Add font map user metrics for Linux.

The method MapFont, defined in pdfium_engine.cc, is used by Chrome on Linux to find a substitute font whenever a pdf file uses a font which is not embedded (or could not be loaded). When this method is called, the method UserMetricsRecordAction will now be called to record that this document has requested a substitute font. Adding similar functionality for other OS's will take more effort just because the MapFont definitions are completely inside pdfium core. BUG=chromium:448584 Review-Url: https://codereview.chromium.org/2398763002 Cr-Commit-Position: refs/heads/master@{#424877}
Denger-Network · Oct 12, 2016 · d24ca04 · d24ca04
1 parent c227350
commit d24ca04
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Showing 9 changed files with 79 additions and 0 deletions.
diff --git a/pdf/out_of_process_instance.cc b/pdf/out_of_process_instance.cc
@@ -282,6 +282,9 @@ OutOfProcessInstance::OutOfProcessInstance(PP_Instance instance)
       preview_document_load_state_(LOAD_STATE_COMPLETE),
       uma_(this),
       told_browser_about_unsupported_feature_(false),
+#if defined(OS_LINUX)
+      font_substitution_reported_(false),
+#endif
       print_preview_page_count_(0),
       last_progress_sent_(0),
       recently_sent_find_update_(false),
@@ -1206,6 +1209,10 @@ void OutOfProcessInstance::DocumentLoadComplete(int page_count) {
   UserMetricsRecordAction("PDF.LoadSuccess");
   uma_.HistogramEnumeration("PDF.DocumentFeature", LOADED_DOCUMENT,
                             FEATURES_COUNT);
+#if defined(OS_LINUX)
+  if (!font_substitution_reported_)
+    uma_.HistogramEnumeration("PDF.IsFontSubstituted", 0, 2);
+#endif
 
   // Note: If we are in print preview mode the scroll location is retained
   // across document loads so we don't want to scroll again and override it.
@@ -1312,6 +1319,15 @@ void OutOfProcessInstance::DocumentLoadFailed() {
   PostMessage(message);
 }
 
+void OutOfProcessInstance::FontSubstituted() {
+#if defined(OS_LINUX)
+  if (font_substitution_reported_)
+    return;
+  font_substitution_reported_ = true;
+  uma_.HistogramEnumeration("PDF.IsFontSubstituted", 1, 2);
+#endif
+}
+
 void OutOfProcessInstance::PreviewDocumentLoadFailed() {
   UserMetricsRecordAction("PDF.PreviewDocumentLoadFailure");
   if (preview_document_load_state_ != LOAD_STATE_LOADING ||

diff --git a/pdf/out_of_process_instance.h b/pdf/out_of_process_instance.h
@@ -128,6 +128,7 @@ class OutOfProcessInstance : public pp::Instance,
   void DocumentPaintOccurred() override;
   void DocumentLoadComplete(int page_count) override;
   void DocumentLoadFailed() override;
+  void FontSubstituted() override;
   pp::Instance* GetPluginInstance() override;
   void DocumentHasUnsupportedFeature(const std::string& feature) override;
   void DocumentLoadProgress(uint32_t available, uint32_t doc_size) override;
@@ -309,6 +310,12 @@ class OutOfProcessInstance : public pp::Instance,
   // the stats if a feature shows up many times per document.
   std::set<std::string> unsupported_features_reported_;
 
+#if defined(OS_LINUX)
+  // Keeps track of whether font substitution has been reported, so we avoid
+  // spamming the stats if a document requested multiple substitutes.
+  bool font_substitution_reported_;
+#endif
+
   // Number of pages in print preview mode, 0 if not in print preview mode.
   int print_preview_page_count_;
   std::vector<int> print_preview_page_numbers_;

diff --git a/pdf/pdf_engine.h b/pdf/pdf_engine.h
@@ -165,6 +165,9 @@ class PDFEngine {
     // Notifies the client that the document has failed to load.
     virtual void DocumentLoadFailed() = 0;
 
+    // Notifies the client that the document has requested substitute fonts.
+    virtual void FontSubstituted() = 0;
+
     virtual pp::Instance* GetPluginInstance() = 0;
 
     // Notifies that an unsupported feature in the PDF was encountered.

diff --git a/pdf/pdfium/pdfium_engine.cc b/pdf/pdfium/pdfium_engine.cc
@@ -110,6 +110,8 @@ const int32_t kMaxProgressivePaintTimeMs = 300;
 // process.
 const int32_t kMaxInitialProgressivePaintTimeMs = 250;
 
+PDFiumEngine* g_engine_for_fontmapper = nullptr;
+
 std::vector<uint32_t> GetPageNumbersFromPrintPageNumberRange(
     const PP_PrintPageNumberRange_Dev* page_ranges,
     uint32_t page_range_count) {
@@ -259,6 +261,9 @@ void* MapFont(struct _FPDF_SYSFONTINFO*, int weight, int italic,
     return nullptr;
   }
 
+  if (g_engine_for_fontmapper)
+    g_engine_for_fontmapper->FontSubstituted();
+
   PP_Resource font_resource = pp::PDF::GetFontFileWithFallback(
       pp::InstanceHandle(g_last_instance_id),
       &description.pp_font_description(),
@@ -1171,6 +1176,10 @@ void PDFiumEngine::UnsupportedFeature(int type) {
   client_->DocumentHasUnsupportedFeature(feature);
 }
 
