From: Ben Gamari <bgamari.foss@gmail.com>
To: notmuch@notmuchmail.org
Subject: [PATCH 1/3] database: Add notmuch_database_compact_close
Date: Fri, 23 Aug 2013 22:55:21 -0400
Message-Id: <1377312923-32274-2-git-send-email-bgamari.foss@gmail.com>
In-Reply-To: <1377312923-32274-1-git-send-email-bgamari.foss@gmail.com>
References: <1377312923-32274-1-git-send-email-bgamari.foss@gmail.com>
Precedence: list

This function uses Xapian's Compactor machinery to compact the notmuch
database. The compacted database is built in a temporary directory and
later moved into place while the original uncompacted database is
preserved.

Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
---
 configure       | 27 +++++++++++++++--
 lib/database.cc | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/notmuch.h   | 15 ++++++++++
 3 files changed, 130 insertions(+), 3 deletions(-)

diff --git a/configure b/configure
index 6166917..ee9e887 100755
--- a/configure
+++ b/configure
@@ -277,7 +277,8 @@ printf "Checking for Xapian development files... "
 have_xapian=0
 for xapian_config in ${XAPIAN_CONFIG}; do
     if ${xapian_config} --version > /dev/null 2>&1; then
-	printf "Yes (%s).\n" $(${xapian_config} --version | sed -e 's/.* //')
+	xapian_version=$(${xapian_config} --version | sed -e 's/.* //')
+	printf "Yes (%s).\n" ${xapian_version}
 	have_xapian=1
 	xapian_cxxflags=$(${xapian_config} --cxxflags)
 	xapian_ldflags=$(${xapian_config} --libs)
@@ -289,6 +290,21 @@ if [ ${have_xapian} = "0" ]; then
     errors=$((errors + 1))
 fi
 
+# Compaction is only supported on Xapian > 1.2.6
+have_xapian_compact=0
+if [ ${have_xapian} = "1" ]; then
+    printf "Checking for Xapian compact support... "
+    case "${xapian_version}" in
+        0.*|1.[01].*|1.2.[0-5])
+            printf "No (only available with Xapian > 1.2.6).\n" ;;
+        [1-9]*.[0-9]*.[0-9]*)
+            have_xapian_compact=1
+            printf "Yes.\n" ;;
+        *)
+            printf "Unknown version.\n" ;;
+    esac
+fi
+
 printf "Checking for GMime development files... "
 have_gmime=0
 IFS=';'
@@ -729,6 +745,9 @@ HAVE_STRCASESTR = ${have_strcasestr}
 # build its own version)
 HAVE_STRSEP = ${have_strsep}
 
+# Whether the Xapian version in use supports compaction
+HAVE_XAPIAN_COMPACT = ${have_xapian_compact}
+
 # Whether the getpwuid_r function is standards-compliant
 # (if not, then notmuch will #define _POSIX_PTHREAD_SEMANTICS
 # to enable the standards-compliant version -- needed for Solaris)
@@ -787,13 +806,15 @@ CONFIGURE_CFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)      \\
 		   -DHAVE_STRCASESTR=\$(HAVE_STRCASESTR)                 \\
 		   -DHAVE_STRSEP=\$(HAVE_STRSEP)                         \\
 		   -DSTD_GETPWUID=\$(STD_GETPWUID)                       \\
-		   -DSTD_ASCTIME=\$(STD_ASCTIME)
+		   -DSTD_ASCTIME=\$(STD_ASCTIME)                         \\
+                   -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT)
 CONFIGURE_CXXFLAGS = -DHAVE_GETLINE=\$(HAVE_GETLINE) \$(GMIME_CFLAGS)    \\
 		     \$(TALLOC_CFLAGS) -DHAVE_VALGRIND=\$(HAVE_VALGRIND) \\
 		     \$(VALGRIND_CFLAGS) \$(XAPIAN_CXXFLAGS)             \\
 		     -DHAVE_STRCASESTR=\$(HAVE_STRCASESTR)               \\
 		     -DHAVE_STRSEP=\$(HAVE_STRSEP)                       \\
 		     -DSTD_GETPWUID=\$(STD_GETPWUID)                     \\
-		     -DSTD_ASCTIME=\$(STD_ASCTIME)
+		     -DSTD_ASCTIME=\$(STD_ASCTIME)                       \\
+                     -DHAVE_XAPIAN_COMPACT=\$(HAVE_XAPIAN_COMPACT)
 CONFIGURE_LDFLAGS =  \$(GMIME_LDFLAGS) \$(TALLOC_LDFLAGS) \$(XAPIAN_LDFLAGS)
 EOF
diff --git a/lib/database.cc b/lib/database.cc
index 5cc0765..b71751d 100644
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -268,6 +268,8 @@ notmuch_status_to_string (notmuch_status_t status)
 	return "Unbalanced number of calls to notmuch_message_freeze/thaw";
     case NOTMUCH_STATUS_UNBALANCED_ATOMIC:
 	return "Unbalanced number of calls to notmuch_database_begin_atomic/end_atomic";
+    case NOTMUCH_STATUS_UNSUPPORTED_OPERATION:
+	return "Unsupported operation";
     default:
     case NOTMUCH_STATUS_LAST_STATUS:
 	return "Unknown error status value";
@@ -800,6 +802,95 @@ notmuch_database_close (notmuch_database_t *notmuch)
     notmuch->date_range_processor = NULL;
 }
 
