rbd: add constants for pool stat options and wrapper for rbd_pool_stats_get()

Added pool stat options constants.
Also implemented GetAllPoolStats() function to introduce
the functionality of rbd_pool_stats_option_add_uint64() and rbd_pool_stats_get()

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

rbd/pool_nautilus.go

@@ -126,3 +126,92 @@ func (poolstats *poolStats) destroy() {
 		poolstats.stats = nil
 	}
 }
+
+// PoolStatOption represents a group of configurable pool stat options.
+type PoolStatOption C.rbd_pool_stat_option_t
+
+const (
+	// PoolStatOptionImages is the representation of
+	// RBD_POOL_STAT_OPTION_IMAGES from librbd.
+	PoolStatOptionImages = PoolStatOption(C.RBD_POOL_STAT_OPTION_IMAGES)
+	// PoolStatOptionImageProvisionedBytes is the representation of
+	// RBD_POOL_STAT_OPTION_IMAGE_PROVISIONED_BYTES from librbd.
+	PoolStatOptionImageProvisionedBytes = PoolStatOption(C.RBD_POOL_STAT_OPTION_IMAGE_PROVISIONED_BYTES)
+	// PoolStatOptionImageMaxProvisionedBytes is the representation of
+	// RBD_POOL_STAT_OPTION_IMAGE_MAX_PROVISIONED_BYTES from librbd.
+	PoolStatOptionImageMaxProvisionedBytes = PoolStatOption(C.RBD_POOL_STAT_OPTION_IMAGE_MAX_PROVISIONED_BYTES)
+	// PoolStatOptionImageSnapshots is the representation of
+	// RBD_POOL_STAT_OPTION_IMAGE_SNAPSHOTS from librbd.
+	PoolStatOptionImageSnapshots = PoolStatOption(C.RBD_POOL_STAT_OPTION_IMAGE_SNAPSHOTS)
+	// PoolStatOptionTrashImages is the representation of
+	// RBD_POOL_STAT_OPTION_TRASH_IMAGES from librbd.
+	PoolStatOptionTrashImages = PoolStatOption(C.RBD_POOL_STAT_OPTION_TRASH_IMAGES)
+	// PoolStatOptionTrashProvisionedBytes is the representation of
+	// RBD_POOL_STAT_OPTION_TRASH_PROVISIONED_BYTES from librbd.
+	PoolStatOptionTrashProvisionedBytes = PoolStatOption(C.RBD_POOL_STAT_OPTION_TRASH_PROVISIONED_BYTES)
+	// PoolStatOptionTrashMaxProvisionedBytes is the representation of
+	// RBD_POOL_STAT_OPTION_TRASH_MAX_PROVISIONED_BYTES from librbd.
+	PoolStatOptionTrashMaxProvisionedBytes = PoolStatOption(C.RBD_POOL_STAT_OPTION_TRASH_MAX_PROVISIONED_BYTES)
+	// PoolStatOptionTrashSnapshots is the representation of
+	// RBD_POOL_STAT_OPTION_TRASH_SNAPSHOTS from librbd.
+	PoolStatOptionTrashSnapshots = PoolStatOption(C.RBD_POOL_STAT_OPTION_TRASH_SNAPSHOTS)
+)
+
+// addPoolStatOption adds the given PoolStatOption to PoolStats.
+//
+// Implements:
+//  int rbd_pool_stats_option_add_uint64(rbd_pool_stats_t stats, int stat_option, uint64_t* stat_val)
+func (poolstats *poolStats) addPoolStatOption(option PoolStatOption, val *uint64) error {
+	ret := C.rbd_pool_stats_option_add_uint64(
+		poolstats.stats,
+		C.int(option),
+		(*C.uint64_t)(val))
+	return getError(ret)
+}
+
+// GetAllPoolStats returns a map of all PoolStatOption(s) to their respective values.
+//
+// Implements:
+//  int rbd_pool_stats_get(rados_ioctx_t io, rbd_pool_stats_t stats);
+func GetAllPoolStats(ioctx *rados.IOContext) (map[PoolStatOption]uint64, error) {
+	var omap = make(map[PoolStatOption]uint64)
+	if ioctx == nil {
+		return omap, ErrNoIOContext
+	}
+
+	poolstats := poolStatsCreate()
+	defer func() {
+		poolstats.destroy()
+	}()
+
+	var keys [8]PoolStatOption
+
+	keys[0] = PoolStatOptionImages
+	keys[1] = PoolStatOptionImageProvisionedBytes
+	keys[2] = PoolStatOptionImageMaxProvisionedBytes
+	keys[3] = PoolStatOptionImageSnapshots
+	keys[4] = PoolStatOptionTrashImages
+	keys[5] = PoolStatOptionTrashProvisionedBytes
+	keys[6] = PoolStatOptionTrashMaxProvisionedBytes
+	keys[7] = PoolStatOptionTrashSnapshots
+
+	ovalArray := make([]uint64, len(keys))
+
+	// add option with the address where the respective value would be stored.
+	for i, key := range keys {
+		err := poolstats.addPoolStatOption(key, &ovalArray[i])
+		if err != nil {
+			return omap, err
+		}
+	}
+
+	ret := C.rbd_pool_stats_get(cephIoctx(ioctx), poolstats.stats)
+	if ret < 0 {
+		return omap, getError(ret)
+	}
+
+	for j, key := range keys {
+		omap[key] = ovalArray[j]
+	}
+	return omap, nil
+}

