Add atomic flushes to rocksdb bindings

rocksdb/extended.cpp

@@ -32,6 +32,11 @@ struct rocksdb_statistics_t { std::shared_ptr<Statistics> rep; };
 struct rocksdb_histogram_data_t { rocksdb::HistogramData* rep; };
 struct rocksdb_options_t { Options rep; };
 
+void rocksdb_options_set_atomic_flush(
+    rocksdb_options_t* opts, unsigned char value) {
+    opts->rep.atomic_flush = value;
+}
+
 rocksdb_statistics_t* rocksdb_create_statistics() {
     rocksdb_statistics_t* result = new rocksdb_statistics_t;
     result->rep = rocksdb::CreateDBStatistics();

rocksdb/extended.h

@@ -43,8 +43,11 @@ extern rocksdb_statistics_t* rocksdb_create_statistics();
 
 /* Options */
 
+extern void rocksdb_options_set_atomic_flush(
+    rocksdb_options_t*, unsigned char);
+
 extern void rocksdb_options_set_statistics(
-    rocksdb_options_t* opt, 
+    rocksdb_options_t* opts, 
     rocksdb_statistics_t* stats);
 
 /* Statistics */

rocksdb/options.go

@@ -358,18 +358,35 @@ func (o *Options) SetKeepLogFileNum(value int) {
 	C.rocksdb_options_set_keep_log_file_num(o.c, C.size_t(value))
 }
 
-// SetAllowMmapReads enable/disable mmap reads for reading sst tables.
+// SetAllowMmapReads enables/disables mmap reads for reading sst tables.
 // Default: false
 func (o *Options) SetAllowMmapReads(value bool) {
 	C.rocksdb_options_set_allow_mmap_reads(o.c, boolToUchar(value))
 }
 
-// SetAllowMmapWrites enable/disable mmap writes for writing sst tables.
+// SetAllowMmapWrites enables/disables mmap writes for writing sst tables.
 // Default: false
 func (o *Options) SetAllowMmapWrites(value bool) {
 	C.rocksdb_options_set_allow_mmap_writes(o.c, boolToUchar(value))
 }
 
+// SetAtomicFlush enables/disables atomic flushes.
+// If true, RocksDB supports flushing multiple column families and committing
+// their results atomically to MANIFEST. Note that it is not
+// necessary to set atomic_flush to true if WAL is always enabled since WAL
+// allows the database to be restored to the last persistent state in WAL.
+// This option is useful when there are column families with writes NOT
+// protected by WAL.
+// For manual flush, application has to specify which column families to
+// flush atomically in db.Flush.
+// For auto-triggered flush, RocksDB atomically flushes ALL column families.
+//
+// Currently, any WAL-enabled writes after atomic flush may be replayed
+// independently if the process crashes later and tries to recover.
+func (o *Options) SetAtomicFlush(value bool) {
+	C.rocksdb_options_set_atomic_flush(o.c, boolToUchar(value))
+}
+
 // SetStatistics sets a statistics object to pass to the DB.
 func (o *Options) SetStatistics(s *Statistics) {
 	C.rocksdb_options_set_statistics(o.c, s.c)