golden/pdfxform a pdf rasterization server

golden/go/pdfxform/main.go

Index: golden/go/pdfxform/main.go
diff --git a/golden/go/pdfxform/main.go b/golden/go/pdfxform/main.go
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+// pdfxform is a server that rasterizes PDF documents into PNG
+package main
+
+import (
+	"bytes"
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"os/user"
+	"path"
+	"path/filepath"
+	"strings"
+	"time"
+
+	"github.com/skia-dev/glog"
+	"go.skia.org/infra/go/auth"
+	"go.skia.org/infra/go/common"
+	"go.skia.org/infra/go/gs"
+	"go.skia.org/infra/go/pdf"
+	"go.skia.org/infra/go/util"
+	"go.skia.org/infra/perf/go/goldingester"
+	"google.golang.org/api/storage/v1"
+)
+
+////////////////////////////////////////////////////////////////////////////////
+
+const (
+	PNG_EXT = "png"
+	PDF_EXT = "pdf"
+)
+
+////////////////////////////////////////////////////////////////////////////////
+
+// md5OfFile calculates the MD5 checksum of a file.
+func md5OfFile(path string) (string, error) {
+	md5 := md5.New()
+	f, err := os.Open(path)
+	if err != nil {
+		return "", err
+	}
+	defer util.Close(f)
+	if _, err = io.Copy(md5, f); err != nil {
+		return "", err
+	}
+	return hex.EncodeToString(md5.Sum(nil)), nil
+}
+
+// removeIfExists is like util.Remove, but logs no error if the file does not exist.
+func removeIfExists(path string) {
+	if err := os.Remove(path); err != nil {
+		if !os.IsNotExist(err) {
+			glog.Errorf("Failed to Remove(%s): %v", path, err)
+		}
+	}
+}
+
+// isPDF returns true if the path appears to point to a PDF file.
+func isPDF(path string) bool {
+	f, err := os.Open(path)
+	if err != nil {
+		return false
+	}
+	defer util.Close(f)
+	buffer := make([]byte, 4)
+	if n, err := f.Read(buffer); n != 4 || err != nil {
+		return false
+	}
+	return string(buffer) == "%PDF"
+}
+
+// writeTo opens a file and dumps the contents of the reader into it.
+func writeTo(path string, reader *io.ReadCloser) error {
+	defer util.Close(*reader)
+	file, err := os.Create(path)
+	if err == nil {
+		_, err = io.Copy(file, *reader)
+	}
+	return err
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+// storageClient struct is used for uploading to cloud storage
+type storageClient struct {
+	httpClient     *http.Client
+	storageService *storage.Service
+}
+
+// getClient returns an authorized storage.Service and the
+// corresponding http.Client; if anything goes wrong, it logs a fatal
+// error.
+func getClient() (storageClient, error) {
+	var client *http.Client
+	var err error
+	if *local {
+		client, err = auth.RunFlow(auth.OAuthConfig(*oauthCacheFile, auth.SCOPE_FULL_CONTROL))
+		// TODO(stephana): Replace auth.RunFlow with auth.NewClient
+		// client, err = auth.NewClient(true, *oauthCacheFile, auth.SCOPE_FULL_CONTROL, auth.SCOPE_GCE)
+	} else {
+		client = auth.GCEServiceAccountClient(&http.Transport{Dial: util.DialTimeout})
+	}
+	if err != nil {
+		return storageClient{}, err
+	}
+	gsService, err := storage.New(client)
+	if err != nil {
+		return storageClient{}, err
+	}
+	return storageClient{httpClient: client, storageService: gsService}, nil
+}
+
+// gsFetch fetch the object's data from google storage
+func gsFetch(object *storage.Object, sc storageClient) (io.ReadCloser, int64, error) {
+	request, err := gs.RequestForStorageURL(object.MediaLink)
+	if err != nil {
+		return nil, -1, err
+	}
+	resp, err := sc.httpClient.Do(request)
+	if err != nil {
+		return nil, -1, err
+	}
+	if resp.StatusCode != 200 {
+		_ = resp.Body.Close()
+		return nil, -1, fmt.Errorf("Failed to retrieve: %s %d %s", object.MediaLink, resp.StatusCode, resp.Status)
+	}
+	return resp.Body, resp.ContentLength, nil
+}
+
+// uploadFile uploads the specified file to the remote dir in Google
+// Storage. It also sets the appropriate ACLs on the uploaded file.
