diff mercurial/store.py @ 47234:616b8f412676

revlogv2: introduce a very basic docket file

This is the first stone toward using a docket file in revlogv2. Right now the
docket is very basic and only store the version number (which is -also- stored
into the index file…) and the other files have fixed name. This new
implementation break transactionally… but they are no test checking
transactionally for revlogv2… So I take this as an opportunity to start small.
They are no usage of revlogv2 outside of tests anyway.

The docket keeps the `.i` naming used by previous version index to preserve a
unique entry point. We could decide to use a different name and look it up
first, or to fully rework this in a future "store" version. However that does
not seems necessary right now.

We will re-introduces transactionality (and associated testing…) in a later
changesets.


A long list of TODOs have been added to the relevant comment.

Differential Revision: https://phab.mercurial-scm.org/D10624

--- a/mercurial/store.py	Mon May 17 15:05:24 2021 +0200
+++ b/mercurial/store.py	Mon May 03 12:34:11 2021 +0200
@@ -389,7 +389,7 @@
 ]
 
 REVLOG_FILES_MAIN_EXT = (b'.i', b'i.tmpcensored')
-REVLOG_FILES_OTHER_EXT = (b'.d', b'.n', b'.nd', b'd.tmpcensored')
+REVLOG_FILES_OTHER_EXT = (b'.idx', b'.d', b'.n', b'.nd', b'd.tmpcensored')
 # files that are "volatile" and might change between listing and streaming
 #
 # note: the ".nd" file are nodemap data and won't "change" but they might be
@@ -397,7 +397,7 @@
 REVLOG_FILES_VOLATILE_EXT = (b'.n', b'.nd')
 
 # some exception to the above matching
-EXCLUDED = re.compile(b'.*undo\.[^/]+\.nd?$')
+EXCLUDED = re.compile(b'.*undo\.[^/]+\.(nd?|i)$')
 
 
 def is_revlog(f, kind, st):
@@ -407,7 +407,7 @@
 
 
 def revlog_type(f):
-    if f.endswith(REVLOG_FILES_MAIN_EXT):
+    if f.endswith(REVLOG_FILES_MAIN_EXT) and EXCLUDED.match(f) is None:
         return FILEFLAGS_REVLOG_MAIN
     elif f.endswith(REVLOG_FILES_OTHER_EXT) and EXCLUDED.match(f) is None:
         t = FILETYPE_FILELOG_OTHER