use unique_ptr for stream api

Bug: skia:6888
Change-Id: I3459b4913982a7cae1c0061697c82cc65ad9a2d8
Reviewed-on: https://skia-review.googlesource.com/26740
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>

1 files changed, 111 insertions, 10 deletions

diff --git a/include/core/SkStream.h b/include/core/SkStream.h
index 5ef8519245..2d7a8c529d 100644
--- a/include/core/SkStream.h
+++ b/include/core/SkStream.h
@@ -101,10 +101,29 @@ public:
      */
     virtual bool rewind() { return false; }
 
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     /** Duplicates this stream. If this cannot be done, returns NULL.
      *  The returned stream will be positioned at the beginning of its data.
      */
     virtual SkStreamRewindable* duplicate() const { return nullptr; }
+    /** Duplicates this stream. If this cannot be done, returns NULL.
+     *  The returned stream will be positioned the same as this stream.
+     */
+    virtual SkStreamSeekable* fork() const { return nullptr; }
+#else
+    /** Duplicates this stream. If this cannot be done, returns NULL.
+     *  The returned stream will be positioned at the beginning of its data.
+     */
+    std::unique_ptr<SkStream> duplicate() const {
+        return std::unique_ptr<SkStream>(this->onDuplicate());
+    }
+    /** Duplicates this stream. If this cannot be done, returns NULL.
+     *  The returned stream will be positioned the same as this stream.
+     */
+    std::unique_ptr<SkStream> fork() const {
+        return std::unique_ptr<SkStream>(this->onFork());
+    }
+#endif
 
 //SkStreamSeekable
     /** Returns true if this stream can report it's current position. */
@@ -124,11 +143,6 @@ public:
      */
     virtual bool move(long /*offset*/) { return false; }
 
-    /** Duplicates this stream. If this cannot be done, returns NULL.
-     *  The returned stream will be positioned the same as this stream.
-     */
-    virtual SkStreamSeekable* fork() const { return nullptr; }
-
 //SkStreamAsset
     /** Returns true if this stream can report it's total length. */
     virtual bool hasLength() const { return false; }
@@ -139,44 +153,97 @@ public:
     /** Returns the starting address for the data. If this cannot be done, returns NULL. */
     //TODO: replace with virtual const SkData* getData()
     virtual const void* getMemoryBase() { return nullptr; }
+
+private:
+#ifndef SK_SUPPORT_LEGACY_STREAM_API
+    virtual SkStream* onDuplicate() const { return nullptr; }
+    virtual SkStream* onFork() const { return nullptr; }
+#endif
 };
 
 /** SkStreamRewindable is a SkStream for which rewind and duplicate are required. */
 class SK_API SkStreamRewindable : public SkStream {
 public:
     bool rewind() override = 0;
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkStreamRewindable* duplicate() const override = 0;
+#else
+    std::unique_ptr<SkStreamRewindable> duplicate() const {
+        return std::unique_ptr<SkStreamRewindable>(this->onDuplicate());
+    }
+private:
+    SkStreamRewindable* onDuplicate() const override = 0;
+#endif
 };
 
 /** SkStreamSeekable is a SkStreamRewindable for which position, seek, move, and fork are required. */
 class SK_API SkStreamSeekable : public SkStreamRewindable {
 public:
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkStreamSeekable* duplicate() const override = 0;
+#else
+    std::unique_ptr<SkStreamSeekable> duplicate() const {
+        return std::unique_ptr<SkStreamSeekable>(this->onDuplicate());
+    }
+#endif
 
     bool hasPosition() const override { return true; }
     size_t getPosition() const override = 0;
     bool seek(size_t position) override = 0;
     bool move(long offset) override = 0;
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkStreamSeekable* fork() const override = 0;
+#else
+    std::unique_ptr<SkStreamSeekable> fork() const {
+        return std::unique_ptr<SkStreamSeekable>(this->onFork());
+    }
+private:
+    SkStreamSeekable* onDuplicate() const override = 0;
+    SkStreamSeekable* onFork() const override = 0;
+#endif
 };
 
