diff contrib/perf.py @ 47072:4c041c71ec01

revlog: introduce an explicit tracking of what the revlog is about

Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.

In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.

So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.

The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.

Differential Revision: https://phab.mercurial-scm.org/D10352

--- a/contrib/perf.py	Tue May 04 08:54:28 2021 -0700
+++ b/contrib/perf.py	Tue Apr 06 05:20:24 2021 +0200
@@ -66,6 +66,8 @@
 import tempfile
 import threading
 import time
+
+import mercurial.revlog
 from mercurial import (
     changegroup,
     cmdutil,
@@ -76,7 +78,6 @@
     hg,
     mdiff,
     merge,
-    revlog,
     util,
 )
 
@@ -119,6 +120,21 @@
 except ImportError:
     profiling = None
 
+try:
+    from mercurial.revlogutils import constants as revlog_constants
+
+    perf_rl_kind = (revlog_constants.KIND_OTHER, b'created-by-perf')
+
+    def revlog(opener, *args, **kwargs):
+        return mercurial.revlog.revlog(opener, perf_rl_kind, *args, **kwargs)
+
+
+except (ImportError, AttributeError):
+    perf_rl_kind = None
+
+    def revlog(opener, *args, **kwargs):
+        return mercurial.revlog.revlog(opener, *args, **kwargs)
+
 
 def identity(a):
     return a
@@ -1809,7 +1825,8 @@
 
     mercurial.revlog._prereadsize = 2 ** 24  # disable lazy parser in old hg
     n = scmutil.revsingle(repo, rev).node()
-    cl = mercurial.revlog.revlog(getsvfs(repo), b"00changelog.i")
+
+    cl = revlog(getsvfs(repo), indexfile=b"00changelog.i")
 
     def d():
         cl.rev(n)
@@ -2602,9 +2619,9 @@
     else:
         raise error.Abort(b'unsupported revlog version: %d' % version)
 
-    parse_index_v1 = getattr(revlog, 'parse_index_v1', None)
+    parse_index_v1 = getattr(mercurial.revlog, 'parse_index_v1', None)
     if parse_index_v1 is None:
-        parse_index_v1 = revlog.revlogio().parseindex
+        parse_index_v1 = mercurial.revlog.revlogio().parseindex
 
     rllen = len(rl)
 
@@ -2620,7 +2637,7 @@
     allnodesrev = list(reversed(allnodes))
 
     def constructor():
-        revlog.revlog(opener, indexfile)
+        revlog(opener, indexfile=indexfile)
 
     def read():
         with opener(indexfile) as fh:
@@ -3042,7 +3059,7 @@
         vfs = vfsmod.vfs(tmpdir)
         vfs.options = getattr(orig.opener, 'options', None)
 
-        dest = revlog.revlog(
+        dest = revlog(
             vfs, indexfile=indexname, datafile=dataname, **revlogkwargs
         )
         if dest._inline: