SkPDF: PDFStream has-a not is-a PDFDict

src/pdf/SkPDFTypes.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 "SkData.h"
 #include "SkDeflate.h"
 #include "SkPDFTypes.h"
 #include "SkPDFUtils.h"
 #include "SkStream.h"
 #include "SkStreamPriv.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 
 SkString* pun(char* x) { return reinterpret_cast<SkString*>(x); }
 const SkString* pun(const char* x) {
@@ skipping 431 matching lines @@
 void SkPDFDict::insertString(const char key[], const char value[]) {
     fRecords.emplace_back(SkPDFUnion::Name(key), SkPDFUnion::String(value));
 }
 
 void SkPDFDict::insertString(const char key[], const SkString& value) {
     fRecords.emplace_back(SkPDFUnion::Name(key), SkPDFUnion::String(value));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
-SkPDFSharedStream::SkPDFSharedStream(SkStreamAsset* data)
-    : fAsset(data), fDict(new SkPDFDict) {
-    SkDEBUGCODE(fDumped = false;)
-    SkASSERT(data);
+SkPDFSharedStream::SkPDFSharedStream(std::unique_ptr<SkStreamAsset> data)
+    : fAsset(std::move(data)) {
+    SkASSERT(fAsset);
 }
 
 SkPDFSharedStream::~SkPDFSharedStream() { this->drop(); }
 
 void SkPDFSharedStream::drop() {
-    fAsset.reset();
-    fDict.reset(nullptr);
-    SkDEBUGCODE(fDumped = true;)
+    fAsset = nullptr;;
+    fDict.drop();
 }
 
 #ifdef SK_PDF_LESS_COMPRESSION
 void SkPDFSharedStream::emitObject(
         SkWStream* stream,
         const SkPDFObjNumMap& objNumMap,
         const SkPDFSubstituteMap& substitutes) const {
-    SkASSERT(!fDumped);
+    SkASSERT(fAsset);
     std::unique_ptr<SkStreamAsset> dup(fAsset->duplicate());
     SkASSERT(dup && dup->hasLength());
     size_t length = dup->getLength();
     stream->writeText("<<");
-    fDict->emitAll(stream, objNumMap, substitutes);
+    fDict.emitAll(stream, objNumMap, substitutes);
     stream->writeText("\n");
     SkPDFUnion::Name("Length").emitObject(
             stream, objNumMap, substitutes);
     stream->writeText(" ");
     SkPDFUnion::Int(length).emitObject(
             stream, objNumMap, substitutes);
     stream->writeText("\n>>stream\n");
     SkStreamCopy(stream, dup.get());
     stream->writeText("\nendstream");
 }
 #else
 void SkPDFSharedStream::emitObject(
         SkWStream* stream,
         const SkPDFObjNumMap& objNumMap,
         const SkPDFSubstituteMap& substitutes) const {
-    SkASSERT(!fDumped);
+    SkASSERT(fAsset);
     SkDynamicMemoryWStream buffer;
     SkDeflateWStream deflateWStream(&buffer);
     // Since emitObject is const, this function doesn't change the dictionary.
     std::unique_ptr<SkStreamAsset> dup(fAsset->duplicate());  // Cheap copy
     SkASSERT(dup);
     SkStreamCopy(&deflateWStream, dup.get());
     deflateWStream.finalize();
     size_t length = buffer.bytesWritten();
     stream->writeText("<<");
-    fDict->emitAll(stream, objNumMap, substitutes);
+    fDict.emitAll(stream, objNumMap, substitutes);
     stream->writeText("\n");
     SkPDFUnion::Name("Length").emitObject(stream, objNumMap, substitutes);
     stream->writeText(" ");
     SkPDFUnion::Int(length).emitObject(stream, objNumMap, substitutes);
     stream->writeText("\n");
     SkPDFUnion::Name("Filter").emitObject(stream, objNumMap, substitutes);
     stream->writeText(" ");
     SkPDFUnion::Name("FlateDecode").emitObject(stream, objNumMap, substitutes);
     stream->writeText(">>");
     stream->writeText(" stream\n");
     buffer.writeToStream(stream);
     stream->writeText("\nendstream");
 }
 #endif
 
