new plumbing package (#118)

* plumbing: now core was renamed to core, and formats and clients moved inside

1 files changed, 94 insertions, 0 deletions

diff --git a/plumbing/object.go b/plumbing/object.go
new file mode 100644
index 0000000..23abd4f
--- /dev/null
+++ b/plumbing/object.go
@@ -0,0 +1,94 @@
+// package plumbing implement the core interfaces and structs used by go-git
+package plumbing
+
+import (
+	"errors"
+	"io"
+)
+
+var (
+	ErrObjectNotFound = errors.New("object not found")
+	// ErrInvalidType is returned when an invalid object type is provided.
+	ErrInvalidType = errors.New("invalid object type")
+)
+
+// Object is a generic representation of any git object
+type Object interface {
+	Hash() Hash
+	Type() ObjectType
+	SetType(ObjectType)
+	Size() int64
+	SetSize(int64)
+	Reader() (io.ReadCloser, error)
+	Writer() (io.WriteCloser, error)
+}
+
+// ObjectType internal object type
+// Integer values from 0 to 7 map to those exposed by git.
+// AnyObject is used to represent any from 0 to 7.
+type ObjectType int8
+
+const (
+	InvalidObject ObjectType = 0
+	CommitObject  ObjectType = 1
+	TreeObject    ObjectType = 2
+	BlobObject    ObjectType = 3
+	TagObject     ObjectType = 4
+	// 5 reserved for future expansion
+	OFSDeltaObject ObjectType = 6
+	REFDeltaObject ObjectType = 7
+
+	AnyObject ObjectType = -127
+)
+
+func (t ObjectType) String() string {
+	switch t {
+	case CommitObject:
+		return "commit"
+	case TreeObject:
+		return "tree"
+	case BlobObject:
+		return "blob"
+	case TagObject:
+		return "tag"
+	case OFSDeltaObject:
+		return "ofs-delta"
+	case REFDeltaObject:
+		return "ref-delta"
+	case AnyObject:
+		return "any"
+	default:
+		return "unknown"
+	}
+}
+
+func (t ObjectType) Bytes() []byte {
+	return []byte(t.String())
+}
+
+// Valid returns true if t is a valid ObjectType.
+func (t ObjectType) Valid() bool {
+	return t >= CommitObject && t <= REFDeltaObject
+}
+
+// ParseObjectType parses a string representation of ObjectType. It returns an
+// error on parse failure.
+func ParseObjectType(value string) (typ ObjectType, err error) {
+	switch value {
+	case "commit":
+		typ = CommitObject
+	case "tree":
+		typ = TreeObject
+	case "blob":
+		typ = BlobObject
+	case "tag":
+		typ = TagObject
+	case "ofs-delta":
+		typ = OFSDeltaObject
+	case "ref-delta":
+		typ = REFDeltaObject
+	default:
+		err = ErrInvalidType
+	}
+	return
+}