+// If the file already exists on the server, do nothing.
+func uploadFile(sc storageClient, input io.Reader, storageBucket, storagePath, accessControlEntity string) (bool, error) {
+	obj, _ := sc.storageService.Objects.Get(storageBucket, storagePath).Do()
+	if obj != nil {
+		return false, nil // noclobber
+	}
+	fullPath := fmt.Sprintf("gs://%s/%s", storageBucket, storagePath)
+	object := &storage.Object{Name: storagePath}
+	if _, err := sc.storageService.Objects.Insert(storageBucket, object).Media(input).Do(); err != nil {
+		return false, fmt.Errorf("Objects.Insert(%s) failed: %s", fullPath, err)
+	}
+	objectAcl := &storage.ObjectAccessControl{
+		Bucket: storageBucket, Entity: accessControlEntity, Object: storagePath, Role: "READER",
+	}
+	if _, err := sc.storageService.ObjectAccessControls.Insert(storageBucket, storagePath, objectAcl).Do(); err != nil {
+		return false, fmt.Errorf("Could not update ACL of %s: %s", fullPath, err)
+	}
+	return true, nil
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+var (
+	local                  = flag.Bool("local", false, "Set to true if not running in prod")
+	oauthCacheFile         = flag.String("oauth_cache_file", "oauth_cache.dat", "Path to look for and store an OAuth token")
+	dataDir                = flag.String("data_dir", "", "Directory to store data in.")
+	failureImage           = flag.String("failure_image", "", "Location of a PNG image; must be set")
+	storageBucket          = flag.String("storage_bucket", "chromium-skia-gm", "The bucket for json, pdf, and png files")
+	storageJsonDirectory   = flag.String("storage_json_directory", "dm-json-v1", "The directory on bucket for json files.")
+	storageImagesDirectory = flag.String("storage_images_directory", "dm-images-v1", "The directory on bucket for png and pdf files.")
+	accessControlEntity    = flag.String("access_control_entity", "domain-google.com", "The entity that has permissions to manage the bucket")
+	graphiteServer         = flag.String("graphite_server", "skia-monitoring:2003", "Where the Graphite metrics ingestion server is running")
+)
+
+// The pdfXformer struct holds state
+type pdfXformer struct {
+	client        storageClient
+	rasterizers   []pdf.Rasterizer
+	results       map[string]map[int]string
+	counter       int
+	identifier    string
+	errorImageMd5 string
+}
+
+// rasterizeOnce applies a single rastetizer to the given pdf file.
+// If the rasterizer fails, use the errorImage.  If everything
+// succeeds, upload the PNG.
