Add flush_client method and fix RepositoryClientNotLocked instance

This may be used to force any in-memory caches for an open client in a
repository to be written out, and then dropped, to reduct memory use.
Only green-albatross implements this, for now.

4 files changed, 21 insertions, 1 deletions

diff --git a/obnamlib/delegator.py b/obnamlib/delegator.py
index baad29fd..e5cf9b66 100644
--- a/obnamlib/delegator.py
+++ b/obnamlib/delegator.py
@@ -171,7 +171,12 @@ class RepositoryDelegator(obnamlib.RepositoryInterface):
 
     def _require_got_client_lock(self, client_name):
         if not self.got_client_lock(client_name):
-            raise obnamlib.RepositoryClientNotLocked()
+            raise obnamlib.RepositoryClientNotLocked(client_name=client_name)
+
+    def flush_client(self, client_name):
+        self._require_got_client_lock(client_name)
+        client = self._lookup_client(client_name)
+        client.flush()
 
     def commit_client(self, client_name):
         self._require_got_client_lock(client_name)
diff --git a/obnamlib/fmt_ga/client.py b/obnamlib/fmt_ga/client.py
index d29c85a6..85417d04 100644
--- a/obnamlib/fmt_ga/client.py
+++ b/obnamlib/fmt_ga/client.py
@@ -74,6 +74,9 @@ class GAClient(object):
     def get_dirname(self):
         return self._dirname
 
+    def flush(self):
+        self._save_file_metadata()
+
     def commit(self):
         self._load_data()
         self._finish_current_generation_if_any()
diff --git a/obnamlib/plugins/backup_plugin.py b/obnamlib/plugins/backup_plugin.py
index e17d0c31..13334432 100644
--- a/obnamlib/plugins/backup_plugin.py
+++ b/obnamlib/plugins/backup_plugin.py
@@ -406,6 +406,10 @@ class BackupPlugin(obnamlib.ObnamPlugin):
                 if e.errno in (errno.ENOSPC, errno.EPIPE):
                     raise
 
+            if metadata.isdir() and not self.pretend:
+                self.repo.flush_client(self.client_name)
+                self.app.dump_memory_profile('after flushing client')
+
             if self.checkpoint_manager.time_for_checkpoint():
                 self.make_checkpoint()
                 self.progress.what(pathname)
diff --git a/obnamlib/repo_interface.py b/obnamlib/repo_interface.py
index b3744de5..f948c68e 100644
--- a/obnamlib/repo_interface.py
+++ b/obnamlib/repo_interface.py
@@ -543,6 +543,14 @@ class RepositoryInterface(object):
         '''
         raise NotImplementedError()
 
+    def flush_client(self, client_name):
+        '''Flush cached data from client. This is not a commit.
+
+        This is a NOP, unless the a specific repository format gives
+        it meaning.
+
+        '''
+
     def commit_client(self, client_name):
         '''Commit changes to client and DO NOT unlock it.