// Merge merges the data associated with the key with the actual data in the database.
func (db *DB) Merge(opts *WriteOptions, key []byte, value []byte) error {
var (
cErr *C.char
cKey = byteToChar(key)
cValue = byteToChar(value)
)
C.rocksdb_merge(db.c, opts.c, cKey, C.size_t(len(key)), cValue, C.size_t(len(value)), &cErr)
return convertErr(cErr)
}
// Merge merges the data associated with the key with the actual data in the database.
func (db *DB) Merge(opts *WriteOptions, key []byte, value []byte) error {
var (
cErr *C.char
cKey = byteToChar(key)
cValue = byteToChar(value)
)
C.rocksdb_merge(db.c, opts.c, cKey, C.size_t(len(key)), cValue, C.size_t(len(value)), &cErr)
if cErr != nil {
defer C.free(unsafe.Pointer(cErr))
return errors.New(C.GoString(cErr))
}
return nil
}
// Merge implements the RocksDB merge operator using the function goMergeInit
// to initialize missing values and goMerge to merge the old and the given
// value into a new value, which is then stored under key.
// Currently 64-bit counter logic is implemented. See the documentation of
// goMerge and goMergeInit for details.
//
// The key and value byte slices may be reused safely. merge takes a copy
// of them before returning.
func (r *RocksDB) Merge(key Key, value []byte) error {
if len(key) == 0 {
return emptyKeyError()
}
// rocksdb_merge calls memcpy() (by way of MemTable::Add)
// when called, so we do not need to worry about these byte slices being
// reclaimed by the GC.
var cErr *C.char
C.rocksdb_merge(
r.rdb,
r.wOpts,
bytesPointer(key),
C.size_t(len(key)),
bytesPointer(value),
C.size_t(len(value)),
&cErr)
if cErr != nil {
return charToErr(cErr)
}
return nil
}