1

/* $Id$ */

     2

     3

/** @file

     4

 * All actions handling saving and loading goes on in this file. The general actions

     5

 * are as follows for saving a game (loading is analogous):

     6

 * <ol>

     7

 * <li>initialize the writer by creating a temporary memory-buffer for it

     8

 * <li>go through all to-be saved elements, each 'chunk' (ChunkHandler) prefixed by a label

     9

 * <li>use their description array (SaveLoad) to know what elements to save and in what version

    10

 *    of the game it was active (used when loading)

    11

 * <li>write all data byte-by-byte to the temporary buffer so it is endian-safe

    12

 * <li>when the buffer is full; flush it to the output (eg save to file) (_sl.buf, _sl.bufp, _sl.bufe)

    13

 * <li>repeat this until everything is done, and flush any remaining output to file

    14

 * </ol>

    15

 * @see ChunkHandler

    16

 * @see SaveLoad

    17

 */

    18

#include "stdafx.h"

    19

#include "openttd.h"

    20

#include "debug.h"

    21

#include "functions.h"

    22

#include "vehicle.h"

    23

#include "station.h"

    24

#include "thread.h"

    25

#include "town.h"

    26

#include "player.h"

    27

#include "saveload.h"

    28

#include "variables.h"

    29

#include <setjmp.h>

    30

    31

enum {

    32

	SAVEGAME_VERSION = 21,

    33

    34

};

    35

    36

uint16 _sl_version;       /// the major savegame version identifier

    37

byte   _sl_minor_version; /// the minor savegame version, DO NOT USE!

    38

    39

typedef void WriterProc(uint len);

    40

typedef uint ReaderProc(void);

    41

    42

typedef uint ReferenceToIntProc(const void *obj, SLRefType rt);

    43

typedef void *IntToReferenceProc(uint index, SLRefType rt);

    44

    45

/** The saveload struct, containing reader-writer functions, bufffer, version, etc. */

    46

static struct {

    47

	bool save;                           /// are we doing a save or a load atm. True when saving

    48

	byte need_length;                    /// ???

    49

	byte block_mode;                     /// ???

    50

	bool error;                          /// did an error occur or not

    51

    52

	int obj_len;                         /// the length of the current object we are busy with

    53

	int array_index, last_array_index;   /// in the case of an array, the current and last positions

    54

    55

	uint32 offs_base;                    /// the offset in number of bytes since we started writing data (eg uncompressed savegame size)

    56

    57

	WriterProc *write_bytes;             /// savegame writer function

    58

	ReaderProc *read_bytes;              /// savegame loader function

    59

    60

	ReferenceToIntProc *ref_to_int_proc; /// function to convert pointers to numbers when saving a game

    61

	IntToReferenceProc *int_to_ref_proc; /// function to convert numbers to pointers when loading a game

    62

    63

	const ChunkHandler* const *chs;      /// the chunk of data that is being processed atm (vehicles, signs, etc.)

    64

	const SaveLoad* const *includes;     /// the internal layouf of the given chunk

    65

    66

	/** When saving/loading savegames, they are always saved to a temporary memory-place

    67

	 * to be flushed to file (save) or to final place (load) when full. */

    68

	byte *bufp, *bufe;                   /// bufp(ointer) gives the current position in the buffer bufe(nd) gives the end of the buffer

    69

    70

	// these 3 may be used by compressor/decompressors.

    71

	byte *buf;                           /// pointer to temporary memory to read/write, initialized by SaveLoadFormat->initread/write

    72

	byte *buf_ori;                       /// pointer to the original memory location of buf, used to free it afterwards

    73

	uint bufsize;                        /// the size of the temporary memory *buf

    74

	FILE *fh;                            /// the file from which is read or written to

    75

    76

	void (*excpt_uninit)(void);          /// the function to execute on any encountered error

    77

	const char *excpt_msg;               /// the error message

    78

	jmp_buf excpt;                       /// @todo used to jump to "exception handler";  really ugly

    79

} _sl;

    80

    81

    82

enum NeedLengthValues {NL_NONE = 0, NL_WANTLENGTH = 1, NL_CALCLENGTH = 2};

    83

    84

/**

    85

 * Fill the input buffer by reading from the file with the given reader

    86

 */

    87

static void SlReadFill(void)

    88

{

    89

	uint len = _sl.read_bytes();

    90

	assert(len != 0);

    91

    92

	_sl.bufp = _sl.buf;

    93

	_sl.bufe = _sl.buf + len;

    94

	_sl.offs_base += len;

    95

}

    96

    97

static inline uint32 SlGetOffs(void) {return _sl.offs_base - (_sl.bufe - _sl.bufp);}

    98

    99

/** Flush the output buffer by writing to disk with the given reader.

