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// License: GPLv3 Copyright: 2023, Kovid Goyal, <kovid at kovidgoyal.net>
package rsync
import (
"bytes"
"encoding/hex"
"fmt"
"io"
"slices"
"strconv"
"strings"
"testing"
"github.com/google/go-cmp/cmp"
"github.com/kovidgoyal/kitty/tools/utils"
)
var _ = fmt.Print
var _ = cmp.Diff
func run_roundtrip_test(t *testing.T, src_data, changed []byte, num_of_patches, total_patch_size int) {
using_serialization := false
t.Helper()
prefix_msg := func() string {
q := utils.IfElse(using_serialization, "with", "without")
return fmt.Sprintf("Running %s serialization: src size: %d changed size: %d difference: %d\n",
q, len(src_data), len(changed), len(changed)-len(src_data))
}
test_equal := func(src_data, output []byte) {
if !bytes.Equal(src_data, output) {
first_diff := min(len(src_data), len(output))
for i := 0; i < first_diff; i++ {
if src_data[i] != output[i] {
first_diff = i
break
}
}
t.Fatalf("%sPatching failed: %d extra_bytes first different byte at: %d\nsrc:\n%s\nchanged:\n%s\noutput:\n%s\n",
prefix_msg(), len(output)-len(src_data), first_diff, string(src_data), string(changed), string(output))
}
}
// first try just the engine without serialization
p := NewPatcher(int64(len(src_data)))
signature := make([]BlockHash, 0, 128)
s_it := p.rsync.CreateSignatureIterator(bytes.NewReader(changed))
for {
s, err := s_it()
if err == nil {
signature = append(signature, s)
} else if err == io.EOF {
break
} else {
t.Fatal(err)
}
}
total_data_in_delta := 0
apply_delta := func(signature []BlockHash) []byte {
delta_ops, err := p.rsync.CreateDelta(bytes.NewReader(src_data), signature)
if err != nil {
t.Fatal(err)
}
if delta_ops[len(delta_ops)-1].Type != OpHash {
t.Fatalf("Last operation was not OpHash")
}
total_data_in_delta = 0
outputbuf := bytes.Buffer{}
for _, op := range delta_ops {
if op.Type == OpData {
total_data_in_delta += len(op.Data)
}
p.rsync.ApplyDelta(&outputbuf, bytes.NewReader(changed), op)
}
return outputbuf.Bytes()
}
test_equal(src_data, apply_delta(signature))
limit := 2 * (p.rsync.BlockSize * num_of_patches)
if limit > -1 && total_data_in_delta > limit {
t.Fatalf("%sUnexpectedly poor delta performance: total_patch_size: %d total_delta_size: %d limit: %d", prefix_msg(), total_patch_size, total_data_in_delta, limit)
}
// Now try with serialization
using_serialization = true
p = NewPatcher(int64(len(changed)))
signature_of_changed := bytes.Buffer{}
ss_it := p.CreateSignatureIterator(bytes.NewReader(changed), &signature_of_changed)
var err error
for {
err = ss_it()
if err == io.EOF {
break
} else if err != nil {
t.Fatal(err)
}
}
d := NewDiffer()
if err := d.AddSignatureData(signature_of_changed.Bytes()); err != nil {
t.Fatal(err)
}
db := bytes.Buffer{}
it := d.CreateDelta(bytes.NewBuffer(src_data), &db)
for {
if err := it(); err != nil {
if err == io.EOF {
break
}
t.Fatal(err)
}
}
deltabuf := db.Bytes()
outputbuf := bytes.Buffer{}
p.StartDelta(&outputbuf, bytes.NewReader(changed))
for len(deltabuf) > 0 {
n := min(123, len(deltabuf))
if err := p.UpdateDelta(deltabuf[:n]); err != nil {
t.Fatal(err)
}
deltabuf = deltabuf[n:]
}
if err := p.FinishDelta(); err != nil {
t.Fatal(err)
}
test_equal(src_data, outputbuf.Bytes())
if limit > -1 && p.total_data_in_delta > limit {
t.Fatalf("%sUnexpectedly poor delta performance: total_patch_size: %d total_delta_size: %d limit: %d", prefix_msg(), total_patch_size, p.total_data_in_delta, limit)
}
}
func generate_data(block_size, num_of_blocks int, extra ...string) []byte {
e := strings.Join(extra, "")
ans := make([]byte, num_of_blocks*block_size+len(e))
utils.Memset(ans, '_')
for i := 0; i < num_of_blocks; i++ {
offset := i * block_size
copy(ans[offset:], strconv.Itoa(i))
}
copy(ans[num_of_blocks*block_size:], e)
return ans
}
func patch_data(data []byte, patches ...string) (num_of_patches, total_patch_size int) {
num_of_patches = len(patches)
for _, patch := range patches {
o, r, _ := strings.Cut(patch, ":")
total_patch_size += len(r)
if offset, err := strconv.Atoi(o); err == nil {
copy(data[offset:], r)
} else {
panic(err)
}
}
return
}
func TestRsyncRoundtrip(t *testing.T) {
block_size := 16
src_data := generate_data(block_size, 16)
changed := slices.Clone(src_data)
num_of_patches, total_patch_size := patch_data(changed, "3:patch1", "16:patch2", "130:ptch3", "176:patch4", "222:XXYY")
run_roundtrip_test(t, src_data, src_data[block_size:], 1, block_size)
run_roundtrip_test(t, src_data, changed, num_of_patches, total_patch_size)
run_roundtrip_test(t, src_data, []byte{}, -1, 0)
run_roundtrip_test(t, src_data, src_data, 0, 0)
run_roundtrip_test(t, src_data, changed[:len(changed)-3], num_of_patches, total_patch_size)
run_roundtrip_test(t, src_data, append(changed[:37], changed[81:]...), num_of_patches, total_patch_size)
block_size = 13
src_data = generate_data(block_size, 17, "trailer")
changed = slices.Clone(src_data)
num_of_patches, total_patch_size = patch_data(changed, "0:patch1", "19:patch2")
run_roundtrip_test(t, src_data, changed, num_of_patches, total_patch_size)
run_roundtrip_test(t, src_data, changed[:len(changed)-3], num_of_patches, total_patch_size)
run_roundtrip_test(t, src_data, append(changed, "xyz..."...), num_of_patches, total_patch_size)
}
func TestRsyncHashers(t *testing.T) {
h := new_xxh3_64()
h.Write([]byte("abcd"))
if diff := cmp.Diff(hex.EncodeToString(h.Sum(nil)), `6497a96f53a89890`); diff != "" {
t.Fatalf("%s", diff)
}
if diff := cmp.Diff(h.Sum64(), uint64(7248448420886124688)); diff != "" {
t.Fatalf("%s", diff)
}
h2 := new_xxh3_128()
h2.Write([]byte("abcd"))
if diff := cmp.Diff(hex.EncodeToString(h2.Sum(nil)), `8d6b60383dfa90c21be79eecd1b1353d`); diff != "" {
t.Fatalf("%s", diff)
}
}
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