tron@2186: /* $Id$ */
tron@2186: 
truelight@0: #include "stdafx.h"
Darkvater@1891: #include "openttd.h"
tron@1093: #include "fileio.h"
tron@2163: #include "functions.h"
Darkvater@4200: #include "string.h"
tron@2159: #include "macros.h"
tron@2153: #include "variables.h"
truelight@6218: #include "debug.h"
truelight@0: 
truelight@0: /*************************************************/
truelight@0: /* FILE IO ROUTINES ******************************/
truelight@0: /*************************************************/
truelight@0: 
truelight@0: #define FIO_BUFFER_SIZE 512
truelight@6218: #define MAX_HANDLES 64
truelight@0: 
truelight@0: typedef struct {
Darkvater@4203: 	byte *buffer, *buffer_end;          ///< position pointer in local buffer and last valid byte of buffer
Darkvater@4203: 	uint32 pos;                         ///< current (system) position in file
Darkvater@4203: 	FILE *cur_fh;                       ///< current file handle
truelight@6218: 	FILE *handles[MAX_HANDLES];         ///< array of file handles we can have open
Darkvater@4203: 	byte buffer_start[FIO_BUFFER_SIZE]; ///< local buffer when read from file
truelight@6218: #if defined(LIMITED_FDS)
truelight@6218: 	uint open_handles;                  ///< current amount of open handles
truelight@6218: 	const char *filename[MAX_HANDLES];  ///< array of filenames we (should) have open
truelight@6218: 	uint usage_count[MAX_HANDLES];      ///< count how many times this file has been opened
truelight@6218: #endif /* LIMITED_FDS */
truelight@0: } Fio;
truelight@0: 
truelight@0: static Fio _fio;
truelight@0: 
truelight@0: // Get current position in file
tron@1093: uint32 FioGetPos(void)
truelight@0: {
truelight@0: 	return _fio.pos + (_fio.buffer - _fio.buffer_start) - FIO_BUFFER_SIZE;
truelight@0: }
truelight@0: 
truelight@0: void FioSeekTo(uint32 pos, int mode)
truelight@0: {
truelight@0: 	if (mode == SEEK_CUR) pos += FioGetPos();
truelight@0: 	_fio.buffer = _fio.buffer_end = _fio.buffer_start + FIO_BUFFER_SIZE;
Darkvater@4203: 	_fio.pos = pos;
Darkvater@4203: 	fseek(_fio.cur_fh, _fio.pos, SEEK_SET);
truelight@0: }
truelight@0: 
truelight@6218: #if defined(LIMITED_FDS)
truelight@6218: static void FioRestoreFile(int slot)
truelight@6218: {
truelight@6218: 	/* Do we still have the file open, or should we reopen it? */
truelight@6218: 	if (_fio.handles[slot] == NULL) {
truelight@6218: 		DEBUG(misc, 6, "Restoring file '%s' in slot '%d' from disk", _fio.filename[slot], slot);
truelight@6218: 		FioOpenFile(slot, _fio.filename[slot]);
truelight@6218: 	}
truelight@6218: 	_fio.usage_count[slot]++;
truelight@6218: }
truelight@6218: #endif /* LIMITED_FDS */
truelight@6218: 
truelight@0: // Seek to a file and a position
truelight@0: void FioSeekToFile(uint32 pos)
truelight@0: {
truelight@6218: 	FILE *f;
truelight@6218: #if defined(LIMITED_FDS)
truelight@6218: 	/* Make sure we have this file open */
truelight@6218: 	FioRestoreFile(pos >> 24);
truelight@6218: #endif /* LIMITED_FDS */
truelight@6218: 	f = _fio.handles[pos >> 24];
truelight@0: 	assert(f != NULL);
truelight@0: 	_fio.cur_fh = f;
Darkvater@4203: 	FioSeekTo(GB(pos, 0, 24), SEEK_SET);
truelight@0: }
truelight@0: 
tron@1093: byte FioReadByte(void)
truelight@0: {
truelight@0: 	if (_fio.buffer == _fio.buffer_end) {
truelight@0: 		_fio.pos += FIO_BUFFER_SIZE;
truelight@0: 		fread(_fio.buffer = _fio.buffer_start, 1, FIO_BUFFER_SIZE, _fio.cur_fh);
truelight@0: 	}
truelight@0: 	return *_fio.buffer++;
truelight@0: }
truelight@0: 
truelight@0: void FioSkipBytes(int n)
truelight@0: {
tron@2952: 	for (;;) {
truelight@0: 		int m = min(_fio.buffer_end - _fio.buffer, n);
truelight@0: 		_fio.buffer += m;
truelight@0: 		n -= m;
truelight@0: 		if (n == 0) break;
truelight@0: 		FioReadByte();
truelight@0: 		n--;
truelight@0: 	}
truelight@0: }
truelight@0: 
tron@1093: uint16 FioReadWord(void)
truelight@0: {
truelight@0: 	byte b = FioReadByte();
truelight@0: 	return (FioReadByte() << 8) | b;
truelight@0: }
truelight@0: 