   100

 * If the buffer pointer has not yet been set up, set it up now. Usually

   101

 * only called when the buffer is full, or there is no more data to be processed

   102

 */

   103

static void SlWriteFill(void)

   104

{

   105

	// flush the buffer to disk (the writer)

   106

	if (_sl.bufp != NULL) {

   107

		uint len = _sl.bufp - _sl.buf;

   108

		_sl.offs_base += len;

   109

		if (len) _sl.write_bytes(len);

   110

	}

   111

   112

	/* All the data from the buffer has been written away, rewind to the beginning

   113

	* to start reading in more data */

   114

	_sl.bufp = _sl.buf;

   115

	_sl.bufe = _sl.buf + _sl.bufsize;

   116

}

   117

   118

/** Error handler, calls longjmp to simulate an exception.

   119

 * @todo this was used to have a central place to handle errors, but it is

   120

 * pretty ugly, and seriously interferes with any multithreaded approaches */

   121

static void NORETURN SlError(const char *msg)

   122

{

   123

	_sl.excpt_msg = msg;

   124

	longjmp(_sl.excpt, 0);

   125

}

   126

   127

/** Read in a single byte from file. If the temporary buffer is full,

   128

 * flush it to its final destination

   129

 * @return return the read byte from file

   130

 */

   131

static inline int SlReadByteInternal(void)

   132

{

   133

	if (_sl.bufp == _sl.bufe) SlReadFill();

   134

	return *_sl.bufp++;

   135

}

   136

   137

/** Wrapper for SlReadByteInternal */

   138

int SlReadByte(void) {return SlReadByteInternal();}

   139

   140

/** Write away a single byte from memory. If the temporary buffer is full,

   141

 * flush it to its destination (file)

   142

 * @param b the byte that is currently written

   143

 */

   144

static inline void SlWriteByteInternal(byte b)

   145

{

   146

	if (_sl.bufp == _sl.bufe) SlWriteFill();

   147

	*_sl.bufp++ = b;

   148

}

   149

   150

/** Wrapper for SlWriteByteInternal */

   151

void SlWriteByte(byte b) {SlWriteByteInternal(b);}

   152

   153

static inline int SlReadUint16(void)

   154

{

   155

	int x = SlReadByte() << 8;

   156

	return x | SlReadByte();

   157

}

   158

   159

static inline uint32 SlReadUint32(void)

   160

{

   161

	uint32 x = SlReadUint16() << 16;

   162

	return x | SlReadUint16();

   163

}

   164

   165

static inline uint64 SlReadUint64(void)

   166

{

   167

	uint32 x = SlReadUint32();

   168

	uint32 y = SlReadUint32();

   169

	return (uint64)x << 32 | y;

   170

}

   171

   172

static inline void SlWriteUint16(uint16 v)

   173

{

   174

	SlWriteByte(GB(v, 8, 8));

   175

	SlWriteByte(GB(v, 0, 8));

   176

}

   177

   178

static inline void SlWriteUint32(uint32 v)

   179

{

   180

	SlWriteUint16(GB(v, 16, 16));

   181

	SlWriteUint16(GB(v,  0, 16));

   182

}

   183

   184

static inline void SlWriteUint64(uint64 x)

   185

{

   186

	SlWriteUint32((uint32)(x >> 32));

   187

	SlWriteUint32((uint32)x);

   188

}

   189

   190

/**

   191

 * Read in the header descriptor of an object or an array.

   192

 * If the highest bit is set (7), then the index is bigger than 127

   193

 * elements, so use the next byte to read in the real value.

   194

 * The actual value is then both bytes added with the first shifted

   195

 * 8 bits to the left, and dropping the highest bit (which only indicated a big index).

   196

 * x = ((x & 0x7F) << 8) + SlReadByte();

   197

 * @return Return the value of the index

   198

 */

   199

static uint SlReadSimpleGamma(void)

   200

{

   201

	uint i = SlReadByte();

   202

	if (HASBIT(i, 7)) {

   203

		i &= ~0x80;

   204

		if (HASBIT(i, 6)) {

   205

			i &= ~0x40;

   206

			if (HASBIT(i, 5)) {

   207

				i &= ~0x20;

   208

				if (HASBIT(i, 4))

   209

					SlError("Unsupported gamma");

   210

				i = (i << 8) | SlReadByte();

   211

			}

   212

			i = (i << 8) | SlReadByte();

   213

		}

   214

		i = (i << 8) | SlReadByte();

   215

	}

   216

	return i;

   217

}

   218

   219

/**

   220

 * Write the header descriptor of an object or an array.