 /** SkStreamAsset is a SkStreamSeekable for which getLength is required. */
 class SK_API SkStreamAsset : public SkStreamSeekable {
 public:
-    SkStreamAsset* duplicate() const override = 0;
-    SkStreamAsset* fork() const override = 0;
-
     bool hasLength() const override { return true; }
     size_t getLength() const override = 0;
+
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
+    SkStreamAsset* duplicate() const override = 0;
+    SkStreamAsset* fork() const override = 0;
+#else
+    std::unique_ptr<SkStreamAsset> duplicate() const {
+        return std::unique_ptr<SkStreamAsset>(this->onDuplicate());
+    }
+    std::unique_ptr<SkStreamAsset> fork() const {
+        return std::unique_ptr<SkStreamAsset>(this->onFork());
+    }
+private:
+    SkStreamAsset* onDuplicate() const override = 0;
+    SkStreamAsset* onFork() const override = 0;
+#endif
 };
 
 /** SkStreamMemory is a SkStreamAsset for which getMemoryBase is required. */
 class SK_API SkStreamMemory : public SkStreamAsset {
 public:
+    const void* getMemoryBase() override = 0;
+
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkStreamMemory* duplicate() const override = 0;
     SkStreamMemory* fork() const override = 0;
-
-    const void* getMemoryBase() override = 0;
+#else
+    std::unique_ptr<SkStreamMemory> duplicate() const {
+        return std::unique_ptr<SkStreamMemory>(this->onDuplicate());
+    }
+    std::unique_ptr<SkStreamMemory> fork() const {
+        return std::unique_ptr<SkStreamMemory>(this->onFork());
+    }
+private:
+    SkStreamMemory* onDuplicate() const override = 0;
+    SkStreamMemory* onFork() const override = 0;
+#endif
 };
 
 class SK_API SkWStream : SkNoncopyable {
@@ -278,12 +345,24 @@ public:
     bool isAtEnd() const override;
 
     bool rewind() override;
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkStreamAsset* duplicate() const override;
+#else
+    std::unique_ptr<SkStreamAsset> duplicate() const {
+        return std::unique_ptr<SkStreamAsset>(this->onDuplicate());
+    }
+#endif
 
     size_t getPosition() const override;
     bool seek(size_t position) override;
     bool move(long offset) override;
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkStreamAsset* fork() const override;
+#else
+    std::unique_ptr<SkStreamAsset> fork() const {
+        return std::unique_ptr<SkStreamAsset>(this->onFork());
+    }
+#endif
 
     size_t getLength() const override;
 
@@ -291,6 +370,11 @@ private:
     explicit SkFILEStream(std::shared_ptr<FILE>, size_t size, size_t offset);
     explicit SkFILEStream(std::shared_ptr<FILE>, size_t size, size_t offset, size_t originalOffset);
 
+#ifndef SK_SUPPORT_LEGACY_STREAM_API
+    SkStreamAsset* onDuplicate() const override;
+    SkStreamAsset* onFork() const override;
+#endif
+
     std::shared_ptr<FILE> fFILE;
     // My own council will I keep on sizes and offsets.
     size_t fSize;
@@ -346,18 +430,35 @@ public:
     size_t peek(void* buffer, size_t size) const override;
 
     bool rewind() override;
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkMemoryStream* duplicate() const override;
+#else
+    std::unique_ptr<SkMemoryStream> duplicate() const {
+        return std::unique_ptr<SkMemoryStream>(this->onDuplicate());
+    }
+#endif
 
     size_t getPosition() const override;
     bool seek(size_t position) override;
     bool move(long offset) override;
+#ifdef SK_SUPPORT_LEGACY_STREAM_API
     SkMemoryStream* fork() const override;
+#else
+    std::unique_ptr<SkMemoryStream> fork() const {
+        return std::unique_ptr<SkMemoryStream>(this->onFork());
+    }
+#endif
 
     size_t getLength() const override;
 
     const void* getMemoryBase() override;
 
 private:
+#ifndef SK_SUPPORT_LEGACY_STREAM_API
+    SkMemoryStream* onDuplicate() const override;
+    SkMemoryStream* onFork() const override;
+#endif
+
     sk_sp<SkData>   fData;
     size_t          fOffset;