Core/File: Add SetSize method (currently missing Posix implementation!)

Former-commit-id: c9ffb545485d90940d620e94fd25a7256d62ab58

include/Nazara/Core/File.hpp

@@ -65,6 +65,7 @@ namespace Nz
 			bool SetCursorPos(CursorPosition pos, Int64 offset = 0);
 			bool SetCursorPos(UInt64 offset) override;
 			bool SetFile(const String& filePath);
+			bool SetSize(UInt64 size);
 
 			File& operator=(const String& filePath);
 			File& operator=(const File&) = delete;

src/Nazara/Core/File.cpp

@@ -454,6 +454,25 @@ namespace Nz
 		return true;
 	}
 
+    /*!
+    * \brief Sets the size of the file
+    * \return true if the file size has correctly changed
+    *
+    * \param size The size the file should have after this call
+    *
+    * \remark The cursor position is not affected by this call
+    * \remark The file must be open in write mode
+    */
+    bool File::SetSize(UInt64 size)
+    {
+        NazaraLock(m_mutex)
+
+        NazaraAssert(IsOpen(), "File is not open");
+        NazaraAssert(IsWritable(), "File is not writable");
+
+        return m_impl->SetSize(size);
+    }
+
 	/*!
 	* \brief Sets the file path
 	* \return A reference to this

src/Nazara/Core/Win32/FileImpl.cpp

@@ -3,6 +3,7 @@
 // For conditions of distribution and use, see copyright notice in Config.hpp
 
 #include <Nazara/Core/Win32/FileImpl.hpp>
+#include <Nazara/Core/CallOnExit.hpp>
 #include <Nazara/Core/Error.hpp>
 #include <Nazara/Core/Win32/Time.hpp>
 #include <memory>
@@ -158,6 +159,31 @@ namespace Nz
 		return SetFilePointerEx(m_handle, distance, nullptr, moveMethod) != 0;
 	}
 
+	bool FileImpl::SetSize(UInt64 size)
+	{
+		UInt64 cursorPos = GetCursorPos();
+
+		CallOnExit resetCursor([this, cursorPos] ()
+		{
+			if (!SetCursorPos(CursorPosition_AtBegin, cursorPos))
+				NazaraWarning("Failed to reset cursor position to previous position: " + Error::GetLastSystemError());
+		});
+
+		if (!SetCursorPos(CursorPosition_AtBegin, size))
+		{
+			NazaraError("Failed to set file size: failed to move cursor position: " + Error::GetLastSystemError());
+			return false;
+		}
+
+		if (!SetEndOfFile(m_handle))
+		{
+			NazaraError("Failed to set file size: " + Error::GetLastSystemError());
+			return false;
+		}
+
+		return true;
+	}
+
 	std::size_t FileImpl::Write(const void* buffer, std::size_t size)
 	{
 		DWORD written = 0;

src/Nazara/Core/Win32/FileImpl.hpp

@@ -32,6 +32,7 @@ namespace Nz
 			bool Open(const String& filePath, UInt32 mode);
 			std::size_t Read(void* buffer, std::size_t size);
 			bool SetCursorPos(CursorPosition pos, Int64 offset);
+			bool SetSize(UInt64 size);
 			std::size_t Write(const void* buffer, std::size_t size);
 
 			FileImpl& operator=(const FileImpl&) = delete;