From ca00d4af80df94b22dd8fd5a997f139ed524b466 Mon Sep 17 00:00:00 2001
From: Prateek Pandey <prateekpandey14@gmail.com>
Date: Fri, 6 Dec 2019 12:50:12 +0530
Subject: [PATCH] refact(size): conversion G to Gi (#59)

Signed-off-by: prateekpandey14 <prateekpandey14@gmail.com>
---
 pkg/utils/v1alpha1/maya.go     | 27 +++++++++++++---------
 pkg/utils/v1alpha1/rounding.go | 41 +++++++++++++++++++++++++++++++++-
 2 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/pkg/utils/v1alpha1/maya.go b/pkg/utils/v1alpha1/maya.go
index 8333b9d4f..841a909e4 100644
--- a/pkg/utils/v1alpha1/maya.go
+++ b/pkg/utils/v1alpha1/maya.go
@@ -69,14 +69,16 @@ func ProvisionVolume(
 		CVCFinalizer,
 	}
 
-	sSize := ByteCount(uint64(size))
+	requestGIB := RoundUpGiB(size)
+	sSize := resource.MustParse(fmt.Sprintf("%dGi", requestGIB))
+
 	cvcObj, err := cvc.NewBuilder().
 		WithName(volName).
 		WithNamespace(OpenEBSNamespace).
 		WithAnnotations(annotations).
 		WithLabelsNew(labels).
 		WithFinalizers(finalizers).
-		WithCapacity(sSize).
+		WithCapacityQty(sSize).
 		WithSource(snapshotID).
 		WithReplicaCount(replicaCount).
 		WithNewVersion(version.Current()).
@@ -185,12 +187,14 @@ func ResizeVolume(
 	size int64,
 ) error {
 
-	sSize := ByteCount(uint64(size))
+	requestGIB := RoundUpGiB(size)
+	desiredSize := resource.MustParse(fmt.Sprintf("%dGi", requestGIB))
+
 	cvc, err := getCVC(volumeID)
 	if err != nil {
 		return err
 	}
-	desiredSize, _ := resource.ParseQuantity(sSize)
+
 	cvcDesiredSize := cvc.Spec.Capacity[corev1.ResourceStorage]
 
 	if (desiredSize).Cmp(cvcDesiredSize) < 0 {
@@ -199,7 +203,7 @@ func ResizeVolume(
 	}
 
 	if cvc.Status.Phase == apismaya.CStorVolumeClaimPhasePending {
-		return handleResize(cvc, sSize)
+		return handleResize(cvc, desiredSize)
 	}
 	cvcActualSize := cvc.Status.Capacity[corev1.ResourceStorage]
 
@@ -211,12 +215,12 @@ func ResizeVolume(
 	if (desiredSize).Cmp(cvcActualSize) == 0 {
 		return nil
 	}
-	return handleResize(cvc, sSize)
+	return handleResize(cvc, desiredSize)
 
 }
 
 func handleResize(
-	cvc *apismaya.CStorVolumeClaim, sSize string,
+	cvc *apismaya.CStorVolumeClaim, sSize resource.Quantity,
 ) error {
 	if err := updateCVCSize(cvc, sSize); err != nil {
 		return err
@@ -227,14 +231,14 @@ func handleResize(
 	return waitAndReverifyResizeStatus(cvc.Name, sSize)
 }
 
-func waitAndReverifyResizeStatus(cvcName, sSize string) error {
+func waitAndReverifyResizeStatus(cvcName string, sSize resource.Quantity) error {
 
 	time.Sleep(5 * time.Second)
 	cvcObj, err := getCVC(cvcName)
 	if err != nil {
 		return err
 	}
-	desiredSize, _ := resource.ParseQuantity(sSize)
+	desiredSize := sSize
 	cvcActualSize := cvcObj.Status.Capacity[corev1.ResourceStorage]
 	if (desiredSize).Cmp(cvcActualSize) != 0 {
 		return fmt.Errorf("ResizeInProgress from: %v to: %v",
@@ -242,9 +246,10 @@ func waitAndReverifyResizeStatus(cvcName, sSize string) error {
 	}
 	return nil
 }
-func updateCVCSize(oldCVCObj *apismaya.CStorVolumeClaim, sSize string) error {
+
+func updateCVCSize(oldCVCObj *apismaya.CStorVolumeClaim, sSize resource.Quantity) error {
 	newCVCObj, err := cvc.BuildFrom(oldCVCObj.DeepCopy()).
-		WithCapacity(sSize).Build()
+		WithCapacityQty(sSize).Build()
 	if err != nil {
 		return err
 	}
diff --git a/pkg/utils/v1alpha1/rounding.go b/pkg/utils/v1alpha1/rounding.go
index 19d60c67e..5af0175b1 100644
--- a/pkg/utils/v1alpha1/rounding.go
+++ b/pkg/utils/v1alpha1/rounding.go
@@ -16,10 +16,14 @@ limitations under the License.
 
 package utils
 
-import "fmt"
+import (
+	"fmt"
+)
 
 const (
 	unit = 1024
+	// GiB ...
+	GiB = 1024 * 1024 * 1024
 )
 
 // ByteCount converts bytes into corresponding unit
@@ -35,3 +39,38 @@ func ByteCount(b uint64) string {
 	return fmt.Sprintf("%d%ci",
 		uint64(b)/uint64(div), "KMGTPE"[index])
 }
+
+// RoundUpBytes rounds up the volume size in bytes upto multiplications of GiB
+// in the unit of Bytes
+func RoundUpBytes(volumeSizeBytes int64) int64 {
+	return roundUpSize(volumeSizeBytes, GiB) * GiB
+}
+
+// RoundUpGiB rounds up the volume size in bytes upto multiplications of GiB
+// in the unit of GiB
+func RoundUpGiB(volumeSizeBytes int64) int64 {
+	return roundUpSize(volumeSizeBytes, GiB)
+}
+
+// BytesToGiB converts Bytes to GiB
+func BytesToGiB(volumeSizeBytes int64) int64 {
+	return volumeSizeBytes / GiB
+}
+
+// GiBToBytes converts GiB to Bytes
+func GiBToBytes(volumeSizeGiB int64) int64 {
+	return volumeSizeGiB * GiB
+}
+
+// roundUpSize calculates how many allocation units are needed to accommodate
+// a volume of given size. E.g. when user wants 1500MiB volume, while AWS
+// EBS,GKE etc allocates volumes in gibibyte-sized chunks,
+// RoundUpSize(1500 * 1024*1024, 1024*1024*1024) returns '2'
+// (2 GiB is the smallest allocatable volume that can hold 1500MiB)
+func roundUpSize(volumeSizeBytes int64, allocationUnitBytes int64) int64 {
+	roundedUp := volumeSizeBytes / allocationUnitBytes
+	if volumeSizeBytes%allocationUnitBytes > 0 {
+		roundedUp++
+	}
+	return roundedUp
+}