name
f.write(texts.primary)
assert stage_files.primary.exists()
assert not stage_files.backup.exists()
assert not stage_files.temporary.exists()
assert not stage_files.probe.exists()
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.primary) == f.name
assert texts.primary == f.read()
# Second write: both exist
with two_phase_open(stage_files.primary, 'w') as f:
assert str(stage_files.temporary) == f.name
f.write(texts.backup)
assert stage_files.primary.exists()
assert stage_files.backup.exists()
assert not stage_files.temporary.exists()
assert not stage_files.probe.exists()
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.primary) == f.name
assert texts.backup == f.read()
assert texts.primary == stage_files.backup.read_text()
# Third write: both exist
with two_phase_open(stage_files.primary, 'w') as f:
assert str(stage_files.temporary) == f.name
f.write(texts.temporary)
assert stage_files.primary.exists()
assert stage_files.backup.exists()
assert not stage_files.temporary.exists()
assert not stage_files.probe.exists()
with two_phase_open(stage_files.primary, 'r') as f:
assert str(stage_files.primary) == f.name
assert texts.temporary == f.read()
assert texts.backup == stage_files.backup.read_text()
def test_simple_read_failure(caplog):
caplog.set_level(logging.INFO)
with TwoPhaserStageFiles() as stage_files:
with pytest.raises(FileNotFoundError):
with two_phase_open(stage_files.primary, 'r') as f:
text = f.read()