SkPDF: Memory improvements for PDF Streams

src/pdf/SkPDFTypes.h

 /*
  * Copyright 2010 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkPDFTypes_DEFINED
 #define SkPDFTypes_DEFINED
 
 #include "SkRefCnt.h"
 #include "SkScalar.h"
+#include "SkStream.h"
 #include "SkString.h"
 #include "SkTDArray.h"
 #include "SkTHash.h"
 #include "SkTypes.h"
 
 class SkPDFObjNumMap;
 class SkPDFObject;
 class SkPDFSubstituteMap;
-class SkWStream;
 
 /** \class SkPDFObject
 
     A PDF Object is the base class for primitive elements in a PDF file.  A
     common subtype is used to ease the use of indirect object references,
     which are common in the PDF format.
 
 */
 class SkPDFObject : public SkRefCnt {
 public:
-    
-
     /** Subclasses must implement this method to print the object to the
      *  PDF file.
      *  @param catalog  The object catalog to use.
      *  @param stream   The writable output stream to send the output to.
      */
     // TODO(halcanary): make this method const
     virtual void emitObject(SkWStream* stream,
                             const SkPDFObjNumMap& objNumMap,
                             const SkPDFSubstituteMap& substitutes) const = 0;
 
@@ skipping 25 matching lines @@
     SkPDFUnion(SkPDFUnion&& other);
     SkPDFUnion& operator=(SkPDFUnion&& other);
 
     ~SkPDFUnion();
 
     /** The following nine functions are the standard way of creating
         SkPDFUnion objects. */
 
     static SkPDFUnion Int(int32_t);
 
-    static SkPDFUnion Int(size_t);
+    static SkPDFUnion Int(size_t v) { return SkPDFUnion::Int(SkToS32(v)); }
 
     static SkPDFUnion Bool(bool);
 
     static SkPDFUnion Scalar(SkScalar);
 
     /** These two functions do NOT take ownership of ptr, and do NOT
         copy the string.  Suitable for passing in static const
         strings. For example:
           SkPDFUnion n = SkPDFUnion::Name("Length");
           SkPDFUnion u = SkPDFUnion::String("Identity"); */
@@ skipping 90 matching lines @@
 #endif  // 0
 
 ////////////////////////////////////////////////////////////////////////////////
 
 /** \class SkPDFArray
 
     An array object in a PDF.
 */
 class SkPDFArray : public SkPDFObject {
 public:
-    
-
     static const int kMaxLen = 8191;
 
     /** Create a PDF array. Maximum length is 8191.
      */
     SkPDFArray();
     virtual ~SkPDFArray();
 
     // The SkPDFObject interface.
     void emitObject(SkWStream* stream,
                     const SkPDFObjNumMap& objNumMap,
@@ skipping 29 matching lines @@
     void append(SkPDFUnion&& value);
     typedef SkPDFObject INHERITED;
 };
 
 /** \class SkPDFDict
 
     A dictionary object in a PDF.
 */
 class SkPDFDict : public SkPDFObject {
 public:
-    
-
     /** Create a PDF dictionary. Maximum number of entries is 4095.
      */
     SkPDFDict();
 
     /** Create a PDF dictionary with a Type entry.
      *  @param type   The value of the Type entry.
      */
     explicit SkPDFDict(const char type[]);
 
     virtual ~SkPDFDict();
@@ skipping 29 matching lines @@
     void insertScalar(const char key[], SkScalar value);
     void insertName(const char key[], const char nameValue[]);
     void insertName(const char key[], const SkString& nameValue);
     void insertString(const char key[], const char value[]);
     void insertString(const char key[], const SkString& value);
 
     /** Remove all entries from the dictionary.
      */
     void clear();
 
+    /** Emit the dictionary, without the "<<" and ">>".
+     */
+    void emitAll(SkWStream* stream,
+                 const SkPDFObjNumMap& objNumMap,
+                 const SkPDFSubstituteMap& substitutes) const;
+
 private:
     struct Record {
         SkPDFUnion fKey;
         SkPDFUnion fValue;
     };
     SkTDArray<Record> fRecords;
     static const int kMaxLen = 4095;
 
     void set(SkPDFUnion&& name, SkPDFUnion&& value);
 
     typedef SkPDFObject INHERITED;
 };
 
+/** \class SkPDFSharedStream
+
+    This class takes an asset and assumes that it is backed by
+    long-lived shared data (for example, an open file
+    descriptor). That is: no memory savings can be made by holding on
+    to a compressed version instead.
+ */
+class SkPDFSharedStream : public SkPDFObject {
+public:
+    // Takes ownership of asset.
+    SkPDFSharedStream(SkStreamAsset* data)
+        : fAsset(data), fDict(SkNEW(SkPDFDict)) {
+        SkASSERT(data);
+    }
+    SkPDFDict* dict() { return fDict; }
+    void emitObject(SkWStream*,
+                    const SkPDFObjNumMap&,
+                    const SkPDFSubstituteMap&) const override;
+    void addResources(SkPDFObjNumMap*,
+                      const SkPDFSubstituteMap&) const override;
+
+private:
+    SkAutoTDelete<SkStreamAsset> fAsset;
+    SkAutoTUnref<SkPDFDict> fDict;
+    typedef SkPDFObject INHERITED;
+};
+
 ////////////////////////////////////////////////////////////////////////////////
 
 /** \class SkPDFObjNumMap
 
     The PDF Object Number Map manages object numbers.  It is used to
     create the PDF cross reference table.
 */
 class SkPDFObjNumMap : SkNoncopyable {
 public:
     /** Add the passed object to the catalog.
@@ skipping 36 matching lines @@
 
     SkPDFObject* operator()(SkPDFObject* o) const {
         return this->getSubstitute(o);
     }
 
 private:
     SkTHashMap<SkPDFObject*, SkPDFObject*> fSubstituteMap;
 };
 
 #endif