isolate: move creation of isolate into UploadTracker

client/cmd/isolate/upload_tracker.go

Index: client/cmd/isolate/upload_tracker.go
diff --git a/client/cmd/isolate/upload_tracker.go b/client/cmd/isolate/upload_tracker.go
index 75f37b8cecc572ae216329874e1b0d7ada2972ed..292e0cdd13a11ada0048fb1f378fbb540723e72f 100644
--- a/client/cmd/isolate/upload_tracker.go
+++ b/client/cmd/isolate/upload_tracker.go
@@ -15,9 +15,11 @@
 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"log"
 	"os"
+	"path/filepath"
 
 	humanize "github.com/dustin/go-humanize"
 	"github.com/luci/luci-go/common/isolated"
@@ -28,15 +30,16 @@ import (
 type UploadTracker struct {
 	checker  *Checker
 	uploader *Uploader
-	files    map[string]isolated.File
+	isol     *isolated.Isolated
 }
 
-// NewUploadTracker constructs an UploadTracker.
-func NewUploadTracker(checker *Checker, uploader *Uploader) *UploadTracker {
+// NewUploadTracker constructs an UploadTracker.  It tracks uploaded files in isol.Files.
+func NewUploadTracker(checker *Checker, uploader *Uploader, isol *isolated.Isolated) *UploadTracker {
+	isol.Files = make(map[string]isolated.File)
 	return &UploadTracker{
 		checker:  checker,
 		uploader: uploader,
-		files:    make(map[string]isolated.File),
+		isol:     isol,
 	}
 }
 
@@ -60,7 +63,7 @@ func (ut *UploadTracker) UploadDeps(parts partitionedDeps) error {
 // Note: files may not have completed uploading until the tracker's Checker and
 // Uploader have been closed.
 func (ut *UploadTracker) Files() map[string]isolated.File {
-	return ut.files
+	return ut.isol.Files
 }
 
 // populateSymlinks adds an isolated.File to files for each provided symlink
@@ -70,7 +73,7 @@ func (ut *UploadTracker) populateSymlinks(symlinks []*Item) error {
 		if err != nil {
 			return fmt.Errorf("unable to resolve symlink for %q: %v", item.Path, err)
 		}
-		ut.files[item.RelPath] = isolated.SymLink(l)
+		ut.isol.Files[item.RelPath] = isolated.SymLink(l)
 	}
 	return nil
 }
@@ -97,7 +100,7 @@ func (ut *UploadTracker) tarAndUploadFiles(smallFiles []*Item) error {
 			Mode:    0644, // Read
 			Digest:  digest,
 		}
-		ut.files[item.RelPath] = isolated.TarFile(item.Digest, int(item.Mode), item.Size)
+		ut.isol.Files[item.RelPath] = isolated.TarFile(item.Digest, int(item.Mode), item.Size)
 
 		ut.checker.AddItem(item, false, func(item *Item, ps *isolatedclient.PushState) {
 			if ps == nil {
@@ -121,7 +124,7 @@ func (ut *UploadTracker) uploadFiles(files []*Item) error {
 			return err
 		}
 		item.Digest = d
-		ut.files[item.RelPath] = isolated.BasicFile(item.Digest, int(item.Mode), item.Size)
+		ut.isol.Files[item.RelPath] = isolated.BasicFile(item.Digest, int(item.Mode), item.Size)
 		ut.checker.AddItem(item, false, func(item *Item, ps *isolatedclient.PushState) {
 			if ps == nil {
 				return
@@ -134,3 +137,33 @@ func (ut *UploadTracker) uploadFiles(files []*Item) error {
 	}
 	return nil
 }
+
+// Finalize creates and uploads the isolate JSON at the isolatePath.
+// It returns the corresponding Item and its contents.
+// Finalize should only be called after UploadDeps.
+func (ut *UploadTracker) Finalize(isolatedPath string) (*Item, []byte, error) {
+	// Marshal the isolated file into JSON, and create an Item to describe it.
+	isolJSON, err := json.Marshal(ut.isol)
+	if err != nil {
+		return nil, []byte{}, err
+	}
+	isolItem := &Item{
+		Path:    isolatedPath,
+		RelPath: filepath.Base(isolatedPath),
+		Digest:  isolated.HashBytes(isolJSON),
+		Size:    int64(len(isolJSON)),
+	}
+
+	// Check and upload isolate JSON.
+	ut.checker.AddItem(isolItem, true, func(item *Item, ps *isolatedclient.PushState) {
+		if ps == nil {
+			return
+		}
+		log.Printf("QUEUED %q for upload", item.RelPath)
+		ut.uploader.UploadBytes(item.RelPath, isolJSON, ps, func() {
+			log.Printf("UPLOADED %q", item.RelPath)
+		})
+	})
+
+	return isolItem, isolJSON, nil
+}