SkPDF: Memory improvements for PDF Streams

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 "SkDeflate.h"
 #include "SkPDFTypes.h"
 #include "SkPDFUtils.h"
-#include "SkStream.h"
-
-#ifdef SK_BUILD_FOR_WIN
-    #define SNPRINTF    _snprintf
-#else
-    #define SNPRINTF    snprintf
-#endif
+#include "SkStreamPriv.h"
 
 ////////////////////////////////////////////////////////////////////////////////
 
 SkString* pun(char* x) { return reinterpret_cast<SkString*>(x); }
 const SkString* pun(const char* x) {
     return reinterpret_cast<const SkString*>(x);
 }
 
 SkPDFUnion::SkPDFUnion(Type t) : fType(t) {}
 
@@ skipping 320 matching lines @@
 SkPDFDict::SkPDFDict() {}
 
 SkPDFDict::~SkPDFDict() { this->clear(); }
 
 SkPDFDict::SkPDFDict(const char type[]) { this->insertName("Type", type); }
 
 void SkPDFDict::emitObject(SkWStream* stream,
                            const SkPDFObjNumMap& objNumMap,
                            const SkPDFSubstituteMap& substitutes) {
     stream->writeText("<<");
+    this->emitAll(stream, objNumMap, substitutes);
+    stream->writeText(">>");
+}
+
+void SkPDFDict::emitAll(SkWStream* stream,
+                        const SkPDFObjNumMap& objNumMap,
+                        const SkPDFSubstituteMap& substitutes) {
     for (int i = 0; i < fRecords.count(); i++) {
         fRecords[i].fKey.emitObject(stream, objNumMap, substitutes);
         stream->writeText(" ");
         fRecords[i].fValue.emitObject(stream, objNumMap, substitutes);
         if (i + 1 < fRecords.count()) {
             stream->writeText("\n");
         }
     }
-    stream->writeText(">>");
 }
 
 void SkPDFDict::addResources(SkPDFObjNumMap* catalog,
                              const SkPDFSubstituteMap& substitutes) const {
     for (int i = 0; i < fRecords.count(); i++) {
         fRecords[i].fKey.addResources(catalog, substitutes);
         fRecords[i].fValue.addResources(catalog, substitutes);
     }
 }
 
@@ skipping 55 matching lines @@
 void SkPDFDict::clear() {
     for (Record& rec : fRecords) {
         rec.fKey.~SkPDFUnion();
         rec.fValue.~SkPDFUnion();
     }
     fRecords.reset();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 
+void SkPDFSharedStream::emitObject(SkWStream* stream,
+                                   const SkPDFObjNumMap& objNumMap,
+                                   const SkPDFSubstituteMap& substitutes) {
+    SkDynamicMemoryWStream buffer;
+    SkDeflateWStream deflateWStream(&buffer);
+    // Note: emitObject isn't marked const, but could be in the future
+    // This is why this function doesn't change the dictionary.
+    SkAutoTDelete<SkStreamAsset> dup(fAsset->duplicate());  // Cheap copy
+    SkStreamCopy(&deflateWStream, dup.get());
+    deflateWStream.finalize();
+    size_t length = buffer.bytesWritten();
+    stream->writeText("<<");
+    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");
+}
+
+void SkPDFSharedStream::addResources(
+        SkPDFObjNumMap* catalog, const SkPDFSubstituteMap& substitutes) const {
+    fDict->addResources(catalog, substitutes);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 SkPDFSubstituteMap::~SkPDFSubstituteMap() {
     fSubstituteMap.foreach(
             [](SkPDFObject*, SkPDFObject** v) { (*v)->unref(); });
 }
 
 void SkPDFSubstituteMap::setSubstitute(SkPDFObject* original,
                                        SkPDFObject* substitute) {
     SkASSERT(original != substitute);
     SkASSERT(!fSubstituteMap.find(original));
     fSubstituteMap.set(original, SkRef(substitute));
@@ skipping 14 matching lines @@
     fObjects.push(obj);
     return true;
 }
 
 int32_t SkPDFObjNumMap::getObjectNumber(SkPDFObject* obj) const {
     int32_t* objectNumberFound = fObjectNumbers.find(obj);
     SkASSERT(objectNumberFound);
     return *objectNumberFound;
 }