Revert "packed: Write packs with deltas"

This reverts commit 17c9aee0e781026353ead4ac749a3ae89c83d007.

1 files changed, 7 insertions, 292 deletions

diff --git a/packed_write_test.go b/packed_write_test.go
index 63fd9266..da7ecfa7 100644
--- a/packed_write_test.go
+++ b/packed_write_test.go
@@ -3,15 +3,12 @@ package furgit
 import (
 	"bytes"
 	"crypto/rand"
+	"errors"
 	"fmt"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"strings"
 	"testing"
-
-	"codeberg.org/lindenii/furgit/internal/bufpool"
-	"codeberg.org/lindenii/furgit/internal/zlibx"
 )
 
 func TestPackHeaderEncodeParseRoundtrip(t *testing.T) {
@@ -172,20 +169,7 @@ func TestPackWriteNoDeltas(t *testing.T) {
 		_ = os.Remove(idxPath)
 	}()
 
-	if err := checkPackStream(packPath, repo.hashAlgo, len(objects)); err != nil {
-		t.Fatalf("pack stream invalid: %v", err)
-	}
-
-	cmd := exec.Command("git", "index-pack", "-o", idxPath, packPath)
-	cmd.Dir = repoPath
-	cmd.Env = append(os.Environ(),
-		"GIT_CONFIG_GLOBAL=/dev/null",
-		"GIT_CONFIG_SYSTEM=/dev/null",
-	)
-	output, err := cmd.CombinedOutput()
-	if err != nil {
-		t.Fatalf("git index-pack failed: %v\n%s", err, output)
-	}
+	_ = gitCmd(t, repoPath, "index-pack", "-o", idxPath, packPath)
 
 	verifyOut := gitCmd(t, repoPath, "verify-pack", "-v", idxPath)
 	seen := make(map[string]struct{})
@@ -220,290 +204,21 @@ func TestPackWriteNoDeltas(t *testing.T) {
 	_ = gitCmd(t, repoPath, "fsck", "--full", "--strict")
 }
 
-func TestPackWriteDeltas(t *testing.T) {
+func TestPackWriteDeltasUnimplemented(t *testing.T) {
 	repoPath, cleanup := setupTestRepo(t)
 	defer cleanup()
 
-	workDir, cleanupWork := setupWorkDir(t)
-	defer cleanupWork()
-
-	const (
-		fileCount = 200
-		fileSize  = 2048
-	)
-	base := bytes.Repeat([]byte("delta-base-"), fileSize/10)
-	for i := 0; i < fileCount; i++ {
-		buf := make([]byte, len(base))
-		copy(buf, base)
-		buf[i%len(buf)] ^= byte(i)
-		name := filepath.Join(workDir, fmt.Sprintf("delta%04d.txt", i))
-		if err := os.WriteFile(name, buf, 0o644); err != nil {
-			t.Fatalf("failed to write %s: %v", name, err)
-		}
-	}
-
-	gitCmd(t, repoPath, "--work-tree="+workDir, "add", ".")
-	gitCmd(t, repoPath, "--work-tree="+workDir, "commit", "-m", "Delta commit")
-	commitHash := gitCmd(t, repoPath, "rev-parse", "HEAD")
-
-	commitBody := gitCatFile(t, repoPath, "commit", commitHash)
-	lines := bytes.Split(commitBody, []byte{'\n'})
-	if len(lines) == 0 || !bytes.HasPrefix(lines[0], []byte("tree ")) {
-		t.Fatalf("commit missing tree header")
-	}
-	treeHash := strings.TrimSpace(string(bytes.TrimPrefix(lines[0], []byte("tree "))))
-
-	lsTree := gitCmd(t, repoPath, "ls-tree", "-r", treeHash)
-	var blobHashes []string
-	for _, line := range strings.Split(lsTree, "\n") {
-		if line == "" {
-			continue
-		}
-		fields := strings.Fields(line)
-		if len(fields) < 3 {
-			t.Fatalf("unexpected ls-tree line: %q", line)
-		}
-		blobHashes = append(blobHashes, fields[2])
-	}
-
 	repo, err := OpenRepository(repoPath)
 	if err != nil {
 		t.Fatalf("OpenRepository failed: %v", err)
 	}
 	defer func() { _ = repo.Close() }()
 