   221

 * If the element is bigger than 127, use 2 bytes for saving

   222

 * and use the highest byte of the first written one as a notice

   223

 * that the length consists of 2 bytes, etc.. like this:

   224

 * 0xxxxxxx

   225

 * 10xxxxxx xxxxxxxx

   226

 * 110xxxxx xxxxxxxx xxxxxxxx

   227

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   228

 * @param i Index being written

   229

 */

   230

   231

static void SlWriteSimpleGamma(uint i)

   232

{

   233

	if (i >= (1 << 7)) {

   234

		if (i >= (1 << 14)) {

   235

			if (i >= (1 << 21)) {

   236

				assert(i < (1 << 28));

   237

				SlWriteByte((byte)0xE0 | (i>>24));

   238

				SlWriteByte((byte)(i>>16));

   239

			} else {

   240

				SlWriteByte((byte)0xC0 | (i>>16));

   241

			}

   242

			SlWriteByte((byte)(i>>8));

   243

		} else {

   244

			SlWriteByte((byte)(0x80 | (i>>8)));

   245

		}

   246

	}

   247

	SlWriteByte(i);

   248

}

   249

   250

/** Return how many bytes used to encode a gamma value */

   251

static inline uint SlGetGammaLength(uint i) {

   252

	return 1 + (i >= (1 << 7)) + (i >= (1 << 14)) + (i >= (1 << 21));

   253

}

   254

   255

static inline int SlReadSparseIndex(void) {return SlReadSimpleGamma();}

   256

static inline void SlWriteSparseIndex(uint index) {SlWriteSimpleGamma(index);}

   257

   258

static inline int SlReadArrayLength(void) {return SlReadSimpleGamma();}

   259

static inline void SlWriteArrayLength(uint length) {SlWriteSimpleGamma(length);}

   260

   261

void SlSetArrayIndex(uint index)

   262

{

   263

	_sl.need_length = NL_WANTLENGTH;

   264

	_sl.array_index = index;

   265

}

   266

   267

/**

   268

 * Iterate through the elements of an array and read the whole thing

   269

 * @return The index of the object, or -1 if we have reached the end of current block

   270

 */

   271

int SlIterateArray(void)

   272

{

   273

	int index;

   274

	static uint32 next_offs;

   275

   276

	/* After reading in the whole array inside the loop

   277

	 * we must have read in all the data, so we must be at end of current block. */

   278

	assert(next_offs == 0 || SlGetOffs() == next_offs);

   279

   280

	while (true) {

   281

		uint length = SlReadArrayLength();

   282

		if (length == 0) {

   283

			next_offs = 0;

   284

			return -1;

   285

		}

   286

   287

		_sl.obj_len = --length;

   288

		next_offs = SlGetOffs() + length;

   289

   290

		switch (_sl.block_mode) {

   291

		case CH_SPARSE_ARRAY: index = SlReadSparseIndex(); break;

   292

		case CH_ARRAY:        index = _sl.array_index++; break;

   293

		default:

   294

			DEBUG(misc, 0) ("SlIterateArray: error");

   295

			return -1; // error

   296

		}

   297

   298

		if (length != 0) return index;

   299

	}

   300

}

   301

   302

/**

   303

 * Sets the length of either a RIFF object or the number of items in an array.

   304

 * This lets us load an object or an array of arbitrary size

   305

 * @param length The length of the sought object/array

   306

 */

   307

void SlSetLength(size_t length)

   308

{

   309

	switch (_sl.need_length) {

   310

	case NL_WANTLENGTH:

   311

		_sl.need_length = NL_NONE;

   312

		switch (_sl.block_mode) {

   313

		case CH_RIFF:

   314

			// Ugly encoding of >16M RIFF chunks

   315

			// The lower 24 bits are normal

   316

			// The uppermost 4 bits are bits 24:27

   317

			assert(length < (1<<28));

   318

			SlWriteUint32((length & 0xFFFFFF) | ((length >> 24) << 28));

   319

			break;

   320

		case CH_ARRAY:

   321

			assert(_sl.last_array_index <= _sl.array_index);

   322

			while (++_sl.last_array_index <= _sl.array_index)

   323

				SlWriteArrayLength(1);

   324

			SlWriteArrayLength(length + 1);

   325

			break;

   326

		case CH_SPARSE_ARRAY:

   327

			SlWriteArrayLength(length + 1 + SlGetGammaLength(_sl.array_index)); // Also include length of sparse index.

