Make SkTypefacePlayback use smart pointers.

This clarifies the ownership of the typefaces as well as removes a use
of SkRefCnt_SafeAssign which is currently a code smell.

Change-Id: I8fec541f71f555c2182b77870979ece87b501901
Reviewed-on: https://skia-review.googlesource.com/140249
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>

src/core/SkPictureData.cpp

@@ -258,17 +258,6 @@ bool SkPictureData::parseStreamTag(SkStream* stream,
                                    uint32_t size,
                                    const SkDeserialProcs& procs,
                                    SkTypefacePlayback* topLevelTFPlayback) {
-    /*
-     *  By the time we encounter BUFFER_SIZE_TAG, we need to have already seen
-     *  its dependents: FACTORY_TAG and TYPEFACE_TAG. These two are not required
-     *  but if they are present, they need to have been seen before the buffer.
-     *
-     *  We assert that if/when we see either of these, that we have not yet seen
-     *  the buffer tag, because if we have, then its too-late to deal with the
-     *  factories or typefaces.
-     */
-    SkDEBUGCODE(bool haveBuffer = false;)
-
     switch (tag) {
         case SK_PICT_READER_TAG:
             SkASSERT(nullptr == fOpData);
@@ -278,7 +267,6 @@ bool SkPictureData::parseStreamTag(SkStream* stream,
             }
             break;
         case SK_PICT_FACTORY_TAG: {
-            SkASSERT(!haveBuffer);
             if (!stream->readU32(&size)) { return false; }
             fFactoryPlayback = skstd::make_unique<SkFactoryPlayback>(size);
             for (size_t i = 0; i < size; i++) {
@@ -293,17 +281,15 @@ bool SkPictureData::parseStreamTag(SkStream* stream,
             }
         } break;
         case SK_PICT_TYPEFACE_TAG: {
-            SkASSERT(!haveBuffer);
-            const int count = SkToInt(size);
-            fTFPlayback.setCount(count);
-            for (int i = 0; i < count; i++) {
+            fTFPlayback.setCount(size);
+            for (uint32_t i = 0; i < size; ++i) {
                 sk_sp<SkTypeface> tf(SkTypeface::MakeDeserialize(stream));
                 if (!tf.get()) {    // failed to deserialize
                     // fTFPlayback asserts it never has a null, so we plop in
                     // the default here.
                     tf = SkTypeface::MakeDefault();
                 }
-                fTFPlayback.set(i, tf.get());
+                fTFPlayback[i] = std::move(tf);
             }
         } break;
         case SK_PICT_PICTURE_TAG: {
@@ -349,7 +335,6 @@ bool SkPictureData::parseStreamTag(SkStream* stream,
             if (!buffer.isValid()) {
                 return false;
             }
-            SkDEBUGCODE(haveBuffer = true;)
         } break;
     }
     return true;    // success

src/core/SkPictureFlat.cpp

@@ -15,42 +15,9 @@
 
 ///////////////////////////////////////////////////////////////////////////////
 
-SkTypefacePlayback::SkTypefacePlayback() : fCount(0), fArray(nullptr) {}
-
-SkTypefacePlayback::~SkTypefacePlayback() {
-    this->reset(nullptr);
-}
-
-void SkTypefacePlayback::reset(const SkRefCntSet* rec) {
-    for (int i = 0; i < fCount; i++) {
-        SkASSERT(fArray[i]);
-        fArray[i]->unref();
-    }
-    delete[] fArray;
-
-    if (rec!= nullptr && rec->count() > 0) {
-        fCount = rec->count();
-        fArray = new SkRefCnt* [fCount];
-        rec->copyToArray(fArray);
-        for (int i = 0; i < fCount; i++) {
-            fArray[i]->ref();
-        }
-    } else {
-        fCount = 0;
-        fArray = nullptr;
-    }
-}
-
-void SkTypefacePlayback::setCount(int count) {
-    this->reset(nullptr);
+SkTypefacePlayback::~SkTypefacePlayback() {}
 
+void SkTypefacePlayback::setCount(size_t count) {
     fCount = count;
-    fArray = new SkRefCnt* [count];
-    sk_bzero(fArray, count * sizeof(SkRefCnt*));
-}
-
-SkRefCnt* SkTypefacePlayback::set(int index, SkRefCnt* obj) {
-    SkASSERT((unsigned)index < (unsigned)fCount);
-    SkRefCnt_SafeAssign(fArray[index], obj);
-    return obj;
+    fArray.reset(new sk_sp<SkTypeface>[count]);
 }

src/core/SkPictureFlat.h

@@ -155,23 +155,25 @@ static inline bool ClipParams_unpackDoAA(uint32_t packed) {
 
 class SkTypefacePlayback {
 public:
-    SkTypefacePlayback();
-    virtual ~SkTypefacePlayback();
+    SkTypefacePlayback() : fCount(0), fArray(nullptr) {}
+    ~SkTypefacePlayback();
 
-    int count() const { return fCount; }
+    void setCount(size_t count);
 
-    void reset(const SkRefCntSet*);
+    size_t count() const { return fCount; }
 
-    void setCount(int count);
-    SkRefCnt* set(int index, SkRefCnt*);
+    sk_sp<SkTypeface>& operator[](size_t index) {
+        SkASSERT(index < fCount);
+        return fArray[index];
+    }
 
     void setupBuffer(SkReadBuffer& buffer) const {
-        buffer.setTypefaceArray((SkTypeface**)fArray, fCount);
+        buffer.setTypefaceArray(fArray.get(), fCount);
     }
 
 protected:
-    int fCount;
-    SkRefCnt** fArray;
+    size_t fCount;
+    std::unique_ptr<sk_sp<SkTypeface>[]> fArray;
 };
 
 class SkFactoryPlayback {

src/core/SkReadBuffer.cpp

@@ -379,7 +379,7 @@ sk_sp<SkTypeface> SkReadBuffer::readTypeface() {
         if (!this->validate(index <= fTFCount)) {
             return nullptr;
         }
-        return sk_ref_sp(fTFArray[index - 1]);
+        return fTFArray[index - 1];
     } else {    // custom
         size_t size = sk_negate_to_size_t(index);
         const void* data = this->skip(size);

src/core/SkReadBuffer.h

@@ -180,7 +180,7 @@ public:
     sk_sp<SkImage> readImage();
     sk_sp<SkTypeface> readTypeface();
 
-    void setTypefaceArray(SkTypeface* array[], int count) {
+    void setTypefaceArray(sk_sp<SkTypeface> array[], int count) {
         fTFArray = array;
         fTFCount = count;
     }
@@ -282,8 +282,8 @@ private:
 
     void* fMemoryPtr;
 
-    SkTypeface** fTFArray;
-    int        fTFCount;
+    sk_sp<SkTypeface>* fTFArray;
+    int                fTFCount;
 
     SkFlattenable::Factory* fFactoryArray;
     int                     fFactoryCount;