revlog: move censor logic out of censor extension
The censor extension is doing very low-level things with revlogs.
It is fundamentally impossible for this logic to remain in the censor
extension while support multiple storage backends: we need each
storage backend to implement censor in its own storage-specific
way.
This commit effectively moves the revlog-specific censoring code to
be a method of revlogs themselves.
We've defined a new API on the file storage interface for censoring
an individual node. Even though the current censoring code doesn't
use it, the API requires a transaction instance because it logically
makes sense for storage backends to require an active transaction
(which implies a held write lock) in order to rewrite storage.
After this commit, the censor extension has been reduced to
boilerplate precondition checking before invoking the generic
storage API.
I tried to keep the code as similar as possible. But some minor
changes were made:
* We use self._io instead of instantiating a new revlogio instance.
* We compare self.version against REVLOGV0 instead of != REVLOGV1
because presumably all future revlog versions will support censoring.
* We use self.opener instead of going through repo.svfs (we don't have
a handle on the repo instance from a revlog).
* "revlog" dropped
* Replace "flog" with "self".
Differential Revision: https://phab.mercurial-scm.org/D4656
from __future__ import absolute_import, print_function
import sys
globalvars = {}
lines = sys.stdin.readlines()
while lines:
l = lines.pop(0)
if l.startswith('SALT'):
print(l[:-1])
elif l.startswith('>>> '):
snippet = l[4:]
while lines and lines[0].startswith('... '):
l = lines.pop(0)
snippet += l[4:]
c = compile(snippet, '<heredoc>', 'single')
try:
exec(c, globalvars)
except Exception as inst:
print(repr(inst))