// createOptions sets the default options for creating, reading, and writing
// from the db. destroyOptions should be called when the options aren't needed
// anymore.
func (r *RocksDB) createOptions() {
// TODO(andybons): Set the cache size.
r.opts = C.rocksdb_options_create()
C.rocksdb_options_set_create_if_missing(r.opts, 1)
// This enables us to use rocksdb_merge with counter semantics.
// See rocksdb.{c,h} for the C implementation.
r.mergeOperator = C.make_merge_operator()
C.rocksdb_options_set_merge_operator(r.opts, r.mergeOperator)
// This enables garbage collection of transaction and response cache rows.
r.compactionFilterFactory = C.make_gc_compaction_filter_factory(unsafe.Pointer(r))
C.rocksdb_options_set_compaction_filter_factory(r.opts, r.compactionFilterFactory)
r.wOpts = C.rocksdb_writeoptions_create()
r.rOpts = C.rocksdb_readoptions_create()
}
// destroyOptions destroys the options used for creating, reading, and writing
// from the db. It is meant to be used in conjunction with createOptions.
func (r *RocksDB) destroyOptions() {
// The merge operator and compaction filter are stored inside of
// r.opts using std::shared_ptrs, so they'll be freed
// automatically. Calling the *_destroy methods directly would
// ignore the shared_ptrs, and a subsequent rocksdb_options_destroy
// would segfault. The following lines zero the shared_ptrs instead,
// which deletes the underlying values.
C.rocksdb_options_set_merge_operator(r.opts, nil)
C.rocksdb_options_set_compaction_filter_factory(r.opts, nil)
C.rocksdb_options_destroy(r.opts)
C.rocksdb_readoptions_destroy(r.rOpts)
C.rocksdb_writeoptions_destroy(r.wOpts)
r.mergeOperator = nil
r.compactionFilterFactory = nil
r.opts = nil
r.rOpts = nil
r.wOpts = nil
}
