diff --git a/cmd/onggi/store.go b/cmd/onggi/store.go
index 36a7f3c..734742c 100644
--- a/cmd/onggi/store.go
+++ b/cmd/onggi/store.go
@@ -365,8 +365,9 @@ func diff(args []string, stdout, stderr io.Writer) int {
fs.SetOutput(stderr)
sf := addStoreFlags(fs)
asJSON := fs.Bool("json", false, "print the diff as JSON")
+ ranges := fs.Bool("ranges", false, "list the changed byte ranges of each file (with --json: [offset, length] pairs)")
if err := fs.Parse(args); err != nil || fs.NArg() != 2 {
- fmt.Fprintln(stderr, "usage: onggi diff --store S [--json] ")
+ fmt.Fprintln(stderr, "usage: onggi diff --store S [--json] [--ranges] ")
return 2
}
ctx := context.Background()
@@ -382,7 +383,7 @@ func diff(args []string, stdout, stderr io.Writer) int {
return 1
}
}
- st, err := s.Diff(ctx, ds[0], ds[1])
+ st, err := s.Diff(ctx, ds[0], ds[1], store.DiffOptions{Ranges: *ranges})
if err != nil {
fmt.Fprintln(stderr, "onggi:", err)
return 1
@@ -412,5 +413,10 @@ func diff(args []string, stdout, stderr io.Writer) int {
fmt.Fprintf(tw, "%s\t%s\t%s\t%s\t%s\t%s\t%d\n", f.Path, f.Base, human(f.Size), human(f.Same), human(f.Moved), human(f.New), f.ChangedRuns)
}
tw.Flush()
+ for _, f := range st.Files {
+ for _, r := range f.Changed {
+ fmt.Fprintf(stdout, "changed %s offset %d length %d (%s)\n", f.Path, r[0], r[1], human(r[1]))
+ }
+ }
return 0
}
diff --git a/pkg/store/diff.go b/pkg/store/diff.go
index b412dbb..4ccb270 100644
--- a/pkg/store/diff.go
+++ b/pkg/store/diff.go
@@ -89,6 +89,15 @@ type FileDiff struct {
SameBlocks int64 `json:"same_blocks"` // bytes in whole BlockSize blocks that are all Same
ChangedRuns int `json:"changed_runs"` // maximal runs of bytes that are not Same
LargestRun int64 `json:"largest_run"`
+ // Changed lists the changed runs as [offset, length] when DiffOptions.Ranges is set (#46):
+ // every other byte is at the same offset in Base. A runtime that holds Base can update only
+ // these ranges.
+ Changed [][2]int64 `json:"changed,omitempty"`
+}
+
+// DiffOptions controls a diff.
+type DiffOptions struct {
+ Ranges bool // list the changed runs of each file
}
// DiffStats sums a diff over the files.
@@ -150,7 +159,7 @@ func abs(x int64) int64 {
}
// Diff compares artifact m against base, both in s.
-func (s *Store) Diff(ctx context.Context, base, m digest.Digest) (DiffStats, error) {
+func (s *Store) Diff(ctx context.Context, base, m digest.Digest, o DiffOptions) (DiffStats, error) {
var st DiffStats
bm, err := s.ReadManifest(ctx, base)
if err != nil {
@@ -214,6 +223,9 @@ func (s *Store) Diff(ctx context.Context, base, m digest.Digest) (DiffStats, err
return
}
fd.ChangedRuns++
+ if o.Ranges {
+ fd.Changed = append(fd.Changed, [2]int64{changedFrom, end - changedFrom})
+ }
fd.LargestRun = max(fd.LargestRun, end-changedFrom)
changedFrom = -1
}
diff --git a/pkg/store/diff_test.go b/pkg/store/diff_test.go
index 9ed13f0..c413f0a 100644
--- a/pkg/store/diff_test.go
+++ b/pkg/store/diff_test.go
@@ -1,6 +1,7 @@
package store
import (
+ "bytes"
"context"
"path/filepath"
"testing"
@@ -28,7 +29,7 @@ func TestDiff(t *testing.T) {
base := pushDir(t, s, map[string][]byte{"decode_B2.rbln": w, "config.json": []byte(`{"batch": 2}`)})
// identical content under another name: all Same, paired by kind
- st, err := s.Diff(ctx, base, pushDir(t, s, map[string][]byte{"decode_B8.rbln": w, "config.json": []byte(`{"batch": 2}`)}))
+ st, err := s.Diff(ctx, base, pushDir(t, s, map[string][]byte{"decode_B8.rbln": w, "config.json": []byte(`{"batch": 2}`)}), DiffOptions{})
if err != nil {
t.Fatal(err)
}
@@ -42,7 +43,7 @@ func TestDiff(t *testing.T) {
// one region overwritten in place
v := append([]byte(nil), w...)
copy(v[3<<20:], random(22, 200<<10))
- st, err = s.Diff(ctx, base, pushDir(t, s, map[string][]byte{"decode_B2.rbln": v}))
+ st, err = s.Diff(ctx, base, pushDir(t, s, map[string][]byte{"decode_B2.rbln": v}), DiffOptions{Ranges: true})
if err != nil {
t.Fatal(err)
}
@@ -57,15 +58,30 @@ func TestDiff(t *testing.T) {
t.Fatalf("no new stored bytes: %+v", st)
}
+ // the ranges cover exactly the bytes that are not at the same offset, in order (#46)
+ var covered, end int64
+ for _, r := range f.Changed {
+ if r[0] < end || r[1] <= 0 || r[0]+r[1] > f.Size {
+ t.Fatalf("ranges out of order or out of the file: %v", f.Changed)
+ }
+ covered, end = covered+r[1], r[0]+r[1]
+ }
+ if len(f.Changed) != f.ChangedRuns || covered != f.Size-f.Same || int64(len(v)) != f.Size {
+ t.Fatalf("ranges %v cover %d B, want %d", f.Changed, covered, f.Size-f.Same)
+ }
+ if !bytes.Equal(v[:f.Changed[0][0]], w[:f.Changed[0][0]]) {
+ t.Fatal("bytes before the first changed range differ from the base")
+ }
+
// the same bytes rearranged in 32 KiB blocks: most found elsewhere in the base, little at the
// same offset; sub-chunks that straddle block boundaries are new
- st, err = s.Diff(ctx, base, pushDir(t, s, map[string][]byte{"decode_B2.rbln": shuffled(w, 23)}))
+ st, err = s.Diff(ctx, base, pushDir(t, s, map[string][]byte{"decode_B2.rbln": shuffled(w, 23)}), DiffOptions{})
if err != nil {
t.Fatal(err)
}
f = st.Files[0]
t.Logf("rearranged: %+v", f)
- if f.Same+f.Moved+f.New != f.Size || f.Moved < f.Size/2 || f.Same > f.Size/10 {
+ if f.Same+f.Moved+f.New != f.Size || f.Moved < f.Size/2 || f.Same > f.Size/10 || f.Changed != nil {
t.Fatalf("rearranged: %+v", f)
}
}