format: Move commitgraph and packfile here

1 files changed, 91 insertions, 0 deletions

diff --git a/format/packfile/ingest/thin_append.go b/format/packfile/ingest/thin_append.go
new file mode 100644
index 00000000..779d477f
--- /dev/null
+++ b/format/packfile/ingest/thin_append.go
@@ -0,0 +1,91 @@
+package ingest
+
+import (
+	"compress/zlib"
+	"hash/crc32"
+	"io"
+
+	"codeberg.org/lindenii/furgit/internal/intconv"
+	objectid "codeberg.org/lindenii/furgit/object/id"
+	objecttype "codeberg.org/lindenii/furgit/object/type"
+)
+
+// appendBaseObject appends one base object as a new packed non-delta entry.
+func appendBaseObject(state *ingestState, id objectid.ObjectID, realType objecttype.Type, content []byte) (int, error) {
+	start := state.stream.consumed
+
+	header := encodePackEntryHeader(realType, int64(len(content)))
+
+	startInt64, err := intconv.Uint64ToInt64(start)
+	if err != nil {
+		return 0, err
+	}
+
+	_, err = state.packFile.WriteAt(header, startInt64)
+	if err != nil {
+		return 0, err
+	}
+
+	headerLenInt64 := int64(len(header))
+	section := &fileSectionWriter{file: state.packFile, off: startInt64 + headerLenInt64}
+	crc := crc32.NewIEEE()
+
+	_, err = crc.Write(header)
+	if err != nil {
+		return 0, err
+	}
+
+	counting := &countingWriter{dst: section}
+
+	zw := zlib.NewWriter(io.MultiWriter(counting, crc))
+
+	_, err = zw.Write(content)
+	if err != nil {
+		return 0, err
+	}
+
+	err = zw.Close()
+	if err != nil {
+		return 0, err
+	}
+
+	headerLenUint64, err := intconv.IntToUint64(len(header))
+	if err != nil {
+		return 0, err
+	}
+
+	countingNUint64, err := intconv.IntToUint64(counting.n)
+	if err != nil {
+		return 0, err
+	}
+
+	packedLen := headerLenUint64 + countingNUint64
+	end := start + packedLen
+	state.stream.consumed = end
+
+	headerLenUint32, err := intconv.IntToUint32(len(header))
+	if err != nil {
+		return 0, err
+	}
+
+	record := objectRecord{
+		offset:       start,
+		headerLen:    headerLenUint32,
+		packedLen:    packedLen,
+		crc32:        crc.Sum32(),
+		packedType:   realType,
+		realType:     realType,
+		declaredSize: int64(len(content)),
+		dataOffset:   start + headerLenUint64,
+		objectID:     id,
+		resolved:     true,
+	}
+
+	recordIdx := len(state.records)
+	state.records = append(state.records, record)
+	state.offsetToRecord[start] = recordIdx
+	state.objectToRecord[id] = recordIdx
+	state.baseCache.add(recordIdx, realType, content)
+
+	return recordIdx, nil
+}