SkPDF: Memory improvements for PDF Streams

src/pdf/SkPDFStream.h

Index: src/pdf/SkPDFStream.h
diff --git a/src/pdf/SkPDFStream.h b/src/pdf/SkPDFStream.h
index d29d9b19badc352071c0866173b282d166af8888..ee062e9d1110df295ea17d936e35b68b4e365a54 100644
--- a/src/pdf/SkPDFStream.h
+++ b/src/pdf/SkPDFStream.h
@@ -27,15 +27,15 @@ class SkPDFStream : public SkPDFDict {
 public:
     /** Create a PDF stream. A Length entry is automatically added to the
      *  stream dictionary.
-     *  @param data   The data part of the stream.  Will be ref()ed.
+     *  @param data   The data part of the stream.  Will not take ownership.
      */
-    explicit SkPDFStream(SkData* data);
+    explicit SkPDFStream(SkData* data) { this->setData(data); }
 
     /** Create a PDF stream. A Length entry is automatically added to the
      *  stream dictionary.
-     *  @param stream The data part of the stream.  Will be duplicate()d.
+     *  @param stream The data part of the stream.  Will not take ownership.
      */
-    explicit SkPDFStream(SkStream* stream);
+    explicit SkPDFStream(SkStream* stream) { this->setData(stream); }
 
     virtual ~SkPDFStream();
 
@@ -45,32 +45,20 @@ public:
                     const SkPDFSubstituteMap& substitutes) override;
 
 protected:
-    enum State {
-        kUnused_State,         //!< The stream hasn't been requested yet.
-        kNoCompression_State,  //!< The stream's been requested in an
-                               //   uncompressed form.
-        kCompressed_State,     //!< The stream's already been compressed.

[tomhudson, 2015/08/19 19:27:51]

Presumably we're always keeping the stream compressed now? Would be nice to have
some information in the commit message about the mechanism of the change, as
well as the deltas to footprint & performance.

-    };
-
     /* Create a PDF stream with no data.  The setData method must be called to
      * set the data.
      */
-    SkPDFStream();
+    SkPDFStream() {}
 
-    void setData(SkData* data);
+    /** Only call this function once. */
     void setData(SkStream* stream);
-
-    size_t dataSize() const;
-
-    void setState(State state) {
-        fState = state;
+    void setData(SkData* data) {
+        SkMemoryStream memoryStream(data);
+        this->setData(&memoryStream);
     }
 
 private:
-    // Indicates what form (or if) the stream has been requested.
-    State fState;
-
-    SkAutoTDelete<SkStreamRewindable> fDataStream;
+    SkAutoTDelete<SkStreamRewindable> fCompressedData;
 
     typedef SkPDFDict INHERITED;
 };