Added MemoryFileStream

2 files changed, 87 insertions, 7 deletions

diff --git a/Common/src/BasicFileStream.cpp b/Common/src/BasicFileStream.cpp
index 643e0e1b..34f9a6b5 100644
--- a/Common/src/BasicFileStream.cpp
+++ b/Common/src/BasicFileStream.cpp
@@ -26,9 +26,9 @@
 
 namespace Diligent
 {
-    BasicFileStream::BasicFileStream(IReferenceCounters *pRefCounters,
-                                     const Diligent::Char *Path, 
-                                     EFileAccessMode Access/* = EFileAccessMode::Read*/) :
+    BasicFileStream::BasicFileStream(IReferenceCounters* pRefCounters,
+                                     const Char*         Path, 
+                                     EFileAccessMode     Access/* = EFileAccessMode::Read*/) :
         TBase(pRefCounters),
         m_FileWrpr(Path, Access)
     {
@@ -36,17 +36,17 @@ namespace Diligent
 
     IMPLEMENT_QUERY_INTERFACE(BasicFileStream, IID_FileStream, TBase)
 
-    bool BasicFileStream::Read(void *Data, size_t BufferSize)
+    bool BasicFileStream::Read(void* Data, size_t Size)
     {
-        return m_FileWrpr->Read( Data, BufferSize );
+        return m_FileWrpr->Read( Data, Size );
     }
 
-    void BasicFileStream::Read( Diligent::IDataBlob *pData )
+    void BasicFileStream::Read( Diligent::IDataBlob* pData )
     {
         return m_FileWrpr->Read( pData );
     }
 
-    bool BasicFileStream::Write(const void *Data, size_t Size)
+    bool BasicFileStream::Write(const void* Data, size_t Size)
     {
         return m_FileWrpr->Write( Data, Size );
     }
diff --git a/Common/src/MemoryFileStream.cpp b/Common/src/MemoryFileStream.cpp
new file mode 100644
index 00000000..cae9c6ce
--- /dev/null
+++ b/Common/src/MemoryFileStream.cpp
@@ -0,0 +1,80 @@
+/*     Copyright 2015-2019 Egor Yusov
+ *  
+ *  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
+ * 
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF ANY PROPRIETARY RIGHTS.
+ *
+ *  In no event and under no legal theory, whether in tort (including negligence), 
+ *  contract, or otherwise, unless required by applicable law (such as deliberate 
+ *  and grossly negligent acts) or agreed to in writing, shall any Contributor be
+ *  liable for any damages, including any direct, indirect, special, incidental, 
+ *  or consequential damages of any character arising as a result of this License or 
+ *  out of the use or inability to use the software (including but not limited to damages 
+ *  for loss of goodwill, work stoppage, computer failure or malfunction, or any and 
+ *  all other commercial damages or losses), even if such Contributor has been advised 
+ *  of the possibility of such damages.
+ */
+
+#include <algorithm>
+#include "pch.h"
+
+#include "MemoryFileStream.h"
+
+namespace Diligent
+{
+    MemoryFileStream::MemoryFileStream(IReferenceCounters* pRefCounters,
+                                       IDataBlob*          pData) :
+        TBase(pRefCounters),
+        m_DataBlob(pData)
+    {
+    }
+
+    IMPLEMENT_QUERY_INTERFACE(MemoryFileStream, IID_FileStream, TBase)
+
+    bool MemoryFileStream::Read(void* Data, size_t Size)
+    {
+        VERIFY_EXPR(m_CurrentOffset <= m_DataBlob->GetSize());
+        auto BytesLeft = m_DataBlob->GetSize() - m_CurrentOffset;
+        auto BytesToRead = std::min(BytesLeft, Size);
+        auto* pSrcData = reinterpret_cast<const Uint8*>(m_DataBlob->GetDataPtr()) + m_CurrentOffset;
+        memcpy(Data, pSrcData, BytesToRead);
+        m_CurrentOffset += BytesToRead;
+        return Size == BytesToRead;
+    }
+
+    void MemoryFileStream::Read( IDataBlob* pData )
+    {
+        auto BytesLeft = m_DataBlob->GetSize() - m_CurrentOffset;
+        pData->Resize(BytesLeft);
+        auto res = Read(pData->GetDataPtr(), pData->GetSize());
+        VERIFY_EXPR(res); (void)res;
+    }
+
+    bool MemoryFileStream::Write(const void* Data, size_t Size)
+    {
+        if (m_CurrentOffset + Size > m_DataBlob->GetSize())
+        {
+            m_DataBlob->Resize(m_CurrentOffset + Size);
+        }
+        auto* DstData = reinterpret_cast<Uint8*>(m_DataBlob->GetDataPtr()) + m_CurrentOffset;
+        memcpy(DstData, Data, Size);
+        m_CurrentOffset += Size;
+        return true;
+    }
+
+    bool MemoryFileStream::IsValid()
+    {
+        return !!m_DataBlob;
+    }
+
+    size_t MemoryFileStream::GetSize()
+    {
+        return m_DataBlob->GetSize();
+    }
+}