+func (xformer *pdfXformer) rasterizeOnce(pdfPath string, rasterizerIndex int) (string, error) {
+	rasterizer := xformer.rasterizers[rasterizerIndex]
+	tempdir := filepath.Dir(pdfPath)
+	pngPath := path.Join(tempdir, fmt.Sprintf("%s.%s", rasterizer.String(), PNG_EXT))
+	defer removeIfExists(pngPath)
+	glog.Infof("> > > > rasterizing with %s", rasterizer)
+	err := rasterizer.Rasterize(pdfPath, pngPath)
+	if err != nil {
+		glog.Warningf("rasterizing %s with %s failed: %s", filepath.Base(pdfPath), rasterizer.String(), err)
+		return xformer.errorImageMd5, nil
+	}
+	md5, err := md5OfFile(pngPath)
+	if err != nil {
+		return "", err
+	}
+	f, err := os.Open(pngPath)
+	if err != nil {
+		return "", err
+	}
+	defer util.Close(f)
+	pngUploadPath := fmt.Sprintf("%s/%s.%s", *storageImagesDirectory, md5, PNG_EXT)
+	didUpload, err := uploadFile(xformer.client, f, *storageBucket, pngUploadPath, *accessControlEntity)
+	if err != nil {
+		return "", err
+	}
+	if didUpload {
+		glog.Infof("> > > > uploaded %s", pngUploadPath)
+	}
+	return md5, nil
+}
+
+// makeTmpDir returns a nicely-named directory for temp files in $TMPDIR
+func (xformer *pdfXformer) makeTmpDir() (string, error) {
+	if xformer.identifier == "" {
+		var host, userName string
+		if h, err := os.Hostname(); err == nil {
+			host = h
+			if i := strings.Index(host, "."); i >= 0 {
+				host = host[:i]
+			}
+		}
+		if currentUser, err := user.Current(); err == nil {
+			userName = currentUser.Username
+		}
+		userName = strings.Replace(userName, `\`, "_", -1)
+		xformer.identifier = fmt.Sprintf("%s.%s.%s.tmp.%d.", filepath.Base(os.Args[0]), host, userName, os.Getpid())
+	}
+	return ioutil.TempDir(*dataDir, xformer.identifier)
+}
+
+func newResult(key map[string]string, rasterizerName, digest string) *goldingester.Result {
+	keyCopy := map[string]string{}
+	for k, v := range key {
+		keyCopy[k] = v
+	}
+	keyCopy["rasterizer"] = rasterizerName
+	options := map[string]string{"ext": PNG_EXT}
+	return &goldingester.Result{Key: keyCopy, Digest: digest, Options: options}
+}
+
+// processResult rasterizes a single PDF result and returns a set of new results.
+func (xformer *pdfXformer) processResult(res goldingester.Result) []*goldingester.Result {
+	rasterizedResults := []*goldingester.Result{}
+	resultMap, found := xformer.results[res.Digest]
+	if found {
+		// Skip rasterizion steps: big win.
+		for index, rasterizer := range xformer.rasterizers {
+			digest, ok := resultMap[index]
+			if ok {
+				rasterizedResults = append(rasterizedResults,
+					newResult(res.Key, rasterizer.String(), digest))
+			} else {
+				glog.Errorf("missing rasterizer %s on %s", rasterizer.String(), res.Digest)
+			}
+		}
+		return rasterizedResults
+	}
+
+	tempdir, err := xformer.makeTmpDir()
+	if err != nil {
+		glog.Errorf("error making temp directory: %s", err)
+		return rasterizedResults
+	}
+	defer util.RemoveAll(tempdir)
+	pdfPath := path.Join(tempdir, fmt.Sprintf("%s.pdf", res.Digest))
+	objectName := fmt.Sprintf("%s/%s.pdf", *storageImagesDirectory, res.Digest)
+	storageURL := fmt.Sprintf("gs://%s/%s", *storageBucket, objectName)
+	object, err := xformer.client.storageService.Objects.Get(*storageBucket, objectName).Do()
+	if err != nil {
+		glog.Errorf("unable to find %s: %s", storageURL, err)
+		return []*goldingester.Result{}
+	}
+	pdfData, _, err := gsFetch(object, xformer.client)
+	if err != nil {
+		glog.Errorf("unable to retrieve %s: %s", storageURL, err)
+		return []*goldingester.Result{}
+	}
+	err = writeTo(pdfPath, &pdfData)
+	if err != nil {
+		glog.Errorf("unable to write file %s: %s", pdfPath, err)
+		return []*goldingester.Result{}
+	}
+	if !isPDF(pdfPath) {
+		glog.Errorf("%s is not a PDF", objectName)
+		return []*goldingester.Result{}
+	}
+	resultMap = map[int]string{}
+	for index, rasterizer := range xformer.rasterizers {
+		digest, err := xformer.rasterizeOnce(pdfPath, index)
+		if err != nil {
+			glog.Errorf("rasterizer %s failed on %s.pdf: %s", rasterizer, res.Digest, err)
+			continue
+		}
+		rasterizedResults = append(rasterizedResults,
+			newResult(res.Key, rasterizer.String(), digest))
+		resultMap[index] = digest
+	}
+	xformer.results[res.Digest] = resultMap
+	return rasterizedResults
+}
+
+// processJsonFile reads a json file and produces a new json file
+// with rasterized results.