tron@1093: uint32 FioReadDword(void)
truelight@0: {
truelight@0: 	uint b = FioReadWord();
truelight@0: 	return (FioReadWord() << 16) | b;
truelight@0: }
truelight@0: 
truelight@0: void FioReadBlock(void *ptr, uint size)
truelight@0: {
truelight@0: 	FioSeekTo(FioGetPos(), SEEK_SET);
truelight@0: 	_fio.pos += size;
truelight@0: 	fread(ptr, 1, size, _fio.cur_fh);
truelight@0: }
truelight@0: 
darkvater@1039: static inline void FioCloseFile(int slot)
darkvater@1039: {
darkvater@1039: 	if (_fio.handles[slot] != NULL) {
tron@1109: 		fclose(_fio.handles[slot]);
darkvater@1039: 		_fio.handles[slot] = NULL;
truelight@6218: #if defined(LIMITED_FDS)
truelight@6218: 		_fio.open_handles--;
truelight@6218: #endif /* LIMITED_FDS */
darkvater@1039: 	}
darkvater@1039: }
darkvater@1039: 
darkvater@1036: void FioCloseAll(void)
truelight@0: {
truelight@0: 	int i;
truelight@0: 
darkvater@1039: 	for (i = 0; i != lengthof(_fio.handles); i++)
darkvater@1039: 		FioCloseFile(i);
truelight@0: }
truelight@0: 
Darkvater@4201: bool FioCheckFileExists(const char *filename)
dominik@1198: {
Darkvater@4202: 	FILE *f = FioFOpenFile(filename);
Darkvater@4202: 	if (f == NULL) return false;
dominik@1198: 
Darkvater@4202: 	fclose(f);
Darkvater@4202: 	return true;
dominik@1198: }
dominik@1198: 
truelight@6218: #if defined(LIMITED_FDS)
truelight@6218: static void FioFreeHandle()
truelight@6218: {
truelight@6218: 	/* If we are about to open a file that will exceed the limit, close a file */
truelight@6218: 	if (_fio.open_handles + 1 == LIMITED_FDS) {
truelight@6218: 		uint i, count;
truelight@6218: 		int slot;
truelight@6218: 
truelight@6218: 		count = UINT_MAX;
truelight@6218: 		slot = -1;
truelight@6218: 		/* Find the file that is used the least */
truelight@6218: 		for (i = 0; i < lengthof(_fio.handles); i++) {
truelight@6218: 			if (_fio.handles[i] != NULL && _fio.usage_count[i] < count) {
truelight@6218: 				count = _fio.usage_count[i];
truelight@6218: 				slot  = i;
truelight@6218: 			}
truelight@6218: 		}
truelight@6218: 		assert(slot != -1);
truelight@6218: 		DEBUG(misc, 6, "Closing filehandler '%s' in slot '%d' because of fd-limit", _fio.filename[slot], slot);
truelight@6218: 		FioCloseFile(slot);
truelight@6218: 	}
truelight@6218: }
truelight@6218: #endif /* LIMITED_FDS */
truelight@6218: 
bjarni@2736: FILE *FioFOpenFile(const char *filename)
bjarni@2736: {
bjarni@2736: 	FILE *f;
bjarni@2736: 	char buf[MAX_PATH];
bjarni@2736: 
Darkvater@5296: 	snprintf(buf, lengthof(buf), "%s%s", _paths.data_dir, filename);
bjarni@2736: 
bjarni@2736: 	f = fopen(buf, "rb");
bjarni@2736: #if !defined(WIN32)
bjarni@2736: 	if (f == NULL) {
Darkvater@5296: 		strtolower(buf + strlen(_paths.data_dir) - 1);
bjarni@2736: 		f = fopen(buf, "rb");
bjarni@2736: 
bjarni@2736: #if defined SECOND_DATA_DIR
bjarni@2736: 		// tries in the 2nd data directory
bjarni@2736: 		if (f == NULL) {
Darkvater@5296: 			snprintf(buf, lengthof(buf), "%s%s", _paths.second_data_dir, filename);
Darkvater@5296: 			strtolower(buf + strlen(_paths.second_data_dir) - 1);
bjarni@2736: 			f = fopen(buf, "rb");
bjarni@2736: 		}
bjarni@2736: #endif
bjarni@2736: 	}
bjarni@2736: #endif
bjarni@2736: 
bjarni@2736: 	return f;
bjarni@2736: }
bjarni@2736: 
truelight@0: void FioOpenFile(int slot, const char *filename)
truelight@0: {
truelight@6218: 	FILE *f;
tron@915: 
truelight@6218: #if defined(LIMITED_FDS)
truelight@6218: 	FioFreeHandle();
truelight@6218: #endif /* LIMITED_FDS */
truelight@6218: 	f = FioFOpenFile(filename);
Darkvater@5296: 	if (f == NULL) error("Cannot open file '%s%s'", _paths.data_dir, filename);
truelight@193: 
darkvater@1039: 	FioCloseFile(slot); // if file was opened before, close it
truelight@0: 	_fio.handles[slot] = f;
truelight@6218: #if defined(LIMITED_FDS)
truelight@6218: 	_fio.filename[slot] = filename;
truelight@6218: 	_fio.usage_count[slot] = 0;
truelight@6218: 	_fio.open_handles++;
truelight@6218: #endif /* LIMITED_FDS */
truelight@0: 	FioSeekToFile(slot << 24);
truelight@0: }