SkPDF: in-place font subsetting

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 "SkTHash.h"
 #include "SkTypes.h"
 
 class SkData;
 class SkPDFObjNumMap;
 class SkPDFObject;
-class SkPDFSubstituteMap;
 class SkStreamAsset;
 class SkString;
 class SkWStream;
 
 #ifdef SK_PDF_IMAGE_STATS
 #include "SkAtomics.h"
 #endif
 
 /** \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.
      */
     virtual void emitObject(SkWStream* stream,
-                            const SkPDFObjNumMap& objNumMap,
-                            const SkPDFSubstituteMap& substitutes) const = 0;
+                            const SkPDFObjNumMap& objNumMap) 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 {}
+    virtual void addResources(SkPDFObjNumMap* catalog) 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:
@@ skipping 50 matching lines @@
     static SkPDFUnion Name(const SkString&);
 
     /** SkPDFUnion::String will encode the passed string. */
     static SkPDFUnion String(const SkString&);
 
     static SkPDFUnion Object(sk_sp<SkPDFObject>);
     static SkPDFUnion ObjRef(sk_sp<SkPDFObject>);
 
     /** These two non-virtual methods mirror SkPDFObject's
         corresponding virtuals. */
-    void emitObject(SkWStream*,
-                    const SkPDFObjNumMap&,
-                    const SkPDFSubstituteMap&) const;
-    void addResources(SkPDFObjNumMap*, const SkPDFSubstituteMap&) const;
+    void emitObject(SkWStream*, const SkPDFObjNumMap&) const;
+    void addResources(SkPDFObjNumMap*) const;
 
     bool isName() const;
 
 private:
     union {
         int32_t fIntValue;
         bool fBoolValue;
         SkScalar fScalarValue;
         const char* fStaticString;
         char fSkString[sizeof(SkString)];
@@ skipping 26 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 
 #if 0  // Enable if needed.
 /** This class is a SkPDFUnion with SkPDFObject virtuals attached.
     The only use case of this is when a non-compound PDF object is
     referenced indirectly. */
 class SkPDFAtom final : public SkPDFObject {
 public:
     void emitObject(SkWStream* stream,
-                    const SkPDFObjNumMap& objNumMap,
-                    const SkPDFSubstituteMap& substitutes) final;
-    void addResources(SkPDFObjNumMap*, const SkPDFSubstituteMap&) const final;
+                    const SkPDFObjNumMap& objNumMap) final;
+    void addResources(SkPDFObjNumMap* const final;
     SkPDFAtom(SkPDFUnion&& v) : fValue(std::move(v) {}
 
 private:
     const SkPDFUnion fValue;
     typedef SkPDFObject INHERITED;
 };
 #endif  // 0
 
 ////////////////////////////////////////////////////////////////////////////////
 
 /** \class SkPDFArray
 
     An array object in a PDF.
 */
 class SkPDFArray final : public SkPDFObject {
 public:
     /** 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;
+                    const SkPDFObjNumMap& objNumMap) const override;
+    void addResources(SkPDFObjNumMap*) 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);
@@ skipping 26 matching lines @@
 public:
     /** Create a PDF dictionary.
      *  @param type   The value of the Type entry, nullptr for no 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;
+                    const SkPDFObjNumMap& objNumMap) const override;
+    void addResources(SkPDFObjNumMap*) 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.
      */
@@ skipping 11 matching lines @@
     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);
 
     /** Emit the dictionary, without the "<<" and ">>".
      */
     void emitAll(SkWStream* stream,
-                 const SkPDFObjNumMap& objNumMap,
-                 const SkPDFSubstituteMap& substitutes) const;
+                 const SkPDFObjNumMap& objNumMap) const;
 
 private:
     struct Record {
         SkPDFUnion fKey;
         SkPDFUnion fValue;
         Record(SkPDFUnion&&, SkPDFUnion&&);
         Record(Record&&) = default;
         Record& operator=(Record&&) = default;
         Record(const Record&) = delete;
         Record& operator=(const Record&) = delete;
     };
     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:
     SkPDFSharedStream(std::unique_ptr<SkStreamAsset> data);
     ~SkPDFSharedStream();
     SkPDFDict* dict() { return &fDict; }
     void emitObject(SkWStream*,
-                    const SkPDFObjNumMap&,
-                    const SkPDFSubstituteMap&) const override;
-    void addResources(SkPDFObjNumMap*,
-                      const SkPDFSubstituteMap&) const override;
+                    const SkPDFObjNumMap&) const override;
+    void addResources(SkPDFObjNumMap*) const override;
     void drop() override;
 
 private:
     std::unique_ptr<SkStreamAsset> fAsset;
     SkPDFDict fDict;
     typedef SkPDFObject INHERITED;
 };
 
 /** \class SkPDFStream
 
@@ skipping 10 matching lines @@
      *  @param data   The data part of the stream.
      *  @param stream The data part of the stream. */
     explicit SkPDFStream(sk_sp<SkData> data);
     explicit SkPDFStream(std::unique_ptr<SkStreamAsset> stream);
     virtual ~SkPDFStream();
 
     SkPDFDict* dict() { return &fDict; }
 
     // The SkPDFObject interface.
     void emitObject(SkWStream* stream,
-                    const SkPDFObjNumMap& objNumMap,
-                    const SkPDFSubstituteMap& substitutes) const override;
-    void addResources(SkPDFObjNumMap*, const SkPDFSubstituteMap&) const final;
+                    const SkPDFObjNumMap& objNumMap) const override;
+    void addResources(SkPDFObjNumMap*) const final;
     void drop() override;
 
 protected:
     /* Create a PDF stream with no data.  The setData method must be called to
      * set the data. */
     SkPDFStream();
 
     /** Only call this function once. */
     void setData(std::unique_ptr<SkStreamAsset> stream);
 
@@ skipping 14 matching lines @@
 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);
+    void addObjectRecursively(SkPDFObject* obj);
 
     /** Get the object number for the passed object.
      *  @param obj         The object of interest.
      */
     int32_t getObjectNumber(SkPDFObject* obj) const;
 
     const SkTArray<sk_sp<SkPDFObject>>& objects() const { return fObjects; }
 
 private:
     SkTArray<sk_sp<SkPDFObject>> fObjects;
     SkTHashMap<SkPDFObject*, int32_t> fObjectNumbers;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
-/** \class SkPDFSubstituteMap
-
-    The PDF Substitute Map manages substitute objects and owns the
-    substitutes.
-*/
-class SkPDFSubstituteMap : SkNoncopyable {
-public:
-    ~SkPDFSubstituteMap();
-    /** Set substitute object for the passed object.
-        Refs substitute.
-     */
-    void setSubstitute(SkPDFObject* original, SkPDFObject* substitute);
-
-    /** Find and return any substitute object set for the passed object. If
-     *  there is none, return the passed object.
-     */
-    SkPDFObject* getSubstitute(SkPDFObject* object) const;
-
-    SkPDFObject* operator()(SkPDFObject* o) const {
-        return this->getSubstitute(o);
-    }
-
-private:
-    SkTHashMap<SkPDFObject*, SkPDFObject*> fSubstituteMap;
-};
-
 #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