src/pdf/SkPDFDocument.cpp - platform/external/skia - Gitiles


 /*
  * 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"
 #include "SkPDFDevice.h"
 #include "SkPDFDocument.h"
 #include "SkPDFFont.h"
 #include "SkPDFPage.h"
 #include "SkPDFTypes.h"
 #include "SkStream.h"
 #include "SkTSet.h"

 static void addResourcesToCatalog(bool firstPage,
                                   SkTSet<SkPDFObject*>* resourceSet,
                                   SkPDFCatalog* catalog) {
     for (int i = 0; i < resourceSet->count(); i++) {
         catalog->addObject((*resourceSet)[i], firstPage);
     }
 }

 static void perform_font_subsetting(SkPDFCatalog* catalog,
                                     const SkTDArray<SkPDFPage*>& pages,
                                     SkTDArray<SkPDFObject*>* substitutes) {
     SkASSERT(catalog);
     SkASSERT(substitutes);

     SkPDFGlyphSetMap usage;
     for (int i = 0; i < pages.count(); ++i) {
         usage.merge(pages[i]->getFontGlyphUsage());
     }
     SkPDFGlyphSetMap::F2BIter iterator(usage);
     const SkPDFGlyphSetMap::FontGlyphSetPair* entry = iterator.next();
     while (entry) {
         SkPDFFont* subsetFont =
             entry->fFont->getFontSubset(entry->fGlyphSet);
         if (subsetFont) {
             catalog->setSubstitute(entry->fFont, subsetFont);
             substitutes->push(subsetFont);  // Transfer ownership to substitutes
         }
         entry = iterator.next();
     }
 }

 SkPDFDocument::SkPDFDocument(Flags flags)
         : fXRefFileOffset(0),
           fTrailerDict(NULL) {
     fCatalog.reset(new SkPDFCatalog(flags));
     fDocCatalog = SkNEW_ARGS(SkPDFDict, ("Catalog"));
     fCatalog->addObject(fDocCatalog, true);
     fFirstPageResources = NULL;
     fOtherPageResources = NULL;
 }

 SkPDFDocument::~SkPDFDocument() {
     fPages.safeUnrefAll();

     // The page tree has both child and parent pointers, so it creates a
     // reference cycle.  We must clear that cycle to properly reclaim memory.
     for (int i = 0; i < fPageTree.count(); i++) {
         fPageTree[i]->clear();
     }
     fPageTree.safeUnrefAll();

     if (fFirstPageResources) {
         fFirstPageResources->safeUnrefAll();
     }
     if (fOtherPageResources) {
         fOtherPageResources->safeUnrefAll();
     }

     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* obj) {
         fCat->setFileOffset(obj, this->offset());
         obj->emit(fOut, fCat, true);
     }

     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;
         }
     }

     fFirstPageResources = SkNEW(SkTSet<SkPDFObject*>);
     fOtherPageResources = SkNEW(SkTSet<SkPDFObject*>);

     // We haven't emitted the document before if fPageTree is empty.
     if (fPageTree.isEmpty()) {
         SkPDFDict* pageTreeRoot;
         SkPDFPage::GeneratePageTree(fPages, fCatalog.get(), &fPageTree,
                                     &pageTreeRoot);
         fDocCatalog->insert("Pages", new SkPDFObjRef(pageTreeRoot))->unref();

         /* TODO(vandebo): output intent
         SkAutoTUnref<SkPDFDict> outputIntent = new SkPDFDict("OutputIntent");
         outputIntent->insert("S", new SkPDFName("GTS_PDFA1"))->unref();
         outputIntent->insert("OutputConditionIdentifier",
                              new SkPDFString("sRGB"))->unref();
         SkAutoTUnref<SkPDFArray> intentArray = new SkPDFArray;
         intentArray->append(outputIntent.get());
         fDocCatalog->insert("OutputIntent", intentArray.get());
         */

         SkAutoTUnref<SkPDFDict> dests(SkNEW(SkPDFDict));

         bool firstPage = true;
         /* The references returned in newResources are transfered to
          * fFirstPageResources or fOtherPageResources depending on firstPage and
          * knownResources doesn't have a reference but just relies on the other
          * two sets to maintain a reference.
          */
         SkTSet<SkPDFObject*> knownResources;

