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go/src/infra/libs/gitiles/object.go

Index: go/src/infra/libs/gitiles/object.go
diff --git a/go/src/infra/libs/gitiles/object.go b/go/src/infra/libs/gitiles/object.go
new file mode 100644
index 0000000000000000000000000000000000000000..8160b9a9512f8ecab8b9ed1e24851deefcd2b4a7
--- /dev/null
+++ b/go/src/infra/libs/gitiles/object.go
@@ -0,0 +1,77 @@
+// 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 gitiles
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"infra/libs/git"
+)
+
+// GetObjectFromPath returns the git Object at the given commit:path, or an error.
+// This will hit the url:
+//   {g.url}/+/{committish}/path/pieces...?format=TEXT
+// Passing NO pieces will return a git.Commit
+// Passing A blank piece (e.g. empty string) will return a git.Tree for the root
+//   tree.
+// Passing non-blank pieces will return a git.Tree or git.Blob depending on
+//   the path.
+func (g *Gitiles) GetObjectFromPath(committish string, pathPieces ...string) (git.InternableObject, error) {
+	ret := make(chan objectResult, 1)
+	g.requests <- objRequest{
+		textRequest{
+			strings.Join(append([]string{"+", committish}, pathPieces...), "/"),
+			nil,
+		},
+		ret,
+	}
+	rslt := <-ret
+	return rslt.object, rslt.err
+}
+
+// Private
+
+type objectResult struct {
+	err    error
+	object git.InternableObject
+}
+
+type objRequest struct {
+	textRequest
+	resultChan chan<- objectResult
+}
+
+func (o objRequest) Process(rsp *http.Response, err error) {
+	var rslt objectResult
+
+	data, err := o.internalProcess(rsp, err)
+	if err != nil {
+		rslt.err = err
+	} else {
+		typ := rsp.Header.Get("X-Gitiles-Object-Type")
+		switch typ {
+		case "blob":
+			rslt.object = git.BlobFromRaw(data)
+		case "tree":
+			// TODO(iannucci): When gitiles supports format=RAW, use that instead
+			if tree, err := git.TreeFromText(data); err != nil {
+				rslt.err = err
+			} else {
+				rslt.object = tree
+			}
+		case "commit":
+			if c, err := git.CommitFromRaw(data); err != nil {
+				rslt.err = err
+			} else {
+				rslt.object = c
+			}
+		default:
+			rslt.err = fmt.Errorf("Unknown object type %#v", typ)
+		}
+	}
+
+	o.resultChan <- rslt
+}