-	var objects []Hash
-	commitID, _ := repo.ParseHash(commitHash)
-	objects = append(objects, commitID)
-	treeID, _ := repo.ParseHash(treeHash)
-	objects = append(objects, treeID)
-	for _, bh := range blobHashes {
-		id, _ := repo.ParseHash(bh)
-		objects = append(objects, id)
-	}
-	expectedOids := append([]string{commitHash, treeHash}, blobHashes...)
-
-	packDir := filepath.Join(repoPath, "objects", "pack")
-	if err := os.MkdirAll(packDir, 0o755); err != nil {
-		t.Fatalf("failed to create pack dir: %v", err)
-	}
-	pf, err := os.CreateTemp(packDir, "furgit-delta-test-*.pack")
-	if err != nil {
-		t.Fatalf("failed to create pack file: %v", err)
-	}
-	packPath := pf.Name()
-	idxPath := strings.TrimSuffix(packPath, ".pack") + ".idx"
-	if _, err := repo.packWrite(pf, objects, packWriteOptions{
-		EnableDeltas:    true,
-		MinDeltaSavings: 1,
-	}); err != nil {
-		_ = pf.Close()
-		t.Fatalf("packWrite failed: %v", err)
-	}
-	if err := pf.Close(); err != nil {
-		t.Fatalf("failed to close pack file: %v", err)
-	}
-
-	defer func() {
-		_ = os.Remove(packPath)
-		_ = os.Remove(idxPath)
-	}()
-
-	if err := checkPackStream(packPath, repo.hashAlgo, len(objects)); err != nil {
-		t.Fatalf("pack stream invalid: %v", err)
-	}
-
-	cmd := exec.Command("git", "index-pack", "-o", idxPath, packPath)
-	cmd.Dir = repoPath
-	cmd.Env = append(os.Environ(),
-		"GIT_CONFIG_GLOBAL=/dev/null",
-		"GIT_CONFIG_SYSTEM=/dev/null",
-	)
-	output, err := cmd.CombinedOutput()
-	if err != nil {
-		t.Fatalf("git index-pack failed: %v\n%s", err, output)
-	}
-
-	verifyOut := gitCmd(t, repoPath, "verify-pack", "-v", idxPath)
-	seen := make(map[string]struct{})
-	for _, line := range strings.Split(verifyOut, "\n") {
-		if strings.TrimSpace(line) == "" {
-			continue
-		}
-		if strings.HasPrefix(line, "chain length") || strings.HasPrefix(line, "non delta") {
-			continue
-		}
-		parts := strings.Fields(line)
-		if len(parts) == 0 {
-			continue
-		}
-		seen[parts[0]] = struct{}{}
-	}
-	for _, oid := range expectedOids {
-		if _, ok := seen[oid]; !ok {
-			t.Fatalf("verify-pack missing object %s", oid)
-		}
-	}
-
-	for _, oid := range expectedOids {
-		if err := removeLooseObject(repoPath, oid); err != nil {
-			t.Fatalf("remove loose object %s: %v", oid, err)
-		}
-	}
-	for _, oid := range expectedOids {
-		_ = gitCmd(t, repoPath, "cat-file", "-p", oid)
-	}
-
-	_ = gitCmd(t, repoPath, "fsck", "--full", "--strict")
-}
-
-func checkPackStream(path string, algo hashAlgorithm, objectCount int) error {
-	data, err := os.ReadFile(path)
-	if err != nil {
-		return err
-	}
-	if len(data) < 12 {
-		return ErrInvalidObject
-	}
-	if readBE32(data[0:4]) != packMagic || readBE32(data[4:8]) != packVersion2 {
-		return ErrInvalidObject
-	}
-	pos := 12
-	hashSize := algo.Size()
-	type objEntry struct {
-		offset uint64
-		ty     ObjectType
-		body   []byte
-	}
-	byOffset := make(map[uint64]objEntry, objectCount)
-	byHash := make(map[string]objEntry, objectCount)
-	for i := 0; i < objectCount; i++ {
-		objOffset := uint64(pos)
-		ty, size, consumed, err := packHeaderParse(data[pos:])
-		if err != nil {
-			return fmt.Errorf("obj %d header at %d: %v", i, pos, err)
-		}
-		pos += consumed
-		baseOffset := uint64(0)
-		baseTy := ObjectTypeInvalid
-		var baseBody []byte
-		var baseHash Hash
-		switch ty {
-		case ObjectTypeOfsDelta:
-			dist, distConsumed, err := packDeltaReadOfsDistance(data[pos:])
-			if err != nil {
-				return fmt.Errorf("obj %d ofs at %d: %v", i, pos, err)
-			}
-			pos += distConsumed
-			if dist == 0 || dist > objOffset {
-				return fmt.Errorf("obj %d ofs at %d: invalid dist", i, pos)
-			}
-			baseOffset = objOffset - dist
