SkPDF: add drop() virtual to release resources early.

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
@@ skipping 33 matching lines @@
                             const SkPDFSubstituteMap& substitutes) const = 0;
 
     /**
      *  Adds all transitive dependencies of this object to the
      *  catalog.  Implementations should respect the catalog's object
      *  substitution map.
      */
     virtual void addResources(SkPDFObjNumMap* catalog,
                               const SkPDFSubstituteMap& substitutes) const {}
 
+    /**
+     *  Release all resources associated with this SkPDFObject.  It is
+     *  an error to call emitObject() or addResources() after calling
+     *  drop().
+     */
+    virtual void drop() {}
+
+    virtual ~SkPDFObject() {}
 private:
     typedef SkRefCnt INHERITED;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
 /**
    A SkPDFUnion is a non-virtualized implementation of the
    non-compound, non-specialized PDF Object types: Name, String,
    Number, Boolean.
@@ skipping 107 matching lines @@
 #endif  // 0
 
 ////////////////////////////////////////////////////////////////////////////////
 
 /** \class SkPDFArray
 
     An array object in a PDF.
 */
 class SkPDFArray final : 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,
                     const SkPDFSubstituteMap& substitutes) const override;
     void addResources(SkPDFObjNumMap*,
                       const SkPDFSubstituteMap&) const override;
+    void drop() override;
 
     /** The size of the array.
      */
     int size() const;
 
     /** Preallocate space for the given number of entries.
      *  @param length The number of array slots to preallocate.
      */
     void reserve(int length);
 
     /** Appends a value to the end of the array.
      *  @param value The value to add to the array.
      */
     void appendInt(int32_t);
     void appendBool(bool);
     void appendScalar(SkScalar);
     void appendName(const char[]);
     void appendName(const SkString&);
     void appendString(const char[]);
     void appendString(const SkString&);
     void appendObject(sk_sp<SkPDFObject>);
     void appendObjRef(sk_sp<SkPDFObject>);
 
 private:
-    SkTDArray<SkPDFUnion> fValues;
+    SkTArray<SkPDFUnion> fValues;
     void append(SkPDFUnion&& value);
-    typedef SkPDFObject INHERITED;
+    SkDEBUGCODE(bool fDumped;)
 };
 
 /** \class SkPDFDict
 
     A dictionary object in a PDF.
 */
 class SkPDFDict : public SkPDFObject {
 public:
-    /** Create a PDF dictionary. Maximum number of entries is 4095.
+    /** Create a PDF dictionary.
+     *  @param type   The value of the Type entry, nullptr for no type.
      */
-    SkPDFDict();
-
-    /** Create a PDF dictionary with a Type entry.
-     *  @param type   The value of the Type entry.
-     */
-    explicit SkPDFDict(const char type[]);
+    explicit SkPDFDict(const char type[] = nullptr);
 
     virtual ~SkPDFDict();
 
     // The SkPDFObject interface.
     void emitObject(SkWStream* stream,
                     const SkPDFObjNumMap& objNumMap,
                     const SkPDFSubstituteMap& substitutes) const override;
     void addResources(SkPDFObjNumMap*,
                       const SkPDFSubstituteMap&) const override;
+    void drop() override;
 
     /** The size of the dictionary.
      */
     int size() const;
 
     /** Add the value to the dictionary with the given key.
      *  @param key   The text of the key for this dictionary entry.
      *  @param value The value for this dictionary entry.
      */
     void insertObject(const char key[], sk_sp<SkPDFObject>);
     void insertObject(const SkString& key, sk_sp<SkPDFObject>);
     void insertObjRef(const char key[], sk_sp<SkPDFObject>);
     void insertObjRef(const SkString& key, sk_sp<SkPDFObject>);
 
     /** Add the value to the dictionary with the given key.
      *  @param key   The text of the key for this dictionary entry.
      *  @param value The value for this dictionary entry.
      */
     void insertBool(const char key[], bool value);
     void insertInt(const char key[], int32_t value);
     void insertInt(const char key[], size_t value);
     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;
+        Record(SkPDFUnion&&, SkPDFUnion&&);
+        Record(Record&&);
+        Record& operator=(Record&&);
+        Record(const Record&) = delete;
+        Record& operator=(const Record&) = delete;
     };
-    SkTDArray<Record> fRecords;
-    static const int kMaxLen = 4095;
-
-    void set(SkPDFUnion&& name, SkPDFUnion&& value);
-
-    typedef SkPDFObject INHERITED;
+    SkTArray<Record> fRecords;
+    SkDEBUGCODE(bool fDumped;)
 };
 
 /** \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 final : public SkPDFObject {
 public:
     // Takes ownership of asset.
-    SkPDFSharedStream(SkStreamAsset* data)
-        : fAsset(data), fDict(new SkPDFDict) { SkASSERT(data); }
+    SkPDFSharedStream(SkStreamAsset* data);
+    ~SkPDFSharedStream();
     SkPDFDict* dict() { return fDict.get(); }
     void emitObject(SkWStream*,
                     const SkPDFObjNumMap&,
                     const SkPDFSubstituteMap&) const override;
     void addResources(SkPDFObjNumMap*,
                       const SkPDFSubstituteMap&) const override;
+    void drop() override;
 
 private:
     SkAutoTDelete<SkStreamAsset> fAsset;
     sk_sp<SkPDFDict> fDict;
+    SkDEBUGCODE(bool fDumped;)
     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.
      *  @param obj         The object to add.
      *  @return True iff the object was not already added to the catalog.
      */
     bool addObject(SkPDFObject* obj);
 
     /** Add the passed object to the catalog, as well as all its dependencies.
      *  @param obj   The object to add.  If nullptr, this is a noop.
      *  @param subs  Will be passed to obj->addResources().
      */
     void addObjectRecursively(SkPDFObject* obj, const SkPDFSubstituteMap& subs);
 
     /** Get the object number for the passed object.
      *  @param obj         The object of interest.
      */
     int32_t getObjectNumber(SkPDFObject* obj) const;
 
-    const SkTDArray<SkPDFObject*>& objects() const { return fObjects; }
+    const SkTArray<sk_sp<SkPDFObject>>& objects() const { return fObjects; }
 
 private:
-    SkTDArray<SkPDFObject*> fObjects;
+    SkTArray<sk_sp<SkPDFObject>> fObjects;
     SkTHashMap<SkPDFObject*, int32_t> fObjectNumbers;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
 /** \class SkPDFSubstituteMap
 
     The PDF Substitute Map manages substitute objects and owns the
     substitutes.
 */
@@ skipping 19 matching lines @@
 };
 
 #ifdef SK_PDF_IMAGE_STATS
 extern SkAtomic<int> gDrawImageCalls;
 extern SkAtomic<int> gJpegImageObjects;
 extern SkAtomic<int> gRegularImageObjects;
 extern void SkPDFImageDumpStats();
 #endif // SK_PDF_IMAGE_STATS
 
 #endif