rados: add snapshot create/remove functions

Added wrappers for pool-wide snapshot create and remove functions.

Signed-off-by: Mudit Agarwal <muagarwa@redhat.com>

rados/snapshot.go

@@ -0,0 +1,40 @@
+package rados
+
+// #cgo LDFLAGS: -lrados
+// #include <stdlib.h>
+// #include <rados/librados.h>
+import "C"
+
+import "unsafe"
+
+// CreateSnap creates a pool-wide snapshot.
+//
+// Implements:
+// int rados_ioctx_snap_create(rados_ioctx_t io, const char *snapname)
+func (ioctx *IOContext) CreateSnap(snapName string) error {
+	if err := ioctx.validate(); err != nil {
+		return err
+	}
+
+	cSnapName := C.CString(snapName)
+	defer C.free(unsafe.Pointer(cSnapName))
+
+	ret := C.rados_ioctx_snap_create(ioctx.ioctx, cSnapName)
+	return getError(ret)
+}
+
+// RemoveSnap deletes the pool snapshot.
+//
+// Implements:
+//  int rados_ioctx_snap_remove(rados_ioctx_t io, const char *snapname)
+func (ioctx *IOContext) RemoveSnap(snapName string) error {
+	if err := ioctx.validate(); err != nil {
+		return err
+	}
+
+	cSnapName := C.CString(snapName)
+	defer C.free(unsafe.Pointer(cSnapName))
+
+	ret := C.rados_ioctx_snap_remove(ioctx.ioctx, cSnapName)
+	return getError(ret)
+}

rados/snapshot_test.go

@@ -0,0 +1,66 @@
+package rados
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func (suite *RadosTestSuite) TestCreateRemoveSnapshot() {
+	suite.SetupConnection()
+
+	suite.T().Run("invalidIOCtx", func(t *testing.T) {
+		ioctx := &IOContext{}
+		err := ioctx.CreateSnap("someSnap")
+		assert.Error(t, err)
+		err = ioctx.RemoveSnap("someSnap")
+		assert.Error(t, err)
+		assert.Equal(t, err, ErrInvalidIOContext)
+	})
+
+	suite.T().Run("NewSnap", func(t *testing.T) {
+		ioctx, err := suite.conn.OpenIOContext(suite.pool)
+		require.NoError(suite.T(), err)
+
+		snapName := "mySnap"
+		err = ioctx.CreateSnap(snapName)
+		assert.NoError(t, err)
+		err = ioctx.RemoveSnap(snapName)
+		assert.NoError(t, err)
+	})
+
+	suite.T().Run("ExistingSnap", func(t *testing.T) {
+		ioctx, err := suite.conn.OpenIOContext(suite.pool)
+		require.NoError(suite.T(), err)
+
+		snapName := "mySnap"
+		err = ioctx.CreateSnap(snapName)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, ioctx.RemoveSnap(snapName))
+		}()
+		err = ioctx.CreateSnap(snapName)
+		assert.Error(t, err)
+	})
+
+	suite.T().Run("NonExistingSnap", func(t *testing.T) {
+		ioctx, err := suite.conn.OpenIOContext(suite.pool)
+		require.NoError(suite.T(), err)
+
+		err = ioctx.RemoveSnap("someSnapName")
+		assert.Error(t, err)
+	})
+
+	// Strangely, this works!!
+	suite.T().Run("EmptySnapNameString", func(t *testing.T) {
+		ioctx, err := suite.conn.OpenIOContext(suite.pool)
+		require.NoError(suite.T(), err)
+
+		err = ioctx.CreateSnap("")
+		assert.NoError(t, err)
+
+		err = ioctx.RemoveSnap("")
+		assert.NoError(t, err)
+	})
+}