-			base, ok := byOffset[baseOffset]
-			if !ok {
-				return fmt.Errorf("obj %d ofs at %d: missing base", i, pos)
-			}
-			baseTy = base.ty
-			baseBody = base.body
-		case ObjectTypeRefDelta:
-			if pos+hashSize > len(data) {
-				return ErrInvalidObject
-			}
-			copy(baseHash.data[:], data[pos:pos+hashSize])
-			baseHash.algo = algo
-			baseEntry, ok := byHash[baseHash.String()]
-			if !ok {
-				return fmt.Errorf("obj %d ref base not found", i)
-			}
-			baseTy = baseEntry.ty
-			baseBody = baseEntry.body
-			pos += hashSize
-		default:
-		}
-
-		payloadBuf, zconsumed, err := zlibx.DecompressSized(data[pos:], size)
-		if err != nil {
-			return fmt.Errorf("obj %d zlib at %d: %v", i, pos, err)
-		}
-		payload := append([]byte(nil), payloadBuf.Bytes()...)
-		payloadBuf.Release()
-		pos += zconsumed
-		switch ty {
-		case ObjectTypeOfsDelta:
-			if baseBody == nil {
-				return fmt.Errorf("obj %d missing base body", i)
-			}
-			baseSize, resultSize, err := readDeltaSizes(payload)
-			if err != nil {
-				return fmt.Errorf("obj %d delta sizes: %v", i, err)
-			}
-			if baseSize != len(baseBody) {
-				return fmt.Errorf("obj %d delta base size mismatch: got %d want %d", i, baseSize, len(baseBody))
-			}
-			out, err := packDeltaApply(bufpool.FromOwned(baseBody), bufpool.FromOwned(payload))
-			if err != nil {
-				return fmt.Errorf("obj %d delta apply: %v", i, err)
-			}
-			body := append([]byte(nil), out.Bytes()...)
-			out.Release()
-			if resultSize != len(body) {
-				return fmt.Errorf("obj %d delta result size mismatch: got %d want %d", i, len(body), resultSize)
-			}
-			byOffset[objOffset] = objEntry{offset: objOffset, ty: baseTy, body: body}
-		case ObjectTypeRefDelta:
-			if baseBody == nil {
-				return fmt.Errorf("obj %d missing ref base body", i)
-			}
-			baseSize, resultSize, err := readDeltaSizes(payload)
-			if err != nil {
-				return fmt.Errorf("obj %d ref delta sizes: %v", i, err)
-			}
-			if baseSize != len(baseBody) {
-				return fmt.Errorf("obj %d ref delta base size mismatch: got %d want %d", i, baseSize, len(baseBody))
-			}
-			out, err := packDeltaApply(bufpool.FromOwned(baseBody), bufpool.FromOwned(payload))
-			if err != nil {
-				return fmt.Errorf("obj %d ref delta apply: %v", i, err)
-			}
-			body := append([]byte(nil), out.Bytes()...)
-			out.Release()
-			if resultSize != len(body) {
-				return fmt.Errorf("obj %d ref delta result size mismatch: got %d want %d", i, len(body), resultSize)
-			}
-			byOffset[objOffset] = objEntry{offset: objOffset, ty: baseTy, body: body}
-		default:
-			if size >= 0 && len(payload) != size {
-				return fmt.Errorf("obj %d size mismatch: got %d want %d", i, len(payload), size)
-			}
-			body := append([]byte(nil), payload...)
-			byOffset[objOffset] = objEntry{offset: objOffset, ty: ty, body: body}
-		}
-
-		entry := byOffset[objOffset]
-		if entry.body != nil && entry.ty != ObjectTypeInvalid {
-			hdr, err := headerForType(entry.ty, entry.body)
-			if err != nil {
-				return err
-			}
-			raw := append(hdr, entry.body...)
-			hash := algo.Sum(raw)
-			byHash[hash.String()] = entry
-		}
-	}
-	return nil
-}
-
-func readDeltaSizes(delta []byte) (int, int, error) {
-	pos := 0
-	baseSize, err := packVarintRead(delta, &pos)
-	if err != nil {
-		return 0, 0, err
-	}
-	resultSize, err := packVarintRead(delta, &pos)
-	if err != nil {
-		return 0, 0, err
+	buf := new(bytes.Buffer)
+	_, err = repo.packWrite(buf, nil, packWriteOptions{EnableDeltas: true})
+	if !errors.Is(err, errPackDeltaUnimplemented) {
+		t.Fatalf("expected errPackDeltaUnimplemented, got %v", err)
 	}
-	return baseSize, resultSize, nil
 }
 
 func removeLooseObject(repoPath, oid string) error {