#include "stdafx.h"
#include <windows.h>
#include "MemoryManagement.h"

static bool TranslateFromMemProtect ( MEM_PROTECTION memProtection, int & OsMemProtection)
{
	switch (memProtection)
	{
	case MEM_NOACCESS: OsMemProtection = PAGE_NOACCESS; break;
	case MEM_READONLY: OsMemProtection = PAGE_READONLY; break;
	case MEM_READWRITE: OsMemProtection = PAGE_READWRITE; break;
	case MEM_EXECUTE_READWRITE: OsMemProtection = PAGE_EXECUTE_READWRITE; break;
	default:
		return false;
	}
	return true;
}

void* AllocateAddressSpace(size_t size)
{
	return VirtualAlloc(NULL, size, MEM_RESERVE | MEM_TOP_DOWN, PAGE_NOACCESS);
}

bool FreeAddressSpace(void* addr, size_t size)
{
	return VirtualFree(addr, 0, MEM_RELEASE) != 0;
}

void* CommitMemory(void* addr, size_t size, MEM_PROTECTION memProtection)
{
	int OsMemProtection;
	if (!TranslateFromMemProtect(memProtection,OsMemProtection))
	{
		return NULL;
	}
	return VirtualAlloc(addr, size, MEM_COMMIT, OsMemProtection);
}

bool DecommitMemory(void* addr, size_t size)
{
    return VirtualFree((void*)addr, size, MEM_DECOMMIT) != 0;
}

bool ProtectMemory(void* addr, size_t size, MEM_PROTECTION memProtection, MEM_PROTECTION * OldProtect)
{
	int OsMemProtection;
	if (!TranslateFromMemProtect(memProtection,OsMemProtection))
	{
		return NULL;
	}

	DWORD OldOsProtect;
    BOOL res = VirtualProtect(addr, size, OsMemProtection, &OldOsProtect);
	if (OldProtect != NULL)
	{
	}
	return res != 0;
}