+func (xformer *pdfXformer) processJsonFile(jsonFileObject *storage.Object) {
+	jsonURL := fmt.Sprintf("gs://%s/%s", *storageBucket, jsonFileObject.Name)
+	if jsonFileObject.Metadata["rasterized"] == "true" {
+		glog.Infof("> > skipping %s (already processed) {%d}", jsonURL, xformer.counter)
+		return
+	}
+	body, length, err := gsFetch(jsonFileObject, xformer.client)
+	if err != nil {
+		glog.Errorf("Failed to fetch %s", jsonURL)
+		return
+	}
+	if 0 == length {
+		util.Close(body)
+		glog.Infof("> > skipping %s (empty file) {%d}", jsonURL, xformer.counter)
+		return
+	}
+	dmstruct := goldingester.DMResults{}
+	err = json.NewDecoder(body).Decode(&dmstruct)
+	util.Close(body)
+	if err != nil {
+		glog.Errorf("Failed to parse %s", jsonURL)
+		return
+	}
+	countPdfResults := 0
+	for _, res := range dmstruct.Results {
+		if res.Options["ext"] == PDF_EXT {
+			countPdfResults++
+		}
+	}
+	if 0 == countPdfResults {
+		glog.Infof("> > 0 PDFs found %s {%d}", jsonURL, xformer.counter)
+		xformer.setRasterized(jsonFileObject)
+		return
+	}
+
+	glog.Infof("> > processing %d pdfs of %d results {%d}", countPdfResults, len(dmstruct.Results), xformer.counter)
+	rasterizedResults := []*goldingester.Result{}
+	i := 0
+	for _, res := range dmstruct.Results {
+		if res.Options["ext"] == PDF_EXT {
+			i++
+			glog.Infof("> > > processing %s.pdf [%d/%d] {%d}", res.Digest, i, countPdfResults, xformer.counter)
+			rasterizedResults = append(rasterizedResults, xformer.processResult(*res)...)
+		}
+	}
+	newDMStruct := goldingester.DMResults{
+		BuildNumber: dmstruct.BuildNumber,
+		GitHash:     dmstruct.GitHash,
+		Key:         dmstruct.Key,
+		Results:     rasterizedResults,
+	}
+	newJson, err := json.Marshal(newDMStruct)
+	if err != nil {
+		glog.Errorf("Unexpected json.Marshal error: %s", err)
+		return
+	}
+
+	now := time.Now()
+	// Change the date; leave most of the rest of the path components.
+	jsonPathComponents := strings.Split(jsonFileObject.Name, "/") // []string
+	if len(jsonPathComponents) < 4 {
+		fmt.Errorf("unexpected number of path components %q", jsonPathComponents)
+		return
+	}
+	jsonPathComponents = jsonPathComponents[len(jsonPathComponents)-4:]
+	jsonPathComponents[1] += "-pdfxformer"
+	jsonUploadPath := fmt.Sprintf("%s/%d/%02d/%02d/%02d/%s",
+		*storageJsonDirectory,
+		now.Year(),
+		int(now.Month()),
+		now.Day(),
+		now.Hour(),
+		strings.Join(jsonPathComponents, "/"))
+
+	_, err = uploadFile(xformer.client, bytes.NewReader(newJson), *storageBucket, jsonUploadPath, *accessControlEntity)
+	glog.Infof("> > wrote gs://%s/%s", *storageBucket, jsonUploadPath)
+	newJsonFileObject, err := xformer.client.storageService.Objects.Get(*storageBucket, jsonUploadPath).Do()
+	if err != nil {
+		glog.Errorf("Failed to find %s: %s", jsonUploadPath, err)
+	} else {
+		xformer.setRasterized(newJsonFileObject)
+	}
+	xformer.setRasterized(jsonFileObject)
+}
+
+// setRasterized sets the rasterized metadata flag of the given storage.Object
+func (xformer *pdfXformer) setRasterized(jsonFileObject *storage.Object) {
+	if nil == jsonFileObject.Metadata {
+		jsonFileObject.Metadata = map[string]string{}
+	}
+	jsonFileObject.Metadata["rasterized"] = "true"
+	_, err := xformer.client.storageService.Objects.Patch(*storageBucket, jsonFileObject.Name, jsonFileObject).Do()