+class NotmuchCompactor : public Xapian::Compactor
+{
+public:
+    virtual void
+    set_status (const std::string &table, const std::string &status)
+    {
+	if (status.length() == 0)
+	    printf ("compacting table %s:\n", table.c_str());
+	else
+	    printf ("     %s\n", status.c_str());
+    }
+};
+
+#if HAVE_XAPIAN_COMPACT
+notmuch_status_t
+notmuch_database_compact_close (notmuch_database_t *notmuch)
+{
+    void *local = talloc_new (NULL);
+    NotmuchCompactor compactor;
+    char *notmuch_path, *xapian_path, *compact_xapian_path, *old_xapian_path;
+    notmuch_status_t ret = NOTMUCH_STATUS_SUCCESS;
+
+    if (! (notmuch_path = talloc_asprintf (local, "%s/%s", notmuch->path, ".notmuch"))) {
+	ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
+	goto DONE;
+    }
+
+    if (! (xapian_path = talloc_asprintf (local, "%s/%s", notmuch_path, "xapian"))) {
+	ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
+	goto DONE;
+    }
+
+    if (! (compact_xapian_path = talloc_asprintf (local, "%s.compact", xapian_path))) {
+	ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
+	goto DONE;
+    }
+
+    if (! (old_xapian_path = talloc_asprintf (local, "%s.old", xapian_path))) {
+	ret = NOTMUCH_STATUS_OUT_OF_MEMORY;
+	goto DONE;
+    }
+
+    try {
+	compactor.set_renumber(false);
+	compactor.add_source(xapian_path);
+	compactor.set_destdir(compact_xapian_path);
+	compactor.compact();
+
+	if (rename(xapian_path, old_xapian_path)) {
+	    fprintf (stderr, "Error moving old database out of the way\n");
+	    ret = NOTMUCH_STATUS_FILE_ERROR;
+	    goto DONE;
+	}
+
+	if (rename(compact_xapian_path, xapian_path)) {
+	    fprintf (stderr, "Error moving compacted database\n");
+	    ret = NOTMUCH_STATUS_FILE_ERROR;
+	    goto DONE;
+	}
+    } catch (Xapian::InvalidArgumentError e) {
+	fprintf (stderr, "Error while compacting: %s", e.get_msg().c_str());
+	ret = NOTMUCH_STATUS_XAPIAN_EXCEPTION;
+	goto DONE;
+    }
+
+    fprintf (stderr, "\n");
+    fprintf (stderr, "\n");
+    fprintf (stderr, "Old database has been moved to %s", old_xapian_path);
+    fprintf (stderr, "\n");
+    fprintf (stderr, "To delete run,\n");
+    fprintf (stderr, "\n");
+    fprintf (stderr, "    rm -R %s\n", old_xapian_path);
+    fprintf (stderr, "\n");
+
+    notmuch_database_close(notmuch);
+
+DONE:
+    talloc_free(local);
+    return ret;
+}
+#else
+notmuch_status_t
+notmuch_database_compact_close (unused (notmuch_database_t *notmuch))
+{
+    fprintf (stderr, "notmuch was compiled against a xapian version lacking compaction support.\n");
+    return NOTMUCH_STATUS_UNSUPPORTED_OPERATION;
+}
+#endif
+
 void
 notmuch_database_destroy (notmuch_database_t *notmuch)
 {
diff --git a/lib/notmuch.h b/lib/notmuch.h
index 998a4ae..e9abd90 100644
--- a/lib/notmuch.h
+++ b/lib/notmuch.h
@@ -101,6 +101,7 @@ typedef enum _notmuch_status {
     NOTMUCH_STATUS_TAG_TOO_LONG,
     NOTMUCH_STATUS_UNBALANCED_FREEZE_THAW,
     NOTMUCH_STATUS_UNBALANCED_ATOMIC,
+    NOTMUCH_STATUS_UNSUPPORTED_OPERATION,
 
     NOTMUCH_STATUS_LAST_STATUS
 } notmuch_status_t;
@@ -215,6 +216,20 @@ notmuch_database_open (const char *path,
 void
 notmuch_database_close (notmuch_database_t *database);
 
+/* Close the given notmuch database and then compact it.
+ *
+ * After notmuch_database_close_compact has been called, calls to
+ * other functions on objects derived from this database may either
+ * behave as if the database had not been closed (e.g., if the
+ * required data has been cached) or may fail with a
+ * NOTMUCH_STATUS_XAPIAN_EXCEPTION.
+ *
+ * notmuch_database_close_compact can be called multiple times.  Later
+ * calls have no effect.
+ */
+notmuch_status_t
+notmuch_database_compact_close (notmuch_database_t *notmuch);
+
 /* Destroy the notmuch database, closing it if necessary and freeing
 * all associated resources. */
 void
-- 
1.8.1.2