rbd/pool_nautilus_test.go

@@ -5,6 +5,7 @@ package rbd
 import (
 	"math/rand"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 )
@@ -131,3 +132,80 @@ func TestPoolInit(t *testing.T) {
 		assert.NoError(t, err)
 	})
 }
+
+func TestGetAllPoolStat(t *testing.T) {
+	conn := radosConnect(t)
+	poolName := GetUUID()
+	err := conn.MakePool(poolName)
+	assert.NoError(t, err)
+
+	ioctx, err := conn.OpenIOContext(poolName)
+	assert.NoError(t, err)
+	assert.NotNil(t, ioctx)
+
+	defer func() {
+		ioctx.Destroy()
+		conn.DeletePool(poolName)
+		conn.Shutdown()
+	}()
+
+	poolstats := poolStatsCreate()
+	defer func() {
+		poolstats.destroy()
+	}()
+
+	var imageName string
+	size := uint64(2 << 20)
+	var expectedSize uint64
+
+	for idx := 0; idx < 3; idx++ {
+		imageName = GetUUID()
+		image, err := Create(ioctx, imageName, size, testImageOrder)
+		assert.NoError(t, err)
+		defer func() {
+			assert.NoError(t, image.Remove())
+		}()
+		expectedSize += size
+	}
+
+	imageName = GetUUID()
+	_, err = Create(ioctx, imageName, size, testImageOrder)
+	assert.NoError(t, err)
+	expectedSize += size
+	img, err := OpenImage(ioctx, imageName, NoSnapshot)
+	assert.NoError(t, err)
+
+	mySnap, err := img.CreateSnapshot("mySnap")
+	assert.NoError(t, err)
+
+	t.Run("NullIOContext", func(t *testing.T) {
+		_, err = GetAllPoolStats(nil)
+		assert.Error(t, err)
+	})
+
+	t.Run("CheckPoolStatOption", func(t *testing.T) {
+		err := img.Resize(size)
+		assert.NoError(t, err)
+		assert.NoError(t, mySnap.Remove())
+		assert.NoError(t, img.Close())
+		err = img.Trash(time.Hour)
+		assert.NoError(t, err)
+		defer func() {
+			trashList, err := GetTrashList(ioctx)
+			assert.NoError(t, err)
+			assert.NoError(t, TrashRemove(ioctx, trashList[0].Id, true))
+		}()
+
+		omap, err := GetAllPoolStats(ioctx)
+		assert.NoError(t, err)
+
+		assert.Equal(t, uint64(3), omap[PoolStatOptionImages])
+		assert.Equal(t, (expectedSize - size), omap[PoolStatOptionImageProvisionedBytes])
+		assert.Equal(t, expectedSize-size, omap[PoolStatOptionImageMaxProvisionedBytes])
+		assert.Equal(t, uint64(0), omap[PoolStatOptionImageSnapshots])
+		assert.Equal(t, uint64(0), omap[PoolStatOptionTrashSnapshots])
+		assert.Equal(t, uint64(1), omap[PoolStatOptionTrashImages])
+		assert.Equal(t, size, omap[PoolStatOptionTrashProvisionedBytes])
+		assert.Equal(t, size, omap[PoolStatOptionTrashMaxProvisionedBytes])
+	})
+}