Wrap SkStreams in IStreams instead of copying data around.
http://codereview.appspot.com/4630062/
git-svn-id: http://skia.googlecode.com/svn/trunk@1694 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/utils/win/SkIStream.h b/include/utils/win/SkIStream.h
new file mode 100644
index 0000000..bc8aff5
--- /dev/null
+++ b/include/utils/win/SkIStream.h
@@ -0,0 +1,135 @@
+/*
+ Copyright 2011 Google Inc.
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#ifndef SkIStream_DEFINED
+#define SkIStream_DEFINED
+
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#include <ole2.h>
+
+class SkStream;
+class SkWStream;
+
+/**
+ * A bare IStream implementation which properly reference counts
+ * but returns E_NOTIMPL for all ISequentialStream and IStream methods.
+ */
+class SkBaseIStream : public IStream {
+private:
+ LONG _refcount;
+
+protected:
+ explicit SkBaseIStream();
+ virtual ~SkBaseIStream();
+
+public:
+ virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid
+ , void ** ppvObject);
+ virtual ULONG STDMETHODCALLTYPE AddRef(void);
+ virtual ULONG STDMETHODCALLTYPE Release(void);
+
+ // ISequentialStream Interface
+public:
+ virtual HRESULT STDMETHODCALLTYPE Read(void* pv, ULONG cb, ULONG* pcbRead);
+
+ virtual HRESULT STDMETHODCALLTYPE Write(void const* pv
+ , ULONG cb
+ , ULONG* pcbWritten);
+
+ // IStream Interface
+public:
+ virtual HRESULT STDMETHODCALLTYPE SetSize(ULARGE_INTEGER);
+
+ virtual HRESULT STDMETHODCALLTYPE CopyTo(IStream*
+ , ULARGE_INTEGER
+ , ULARGE_INTEGER*
+ , ULARGE_INTEGER*);
+
+ virtual HRESULT STDMETHODCALLTYPE Commit(DWORD);
+
+ virtual HRESULT STDMETHODCALLTYPE Revert(void);
+
+ virtual HRESULT STDMETHODCALLTYPE LockRegion(ULARGE_INTEGER
+ , ULARGE_INTEGER
+ , DWORD);
+
+ virtual HRESULT STDMETHODCALLTYPE UnlockRegion(ULARGE_INTEGER
+ , ULARGE_INTEGER
+ , DWORD);
+
+ virtual HRESULT STDMETHODCALLTYPE Clone(IStream **);
+
+ virtual HRESULT STDMETHODCALLTYPE Seek(LARGE_INTEGER liDistanceToMove
+ , DWORD dwOrigin
+ , ULARGE_INTEGER* lpNewFilePointer);
+
+ virtual HRESULT STDMETHODCALLTYPE Stat(STATSTG* pStatstg
+ , DWORD grfStatFlag);
+};
+
+/**
+ * A minimal read-only IStream implementation which wraps an SkIStream.
+ */
+class SkIStream : public SkBaseIStream {
+private:
+ SkStream *fSkStream;
+ bool fUnrefOnRelease;
+
+ SkIStream(SkStream* stream, bool unrefOnRelease);
+ virtual ~SkIStream();
+
+public:
+ HRESULT static CreateFromSkStream(SkStream* stream
+ , bool unrefOnRelease
+ , IStream ** ppStream);
+
+ virtual HRESULT STDMETHODCALLTYPE Read(void* pv, ULONG cb, ULONG* pcbRead);
+
+ virtual HRESULT STDMETHODCALLTYPE Write(void const* pv
+ , ULONG cb
+ , ULONG* pcbWritten);
+
+ virtual HRESULT STDMETHODCALLTYPE Seek(LARGE_INTEGER liDistanceToMove
+ , DWORD dwOrigin
+ , ULARGE_INTEGER* lpNewFilePointer);
+
+ virtual HRESULT STDMETHODCALLTYPE Stat(STATSTG* pStatstg
+ , DWORD grfStatFlag);
+};
+
+/**
+ * A minimal write-only IStream implementation which wraps an SkWIStream.
+ */
+class SkWIStream : public SkBaseIStream {
+private:
+ SkWStream *fSkWStream;
+
+ SkWIStream(SkWStream* stream);
+ virtual ~SkWIStream();
+
+public:
+ HRESULT static CreateFromSkWStream(SkWStream* stream, IStream ** ppStream);
+
+ virtual HRESULT STDMETHODCALLTYPE Write(void const* pv
+ , ULONG cb
+ , ULONG* pcbWritten);
+
+ virtual HRESULT STDMETHODCALLTYPE Stat(STATSTG* pStatstg
+ , DWORD grfStatFlag);
+};
+
+#endif