         // mergeInto returns the number of duplicates.
         // If there are duplicates, there is a bug and we mess ref counting.
         SkDEBUGCODE(int duplicates =) knownResources.mergeInto(*fFirstPageResources);
         SkASSERT(duplicates == 0);

         for (int i = 0; i < fPages.count(); i++) {
             if (i == 1) {
                 firstPage = false;
                 SkDEBUGCODE(duplicates =) knownResources.mergeInto(*fOtherPageResources);
             }
             SkTSet<SkPDFObject*> newResources;
             fPages[i]->finalizePage(
                 fCatalog.get(), firstPage, knownResources, &newResources);
             addResourcesToCatalog(firstPage, &newResources, fCatalog.get());
             if (firstPage) {
                 SkDEBUGCODE(duplicates =) fFirstPageResources->mergeInto(newResources);
             } else {
                 SkDEBUGCODE(duplicates =) fOtherPageResources->mergeInto(newResources);
             }
             SkASSERT(duplicates == 0);

             SkDEBUGCODE(duplicates =) knownResources.mergeInto(newResources);
             SkASSERT(duplicates == 0);

             fPages[i]->appendDestinations(dests);
         }

         if (dests->size() > 0) {
             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);
     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]);
     }

     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();
     int64_t objCount = fCatalog->emitXrefTable(stream, fPages.count() > 1);
     emitFooter(stream, objCount);
     return true;
 }

 bool SkPDFDocument::setPage(int pageNumber, SkPDFDevice* pdfDevice) {
     if (!fPageTree.isEmpty()) {
         return false;
     }

     pageNumber--;
     SkASSERT(pageNumber >= 0);

     if (pageNumber >= fPages.count()) {
         int oldSize = fPages.count();
         fPages.setCount(pageNumber + 1);
         for (int i = oldSize; i <= pageNumber; i++) {
             fPages[i] = NULL;
         }
     }

     SkPDFPage* page = new SkPDFPage(pdfDevice);
     SkSafeUnref(fPages[pageNumber]);
     fPages[pageNumber] = page;  // Reference from new passed to fPages.
     return true;
 }

 bool SkPDFDocument::appendPage(SkPDFDevice* pdfDevice) {
     if (!fPageTree.isEmpty()) {
         return false;
     }

     SkPDFPage* page = new SkPDFPage(pdfDevice);
     fPages.push(page);  // Reference from new passed to fPages.
     return true;
 }

 // Deprecated.
 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;
 }

 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;

     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]->canSubset()) {
                     notSubsettable++;
                 }
                 if (!fontResources[font]->canEmbed()) {
                     notEmbeddable++;
                 }
             }
         }
     }
     if (notSubsettableCount) {
         *notSubsettableCount = notSubsettable;

     }
     if (notEmbeddableCount) {
         *notEmbeddableCount = notEmbeddable;
     }
 }

 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");
 }

 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");
 }

	/*
	* 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"
	#include "SkPDFDevice.h"
	#include "SkPDFDocument.h"
	#include "SkPDFFont.h"
	#include "SkPDFPage.h"
	#include "SkPDFTypes.h"
	#include "SkStream.h"
	#include "SkTSet.h"

	static void addResourcesToCatalog(bool firstPage,
	SkTSet<SkPDFObject> resourceSet,
	SkPDFCatalog* catalog) {
	for (int i = 0; i < resourceSet->count(); i++) {
	catalog->addObject((*resourceSet)[i], firstPage);
	}
	}

	static void perform_font_subsetting(SkPDFCatalog* catalog,
	const SkTDArray<SkPDFPage*>& pages,
	SkTDArray<SkPDFObject> substitutes) {
	SkASSERT(catalog);
	SkASSERT(substitutes);

	SkPDFGlyphSetMap usage;
	for (int i = 0; i < pages.count(); ++i) {
	usage.merge(pages[i]->getFontGlyphUsage());
	}
	SkPDFGlyphSetMap::F2BIter iterator(usage);
	const SkPDFGlyphSetMap::FontGlyphSetPair* entry = iterator.next();
	while (entry) {
	SkPDFFont* subsetFont =
	entry->fFont->getFontSubset(entry->fGlyphSet);
	if (subsetFont) {
	catalog->setSubstitute(entry->fFont, subsetFont);
	substitutes->push(subsetFont); // Transfer ownership to substitutes
	}
	entry = iterator.next();
	}
	}

	SkPDFDocument::SkPDFDocument(Flags flags)
	: fXRefFileOffset(0),
	fTrailerDict(NULL) {
	fCatalog.reset(new SkPDFCatalog(flags));
	fDocCatalog = SkNEW_ARGS(SkPDFDict, ("Catalog"));
	fCatalog->addObject(fDocCatalog, true);
	fFirstPageResources = NULL;
	fOtherPageResources = NULL;
	}

	SkPDFDocument::~SkPDFDocument() {
	fPages.safeUnrefAll();

	// The page tree has both child and parent pointers, so it creates a
	// reference cycle. We must clear that cycle to properly reclaim memory.
	for (int i = 0; i < fPageTree.count(); i++) {
	fPageTree[i]->clear();
	}
	fPageTree.safeUnrefAll();

	if (fFirstPageResources) {
	fFirstPageResources->safeUnrefAll();
	}
	if (fOtherPageResources) {
	fOtherPageResources->safeUnrefAll();
	}

