From cbe8b458b2cc44c79e075cc061f8b452566e9de7 Mon Sep 17 00:00:00 2001
From: Valentin Rothberg <vrothberg@redhat.com>
Date: Mon, 17 Oct 2022 14:26:03 +0200
Subject: [PATCH] libimage: add LayersDiskUsage

Add an API to query the sum of the layer sizes.  This data is needed to
fix containers/podman/issues/16135.

Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>
---
 libimage/corrupted_test.go |  2 ++
 libimage/disk_usage.go     | 14 ++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/libimage/corrupted_test.go b/libimage/corrupted_test.go
index 011d9953a..685419d0a 100644
--- a/libimage/corrupted_test.go
+++ b/libimage/corrupted_test.go
@@ -43,6 +43,8 @@ func TestCorruptedLayers(t *testing.T) {
 	// Disk usage works.
 	_, err = runtime.DiskUsage(ctx)
 	require.NoError(t, err, "disk usage works on healthy image")
+	_, err = runtime.LayersDiskUsage(ctx)
+	require.NoError(t, err, "layers disk usage works on healthy image")
 
 	// Now remove one layer from the layers.json index in the storage.  The
 	// image will still be listed in the container storage but attempting
diff --git a/libimage/disk_usage.go b/libimage/disk_usage.go
index 2cde09846..455bbec55 100644
--- a/libimage/disk_usage.go
+++ b/libimage/disk_usage.go
@@ -5,6 +5,20 @@ import (
 	"time"
 )
 
+// LayersDiskUsage returns the sum of the size of all layers in the current store.
+func (r *Runtime) LayersDiskUsage(ctx context.Context) (int64, error) {
+	layers, err := r.store.Layers()
+	if err != nil {
+		return -1, err
+	}
+
+	var size int64
+	for _, l := range layers {
+		size += l.UncompressedSize
+	}
+
+	return size, nil
+}
 // ImageDiskUsage reports the total size of an image.  That is the size
 type ImageDiskUsage struct {
 	// Number of containers using the image.