golden/pdfxform a pdf rasterization server

golden/go/pdfxform/main.go

+// 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()
+        }
+}