Subject: Re: Patch: Flush and Reopen
From: Martin Owens <doctormo@gmail.com>
To: Austin Clements <amdragon@MIT.EDU>
In-Reply-To: <20110912002327.GC23603@mit.edu>
References: <1315445674.32058.183.camel@delen>
	<CAH-f9WtuYYuksfTHL1ZMmoRF6kyL7iFu9BXDzGn-wWGniSvf9w@mail.gmail.com>
	<1315536861.2435.34.camel@delen> <87obyuj7q1.fsf@zancas.localnet>
	<1315590950.2435.59.camel@delen>
	<CAH-f9WtuL48RtaJ9njxHyCy5cqhhrxdz+30ydE11rq41Lu06pA@mail.gmail.com>
	<1315615433.2435.62.camel@delen>  <20110912002327.GC23603@mit.edu>
Content-Type: multipart/mixed; boundary="=-BYbaCrqc5AZGCLvtRXrH"
Date: Sun, 11 Sep 2011 21:04:39 -0400
Message-ID: <1315789479.2435.75.camel@delen>
Mime-Version: 1.0
Cc: Notmuch developer list <notmuch@notmuchmail.org>
Precedence: list


--=-BYbaCrqc5AZGCLvtRXrH
Content-Type: text/plain
Content-Transfer-Encoding: 7bit

Previous Email was sans-attachment. See below.


--=-BYbaCrqc5AZGCLvtRXrH
Content-Disposition: attachment;
 filename*0=0001-Add-flush-and-reopen-to-notmuch-database-python-bind.pat;
 filename*1=ch
Content-Type: text/x-patch;
 name="0001-Add-flush-and-reopen-to-notmuch-database-python-bind.patch";
 charset="UTF-8"
Content-Transfer-Encoding: 7bit

>From 2d247d56660689dee5ae58c252621f9343044dd8 Mon Sep 17 00:00:00 2001
From: Martin Owens <doctormo@gmail.com>
Date: Sun, 11 Sep 2011 20:51:35 -0400
Subject: [PATCH] Add flush and reopen to notmuch database + python bindings.

Flush and reopen methods in the libnotmuch and python bindings
allows concurent access to the database. Flush allows read_write
databases to commit their changes, forcing a flush to disk and
reopen allows a database to reread from the disk when changes
are detected or known about.
---
 bindings/python/notmuch/database.py |   10 ++++++++++
 lib/database.cc                     |   28 ++++++++++++++++++++++++----
 lib/notmuch.h                       |    8 ++++++++
 3 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/bindings/python/notmuch/database.py b/bindings/python/notmuch/database.py
index f18ca14..b6c1c31 100644
--- a/bindings/python/notmuch/database.py
+++ b/bindings/python/notmuch/database.py
@@ -432,6 +432,16 @@ class Database(object):
 
         return Query(self, querystring)
 
+    def reopen(self):
+        """Reopens a read only database, when the data has changed, this is required."""
+        if self._db is not None:
+            nmlib.notmuch_database_reopen(self._db)
+
+    def flush(self):
+        """Flushes the search database, only available when in read-write."""
+        if self._db is not None:
+            nmlib.notmuch_database_flush(self._db)
+
     def __repr__(self):
         return "'Notmuch DB " + self.get_path() + "'"
 
diff --git a/lib/database.cc b/lib/database.cc
index 9c2f4ec..9258137 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -700,18 +700,38 @@ notmuch_database_open (const char *path,
 }
 
 void
-notmuch_database_close (notmuch_database_t *notmuch)
+notmuch_database_reopen (notmuch_database_t *notmuch)
+{
+    try {
+	notmuch->xapian_db->reopen ();
+    } catch (const Xapian::Error &error) {
+	if (! notmuch->exception_reported) {
+	    fprintf (stderr, "Error: A Xapian exception reopening database: %s\n",
+	    error.get_msg().c_str());
+	    notmuch->exception_reported = TRUE;
+	}
+    }
+}
+
+void
+notmuch_database_flush (notmuch_database_t *notmuch)
 {
     try {
 	if (notmuch->mode == NOTMUCH_DATABASE_MODE_READ_WRITE)
 	    (static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db))->flush ();
-    } catch (const Xapian::Error &error) {
+	} catch (const Xapian::Error &error) {
 	if (! notmuch->exception_reported) {
-	    fprintf (stderr, "Error: A Xapian exception occurred flushing database: %s\n",
-		     error.get_msg().c_str());
+	    fprintf (stderr, "Error: A Xapian exception flushing database: %s\n",
+	    error.get_msg().c_str());
+	    notmuch->exception_reported = TRUE;
 	}
     }
+}
 
+void
+notmuch_database_close (notmuch_database_t *notmuch)
+{
+    notmuch_database_flush (notmuch);
     delete notmuch->term_gen;
     delete notmuch->query_parser;
     delete notmuch->xapian_db;
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 974be8d..ca87b89 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -171,6 +171,14 @@ notmuch_database_t *
 notmuch_database_open (const char *path,
 		       notmuch_database_mode_t mode);
 
+/* Reopen a read_only database when the data source has changed */
+void
+notmuch_database_reopen (notmuch_database_t *database);
+
+/* Force a flush of the xapian database, also done on close */
+void
+notmuch_database_flush (notmuch_database_t *database);
+
 /* Close the given notmuch database, freeing all associated
  * resources. See notmuch_database_open. */
 void
-- 
1.7.1


--=-BYbaCrqc5AZGCLvtRXrH--