+	if err != nil {
+		glog.Errorf("Failed to update metadata of %s: %s", jsonFileObject.Name, err)
+	} else {
+		glog.Infof("> > Updated metadata of %s", jsonFileObject.Name)
+	}
+}
+
+// processTimeRange calls gs.GetLatestGSDirs to get a list of
+func (xformer *pdfXformer) processTimeRange(start time.Time, end time.Time) {
+	glog.Infof("Processing time range: (%s, %s)", start.Truncate(time.Second), end.Truncate(time.Second))
+	for _, dir := range gs.GetLatestGSDirs(start.Unix(), end.Unix(), *storageJsonDirectory) {
+		glog.Infof("> Reading gs://%s/%s\n", *storageBucket, dir)
+		requestedObjects := xformer.client.storageService.Objects.List(*storageBucket).Prefix(dir).Fields(
+			"nextPageToken", "items/updated", "items/md5Hash", "items/mediaLink", "items/name", "items/metadata")
+		for requestedObjects != nil {
+			responseObjects, err := requestedObjects.Do()
+			if err != nil {
+				glog.Errorf("request %#v failed: %s", requestedObjects, err)
+			} else {
+				for _, jsonObject := range responseObjects.Items {
+					xformer.counter++
+					glog.Infof("> > Processing object:  gs://%s/%s {%d}", *storageBucket, jsonObject.Name, xformer.counter)
+					xformer.processJsonFile(jsonObject)
+				}
+			}
+			if len(responseObjects.NextPageToken) > 0 {
+				requestedObjects.PageToken(responseObjects.NextPageToken)
+			} else {
+				requestedObjects = nil
+			}
+		}
+	}
+	glog.Infof("finished time range.")
+}
+
+// uploadErrorImage should be run once to verify that the image is there
+func (xformer *pdfXformer) uploadErrorImage(path string) error {
+	if "" == path {
+		glog.Fatalf("Missing --path argument")
+	}
+	errorImageMd5, err := md5OfFile(path)
+	if err != nil {
+		glog.Fatalf("Bad --path argument")
+	}
+	errorImageFileReader, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer util.Close(errorImageFileReader)
+	errorImagePath := fmt.Sprintf("%s/%s.png", *storageImagesDirectory, errorImageMd5)
+	_, err = uploadFile(xformer.client, errorImageFileReader, *storageBucket, errorImagePath, *accessControlEntity)
+	if err != nil {
+		return err
+	}
+	xformer.errorImageMd5 = errorImageMd5
+	return nil
+}
+
+func main() {
+	flag.Parse()
+	common.InitWithMetrics("pdfxform", graphiteServer)
+
+	client, err := getClient()
+	if err != nil {
+		glog.Fatal(err)
+	}
+	xformer := pdfXformer{
+		client:  client,
+		results: map[string]map[int]string{},
+	}
+
+	err = xformer.uploadErrorImage(*failureImage)
+	if err != nil {
+		// If we can't upload this, we can't upload anything.
+		glog.Fatalf("Filed to upload error image: %s", err)
+	}
+
+	for _, rasterizer := range []pdf.Rasterizer{pdf.Pdfium{}, pdf.Poppler{}} {
+		if rasterizer.Enabled() {
+			xformer.rasterizers = append(xformer.rasterizers, rasterizer)
+		} else {
+			glog.Infof("rasterizer %s is disabled", rasterizer.String())
+		}
+	}
+	if len(xformer.rasterizers) == 0 {
+		glog.Fatalf("no rasterizers found")
+	}
+
+	end := time.Now()
+	start := end.Add(-172 * time.Hour)
+	xformer.processTimeRange(start, end)
+	glog.Flush() // Flush before waiting for next tick; it may be a while.
+	for _ = range time.Tick(time.Minute) {
+		start, end = end, time.Now()
+		xformer.processTimeRange(start, end)
+		glog.Flush()
+	}
+}