stop using pointer in ImageTag (#7)

internal/report/table.go

@@ -19,6 +19,7 @@ type TableWriter struct {
 func (w TableWriter) Write(tags types.ImageTags) (err error) {
 	table := tablewriter.NewWriter(os.Stdout)
 	table.SetHeader([]string{"Tag", "Size", "Created At", "Uploaded At"})
+
 	for _, tag := range tags {
 		table.Append([]string{
 			strings.Join(tag.Tags, ","),
@@ -33,16 +34,16 @@ func (w TableWriter) Write(tags types.ImageTags) (err error) {
 	return nil
 }
 
-func getBytesize(b *int) string {
-	if b == nil {
+func getBytesize(b int) string {
+	if b == 0 {
 		return "-"
 	}
-	return utils.ByteSize(*b)
+	return utils.ByteSize(b)
 }
 
-func ttos(t *time.Time) string {
-	if t == nil {
+func ttos(t time.Time) string {
+	if t.IsZero() {
 		return "NULL"
 	}
-	return (*t).Format(time.RFC3339)
+	return t.Format(time.RFC3339)
 }

internal/types/types.go

@@ -2,8 +2,10 @@ package types
 
 import "time"
 
-const ITEM_PER_PAGE = 10
+// ImagePerPage :
+const ImagePerPage = 10
 
+// RequestOption : container registry information
 type RequestOption struct {
 	MaxCount        int
 	AuthURL         string
@@ -17,29 +19,31 @@ type RequestOption struct {
 	Timeout         time.Duration
 }
 
+// FilterOption : tag pattern
 type FilterOption struct {
 	Contain string
 }
 
+// ImageTag : tag information
 type ImageTag struct {
-	Tags       []string   `json:"tags"`
-	Byte       *int       `json:"byte"`
-	CreatedAt  *time.Time `json:"created_at"`
-	UploadedAt *time.Time `json:"uploaded_at"`
+	Tags       []string  `json:"tags"`
+	Byte       int       `json:"byte"`
+	CreatedAt  time.Time `json:"created_at"`
+	UploadedAt time.Time `json:"uploaded_at"`
 }
 
+// ImageTags : tag information slice
 type ImageTags []ImageTag
 
 func (t ImageTags) Len() int      { return len(t) }
 func (t ImageTags) Swap(i, j int) { t[i], t[j] = t[j], t[i] }
 func (t ImageTags) Less(i, j int) bool {
-	if t[i].UploadedAt != nil && t[j].UploadedAt != nil {
-		return (*(t[i].UploadedAt)).After(*(t[j].UploadedAt))
+	if !t[i].UploadedAt.IsZero() && !t[j].UploadedAt.IsZero() {
+		return (t[i].UploadedAt).After((t[j].UploadedAt))
 	}
 
-	if t[i].CreatedAt != nil && t[j].CreatedAt != nil {
-		return (*(t[i].CreatedAt)).After(*(t[j].CreatedAt))
+	if !t[i].CreatedAt.IsZero() && !t[j].CreatedAt.IsZero() {
+		return (t[i].CreatedAt).After((t[j].CreatedAt))
 	}
-
 	return true
 }

pkg/provider/dockerhub/dockerhub.go

@@ -92,8 +92,8 @@ func (p *DockerHub) convertResultToTag(summaries []ImageSummary) types.ImageTags
 		}
 		tags = append(tags, types.ImageTag{
 			Tags:      tagNames,
-			Byte:      &detail.FullSize,
-			CreatedAt: &createdAt,
+			Byte:      detail.FullSize,
+			CreatedAt: createdAt,
 		})
 	}
 	return tags
@@ -113,11 +113,11 @@ func getTagResponse(ctx context.Context, auth dockertypes.AuthConfig, timeout ti
 }
 
 func calcMaxRequestPage(totalCnt, needCnt int, option *types.FilterOption) int {
-	maxPage := totalCnt/types.ITEM_PER_PAGE + 1
+	maxPage := totalCnt/types.ImagePerPage + 1
 	if needCnt == 0 || option.Contain != "" {
 		return maxPage
 	}
-	needPage := needCnt/types.ITEM_PER_PAGE + 1
+	needPage := needCnt/types.ImagePerPage + 1
 	if needPage >= maxPage {
 		return maxPage
 	}

pkg/provider/ecr/aws.go

@@ -76,11 +76,15 @@ func (p *ECR) Run(ctx context.Context, domain, repository string, reqOpt *types.
 			continue
 		}
 
+		var pushedAt time.Time
+		if detail.ImagePushedAt != nil {
+			pushedAt = *detail.ImagePushedAt
+		}
 		imageTags = append(imageTags, types.ImageTag{
 			Tags:       tags,
 			Byte:       getIntByte(detail.ImageSizeInBytes),
-			CreatedAt:  nil,
-			UploadedAt: detail.ImagePushedAt,
+			CreatedAt:  time.Time{},
+			UploadedAt: pushedAt,
 		})
 	}
 
@@ -110,10 +114,9 @@ func getSession(option *types.RequestOption) (*session.Session, error) {
 	})
 }
 
-func getIntByte(b *int64) *int {
+func getIntByte(b *int64) int {
 	if b == nil {
-		return nil
+		return 0
 	}
-	i := int(*b)
-	return &i
+	return int(*b)
 }

pkg/provider/gcr/gcr.go

@@ -76,8 +76,8 @@ func (p *GCR) Run(ctx context.Context, domain, repository string, reqOpt *types.
 		imageTags = append(imageTags, types.ImageTag{
 			Tags:       detail.Tag,
 			Byte:       getIntByte(detail.ImageSizeBytes),
-			CreatedAt:  &createdAt,
-			UploadedAt: &uploadedAt,
+			CreatedAt:  createdAt,
+			UploadedAt: uploadedAt,
 		})
 	}
 	return imageTags, nil
@@ -141,10 +141,10 @@ func (p *GCR) getCredential(ctx context.Context) (username, password string, err
 	return helper.Get(p.domain)
 }
 
-func getIntByte(strB string) *int {
+func getIntByte(strB string) int {
 	b, err := strconv.Atoi(strB)
 	if err != nil {
-		return nil
+		return 0
 	}
-	return &b
+	return b
 }