Add pinnable slice

db.go

@@ -264,6 +264,20 @@ func (db *DB) GetCF(opts *ReadOptions, cf *ColumnFamilyHandle, key []byte) (*Sli
 	return NewSlice(cValue, cValLen), nil
 }
 
+// GetPinned returns the data associated with the key from the database.
+func (db *DB) GetPinned(opts *ReadOptions, key []byte) (*PinnableSliceHandle, error) {
+	var (
+		cErr *C.char
+		cKey = byteToChar(key)
+	)
+	cHandle := C.rocksdb_get_pinned(db.c, opts.c, cKey, C.size_t(len(key)), &cErr)
+	if cErr != nil {
+		defer C.free(unsafe.Pointer(cErr))
+		return nil, errors.New(C.GoString(cErr))
+	}
+	return NewNativePinnableSliceHandle(cHandle), nil
+}
+
 // MultiGet returns the data associated with the passed keys from the database
 func (db *DB) MultiGet(opts *ReadOptions, keys ...[]byte) (Slices, error) {
 	cKeys, cKeySizes := byteSlicesToCSlices(keys)

db_test.go

@@ -21,6 +21,7 @@ func TestDBCRUD(t *testing.T) {
 		givenKey  = []byte("hello")
 		givenVal1 = []byte("world1")
 		givenVal2 = []byte("world2")
+		givenVal3 = []byte("world2")
 		wo        = NewDefaultWriteOptions()
 		ro        = NewDefaultReadOptions()
 	)
@@ -41,11 +42,23 @@ func TestDBCRUD(t *testing.T) {
 	ensure.Nil(t, err)
 	ensure.DeepEqual(t, v2.Data(), givenVal2)
 
+	// retrieve pinned
+	v3, err := db.GetPinned(ro, givenKey)
+	defer v3.Destroy()
+	ensure.Nil(t, err)
+	ensure.DeepEqual(t, v3.Data(), givenVal3)
+
 	// delete
 	ensure.Nil(t, db.Delete(wo, givenKey))
-	v3, err := db.Get(ro, givenKey)
+	v4, err := db.Get(ro, givenKey)
 	ensure.Nil(t, err)
-	ensure.True(t, v3.Data() == nil)
+	ensure.True(t, v4.Data() == nil)
+
+	// retrieve missing pinned
+	v5, err := db.GetPinned(ro, givenKey)
+	defer v5.Destroy()
+	ensure.Nil(t, err)
+	ensure.Nil(t, v5.Data())
 }
 
 func TestDBCRUDDBPaths(t *testing.T) {

slice.go

@@ -1,6 +1,7 @@
 package gorocksdb
 
 // #include <stdlib.h>
+// #include "rocksdb/c.h"
 import "C"
 import "unsafe"
 
@@ -48,3 +49,30 @@ func (s *Slice) Free() {
 		s.freed = true
 	}
 }
+
+// PinnableSliceHandle represents a handle to a PinnableSlice.
+type PinnableSliceHandle struct {
+	c *C.rocksdb_pinnableslice_t
+}
+
+// NewNativePinnableSliceHandle creates a PinnableSliceHandle object.
+func NewNativePinnableSliceHandle(c *C.rocksdb_pinnableslice_t) *PinnableSliceHandle {
+	return &PinnableSliceHandle{c}
+}
+
+// Data returns the data of the slice.
+func (h *PinnableSliceHandle) Data() []byte {
+	if h.c == nil {
+		return nil
+	}
+
+	var cValLen C.size_t
+	cValue := C.rocksdb_pinnableslice_value(h.c, &cValLen)
+
+	return charToByte(cValue, cValLen)
+}
+
+// Destroy calls the destructor of the underlying pinnable slice handle.
+func (h *PinnableSliceHandle) Destroy() {
+	C.rocksdb_pinnableslice_destroy(h.c)
+}