Implement preliminary IO.

It might be a good idea to eschew the structs and access the data
directly from the view.

Alternatively, the serialization functions might be rewritten to
simply memcpy the structs, after either adding __attribute__((packed))
or ensuring consistent padding.

1 files changed, 36 insertions, 0 deletions

diff --git a/c/data.cpp b/c/data.cpp
index e28378e..1a78ef2 100644
--- a/c/data.cpp
+++ b/c/data.cpp
@@ -1,6 +1,8 @@
 #include <memory>
+#include <vector>
 
 #include "data.h"
+#include "win.h"
 
 template <typename T>
 inline unsigned char* ValToBuf(const T& val, unsigned char* const buf)
@@ -16,6 +18,40 @@ inline unsigned char* BufToVal(unsigned char* const buf, T& val)
 	return buf+sizeof(val);
 }
 
+DatView::DatView(const wchar_t* const filename, const size_t cb)
+{
+	hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
+	    0, nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
+	if (hf == INVALID_HANDLE_VALUE) {
+		if (GetLastError() == ERROR_FILE_NOT_FOUND) {
+			hf = CreateFile(filename, GENERIC_READ|GENERIC_WRITE,
+			    0, nullptr, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr);
+			if (hf == INVALID_HANDLE_VALUE)
+				throw Win32Error{};
+		} else
+			throw Win32Error{};
+	}
+
+	LARGE_INTEGER cbMap;
+	cbMap.QuadPart = cb;
+	hm = CreateFileMapping(hf, nullptr, PAGE_READWRITE,
+	    cbMap.HighPart, cbMap.LowPart, nullptr);
+	if (!hm)
+		throw Win32Error{};
+
+	view = MapViewOfFile(hm, FILE_MAP_ALL_ACCESS, 0, 0, 0);
+	if (!view)
+		throw Win32Error{};
+}
+
+DatView::~DatView()
+{
+	FlushViewOfFile(view, 0);
+	UnmapViewOfFile(view);
+	CloseHandle(hm);
+	CloseHandle(hf);
+}
+
 unsigned char* Serialize(const ElvData& e, unsigned char* buf)
 {
 	unsigned char version = 'a';