1 files changed, 92 insertions, 0 deletions
diff --git a/format/packfile/ingest/entry.go b/format/packfile/ingest/entry.go
new file mode 100644
index 00000000..4e2cab55
--- /dev/null
+++ b/format/packfile/ingest/entry.go
@@ -0,0 +1,92 @@
+package ingest
+
+import (
+	"fmt"
+
+	objecttype "codeberg.org/lindenii/furgit/object/type"
+	packfmt "codeberg.org/lindenii/furgit/format/packfile"
+)
+
+// scanOneEntry scans one pack entry from stream and appends one record.
+func scanOneEntry(state *ingestState, startOffset uint64) (uint64, error) {
+	state.stream.beginEntryCRC()
+
+	record, err := parseEntryPrefix(state, startOffset)
+	if err != nil {
+		return 0, err
+	}
+
+	payloadStartConsumed := state.stream.consumed
+
+	contentLen, oid, err := drainEntryPayload(state, record)
+	if err != nil {
+		return 0, err
+	}
+
+	consumedInput := state.stream.consumed - payloadStartConsumed
+
+	if contentLen != record.declaredSize {
+		return 0, &MalformedPackEntryError{
+			Offset: startOffset,
+			Reason: fmt.Sprintf("inflated size mismatch got %d want %d", contentLen, record.declaredSize),
+		}
+	}
+
+	endOffset := startOffset + uint64(record.headerLen) + consumedInput
+	if endOffset > state.stream.consumed {
+		return 0, &MalformedPackEntryError{
+			Offset: startOffset,
+			Reason: fmt.Sprintf("entry end offset overflow got %d > stream %d", endOffset, state.stream.consumed),
+		}
+	}
+
+	record.packedLen = endOffset - startOffset
+
+	record.dataOffset = startOffset + uint64(record.headerLen)
+	if record.packedLen < uint64(record.headerLen) {
+		return 0, &MalformedPackEntryError{Offset: startOffset, Reason: "negative payload span"}
+	}
+
+	crc, err := state.stream.endEntryCRC()
+	if err != nil {
+		return 0, err
+	}
+
+	record.crc32 = crc
+
+	if packfmt.IsBaseObjectType(record.packedType) {
+		record.objectID = oid
+		record.realType = record.packedType
+		record.resolved = true
+	}
+
+	recordIdx := len(state.records)
+	state.records = append(state.records, record)
+
+	state.offsetToRecord[record.offset] = recordIdx
+	if record.resolved {
+		state.objectToRecord[record.objectID] = recordIdx
+	}
+
+	switch record.packedType {
+	case objecttype.TypeOfsDelta:
+		state.ofsDeltas = append(state.ofsDeltas, ofsDeltaRef{
+			baseOffset: record.baseOffset,
+			recordIdx:  recordIdx,
+		})
+	case objecttype.TypeRefDelta:
+		state.refDeltas = append(state.refDeltas, refDeltaRef{
+			baseObject: record.baseObject,
+			recordIdx:  recordIdx,
+		})
+	case objecttype.TypeInvalid,
+		objecttype.TypeCommit,
+		objecttype.TypeTree,
+		objecttype.TypeBlob,
+		objecttype.TypeTag,
+		objecttype.TypeFuture:
+	default:
+	}
+
+	return endOffset, nil
+}