diff mercurial/helptext/internals/requirements.txt @ 44841:526d69eeea31

upgrade: support upgrade and downgrade from persistent nodemap

The requirements is now recognised and dealt with and the associated files
properly handled.

The persistent nodemap should be ready for usage in the field now.

Differential Revision: https://phab.mercurial-scm.org/D8431

--- a/mercurial/helptext/internals/requirements.txt	Tue May 12 11:39:50 2020 +0200
+++ b/mercurial/helptext/internals/requirements.txt	Tue Apr 14 06:09:14 2020 +0200
@@ -142,3 +142,16 @@
 August 2019). The requirement will only be present on repositories
 that have opted in to this format (by having
 ``format.bookmarks-in-store=true`` set when they were created).
+
+persistent-nodemap
+==================
+
+The `nodemap` index (mapping nodeid to local revision number) is persisted on
+disk. This provides speed benefit (if the associated native code is used). The
+persistent nodemap is only used for two revlogs: the changelog and the
+manifestlog.
+
+Support for this requirement was added in Mercurial 5.5 (released August 2020).
+Note that as of 5.5, only installations compiled with the Rust extension will
+benefit from a speedup. The other installations will do the necessary work to
+keep the index up to date, but will suffer a slowdown.