+void PDFiumEngine::FontSubstituted() {
+  client_->FontSubstituted();
+}
+
 void PDFiumEngine::ContinueFind(int32_t result) {
   StartFind(current_find_text_, result != 0);
 }
@@ -1223,6 +1232,7 @@ void PDFiumEngine::PrintBegin() {
 pp::Resource PDFiumEngine::PrintPages(
     const PP_PrintPageNumberRange_Dev* page_ranges, uint32_t page_range_count,
     const PP_PrintSettings_Dev& print_settings) {
+  ScopedSubstFont scoped_subst_font(this);
   if (HasPermission(PDFEngine::PERMISSION_PRINT_HIGH_QUALITY))
     return PrintPagesAsPDF(page_ranges, page_range_count, print_settings);
   else if (HasPermission(PDFEngine::PERMISSION_PRINT_LOW_QUALITY))
@@ -1375,6 +1385,7 @@ pp::Buffer_Dev PDFiumEngine::PrintPagesAsRasterPDF(
 
 pp::Buffer_Dev PDFiumEngine::GetFlattenedPrintData(const FPDF_DOCUMENT& doc) {
   pp::Buffer_Dev buffer;
+  ScopedSubstFont scoped_subst_font(this);
   int page_count = FPDF_GetPageCount(doc);
   for (int i = 0; i < page_count; ++i) {
     FPDF_PAGE page = FPDF_LoadPage(doc, i);
@@ -2453,6 +2464,7 @@ void PDFiumEngine::LoadDocument() {
     return;
 
   ScopedUnsupportedFeature scoped_unsupported_feature(this);
+  ScopedSubstFont scoped_subst_font(this);
   bool needs_password = false;
   if (TryLoadingDoc(std::string(), &needs_password)) {
     ContinueLoadingDocument(std::string());
@@ -2517,6 +2529,7 @@ void PDFiumEngine::OnGetPasswordComplete(int32_t result,
 
 void PDFiumEngine::ContinueLoadingDocument(const std::string& password) {
   ScopedUnsupportedFeature scoped_unsupported_feature(this);
+  ScopedSubstFont scoped_subst_font(this);
 
   bool needs_password = false;
   bool loaded = TryLoadingDoc(password, &needs_password);
@@ -3733,6 +3746,15 @@ ScopedUnsupportedFeature::~ScopedUnsupportedFeature() {
   g_engine_for_unsupported = old_engine_;
 }
 
+ScopedSubstFont::ScopedSubstFont(PDFiumEngine* engine)
+    : old_engine_(g_engine_for_fontmapper) {
+  g_engine_for_fontmapper = engine;
+}
+
+ScopedSubstFont::~ScopedSubstFont() {
+  g_engine_for_fontmapper = old_engine_;
+}
+
 namespace {
 
 base::LazyInstance<PDFiumEngineExports>::Leaky g_pdf_engine_exports =

diff --git a/pdf/pdfium/pdfium_engine.h b/pdf/pdfium/pdfium_engine.h
@@ -120,6 +120,7 @@ class PDFiumEngine : public PDFEngine,
   void OnDocumentComplete() override;
 
   void UnsupportedFeature(int type);
+  void FontSubstituted();
 
   std::string current_find_text() const { return current_find_text_; }
 
@@ -742,6 +743,21 @@ class ScopedUnsupportedFeature {
 
  private:
   PDFiumEngine* const old_engine_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedUnsupportedFeature);
+};
+
+// Create a local variable of this when calling PDFium functions which can call
+// our global callback when a substitute font is mapped.
+class ScopedSubstFont {
+ public:
+  explicit ScopedSubstFont(PDFiumEngine* engine);
+  ~ScopedSubstFont();
+
+ private:
+  PDFiumEngine* const old_engine_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedSubstFont);
 };
 
 class PDFiumEngineExports : public PDFEngineExports {

diff --git a/pdf/pdfium/pdfium_page.cc b/pdf/pdfium/pdfium_page.cc
@@ -118,6 +118,7 @@ void PDFiumPage::Unload() {
 
 FPDF_PAGE PDFiumPage::GetPage() {
   ScopedUnsupportedFeature scoped_unsupported_feature(engine_);
+  ScopedSubstFont scoped_subst_font(engine_);
   if (!available_)
     return nullptr;
   if (!page_) {
@@ -132,6 +133,7 @@ FPDF_PAGE PDFiumPage::GetPage() {
 
 FPDF_PAGE PDFiumPage::GetPrintPage() {
   ScopedUnsupportedFeature scoped_unsupported_feature(engine_);
+  ScopedSubstFont scoped_subst_font(engine_);
   if (!available_)
     return nullptr;
   if (!page_) {

diff --git a/pdf/preview_mode_client.cc b/pdf/preview_mode_client.cc
@@ -146,6 +146,10 @@ void PreviewModeClient::DocumentHasUnsupportedFeature(
   NOTREACHED();
 }
 
+void PreviewModeClient::FontSubstituted() {
+  NOTREACHED();
+}
+
 void PreviewModeClient::DocumentLoadProgress(uint32_t available,
                                              uint32_t doc_size) {}
 

diff --git a/pdf/preview_mode_client.h b/pdf/preview_mode_client.h
@@ -65,6 +65,7 @@ class PreviewModeClient : public PDFEngine::Client {
   void DocumentPaintOccurred() override;
   void DocumentLoadComplete(int page_count) override;
   void DocumentLoadFailed() override;
+  void FontSubstituted() override;
   pp::Instance* GetPluginInstance() override;
   void DocumentHasUnsupportedFeature(const std::string& feature) override;
   void DocumentLoadProgress(uint32_t available, uint32_t doc_size) override;

diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
@@ -42021,6 +42021,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="PDF.IsFontSubstituted" enum="Boolean">
+  <owner>npm@chromium.org</owner>
+  <summary>
+    Tracks documents opened in the PDF viewer where substitute fonts need to be
+    used.
+  </summary>
+</histogram>
+
 <histogram name="Pepper.InterfaceUsed" enum="PepperInterface">
   <owner>sehr@chromium.org</owner>
   <owner>bradnelson@chromium.org</owner>