##// END OF EJS Templates
revlog: improve the robustness of the splitting process...
revlog: improve the robustness of the splitting process The previous "in-place" splitting, preserving the splitting on transaction failure had a couple of issue in case of transaction rollback: - a race windows that could still lead to a crash and data loss - it corrupted the `fncache`. So instead, we use a new approach that we summarized as "we do a backup of the inline revlog pre-split, and we restore this in case of failure". To make readers live easier, we don't overwrite the inline index file until transaction finalization. (once the transaction get into its finalization phase, it is not expected to rollback, unless some crash happens). To do so, we write the index of the split index in a temporary file that we use until transaction finalization. We also keep a backup of the initial inline file to be able to rollback the split if needed. As a result, transaction rollback cancel the split and no longer corrupt fncache. We also no longer have a small inconsistency windows where the transaction could be unrecoverable.

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__init__.py
53 lines | 1.5 KiB | text/x-python | PythonLexer
import os
import time
# work around check-code complains
#
# This is a simple log level module doing simple test related work, we can't
# import more things, and we do not need it.
environ = getattr(os, 'environ')
def wait_on_cfg(ui, cfg, timeout=10):
"""synchronize on the `cfg` config path
Use this to synchronize commands during race tests.
"""
full_config = b'sync.' + cfg
wait_config = full_config + b'-timeout'
sync_path = ui.config(b'devel', full_config)
if sync_path is not None:
timeout = ui.config(b'devel', wait_config)
ready_path = sync_path + b'.waiting'
write_file(ready_path)
wait_file(sync_path, timeout=timeout)
def _timeout_factor():
"""return the current modification to timeout"""
default = int(environ.get('HGTEST_TIMEOUT_DEFAULT', 360))
current = int(environ.get('HGTEST_TIMEOUT', default))
if current == 0:
return 1
return current / float(default)
def wait_file(path, timeout=10):
timeout *= _timeout_factor()
start = time.time()
while not os.path.exists(path):
if timeout and time.time() - start > timeout:
raise RuntimeError(b"timed out waiting for file: %s" % path)
time.sleep(0.01)
def write_file(path, content=b''):
if content:
write_path = b'%s.tmp' % path
else:
write_path = path
with open(write_path, 'wb') as f:
f.write(content)
if path != write_path:
os.rename(write_path, path)