Use swarming in create_pagesets CT task

ct/go/worker_scripts/create_pagesets/main.go

Index: ct/go/worker_scripts/create_pagesets/main.go
diff --git a/ct/go/worker_scripts/create_pagesets/main.go b/ct/go/worker_scripts/create_pagesets/main.go
index aa2902cf53391c35e7f59af1cdf5c019aa90da6b..38dffab8dc16e3f3de5bb9413dde02bb62287857 100644
--- a/ct/go/worker_scripts/create_pagesets/main.go
+++ b/ct/go/worker_scripts/create_pagesets/main.go
@@ -6,8 +6,8 @@ import (
 	"flag"
 	"io"
 	"os"
+	"path"
 	"path/filepath"
-	"runtime"
 	"time"
 
 	"github.com/skia-dev/glog"
@@ -21,8 +21,9 @@ import (
 )
 
 var (
-	workerNum   = flag.Int("worker_num", 1, "The number of this CT worker. It will be in the {1..100} range.")
-	pagesetType = flag.String("pageset_type", util.PAGESET_TYPE_MOBILE_10k, "The type of pagesets to create from the Alexa CSV list. Eg: 10k, Mobile10k, All.")
+	startRange  = flag.Int("start_range", 1, "The number this worker will start creating page sets from.")
+	num         = flag.Int("num", 100, "The total number of pagesets to process starting from the start_range.")
+	pagesetType = flag.String("pageset_type", util.PAGESET_TYPE_MOBILE_10k, "The type of pagesets to create from the CSV list in util.PagesetTypeToInfo.")
 )
 
 func main() {
@@ -30,14 +31,12 @@ func main() {
 	worker_common.Init()
 	defer util.TimeTrack(time.Now(), "Creating Pagesets")
 	defer glog.Flush()
-	// Create the task file so that the master knows this worker is still busy.
-	skutil.LogErr(util.CreateTaskFile(util.ACTIVITY_CREATING_PAGESETS))
-	defer util.DeleteTaskFile(util.ACTIVITY_CREATING_PAGESETS)
 
 	// Delete and remake the local pagesets directory.
 	pathToPagesets := filepath.Join(util.PagesetsDir, *pagesetType)
 	skutil.RemoveAll(pathToPagesets)
 	skutil.MkdirAll(pathToPagesets, 0700)
+	defer skutil.RemoveAll(pathToPagesets)
 
 	// Get info about the specified pageset type.
 	pagesetTypeInfo := util.PagesetTypeToInfo[*pagesetType]
@@ -70,43 +69,36 @@ func main() {
 		return
 	}
 
-	// Figure out which pagesets this worker should generate.
-	numPagesPerSlave := numPages / util.NumWorkers()
-	if *worker_common.Local {
-		// When running locally, just do 10 pagesets to make things fast.
-		numPagesPerSlave = 10
-	}
-	startNum := (*workerNum-1)*numPagesPerSlave + 1
-	endNum := *workerNum * numPagesPerSlave
+	// Figure out the endRange of this worker.
+	endRange := skutil.MinInt(*startRange+*num-1, numPages)
 
 	// Construct path to the create_page_set.py python script.
-	_, currentFile, _, _ := runtime.Caller(0)
-	createPageSetScript := filepath.Join(
-		filepath.Dir((filepath.Dir(filepath.Dir(filepath.Dir(currentFile))))),
-		"py", "create_page_set.py")
+	pathToPyFiles := util.GetPathToPyFiles(!*worker_common.Local)
+	createPageSetScript := filepath.Join(pathToPyFiles, "create_page_set.py")
 
 	// Execute the create_page_set.py python script.
 	timeoutSecs := util.PagesetTypeToInfo[*pagesetType].CreatePagesetsTimeoutSecs
-	for currNum := startNum; currNum <= endNum; currNum++ {
+	for currNum := *startRange; currNum <= endRange; currNum++ {
+		destDir := path.Join(pathToPagesets, strconv.Itoa(currNum))
+		if err := os.MkdirAll(destDir, 0700); err != nil {
+			glog.Error(err)
+			return
+		}
 		args := []string{
 			createPageSetScript,
 			"-s", strconv.Itoa(currNum),
-			"-e", strconv.Itoa(currNum),
 			"-c", csvFile,
 			"-p", *pagesetType,
 			"-u", userAgent,
-			"-o", pathToPagesets,
+			"-o", destDir,
 		}
 		if err := util.ExecuteCmd("python", args, []string{}, time.Duration(timeoutSecs)*time.Second, nil, nil); err != nil {
 			glog.Error(err)
 			return
 		}
 	}
-	// Write timestamp to the pagesets dir.
-	skutil.LogErr(util.CreateTimestampFile(pathToPagesets))
-
-	// Upload pagesets dir to Google Storage.
-	if err := gs.UploadWorkerArtifacts(util.PAGESETS_DIR_NAME, *pagesetType, *workerNum); err != nil {
+	// Upload all page sets to Google Storage.
+	if err := gs.UploadSwarmingArtifacts(util.PAGESETS_DIR_NAME, *pagesetType); err != nil {
 		glog.Error(err)
 		return
 	}