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

3 files changed, 219 insertions, 0 deletions

diff --git a/include/utils/win/SkAutoCoInitialize.h b/include/utils/win/SkAutoCoInitialize.h
new file mode 100644
index 0000000000..8819047eef
--- /dev/null
+++ b/include/utils/win/SkAutoCoInitialize.h
@@ -0,0 +1,37 @@
+/*
+    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 SkAutoCo_DEFINED
+#define SkAutoCo_DEFINED
+
+#define WIN32_LEAN_AND_MEAN
+#include <Windows.h>
+#include "SkTemplates.h"
+
+/**
+ * An instance of this class initializes COM on creation
+ * and closes the COM library on destruction.
+ */
+class AutoCoInitialize : SkNoncopyable {
+private:
+    HRESULT fHR;
+public:
+    AutoCoInitialize();
+    ~AutoCoInitialize();
+    HRESULT getHR();
+};
+
+#endif
diff --git a/include/utils/win/SkIStream.h b/include/utils/win/SkIStream.h
new file mode 100644
index 0000000000..bc8aff5560
--- /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
diff --git a/include/utils/win/SkTScopedComPtr.h b/include/utils/win/SkTScopedComPtr.h
new file mode 100644
index 0000000000..202dc7e83f
--- /dev/null
+++ b/include/utils/win/SkTScopedComPtr.h
@@ -0,0 +1,47 @@
+/*
+    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 SkSkTScopedPtr_DEFINED
+#define SkSkTScopedPtr_DEFINED
+
+#include "SkTemplates.h"
+
+template<typename T>
+class SkTScopedComPtr : SkNoncopyable {
+private:
+    T *fPtr;
+
+public:
+    explicit SkTScopedComPtr(T *ptr = NULL) : fPtr(ptr) { }
+    ~SkTScopedComPtr() {
+        if (NULL != fPtr) {
+            fPtr->Release();
+            fPtr = NULL;
+        }
+    }
+    T &operator*() const { return *fPtr; }
+    T *operator->() const { return fPtr; }
+    /**
+     * Returns the address of the underlying pointer.
+     * This is dangerous -- it breaks encapsulation and the reference escapes.
+     * Must only be used on instances currently pointing to NULL,
+     * and only to initialize the instance.
+     */
+    T **operator&() { SkASSERT(fPtr == NULL); return &fPtr; }
+    T *get() const { return fPtr; }
+};
+
+#endif