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go/src/infra/libs/git/types.go

Index: go/src/infra/libs/git/types.go
diff --git a/go/src/infra/libs/git/types.go b/go/src/infra/libs/git/types.go
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+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package git
+
+import (
+	"fmt"
+)
+
+// Interfaces //////////////////////////////////////////////////////////////////
+
+type Identifiable interface {
+	ID() *ObjectID
+}
+
+// Object is the barest essence of a git object. It has a Type, and Id, and it
+// can tell you if this instance is 'complete' (does it contain all the data
+// necessary to re-create ID()?).
+//
+// If Complete() is true, you can down-cast this to:
+//   *Tree, *Blob, *Commit
+//
+// If Complete() is false, you can down-cast this to:
+//   *Tree, EmptyObject
+//
+// Note that Tree's are never EmptyObject's.
+type Object interface {
+	Identifiable
+
+	Type() ObjectType
+
+	// Returns True iff RawString will produce a string which, when hashed,
+	// matches ID()
+	Complete() bool
+}
+
+// InternableObject is an Object which may be interned into a git repo
+// (e.g. hash-object'd). EmptyObjects are NOT InternableObjects.
+type InternableObject interface {
+	fmt.Stringer
+	Object
+
+	// A hash-object compatible string. May panic if this is an Object which is
+	// !Complete(). Note that for Trees this does NOT imply that all of the
+	// Tree's children are Complete().
+	RawString() string
+}
+
+type GitService interface {
+	Intern(InternableObject) (*ObjectID, error)
+	HasObjectID(Identifiable) bool
+	GetObjectID(Identifiable) (InternableObject, error)
+	ObjectInfo(string) *ObjectInfo
+}
+
+// Concrete Types //////////////////////////////////////////////////////////////
+
+type ObjectInfo struct {
+	Type ObjectType
+	Size int
+	ID   *ObjectID
+}