/* vim: set ts=4 sw=4 tw=99 et:

  *

  * Copyright (C) 2012 David Anderson

  *

  * This file is part of SourcePawn.

  *

  * SourcePawn is free software: you can redistribute it and/or modify it under

  * the terms of the GNU General Public License as published by the Free

  * Software Foundation, either version 3 of the License, or (at your option)

  * any later version.

  * 

  * SourcePawn is distributed in the hope that it will be useful, but WITHOUT ANY

  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License along with

  * SourcePawn. If not, see http://www.gnu.org/licenses/.

  */

 #define WIN32_LEAN_AND_MEAN

 #include <Windows.h>

 #include <direct.h>

 #include <sys/stat.h>

 #include "Platform.h"

 using namespace ke;

 static inline DWORD

 ToProtBits(OS::Protection prot)

 {

     switch (prot) {

       case OS::Prot_ReadWrite:

         return PAGE_READWRITE;

       case OS::Prot_ReadWriteExecute:

         return PAGE_EXECUTE_READWRITE;

       default:

         assert(prot == OS::Prot_ReadExecute);

         return PAGE_EXECUTE_READ;

     }

 }

 Address

 OS::MapMemory(size_t amount, MapMode mode, Protection prot_)

 {

     DWORD prot = ToProtBits(prot_);

     DWORD type = MEM_RESERVE;

     if (mode == Map_Commit)

         type |= MEM_COMMIT;

     return (Address)VirtualAlloc(NULL, amount, type, prot);

 }

 bool

 OS::CommitMemory(Address address, size_t amount, Protection prot_)

 {

     DWORD prot = ToProtBits(prot_);

     return !!VirtualAlloc(address, amount, MEM_COMMIT, prot);

 }

 void

 OS::UnmapMemory(Address address, size_t size)

 {

     VirtualFree(address, 0, MEM_RELEASE);

 }

 static Address

 MapMemoryAt(Address address, size_t amount, OS::MapMode mode, OS::Protection prot_)

 {

     DWORD bits = ToProtBits(prot_);

     DWORD flags = MEM_RESERVE;

     if (mode == OS::Map_Commit)

         flags |= MEM_COMMIT;

     return (Address)VirtualAlloc((LPVOID)address, amount, flags, bits);

 }

 OS::AlignableMapping

 OS::MapAlignedMemory(size_t amount, size_t alignment, MapMode mode)

 {

     Address addr = MapMemory(amount, mode, OS::Prot_ReadWrite);

     if (!addr)

         return AlignableMapping(NULL, alignment, 0);

     if (!IsAligned(addr, alignment)) {

         UnmapMemory(addr, amount);

         // Try to grab the next available aligned address.

         addr = AlignedBase(addr, alignment);

         addr = MapMemoryAt(addr + alignment, amount, mode, OS::Prot_ReadWrite);

         while (!addr) {

             // Try to over-allocate to get the right region. This can race

             // with other threads; we expect this to be rare. If this turns

             // out to be a problem, the API is set up such that we can just

             // return two pointers: the base, and the aligned address into

             // the over-allocated region.

             addr = MapMemory(amount + alignment, mode, OS::Prot_ReadWrite);

             if (!addr)

                 return AlignableMapping(NULL, alignment, 0);

             UnmapMemory(addr, amount + alignment);

             addr = AlignedBase(addr, alignment);

             addr = MapMemoryAt(addr + alignment, amount, mode, OS::Prot_ReadWrite);

         }

     }

     return AlignableMapping(addr, alignment, amount);

 }

 void

 OS::UnmapAlignedMemory(Address address, size_t size)

 {

     OS::UnmapMemory(address, size);

 }

 bool

 OS::GetAbsolutePath(const char *path, AutoFree<char> &chars)

 {

     char try1[MAX_PATH];

     DWORD result = GetFullPathName(path, sizeof(try1), try1, NULL);

     if (result <= 0)

         return false;

     // +1 because if result < MAX_PATH, it doesn't include the null terminator.

     chars = (char *)calloc(result + 1, sizeof(char));

     if (!*chars)

         return false;

     if (result <= MAX_PATH) {

         strcpy(*chars, try1);

         return true;

     }

     // We should get the same output on the next try.

     return GetFullPathName(path, result, *chars, NULL) == result - 1;

 }

 bool

 OS::SplitPath(const char *path, AutoFree<char> &base, AutoFree<char> &name)

 {

     size_t len = strlen(path);

     // Skip trailing slashes.

     while (len > 1 && (path[len - 1] == '/' || path[len - 1] == '\\'))

         len--;

     for (size_t i = len - 1; i < len; i--) {

         if (path[i] == '\\' || path[i] == '/') {

             name = (char *)calloc(len - i, sizeof(char));

             if (!*name)

                 return false;

             strcpy(*name, &path[i + 1]);

             base = (char *)calloc(i + 1, sizeof(char));

             if (!*base)

                 return false;

             memcpy(*base, path, i);

             (*base)[i] = '\0';

             return true;

         }

     }

     // The path should have been absolute, which contains at least one separator.

     return false;

 }

 const char *

 OS::PathSeparator()

 {

     return "\\";

 }

 OS::PathType

 OS::InspectPath(const char *path)

 {

     struct _stat s;

     int result = _stat(path, &s);

     if (result != 0)

         return OS::Path_Invalid;

     if (s.st_mode & _S_IFDIR)

         return OS::Path_Folder;

     if (s.st_mode & _S_IFREG)

         return OS::Path_File;

     return OS::Path_Invalid;

 }