Simplify reference management in SkPDF

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 "SkMutex.h"
 #include "SkRefCnt.h"
 #include "SkScalar.h"
 #include "SkString.h"
 #include "SkTDArray.h"
 #include "SkTSet.h"
 #include "SkTypes.h"
 
 class SkPDFCatalog;
 class SkWStream;
 
+class SkPDFObject;
+
 /** \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:
     SK_DECLARE_INST_COUNT(SkPDFObject)
 
     /** 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, SkPDFCatalog* catalog) = 0;
 
-    /** For non-primitive objects (i.e. objects defined outside this file),
-     *  this method will add to newResourceObjects any objects that this method
-     *  depends on, but not already in knownResourceObjects. This operates
-     *  recursively so if this object depends on another object and that object
-     *  depends on two more, all three objects will be added.
+    /**
+     *  Adds all transitive dependencies of this object to resourceSet.
      *
-     *  @param knownResourceObjects  The set of resources to be ignored.
-     *  @param newResourceObjects  The set to append dependant resources to.
+     *  @param catalog Implementations should respect the catalog's
+     *                 object substitution map.
      */
-    virtual void getResources(const SkTSet<SkPDFObject*>& knownResourceObjects,
-                              SkTSet<SkPDFObject*>* newResourceObjects);
-
-    /** Static helper function to add a resource to a list.  The list takes
-     *  a reference.
-     * @param resource  The resource to add.
-     * @param list      The list to add the resource to.
-     */
-    static void AddResourceHelper(SkPDFObject* resource,
-                                  SkTDArray<SkPDFObject*>* list);
-
-    /** Static helper function to copy and reference the resources (and all
-     *   their subresources) into a new list.
-     * @param resources The resource list.
-     * @param newResourceObjects All the resource objects (recursively) used on
-     *                         the page are added to this array.  This gives
-     *                         the caller a chance to deduplicate resources
-     *                         across pages.
-     * @param knownResourceObjects  The set of resources to be ignored.
-     */
-    static void GetResourcesHelper(
-            const SkTDArray<SkPDFObject*>* resources,
-            const SkTSet<SkPDFObject*>& knownResourceObjects,
-            SkTSet<SkPDFObject*>* newResourceObjects);
+    virtual void addResources(SkTSet<SkPDFObject*>* resourceSet,
+                              SkPDFCatalog* catalog) const {}
 
 private:
     typedef SkRefCnt INHERITED;
 };
 
 /** \class SkPDFObjRef
 
     An indirect reference to a PDF object.
 */
 class SkPDFObjRef : public SkPDFObject {
 public:
     SK_DECLARE_INST_COUNT(SkPDFObjRef)
 
     /** Create a reference to an existing SkPDFObject.
      *  @param obj The object to reference.
      */
     explicit SkPDFObjRef(SkPDFObject* obj);
     virtual ~SkPDFObjRef();
 
     // The SkPDFObject interface.
     virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog) SK_OVERRIDE;
+    virtual void addResources(SkTSet<SkPDFObject*>*, SkPDFCatalog*) const SK_OVERRIDE;
 
 private:
     SkAutoTUnref<SkPDFObject> fObj;
 
     typedef SkPDFObject INHERITED;
 };
 
 /** \class SkPDFInt
 
     An integer object in a PDF.
@@ skipping 143 matching lines @@
 public:
     SK_DECLARE_INST_COUNT(SkPDFArray)
 
     /** Create a PDF array. Maximum length is 8191.
      */
     SkPDFArray();
     virtual ~SkPDFArray();
 
     // The SkPDFObject interface.
     virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog) SK_OVERRIDE;
+    virtual void addResources(SkTSet<SkPDFObject*>*, SkPDFCatalog*) const SK_OVERRIDE;
 
     /** The size of the array.
      */
     int size() { return fValue.count(); }
 
     /** Preallocate space for the given number of entries.
      *  @param length The number of array slots to preallocate.
      */
     void reserve(int length);
 
@@ skipping 51 matching lines @@
 
     /** Create a PDF dictionary with a Type entry.
      *  @param type   The value of the Type entry.
      */
     explicit SkPDFDict(const char type[]);
 
     virtual ~SkPDFDict();
 
     // The SkPDFObject interface.
     virtual void emitObject(SkWStream* stream, SkPDFCatalog* catalog) SK_OVERRIDE;
+    virtual void addResources(SkTSet<SkPDFObject*>*, SkPDFCatalog*) const SK_OVERRIDE;
 
     /** The size of the dictionary.
      */
     int size() const;
 
     /** Add the value to the dictionary with the given key.  Refs value.
      *  @param key   The key for this dictionary entry.
      *  @param value The value for this dictionary entry.
      *  @return The value argument is returned.
      */
@@ skipping 66 matching lines @@
 
     mutable SkMutex fMutex;  // protects modifications to fValue
     SkTDArray<struct Rec> fValue;
 
     SkPDFObject* append(SkPDFName* key, SkPDFObject* value);
 
     typedef SkPDFObject INHERITED;
 };
 
 #endif