 void SkPDFSharedStream::addResources(
         SkPDFObjNumMap* catalog, const SkPDFSubstituteMap& substitutes) const {
-    SkASSERT(!fDumped);
-    fDict->addResources(catalog, substitutes);
+    SkASSERT(fAsset);
+    fDict.addResources(catalog, substitutes);
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+
+SkPDFStream:: SkPDFStream(sk_sp<SkData> data) {
+    this->setData(std::unique_ptr<SkStreamAsset>(
+                          new SkMemoryStream(std::move(data))));
+}
+
+SkPDFStream::SkPDFStream(std::unique_ptr<SkStreamAsset> stream) {
+    this->setData(std::move(stream));
+}
+
+SkPDFStream::SkPDFStream() {}
+
+SkPDFStream::~SkPDFStream() {}
+
+void SkPDFStream::addResources(
+        SkPDFObjNumMap* catalog, const SkPDFSubstituteMap& substitutes) const {
+    SkASSERT(fCompressedData);
+    fDict.addResources(catalog, substitutes);
+}
+
+void SkPDFStream::drop() {
+    fCompressedData.reset(nullptr);
+    fDict.drop();
+}
+
+void SkPDFStream::emitObject(SkWStream* stream,
+                             const SkPDFObjNumMap& objNumMap,
+                             const SkPDFSubstituteMap& substitutes) const {
+    SkASSERT(fCompressedData);
+    fDict.emitObject(stream, objNumMap, substitutes);
+    // duplicate (a cheap operation) preserves const on fCompressedData.
+    std::unique_ptr<SkStreamAsset> dup(fCompressedData->duplicate());
+    SkASSERT(dup);
+    SkASSERT(dup->hasLength());
+    stream->writeText(" stream\n");
+    stream->writeStream(dup.get(), dup->getLength());
+    stream->writeText("\nendstream");
+}
+
+void SkPDFStream::setData(std::unique_ptr<SkStreamAsset> stream) {
+    SkASSERT(!fCompressedData);  // Only call this function once.
+    SkASSERT(stream);
+    // Code assumes that the stream starts at the beginning.
+
+    #ifdef SK_PDF_LESS_COMPRESSION
+    fCompressedData = std::move(stream);
+    SkASSERT(fCompressedData && fCompressedData->hasLength());
+    fDict.insertInt("Length", fCompressedData->getLength());
+    #else
+
+    SkASSERT(stream->hasLength());
+    SkDynamicMemoryWStream compressedData;
+    SkDeflateWStream deflateWStream(&compressedData);
+    SkStreamCopy(&deflateWStream, stream.get());
+    deflateWStream.finalize();
+    size_t compressedLength = compressedData.bytesWritten();
+    size_t originalLength = stream->getLength();
+
+    if (originalLength <= compressedLength + strlen("/Filter_/FlateDecode_")) {
+        SkAssertResult(stream->rewind());
+        fCompressedData = std::move(stream);
+        fDict.insertInt("Length", originalLength);
+        return;
+    }
+    fCompressedData.reset(compressedData.detachAsStream());
+    fDict.insertName("Filter", "FlateDecode");
+    fDict.insertInt("Length", compressedLength);
+    #endif
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
 SkPDFSubstituteMap::~SkPDFSubstituteMap() {
     fSubstituteMap.foreach(
             [](SkPDFObject*, SkPDFObject** v) { (*v)->unref(); });
 }
 
 void SkPDFSubstituteMap::setSubstitute(SkPDFObject* original,
@@ skipping 39 matching lines @@
 
 void SkPDFImageDumpStats() {
     SkDebugf("\ntotal PDF drawImage/drawBitmap calls: %d\n"
              "total PDF jpeg images: %d\n"
              "total PDF regular images: %d\n",
              gDrawImageCalls.load(),
              gJpegImageObjects.load(),
              gRegularImageObjects.load());
 }
 #endif // SK_PDF_IMAGE_STATS