--- a/mercurial/revlogutils/debug.py	Wed Nov 23 19:08:27 2022 +0100
+++ b/mercurial/revlogutils/debug.py	Mon Nov 07 14:13:59 2022 -0500
@@ -216,3 +216,54 @@
         fm.plain(b'\n')
 
     fm.end()
+
+
+def dump(ui, revlog):
+    """perform the work for `hg debugrevlog --dump"""
+    # XXX seems redundant with debug index ?
+    r = revlog
+    numrevs = len(r)
+    ui.write(
+        (
+            b"# rev p1rev p2rev start   end deltastart base   p1   p2"
+            b" rawsize totalsize compression heads chainlen\n"
+        )
+    )
+    ts = 0
+    heads = set()
+
+    for rev in range(numrevs):
+        dbase = r.deltaparent(rev)
+        if dbase == -1:
+            dbase = rev
+        cbase = r.chainbase(rev)
+        clen = r.chainlen(rev)
+        p1, p2 = r.parentrevs(rev)
+        rs = r.rawsize(rev)
+        ts = ts + rs
+        heads -= set(r.parentrevs(rev))
+        heads.add(rev)
+        try:
+            compression = ts / r.end(rev)
+        except ZeroDivisionError:
+            compression = 0
+        ui.write(
+            b"%5d %5d %5d %5d %5d %10d %4d %4d %4d %7d %9d "
+            b"%11d %5d %8d\n"
+            % (
+                rev,
+                p1,
+                p2,
+                r.start(rev),
+                r.end(rev),
+                r.start(dbase),
+                r.start(cbase),
+                r.start(p1),
+                r.start(p2),
+                rs,
+                ts,
+                compression,
+                len(heads),
+                clen,
+            )
+        )