verify: introduce a notion of "level"

verify: introduce a notion of "level"

Some checks are slower than others, to help the user to run the checks he needs,
we are about to introduce new flag to select faster vs deeper runs. This put
the scaffolding in place to do this.

--- a/mercurial/hg.py	Sat Apr 13 23:18:56 2019 -0700
+++ b/mercurial/hg.py	Wed Apr 17 01:12:21 2019 +0200
@@ -1092,9 +1092,9 @@
     recurse()
     return 0 # exit code is zero since we found outgoing changes
 
-def verify(repo):
+def verify(repo, level=None):
     """verify the consistency of a repository"""
-    ret = verifymod.verify(repo)
+    ret = verifymod.verify(repo, level=level)
 
     # Broken subrepo references in hidden csets don't seem worth worrying about,
     # since they can't be pushed/pulled, and --hidden can be used if they are a

--- a/mercurial/verify.py	Sat Apr 13 23:18:56 2019 -0700
+++ b/mercurial/verify.py	Wed Apr 17 01:12:21 2019 +0200
@@ -22,9 +22,12 @@
     util,
 )
 
-def verify(repo):
+VERIFY_DEFAULT = 0
+
+def verify(repo, level=None):
     with repo.lock():
-        return verifier(repo).verify()
+        v = verifier(repo, level)
+        return v.verify()
 
 def _normpath(f):
     # under hg < 2.4, convert didn't sanitize paths properly, so a
@@ -34,10 +37,13 @@
     return f
 
 class verifier(object):
-    def __init__(self, repo):
+    def __init__(self, repo, level=None):
         self.repo = repo.unfiltered()
         self.ui = repo.ui
         self.match = repo.narrowmatch()
+        if level is None:
+            level = VERIFY_DEFAULT
+        self._level = level
         self.badrevs = set()
         self.errors = 0
         self.warnings = 0