1 files changed, 58 insertions, 0 deletions
diff --git a/format/commitgraph/read/errors.go b/format/commitgraph/read/errors.go
new file mode 100644
index 00000000..9d0eca04
--- /dev/null
+++ b/format/commitgraph/read/errors.go
@@ -0,0 +1,58 @@
+package read
+
+import (
+	"fmt"
+
+	"codeberg.org/lindenii/furgit/objectid"
+)
+
+// ErrNotFound reports a missing commit graph entry by object ID.
+type ErrNotFound struct {
+	OID objectid.ObjectID
+}
+
+// Error implements error.
+func (err *ErrNotFound) Error() string {
+	return fmt.Sprintf("format/commitgraph: object not found: %s", err.OID)
+}
+
+// ErrPositionOutOfRange reports an invalid graph position.
+type ErrPositionOutOfRange struct {
+	Pos Position
+}
+
+// Error implements error.
+func (err *ErrPositionOutOfRange) Error() string {
+	return fmt.Sprintf("format/commitgraph: position out of range: graph=%d index=%d", err.Pos.Graph, err.Pos.Index)
+}
+
+// ErrMalformed reports malformed commit-graph data.
+type ErrMalformed struct {
+	Path   string
+	Reason string
+}
+
+// Error implements error.
+func (err *ErrMalformed) Error() string {
+	return fmt.Sprintf("format/commitgraph: malformed %q: %s", err.Path, err.Reason)
+}
+
+// ErrUnsupportedVersion reports unsupported commit-graph version.
+type ErrUnsupportedVersion struct {
+	Version uint8
+}
+
+// Error implements error.
+func (err *ErrUnsupportedVersion) Error() string {
+	return fmt.Sprintf("format/commitgraph: unsupported version %d", err.Version)
+}
+
+// ErrBloomUnavailable reports missing changed-path bloom data at one position.
+type ErrBloomUnavailable struct {
+	Pos Position
+}
+
+// Error implements error.
+func (err *ErrBloomUnavailable) Error() string {
+	return fmt.Sprintf("format/commitgraph: bloom unavailable at position graph=%d index=%d", err.Pos.Graph, err.Pos.Index)
+}