Mercurial > hg
view mercurial/txnutil.py @ 51758:421c9b3f2f4e
commit: set whole manifest entries at once (node with its associated flags)
Add a new function manifest.set that sets whole manifest entries at once,
so the caller doesn't have to do two separate operations:
m[p] = n
m.set_flags(f)
becomes:
m.set(p, n, f)
This obviously saves an extra lookup by path, and it also lets the
underlying manifest implementation to be more efficient as
it doesn't have to deal with partially-specified entries.
It makes the interaction conceptually simpler, as well, since we don't
have to go through an intermediate state of incorrect
partially-written entry.
(the real motivation for this change is an alternative manifest
implementation where we batch pending writes, and dealing with
fully defined entries makes the batching logic muchsimpler while
avoiding slowdown due to alternating writes and reads)
author | Arseniy Alekseyev <aalekseyev@janestreet.com> |
---|---|
date | Thu, 01 Aug 2024 13:38:31 +0100 |
parents | 2e726c934fcd |
children | f4733654f144 |
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# txnutil.py - transaction related utilities # # Copyright FUJIWARA Katsunori <foozy@lares.dti.ne.jp> and others # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from . import encoding def mayhavepending(root): """return whether 'root' may have pending changes, which are visible to this process. """ return root == encoding.environ.get(b'HG_PENDING') def trypending(root, vfs, filename, **kwargs): """Open file to be read according to HG_PENDING environment variable This opens '.pending' of specified 'filename' only when HG_PENDING is equal to 'root'. This returns '(fp, is_pending_opened)' tuple. """ if mayhavepending(root): try: return (vfs(b'%s.pending' % filename, **kwargs), True) except FileNotFoundError: pass return (vfs(filename, **kwargs), False)