repositories: implemented faster dedicated checks for empty repositories

vcsserver/git.py

@@ -129,6 +129,15 b' class GitRemote(object):'
         return params
 
     @reraise_safe_exceptions
+    def is_empty(self, wire):
+        repo = self._factory.repo(wire)
+        try:
+            return not repo.head()
+        except Exception:
+            log.exception("failed to read object_store")
+            return True
+
+    @reraise_safe_exceptions
     def add_object(self, wire, content):
         repo = self._factory.repo(wire)
         blob = objects.Blob()

vcsserver/hg.py

@@ -172,6 +172,16 b' class HgRemote(object):'
         return util.version()
 
     @reraise_safe_exceptions
+    def is_empty(self, wire):
+        repo = self._factory.repo(wire)
+
+        try:
+            return len(repo) == 0
+        except Exception:
+            log.exception("failed to read object_store")
+            return False
+
+    @reraise_safe_exceptions
     def archive_repo(self, archive_path, mtime, file_info, kind):
         if kind == "tgz":
             archiver = archival.tarit(archive_path, mtime, "gz")

vcsserver/svn.py

@@ -139,6 +139,16 b' class SvnRemote(object):'
             svn_ver = None
         return svn_ver
 
+    @reraise_safe_exceptions
+    def is_empty(self, wire):
+        repo = self._factory.repo(wire)
+
+        try:
+            return self.lookup(wire, -1) == 0
+        except Exception:
+            log.exception("failed to read object_store")
+            return False
+
     def check_url(self, url, config_items):
         # this can throw exception if not installed, but we detect this
         from hgsubversion import svnrepo