   328

			SlWriteSparseIndex(_sl.array_index);

   329

			break;

   330

		default: NOT_REACHED();

   331

		} break;

   332

	case NL_CALCLENGTH:

   333

		_sl.obj_len += length;

   334

		break;

   335

	}

   336

}

   337

   338

/**

   339

 * Save/Load bytes. These do not need to be converted to Little/Big Endian

   340

 * so directly write them or read them to/from file

   341

 * @param ptr The source or destination of the object being manipulated

   342

 * @param length number of bytes this fast CopyBytes lasts

   343

 */

   344

static void SlCopyBytes(void *ptr, size_t length)

   345

{

   346

	byte *p = (byte*)ptr;

   347

   348

	if (_sl.save) {

   349

		for (; length != 0; length--) {SlWriteByteInternal(*p++);}

   350

	} else {

   351

		for (; length != 0; length--) {*p++ = SlReadByteInternal();}

   352

	}

   353

}

   354

   355

#if 0

   356

/**

   357

 * Read in bytes from the file/data structure but don't do

   358

 * anything with them

   359

 * NOTICE: currently unused

   360

 * @param length The amount of bytes that is being treated this way

   361

 */

   362

static inline void SlSkipBytes(size_t length)

   363

{

   364

	for (; length != 0; length--)

   365

		SlReadByte();

   366

}

   367

#endif

   368

   369

/* Get the length of the current object */

   370

uint SlGetFieldLength(void) {return _sl.obj_len;}

   371

   372

/**

   373

 * Handle all conversion and typechecking of variables here.

   374

 * In the case of saving, read in the actual value from the struct

   375

 * and then write them to file, endian safely. Loading a value

   376

 * goes exactly the opposite way

   377

 * @param ptr The object being filled/read

   378

 * @param conv @VarType type of the current element of the struct

   379

 */

   380

static void SlSaveLoadConv(void *ptr, VarType conv)

   381

{

   382

	int64 x = 0;

   383

   384

	if (_sl.save) { /* SAVE values */

   385

		/* Read a value from the struct. These ARE endian safe. */

   386

		switch ((conv >> 4) & 0xF) {

   387

		case SLE_VAR_I8   >> 4: x = *(int8*)ptr; break;

   388

		case SLE_VAR_U8   >> 4: x = *(byte*)ptr; break;

   389

		case SLE_VAR_I16  >> 4: x = *(int16*)ptr; break;

   390

		case SLE_VAR_U16  >> 4: x = *(uint16*)ptr; break;

   391

		case SLE_VAR_I32  >> 4: x = *(int32*)ptr; break;

   392

		case SLE_VAR_U32  >> 4: x = *(uint32*)ptr; break;

   393

		case SLE_VAR_I64  >> 4: x = *(int64*)ptr; break;

   394

		case SLE_VAR_U64  >> 4: x = *(uint64*)ptr; break;

   395

		case SLE_VAR_NULL >> 4: x = 0; break;

   396

		default: NOT_REACHED();

   397

		}

   398

   399

		// Write the value to the file and check if its value is in the desired range

   400

		switch (conv & 0xF) {

   401

		case SLE_FILE_I8: assert(x >= -128 && x <= 127);     SlWriteByte(x);break;

   402

		case SLE_FILE_U8: assert(x >= 0 && x <= 255);        SlWriteByte(x);break;

   403

		case SLE_FILE_I16:assert(x >= -32768 && x <= 32767); SlWriteUint16(x);break;

   404

		case SLE_FILE_STRINGID:

   405

		case SLE_FILE_U16:assert(x >= 0 && x <= 65535);      SlWriteUint16(x);break;

   406

		case SLE_FILE_I32: case SLE_FILE_U32:                SlWriteUint32((uint32)x);break;

   407

		case SLE_FILE_I64: case SLE_FILE_U64:                SlWriteUint64(x);break;

   408

		default: NOT_REACHED();

   409

		}

   410

	} else { /* LOAD values */

   411

   412

		// Read a value from the file

   413

		switch (conv & 0xF) {

   414

		case SLE_FILE_I8:  x = (int8)SlReadByte(); break;

