From: Keith Packard <keithp@keithp.com>
Date: Wed, 18 Nov 2009 02:33:42 +0000 (-0800)
Subject: Fix "too many open files" bug by closing message files when done with them.
X-Git-Tag: 0.1~465
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=d025e89ac7ccecc9a6bbea5e867fcc15589f81b5;p=notmuch.git

Fix "too many open files" bug by closing message files when done with them.

The message file header parsing code parses only enough of the file to
find the desired header fields, then it leaves the file open until the
next header parsing call or when the message is no longer in use. If a
large number of messages end up being active, this will quickly run
out of file descriptors.

Here, we add support to explicitly close the message file within a
message, (_notmuch_message_close) and call that from thread
construction code.

Signed-off-by: Keith Packard <keithp@keithp.com>

Edited-by: Carl Worth <cworth@cworth.org>:

Many portions of Keith's original patch have since been solved other
ways, (such as the code that changed the handling of the In-Reply-To
header). So the final version is clean enough that I think even Keith
would be happy to have his name on it.
---

diff --git a/lib/message.cc b/lib/message.cc
index cb902643..5f8db50f 100644
--- a/lib/message.cc
+++ b/lib/message.cc
@@ -547,6 +547,19 @@ _notmuch_message_sync (notmuch_message_t *message)
     db->replace_document (message->doc_id, message->doc);
 }
 
+/* Ensure that 'message' is not holding any file object open. Future
+ * calls to various functions will still automatically open the
+ * message file as needed.
+ */
+void
+_notmuch_message_close (notmuch_message_t *message)
+{
+    if (message->message_file) {
+	notmuch_message_file_close (message->message_file);
+	message->message_file = NULL;
+    }
+}
+
 /* Add a name:value term to 'message', (the actual term will be
  * encoded by prefixing the value with a short prefix). See
  * NORMAL_PREFIX and BOOLEAN_PREFIX arrays for the mapping of term
diff --git a/lib/notmuch-private.h b/lib/notmuch-private.h
index c398c80a..ddf0674a 100644
--- a/lib/notmuch-private.h
+++ b/lib/notmuch-private.h
@@ -207,6 +207,9 @@ _notmuch_message_set_date (notmuch_message_t *message,
 void
 _notmuch_message_sync (notmuch_message_t *message);
 
+void
+_notmuch_message_close (notmuch_message_t *message);
+
 /* index.cc */
 
 notmuch_status_t
diff --git a/lib/thread.cc b/lib/thread.cc
index e38a5b2e..baa9e7e8 100644
--- a/lib/thread.cc
+++ b/lib/thread.cc
@@ -207,6 +207,7 @@ _notmuch_thread_create (void *ctx,
     const char *thread_id_query_string, *matched_query_string;
     notmuch_query_t *thread_id_query, *matched_query;
     notmuch_messages_t *messages;
+    notmuch_message_t *message;
 
     thread_id_query_string = talloc_asprintf (ctx, "thread:%s", thread_id);
     if (unlikely (query_string == NULL))
@@ -263,7 +264,9 @@ _notmuch_thread_create (void *ctx,
 	 notmuch_messages_has_more (messages);
 	 notmuch_messages_advance (messages))
     {
-	_thread_add_message (thread, notmuch_messages_get (messages));
+	message = notmuch_messages_get (messages);
+	_thread_add_message (thread, message);
+	_notmuch_message_close (message);
     }
 
     notmuch_query_destroy (thread_id_query);
@@ -272,7 +275,9 @@ _notmuch_thread_create (void *ctx,
 	 notmuch_messages_has_more (messages);
 	 notmuch_messages_advance (messages))
     {
-	_thread_add_matched_message (thread, notmuch_messages_get (messages));
+	message = notmuch_messages_get (messages);
+	_thread_add_matched_message (thread, message);
+	_notmuch_message_close (message);
     }
 
     notmuch_query_destroy (matched_query);