lib: Add notmuch_database_{begin,end}_atomic.

[notmuch] / lib / database.cc

diff --git a/lib/database.cc b/lib/database.cc
index 7f79cf47bda767a1463ae418ea5d713f950ac3c4..48abbe8e7c72bf01e0e46b00c36b89775b29b942 100644 (file)
--- a/lib/database.cc
+++ b/lib/database.cc
@@ -69,7 +69,7 @@ typedef struct {
  *
  *    Multiple terms of given prefix:
  *
- *     reference: All message IDs from In-Reply-To and Re ferences
+ *     reference: All message IDs from In-Reply-To and References
  *                headers in the message.
  *
  *     tag:       Any tags associated with this message by the user.
@@ -137,7 +137,7 @@ typedef struct {
  *                     ASCII integer. The initial database version
  *                     was 1, (though a schema existed before that
  *                     were no "version" database value existed at
- *                     all). Succesive versions are allocated as
+ *                     all). Successive versions are allocated as
  *                     changes are made to the database (such as by
  *                     indexing new fields).
  *
@@ -148,7 +148,7 @@ typedef struct {
  *                     incremented for each thread ID.
  *
  *     thread_id_*     A pre-allocated thread ID for a particular
- *                     message. This is actually an arbitarily large
+ *                     message. This is actually an arbitrarily large
  *                     family of metadata name. Any particular name is
  *                     formed by concatenating "thread_id_" with a message
  *                     ID (or the SHA1 sum of a message ID if it is very
@@ -422,7 +422,7 @@ skip_space_and_comments (const char **str)
 }
 
 /* Parse an RFC 822 message-id, discarding whitespace, any RFC 822
- * comments, and the '<' and '>' delimeters.
+ * comments, and the '<' and '>' delimiters.
  *
  * If not NULL, then *next will be made to point to the first character
  * not parsed, (possibly pointing to the final '\0' terminator.
@@ -974,6 +974,50 @@ notmuch_database_upgrade (notmuch_database_t *notmuch,
     return NOTMUCH_STATUS_SUCCESS;
 }
 
+notmuch_status_t
+notmuch_database_begin_atomic (notmuch_database_t *notmuch)
+{
+    if (notmuch->mode == NOTMUCH_DATABASE_MODE_READ_ONLY)
+       return NOTMUCH_STATUS_SUCCESS;
+
+    try {
+       (static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db))->begin_transaction (false);
+    } catch (const Xapian::Error &error) {
+       fprintf (stderr, "A Xapian exception occurred beginning transaction: %s.\n",
+                error.get_msg().c_str());
+       notmuch->exception_reported = TRUE;
+       return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
+    }
+    return NOTMUCH_STATUS_SUCCESS;
+}
+
+notmuch_status_t
+notmuch_database_end_atomic (notmuch_database_t *notmuch)
+{
+    Xapian::WritableDatabase *db;
+
+    if (notmuch->mode == NOTMUCH_DATABASE_MODE_READ_ONLY)
+       return NOTMUCH_STATUS_SUCCESS;
+
+    db = static_cast <Xapian::WritableDatabase *> (notmuch->xapian_db);
+    try {
+       db->commit_transaction ();
+
+       /* This is a hack for testing.  Xapian never flushes on a
+        * non-flushed commit, even if the flush threshold is 1.
+        * However, we rely on flushing to test atomicity. */
+       const char *thresh = getenv ("XAPIAN_FLUSH_THRESHOLD");
+       if (thresh && atoi (thresh) == 1)
+           db->commit ();
+    } catch (const Xapian::Error &error) {
+       fprintf (stderr, "A Xapian exception occurred committing transaction: %s.\n",
+                error.get_msg().c_str());
+       notmuch->exception_reported = TRUE;
+       return NOTMUCH_STATUS_XAPIAN_EXCEPTION;
+    }
+    return NOTMUCH_STATUS_SUCCESS;
+}
+
 /* We allow the user to use arbitrarily long paths for directories. But
  * we have a term-length limit. So if we exceed that, we'll use the
  * SHA-1 of the path for the database term.
@@ -1149,7 +1193,7 @@ _notmuch_database_filename_to_direntry (void *ctx,
 
 /* Given a legal 'path' for the database, return the relative path.
  *
- * The return value will be a pointer to the originl path contents,
+ * The return value will be a pointer to the original path contents,
  * and will be either the original string (if 'path' was relative) or
  * a portion of the string (if path was absolute and begins with the
  * database path).
@@ -1476,7 +1520,7 @@ _notmuch_database_link_message_to_children (notmuch_database_t *notmuch,
  * In all cases, we assign to the current message the first thread_id
  * found (through either parent or child). We will also merge any
  * existing, distinct threads where this message belongs to both,
- * (which is not uncommon when mesages are processed out of order).
+ * (which is not uncommon when messages are processed out of order).
  *
  * Finally, if no thread ID has been found through parent or child, we
  * call _notmuch_message_generate_thread_id to generate a new thread