	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* obj) {
	fCat->setFileOffset(obj, this->offset());
	obj->emit(fOut, fCat, true);
	}

	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;
	}
	}

	fFirstPageResources = SkNEW(SkTSet<SkPDFObject*>);
	fOtherPageResources = SkNEW(SkTSet<SkPDFObject*>);

	// We haven't emitted the document before if fPageTree is empty.
	if (fPageTree.isEmpty()) {
	SkPDFDict* pageTreeRoot;
	SkPDFPage::GeneratePageTree(fPages, fCatalog.get(), &fPageTree,
	&pageTreeRoot);
	fDocCatalog->insert("Pages", new SkPDFObjRef(pageTreeRoot))->unref();

	/* TODO(vandebo): output intent
	SkAutoTUnref<SkPDFDict> outputIntent = new SkPDFDict("OutputIntent");
	outputIntent->insert("S", new SkPDFName("GTS_PDFA1"))->unref();
	outputIntent->insert("OutputConditionIdentifier",
	new SkPDFString("sRGB"))->unref();
	SkAutoTUnref<SkPDFArray> intentArray = new SkPDFArray;
	intentArray->append(outputIntent.get());
	fDocCatalog->insert("OutputIntent", intentArray.get());
	*/

	SkAutoTUnref<SkPDFDict> dests(SkNEW(SkPDFDict));

	bool firstPage = true;
	/* The references returned in newResources are transfered to
	* fFirstPageResources or fOtherPageResources depending on firstPage and
	* knownResources doesn't have a reference but just relies on the other
	* two sets to maintain a reference.
	*/
	SkTSet<SkPDFObject*> knownResources;

	// mergeInto returns the number of duplicates.
	// If there are duplicates, there is a bug and we mess ref counting.
	SkDEBUGCODE(int duplicates =) knownResources.mergeInto(*fFirstPageResources);
	SkASSERT(duplicates == 0);

	for (int i = 0; i < fPages.count(); i++) {
	if (i == 1) {
	firstPage = false;
	SkDEBUGCODE(duplicates =) knownResources.mergeInto(*fOtherPageResources);
	}
	SkTSet<SkPDFObject*> newResources;
	fPages[i]->finalizePage(
	fCatalog.get(), firstPage, knownResources, &newResources);
	addResourcesToCatalog(firstPage, &newResources, fCatalog.get());
	if (firstPage) {
	SkDEBUGCODE(duplicates =) fFirstPageResources->mergeInto(newResources);
	} else {
	SkDEBUGCODE(duplicates =) fOtherPageResources->mergeInto(newResources);
	}
	SkASSERT(duplicates == 0);

	SkDEBUGCODE(duplicates =) knownResources.mergeInto(newResources);
	SkASSERT(duplicates == 0);

	fPages[i]->appendDestinations(dests);
	}

	if (dests->size() > 0) {
	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);
	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]);
	}

	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();
	int64_t objCount = fCatalog->emitXrefTable(stream, fPages.count() > 1);
	emitFooter(stream, objCount);
	return true;
	}

	bool SkPDFDocument::setPage(int pageNumber, SkPDFDevice* pdfDevice) {
	if (!fPageTree.isEmpty()) {
	return false;
	}

	pageNumber--;
	SkASSERT(pageNumber >= 0);

	if (pageNumber >= fPages.count()) {
	int oldSize = fPages.count();
	fPages.setCount(pageNumber + 1);
	for (int i = oldSize; i <= pageNumber; i++) {
	fPages[i] = NULL;
	}
	}

	SkPDFPage* page = new SkPDFPage(pdfDevice);
	SkSafeUnref(fPages[pageNumber]);
	fPages[pageNumber] = page; // Reference from new passed to fPages.
	return true;
	}

	bool SkPDFDocument::appendPage(SkPDFDevice* pdfDevice) {
	if (!fPageTree.isEmpty()) {
	return false;
	}

	SkPDFPage* page = new SkPDFPage(pdfDevice);
	fPages.push(page); // Reference from new passed to fPages.
	return true;
	}

	// Deprecated.
	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;
	}

	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;

	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]->canSubset()) {
	notSubsettable++;
	}
	if (!fontResources[font]->canEmbed()) {
	notEmbeddable++;
	}
	}
	}
	}
	if (notSubsettableCount) {
	*notSubsettableCount = notSubsettable;

	}
	if (notEmbeddableCount) {
	*notEmbeddableCount = notEmbeddable;
	}
	}

	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");
	}

	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");
	}