# HG changeset patch
# User Gregory Szorc <gregory.szorc@gmail.com>
# Date 1474744950 25200
# Node ID bd6df07ccc24651faa658c753e75e365d646dac6
# Parent  973cf6c3de3061f53f586f6a308a1310c6e47fcd
perf: add perfchangegroupchangelog command

This command can be used for testing the performance of producing the
changelog portion of a changegroup.

We could use additional perf* commands for testing other parts of
changegroup. Those can be written another time, when they are needed.
(And those may want to refactor the changegroup generation API so code
can be reused.) Speaking of code reuse, yes, this command does reinvent
a small wheel. I didn't want to scope bloat to change the changegroup
API because that will invite bikeshedding.

diff -r 973cf6c3de30 -r bd6df07ccc24 contrib/perf.py
--- a/contrib/perf.py	Sat Sep 24 10:44:37 2016 -0700
+++ b/contrib/perf.py	Sat Sep 24 12:22:30 2016 -0700
@@ -25,6 +25,7 @@
 import sys
 import time
 from mercurial import (
+    changegroup,
     cmdutil,
     commands,
     copies,
@@ -279,6 +280,37 @@
     timer(d)
     fm.end()
 
+@command('perfchangegroupchangelog', formatteropts +
+         [('', 'version', '02', 'changegroup version'),
+          ('r', 'rev', '', 'revisions to add to changegroup')])
+def perfchangegroupchangelog(ui, repo, version='02', rev=None, **opts):
+    """Benchmark producing a changelog group for a changegroup.
+
+    This measures the time spent processing the changelog during a
+    bundle operation. This occurs during `hg bundle` and on a server
+    processing a `getbundle` wire protocol request (handles clones
+    and pull requests).
+
+    By default, all revisions are added to the changegroup.
+    """
+    cl = repo.changelog
+    revs = [cl.lookup(r) for r in repo.revs(rev or 'all()')]
+    bundler = changegroup.getbundler(version, repo)
+
+    def lookup(node):
+        # The real bundler reads the revision in order to access the
+        # manifest node and files list. Do that here.
+        cl.read(node)
+        return node
+
+    def d():
+        for chunk in bundler.group(revs, cl, lookup):
+            pass
+
+    timer, fm = gettimer(ui, opts)
+    timer(d)
+    fm.end()
+
 @command('perfdirs', formatteropts)
 def perfdirs(ui, repo, **opts):
     timer, fm = gettimer(ui, opts)
diff -r 973cf6c3de30 -r bd6df07ccc24 tests/test-contrib-perf.t
--- a/tests/test-contrib-perf.t	Sat Sep 24 10:44:37 2016 -0700
+++ b/tests/test-contrib-perf.t	Sat Sep 24 12:22:30 2016 -0700
@@ -53,6 +53,8 @@
    perfbranchmap
                  benchmark the update of a branchmap
    perfcca       (no help text available)
+   perfchangegroupchangelog
+                 Benchmark producing a changelog group for a changegroup.
    perfchangeset
                  (no help text available)
    perfctxfiles  (no help text available)
@@ -112,6 +114,7 @@
   $ hg perfannotate a
   $ hg perfbranchmap
   $ hg perfcca
+  $ hg perfchangegroupchangelog
   $ hg perfchangeset 2
   $ hg perfctxfiles 2
   $ hg perfdiffwd