sparse: move profile reading into core

One more step towards weaning off methods on repo instances and
moving code to core. While this function is only used once and
is simple, it needs to exist on its own so Facebook can monkeypatch
it to enable simplecache integration.

hgext/sparse.py

@@ -431,7 +431,7 b' def _wraprepo(ui, repo):'
                     visited.add(profile)
 
                     try:
-                        raw = self.getrawprofile(profile, rev)
+                        raw = sparse.readprofile(self, profile, rev)
                     except error.ManifestLookupError:
                         msg = (
                             "warning: sparse profile '%s' not found "
@@ -455,11 +455,6 b' def _wraprepo(ui, repo):'
                 includes.add('.hg*')
             return includes, excludes, profiles
 
-        def getrawprofile(self, profile, changeid):
-            # TODO add some kind of cache here because this incurs a manifest
-            # resolve and can be slow.
-            return self.filectx(profile, changeid=changeid).data()
-
         def _sparsechecksum(self, path):
             data = self.vfs.read(path)
             return hashlib.sha1(data).hexdigest()

mercurial/sparse.py

@@ -46,3 +46,10 b' def parseconfig(ui, raw):'
             current.add(line)
 
     return includes, excludes, profiles
+
+# Exists as separate function to facilitate monkeypatching.
+def readprofile(repo, profile, changeid):
+    """Resolve the raw content of a sparse profile file."""
+    # TODO add some kind of cache here because this incurs a manifest
+    # resolve and can be slow.
+    return repo.filectx(profile, changeid=changeid).data()