fsdirrwops.cpp

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/*
 * The ManaPlus Client
 * Copyright (C) 2013-2019 The ManaPlus Developers
 * Copyright (C) 2019-2021 Andrei Karas
 *
 * This file is part of The ManaPlus Client.
 *
 * This program 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 2 of the License, or
 * any later version.
 *
 * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "fs/virtfs/fsdirrwops.h"
 
#include "fs/virtfs/file.h"
 
#include "utils/cast.h"
#include "utils/checkutils.h"
 
PRAGMA48(GCC diagnostic push)
PRAGMA48(GCC diagnostic ignored "-Wshadow")
#include <SDL_rwops.h>
PRAGMA48(GCC diagnostic pop)
 
#include "debug.h"
 
namespace VirtFs
{
 
namespace FsDir
{
 RWOPSINT rwops_seek(SDL_RWops *const rw,
 const RWOPSINT offset,
 const int whence)
 {
 if (rw == nullptr)
 return -1;
 File *const handle = static_cast<File *>(
 rw->hidden.unknown.data1);
 FILEHTYPE fd = handle->mFd;
 RWOPSINT pos = 0;
 
 if (whence == SEEK_SET)
 {
 pos = offset;
 }
 else if (whence == SEEK_CUR)
 {
#ifdef USE_FILE_FOPEN
 const int64_t current = ftell(fd);
#else // USE_FILE_FOPEN
 const int64_t current = lseek(fd, 0, SEEK_CUR);
#endif // USE_FILE_FOPEN
 
 if (current == -1)
 {
 logger->assertLog(
 "VirtFs::rwops_seek: Can't find position in file.");
 return -1;
 }
 
 pos = CAST_S32(current);
 if (static_cast<int64_t>(pos) != current)
 {
 logger->assertLog("VirtFs::rwops_seek: "
 "Can't fit current file position in an int!");
 return -1;
 }
 
 if (offset == 0) /* this is a "tell" call. We're done. */
 return pos;
 
 pos += offset;
 }
 else if (whence == SEEK_END)
 {
 int64_t len = 0;
#ifdef USE_FILE_FOPEN
 const long curpos = ftell(fd);
 if (curpos < 0)
 {
 reportAlways("FsDir::fileLength ftell error.")
 return -1;
 }
 fseek(fd, 0, SEEK_END);
 len = ftell(fd);
// fseek(fd, curpos, SEEK_SET);
#else // USE_FILE_FOPEN
 struct stat statbuf;
 if (fstat(fd, &statbuf) == -1)
 {
 reportAlways("FsDir::fileLength error.")
 len = -1;
 }
 else
 {
 len = static_cast<int64_t>(statbuf.st_size);
 }
#endif // USE_FILE_FOPEN
 
 if (len == -1)
 {
#ifdef USE_FILE_FOPEN
 if (fseek(fd, curpos, SEEK_SET) < 0)
 {
 reportAlways("FsDir::fileLength fseek error.")
 }
#endif // USE_FILE_FOPEN
 logger->assertLog(
 "VirtFs::rwops_seek:Can't find end of file.");
 return -1;
 }
 
 pos = static_cast<RWOPSINT>(len);
 if (static_cast<int64_t>(pos) != len)
 {
#ifdef USE_FILE_FOPEN
 fseek(fd, curpos, SEEK_SET);
#endif // USE_FILE_FOPEN
 logger->assertLog("VirtFs::rwops_seek: "
 "Can't fit end-of-file position in an int!");
 return -1;
 }
 
 pos += offset;
 }
 else
 {
 logger->assertLog(
 "VirtFs::rwops_seek: Invalid 'whence' parameter.");
 return -1;
 }
 
 if (pos < 0)
 {
 logger->assertLog("VirtFs::rwops_seek: "
 "Attempt to seek past start of file.");
 return -1;
 }
 
 const int64_t res = FILESEEK(fd, pos, SEEK_SET);
 if (res == -1)
 {
 logger->assertLog("VirtFs::rwops_seek: seek error.");
 return -1;
 }
 
 return pos;
 }
 
 RWOPSSIZE rwops_read(SDL_RWops *const rw,
 void *const ptr,
 const RWOPSSIZE size,
 const RWOPSSIZE maxnum)
 {
 if (rw == nullptr)
 return 0;
 File *const handle = static_cast<File *>(
 rw->hidden.unknown.data1);
 FILEHTYPE fd = handle->mFd;
 
#ifdef USE_FILE_FOPEN
 const int64_t rc = fread(ptr, size, maxnum, fd);
#else // USE_FILE_FOPEN
 int max = size * maxnum;
 int cnt = ::read(fd, ptr, max);
 if (cnt <= 0)
 return cnt;
 const int64_t rc = cnt / size;
#endif // USE_FILE_FOPEN
 
#ifndef USE_FILE_FOPEN
 if (rc != static_cast<int64_t>(maxnum))
 {
 const int64_t pos = lseek(fd, 0, SEEK_CUR);
 struct stat statbuf;
 if (fstat(fd, &statbuf) == -1)
 {
 reportAlways("FsDir::fileLength error.")
 return CAST_S32(rc);
 }
 }
#endif // USE_FILE_FOPEN
 return CAST_S32(rc);
 }
 
 RWOPSSIZE rwops_write(SDL_RWops *const rw,
 const void *const ptr,
 const RWOPSSIZE size,
 const RWOPSSIZE maxnum)
 {
 if (rw == nullptr)
 return 0;
 File *const handle = static_cast<File *>(
 rw->hidden.unknown.data1);
 FILEHTYPE fd = handle->mFd;
 
#ifdef USE_FILE_FOPEN
 const int64_t rc = fwrite(ptr, size, maxnum, fd);
#else // USE_FILE_FOPEN
 int max = size * maxnum;
 int cnt = ::write(fd, ptr, max);
 if (cnt <= 0)
 return cnt;
 const int64_t rc = cnt / size;
#endif // USE_FILE_FOPEN
 
#ifndef USE_FILE_FOPEN
 if (rc != static_cast<int64_t>(maxnum))
 {
 const int64_t pos = lseek(fd, 0, SEEK_CUR);
 struct stat statbuf;
 if (fstat(fd, &statbuf) == -1)
 {
 reportAlways("FsDir::fileLength error.")
 return CAST_S32(rc);
 }
 }
#endif // USE_FILE_FOPEN
 
 return CAST_S32(rc);
 }
 
 int rwops_close(SDL_RWops *const rw)
 {
 if (rw == nullptr)
 return 0;
 File *const handle = static_cast<File*>(
 rw->hidden.unknown.data1);
 delete handle;
 SDL_FreeRW(rw);
 return 0;
 }
 
#ifdef USE_SDL2
 RWOPSINT rwops_size(SDL_RWops *const rw)
 {
 File *const handle = static_cast<File *>(
 rw->hidden.unknown.data1);
 FILEHTYPE fd = handle->mFd;
#ifdef USE_FILE_FOPEN
 const long pos = ftell(fd);
 fseek(fd, 0, SEEK_END);
 const long sz = ftell(fd);
 fseek(fd, pos, SEEK_SET);
 return sz;
#else // USE_FILE_FOPEN
 struct stat statbuf;
 if (fstat(fd, &statbuf) == -1)
 {
 reportAlways("FsDir::fileLength error.")
 return -1;
 }
 return static_cast<int64_t>(statbuf.st_size);
#endif // USE_FILE_FOPEN
 }
#endif // USE_SDL2
 
} // namespace FsDir
 
} // namespace VirtFs