   415

		case SLE_FILE_U8:  x = (byte)SlReadByte(); break;

   416

		case SLE_FILE_I16: x = (int16)SlReadUint16(); break;

   417

		case SLE_FILE_U16: x = (uint16)SlReadUint16(); break;

   418

		case SLE_FILE_I32: x = (int32)SlReadUint32(); break;

   419

		case SLE_FILE_U32: x = (uint32)SlReadUint32(); break;

   420

		case SLE_FILE_I64: x = (int64)SlReadUint64(); break;

   421

		case SLE_FILE_U64: x = (uint64)SlReadUint64(); break;

   422

		case SLE_FILE_STRINGID: x = RemapOldStringID((uint16)SlReadUint16()); break;

   423

		default: NOT_REACHED();

   424

		}

   425

   426

		/* Write The value to the struct. These ARE endian safe. */

   427

		switch ((conv >> 4) & 0xF) {

   428

		case SLE_VAR_I8   >> 4:  *(int8*)ptr = x; break;

   429

		case SLE_VAR_U8   >> 4:  *(byte*)ptr = x; break;

   430

		case SLE_VAR_I16  >> 4: *(int16*)ptr = x; break;

   431

		case SLE_VAR_U16  >> 4: *(uint16*)ptr = x; break;

   432

		case SLE_VAR_I32  >> 4: *(int32*)ptr = x; break;

   433

		case SLE_VAR_U32  >> 4: *(uint32*)ptr = x; break;

   434

		case SLE_VAR_I64  >> 4: *(int64*)ptr = x; break;

   435

		case SLE_VAR_U64  >> 4: *(uint64*)ptr = x; break;

   436

		case SLE_VAR_NULL >> 4: break;

   437

		default: NOT_REACHED();

   438

		}

   439

	}

   440

}

   441

   442

/* Length in bytes of the various datatypes in a savefile. These

   443

 * sizes are guaranteed by assert_compiles in stdafx.h */

   444

static const byte _conv_lengths[] = {1, 1, 2, 2, 4, 4, 8, 8, 2};

   445

   446

/**

   447

 * Return the size in bytes of a certain type of normal/atomic variable

   448

 * @param var The variable the size is being asked of (NOTICE: unused)

   449

 * @param conv @VarType type of variable that is used for calculating the size

   450

 * @return Return the size of this type in byes

   451

 */

   452

static inline size_t SlCalcConvLen(const void *var, VarType conv) {return _conv_lengths[conv & 0xF];}

   453

   454

/**

   455

 * Return the size in bytes of a reference (pointer)

   456

 */

   457

static inline size_t SlCalcRefLen(void) {return 2;}

   458

   459

/**

   460

 * Return the size in bytes of a certain type of atomic array

   461

 * @param array The variable the size is being asked of (NOTICE: unused)

   462

 * @param length The length of the array counted in elements

   463

 * @param conv @VarType type of the variable that is used in calculating the size

   464

 */

   465

static inline size_t SlCalcArrayLen(const void *array, uint length, VarType conv) {return _conv_lengths[conv & 0xF] * length;}

   466

   467

/**

   468

 * Save/Load an array.

   469

 * @param array The array being manipulated

   470

 * @param length The length of the array in elements

   471

 * @param conv @VarType type of the atomic array (int, byte, uint64, etc.)

   472

 */

   473

void SlArray(void *array, uint length, VarType conv)

   474

{

   475

	static const byte conv_mem_size[] = {1, 1, 2, 2, 4, 4, 8, 8, 0};

   476

   477

	// Automatically calculate the length?

   478

	if (_sl.need_length != NL_NONE) {

   479

		SlSetLength(SlCalcArrayLen(array, length, conv));

   480

		// Determine length only?

   481

		if (_sl.need_length == NL_CALCLENGTH)

   482

			return;

   483

	}

   484

   485

	/* NOTICE - handle some buggy stuff, in really old versions everything was saved

   486

	 * as a byte-type. So detect this, and adjust array size accordingly */

   487

	if (!_sl.save && _sl_version == 0) {

   488

		if (conv == SLE_INT16 || conv == SLE_UINT16 || conv == SLE_STRINGID) {

   489

			length *= 2; // int16, uint16 and StringID are 2 bytes in size

   490

			conv = SLE_INT8;

   491

		} else if (conv == SLE_INT32 || conv == SLE_UINT32) {

   492

			length *= 4; // int32 and uint32 are 4 bytes in size

   493

			conv = SLE_INT8;

   494

		}

   495

	}

   496