Simplify reference management in SkPDF

src/pdf/SkPDFDocument.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkPDFCatalog.h"
@@ skipping 64 matching lines @@
     }
 
     fSubstitutes.safeUnrefAll();
 
     fDocCatalog->unref();
     SkSafeUnref(fTrailerDict);
     SkDELETE(fFirstPageResources);
     SkDELETE(fOtherPageResources);
 }
 
-namespace {
-class Streamer {
-public:
-    Streamer(SkPDFCatalog* cat, SkWStream* out)
-        : fCat(cat), fOut(out), fBaseOffset(SkToOffT(out->bytesWritten())) {
-    }
-
-    void stream(SkPDFObject* object) {
-        fCat->setFileOffset(object, this->offset());
-        SkPDFObject* realObject = fCat->getSubstituteObject(object);
-        fCat->emitObjectNumber(fOut, realObject);
-        fOut->writeText(" obj\n");
-        realObject->emitObject(fOut, fCat);
-        fOut->writeText("\nendobj\n");
-    }
-
-    off_t offset() {
-        return SkToOffT(fOut->bytesWritten()) - fBaseOffset;
-    }
-
-private:
-    SkPDFCatalog* const fCat;
-    SkWStream* const fOut;
-    const off_t fBaseOffset;
-};
-}  // namespace
-
 bool SkPDFDocument::emitPDF(SkWStream* stream) {
     if (fPages.isEmpty()) {
         return false;
     }
     for (int i = 0; i < fPages.count(); i++) {
         if (fPages[i] == NULL) {
             return false;
         }
     }
 
@@ skipping 58 matching lines @@
             SkPDFDict* raw_dests = dests.get();
             fFirstPageResources->add(dests.detach());  // Transfer ownership.
             fCatalog->addObject(raw_dests, true /* onFirstPage */);
             fDocCatalog->insert("Dests", SkNEW_ARGS(SkPDFObjRef, (raw_dests)))->unref();
         }
 
         // Build font subsetting info before proceeding.
         perform_font_subsetting(fCatalog.get(), fPages, &fSubstitutes);
     }
 
-    Streamer out(fCatalog, stream);
+    SkTSet<SkPDFObject*> resourceSet;
+    if (resourceSet.add(fDocCatalog)) {
+        fDocCatalog->addResources(&resourceSet, fCatalog);
+    }
+    off_t baseOffset = SkToOffT(stream->bytesWritten());
     emitHeader(stream);
-
-    out.stream(fDocCatalog);
-    out.stream(fPages[0]);
-    out.stream(fPages[0]->getContentStream());
-
-    for (int i = 0; i < fFirstPageResources->count(); i++) {
-        out.stream((*fFirstPageResources)[i]);
+    for (int i = 0; i < resourceSet.count(); ++i) {
+        SkPDFObject* object = resourceSet[i];
+        fCatalog->setFileOffset(object,
+                                SkToOffT(stream->bytesWritten()) - baseOffset);
+        SkASSERT(object == fCatalog->getSubstituteObject(object));
+        stream->writeDecAsText(fCatalog->getObjectNumber(object));
+        stream->writeText(" 0 obj\n");  // Generation number is always 0.
+        object->emitObject(stream, fCatalog);
+        stream->writeText("\nendobj\n");
     }
-
-    SkTSet<SkPDFObject*>* firstPageSubstituteResources =
-            fCatalog->getSubstituteList(true);
-    for (int i = 0; i < firstPageSubstituteResources->count(); ++i) {
-        out.stream((*firstPageSubstituteResources)[i]);
-    }
-    // TODO(vandebo): Support linearized format
-    // if (fPages.size() > 1) {
-    //     // TODO(vandebo): Save the file offset for the first page xref table.
-    //     fCatalog->emitXrefTable(stream, true);
-    // }
-
-    for (int i = 0; i < fPageTree.count(); i++) {
-        out.stream(fPageTree[i]);
-    }
-
-    for (int i = 1; i < fPages.count(); i++) {
-        out.stream(fPages[i]->getContentStream());
-    }
-
-    for (int i = 0; i < fOtherPageResources->count(); i++) {
-        out.stream((*fOtherPageResources)[i]);
-    }
-
-    SkTSet<SkPDFObject*>* otherSubstituteResources =
-            fCatalog->getSubstituteList(false);
-    for (int i = 0; i < otherSubstituteResources->count(); ++i) {
-        out.stream((*otherSubstituteResources)[i]);
-    }
-
-    fXRefFileOffset = out.offset();
+    fXRefFileOffset = SkToOffT(stream->bytesWritten()) - baseOffset;
     int64_t objCount = fCatalog->emitXrefTable(stream, fPages.count() > 1);
     emitFooter(stream, objCount);
     return true;
 }
 
