OpenTTD-patches/fileio.c

134 lines
2.5 KiB
C
Raw Normal View History

#include "stdafx.h"
#include "ttd.h"
#if defined(UNIX)
#include <ctype.h> // required for tolower()
#endif
/*************************************************/
/* FILE IO ROUTINES ******************************/
/*************************************************/
#define FIO_BUFFER_SIZE 512
typedef struct {
byte *buffer, *buffer_end;
uint32 pos;
FILE *cur_fh;
FILE *handles[32];
byte buffer_start[512];
} Fio;
static Fio _fio;
// Get current position in file
uint32 FioGetPos()
{
return _fio.pos + (_fio.buffer - _fio.buffer_start) - FIO_BUFFER_SIZE;
}
void FioSeekTo(uint32 pos, int mode)
{
if (mode == SEEK_CUR) pos += FioGetPos();
_fio.buffer = _fio.buffer_end = _fio.buffer_start + FIO_BUFFER_SIZE;
fseek(_fio.cur_fh, (_fio.pos=pos), SEEK_SET);
}
// Seek to a file and a position
void FioSeekToFile(uint32 pos)
{
FILE *f = _fio.handles[pos >> 24];
assert(f != NULL);
_fio.cur_fh = f;
FioSeekTo(pos & 0xFFFFFF, SEEK_SET);
}
byte FioReadByte()
{
if (_fio.buffer == _fio.buffer_end) {
_fio.pos += FIO_BUFFER_SIZE;
fread(_fio.buffer = _fio.buffer_start, 1, FIO_BUFFER_SIZE, _fio.cur_fh);
}
return *_fio.buffer++;
}
void FioSkipBytes(int n)
{
for(;;) {
int m = min(_fio.buffer_end - _fio.buffer, n);
_fio.buffer += m;
n -= m;
if (n == 0) break;
FioReadByte();
n--;
}
}
uint16 FioReadWord()
{
byte b = FioReadByte();
return (FioReadByte() << 8) | b;
}
uint32 FioReadDword()
{
uint b = FioReadWord();
return (FioReadWord() << 16) | b;
}
void FioReadBlock(void *ptr, uint size)
{
FioSeekTo(FioGetPos(), SEEK_SET);
_fio.pos += size;
fread(ptr, 1, size, _fio.cur_fh);
}
void FioCloseAll()
{
int i;
for(i=0; i!=lengthof(_fio.handles); i++) {
if (_fio.handles[i] != NULL) {
fclose(_fio.handles[i]);
_fio.handles[i] = NULL;
}
}
}
void FioOpenFile(int slot, const char *filename)
{
FILE *f;
char buf[MAX_PATH];
sprintf(buf, "%s%s", _path.data_dir, filename);
f = fopen(buf, "rb");
#if !defined(WIN32)
if (f == NULL) {
char *s;
// Make lower case and try again
for(s=buf + strlen(_path.data_dir) - 1; *s != 0; s++)
*s = tolower(*s);
f = fopen(buf, "rb");
#if defined SECOND_DATA_DIR
// tries in the 2nd data directory
if (f == NULL) {
sprintf(buf, "%s%s", _path.second_data_dir, filename);
for(s=buf + strlen(_path.second_data_dir) - 1; *s != 0; s++)
*s = tolower(*s);
f = fopen(buf, "rb");
}
#endif
}
#endif
if (f == NULL)
error("Cannot open file '%s'", buf);
_fio.handles[slot] = f;
FioSeekToFile(slot << 24);
}