feat: add support for alternative ordering strategies (#424)

1 files changed, 61 insertions, 0 deletions

diff --git a/dive/filetree/order_strategy.go b/dive/filetree/order_strategy.go
new file mode 100644
index 0000000..1838dd8
--- /dev/null
+++ b/dive/filetree/order_strategy.go
@@ -0,0 +1,61 @@
+package filetree
+
+import (
+	"sort"
+)
+
+type SortOrder int
+
+const (
+	ByName = iota
+	BySizeDesc
+
+	NumSortOrderConventions
+)
+
+type OrderStrategy interface {
+	orderKeys(files map[string]*FileNode) []string
+}
+
+func GetSortOrderStrategy(sortOrder SortOrder) OrderStrategy {
+	switch sortOrder {
+	case ByName:
+		return orderByNameStrategy{}
+	case BySizeDesc:
+		return orderBySizeDescStrategy{}
+	}
+	return orderByNameStrategy{}
+}
+
+type orderByNameStrategy struct{}
+
+func (orderByNameStrategy) orderKeys(files map[string]*FileNode) []string {
+	var keys []string
+	for key := range files {
+		keys = append(keys, key)
+	}
+
+	sort.Strings(keys)
+
+	return keys
+}
+
+type orderBySizeDescStrategy struct{}
+
+func (orderBySizeDescStrategy) orderKeys(files map[string]*FileNode) []string {
+	var keys []string
+	for key := range files {
+		keys = append(keys, key)
+	}
+
+	sort.Slice(keys, func(i, j int) bool {
+		ki, kj := keys[i], keys[j]
+		ni, nj := files[ki], files[kj]
+		if ni.GetSize() == nj.GetSize() {
+			return ki < kj
+		}
+		return ni.GetSize() > nj.GetSize()
+	})
+
+	return keys
+}