+// TODO(halcanary): remove this method, since it is unused.
 bool SkPDFDocument::setPage(int pageNumber, SkPDFDevice* pdfDevice) {
     if (!fPageTree.isEmpty()) {
         return false;
     }
 
     pageNumber--;
     SkASSERT(pageNumber >= 0);
 
     if (pageNumber >= fPages.count()) {
         int oldSize = fPages.count();
@@ skipping 13 matching lines @@
     if (!fPageTree.isEmpty()) {
         return false;
     }
 
     SkPDFPage* page = new SkPDFPage(pdfDevice);
     fPages.push(page);  // Reference from new passed to fPages.
     return true;
 }
 
 // Deprecated.
+// TODO(halcanary): remove
 void SkPDFDocument::getCountOfFontTypes(
         int counts[SkAdvancedTypefaceMetrics::kOther_Font + 2]) const {
     sk_bzero(counts, sizeof(int) *
                      (SkAdvancedTypefaceMetrics::kOther_Font + 2));
     SkTDArray<SkFontID> seenFonts;
     int notEmbeddable = 0;
 
     for (int pageNumber = 0; pageNumber < fPages.count(); pageNumber++) {
         const SkTDArray<SkPDFFont*>& fontResources =
                 fPages[pageNumber]->getFontResources();
         for (int font = 0; font < fontResources.count(); font++) {
             SkFontID fontID = fontResources[font]->typeface()->uniqueID();
             if (seenFonts.find(fontID) == -1) {
                 counts[fontResources[font]->getType()]++;
                 seenFonts.push(fontID);
                 if (!fontResources[font]->canEmbed()) {
                     notEmbeddable++;
                 }
             }
         }
     }
     counts[SkAdvancedTypefaceMetrics::kOther_Font + 1] = notEmbeddable;
 }
 
+// TODO(halcanary): expose notEmbeddableCount in SkDocument
 void SkPDFDocument::getCountOfFontTypes(
         int counts[SkAdvancedTypefaceMetrics::kOther_Font + 1],
         int* notSubsettableCount,
         int* notEmbeddableCount) const {
     sk_bzero(counts, sizeof(int) *
                      (SkAdvancedTypefaceMetrics::kOther_Font + 1));
     SkTDArray<SkFontID> seenFonts;
     int notSubsettable = 0;
     int notEmbeddable = 0;
 
@@ skipping 24 matching lines @@
 }
 
 void SkPDFDocument::emitHeader(SkWStream* stream) {
     stream->writeText("%PDF-1.4\n%");
     // The PDF spec recommends including a comment with four bytes, all
     // with their high bits set.  This is "Skia" with the high bits set.
     stream->write32(0xD3EBE9E1);
     stream->writeText("\n");
 }
 
+//TODO(halcanary): remove this function
 size_t SkPDFDocument::headerSize() {
     SkDynamicMemoryWStream buffer;
     emitHeader(&buffer);
     return buffer.getOffset();
 }
 
 void SkPDFDocument::emitFooter(SkWStream* stream, int64_t objCount) {
     if (NULL == fTrailerDict) {
         fTrailerDict = SkNEW(SkPDFDict);
 
         // TODO(vandebo): Linearized format will take a Prev entry too.
         // TODO(vandebo): PDF/A requires an ID entry.
         fTrailerDict->insertInt("Size", int(objCount));
         fTrailerDict->insert("Root", new SkPDFObjRef(fDocCatalog))->unref();
     }
 
     stream->writeText("trailer\n");
     fTrailerDict->emitObject(stream, fCatalog.get());
     stream->writeText("\nstartxref\n");
     stream->writeBigDecAsText(fXRefFileOffset);
     stream->writeText("\n%%EOF");
 }