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 "town.h"

    25

#include "player.h"

    26

#include "saveload.h"

    27

#include "variables.h"

    28

    29

enum {

    30

	SAVEGAME_MAJOR_VERSION = 15,

    31

	SAVEGAME_MINOR_VERSION = 0,

    32

    33

	SAVEGAME_LOADABLE_VERSION = (SAVEGAME_MAJOR_VERSION << 8) + SAVEGAME_MINOR_VERSION

    34

};

    35

    36

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

    37

    38

SaverLoader _sl;

    39

    40

/**

    41

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

    42

 */

    43

static void SlReadFill(void)

    44

{

    45

	uint len = _sl.read_bytes();

    46

	assert(len != 0);

    47

    48

	_sl.bufp = _sl.buf;

    49

	_sl.bufe = _sl.buf + len;

    50

	_sl.offs_base += len;

    51

}

    52

    53

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

    54

    55

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

    56

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

    57

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

    58

 */

    59

static void SlWriteFill(void)

    60

{

    61

	// flush the buffer to disk (the writer)

    62

	if (_sl.bufp != NULL) {

    63

		uint len = _sl.bufp - _sl.buf;

    64

		_sl.offs_base += len;

    65

		if (len) _sl.write_bytes(len);

    66

	}

    67

    68

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

    69

	* to start reading in more data */

    70

	_sl.bufp = _sl.buf;

    71

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

    72

}

    73

    74

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

    75

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

    76

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

    77

static void NORETURN SlError(const char *msg)

    78

{

    79

	_sl.excpt_msg = msg;

    80

	longjmp(_sl.excpt, 0);

    81

}

    82

    83

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

    84

 * flush it to its final destination

    85

 * @return return the read byte from file

    86

 */

    87

static inline int SlReadByteInternal(void)

    88

{

    89

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

    90

	return *_sl.bufp++;

    91

}

    92

    93

/** Wrapper for SlReadByteInternal */

    94

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

    95

    96

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

    97

 * flush it to its destination (file)

    98

 * @param b the byte that is currently written

    99

 */

   100

static inline void SlWriteByteInternal(byte b)

   101

{

   102

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

   103

	*_sl.bufp++ = b;

   104

}

   105

   106

/** Wrapper for SlWriteByteInternal */

   107

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

   108

   109

static inline int SlReadUint16(void)

   110

{

   111

	int x = SlReadByte() << 8;

   112

	return x | SlReadByte();

   113

}

   114

   115

static inline uint32 SlReadUint32(void)

   116

{

   117

	uint32 x = SlReadUint16() << 16;

   118

	return x | SlReadUint16();

   119

}

   120

   121

static inline uint64 SlReadUint64(void)

   122

{

   123

	uint32 x = SlReadUint32();

   124

	uint32 y = SlReadUint32();

   125

	return (uint64)x << 32 | y;

   126

}

   127

   128

static inline void SlWriteUint16(uint16 v)

   129

{

   130

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

   131

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

   132

}

   133

   134

static inline void SlWriteUint32(uint32 v)

   135

{

   136

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

   137

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

   138

}

   139

   140

static inline void SlWriteUint64(uint64 x)

   141

{

   142

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

   143

	SlWriteUint32((uint32)x);

   144

}

   145

   146

/**

   147

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

   148

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

   149

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

   150

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

   151

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

   152

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

   153

 * @return Return the value of the index

   154

 */

   155

static uint SlReadSimpleGamma(void)

   156

{

   157

	uint i = SlReadByte();

   158

	if (HASBIT(i, 7)) {

   159

		i &= ~0x80;

   160

		if (HASBIT(i, 6)) {

   161

			i &= ~0x40;

   162

			if (HASBIT(i, 5)) {

   163

				i &= ~0x20;

   164

				if (HASBIT(i, 4))

   165

					SlError("Unsupported gamma");

   166

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

   167

			}

   168

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

   169

		}

   170

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

   171

	}

   172

	return i;

   173

}

   174

   175

/**

   176

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

   177

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

   178

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

   179

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

   180

 * 0xxxxxxx

   181

 * 10xxxxxx xxxxxxxx

   182

 * 110xxxxx xxxxxxxx xxxxxxxx

   183

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   184

 * @param i Index being written

   185

 */

   186

   187

static void SlWriteSimpleGamma(uint i)

   188

{

   189

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

   190

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

   191

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

   192

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

   193

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

   194

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

   195

			} else {

   196

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

   197

			}

   198

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

   199

		} else {

   200

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

   201

		}

   202

	}

   203

	SlWriteByte(i);

   204

}

   205

   206

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

   207

static inline uint SlGetGammaLength(uint i) {

   208

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

   209

}

   210

   211

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

   212

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

   213

   214

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

   215

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

   216

   217

void SlSetArrayIndex(uint index)

   218

{

   219

	_sl.need_length = NL_WANTLENGTH;

   220

	_sl.array_index = index;

   221

}

   222

   223

/**

   224

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

   225

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

   226

 */

   227

int SlIterateArray(void)

   228

{

   229

	int index;

   230

	static uint32 next_offs;

   231

   232

	/* After reading in the whole array inside the loop

   233

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

   234

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

   235

   236

	while (true) {

   237

		uint length = SlReadArrayLength();

   238

		if (length == 0) {

   239

			next_offs = 0;

   240

			return -1;

   241

		}

   242

   243

		_sl.obj_len = --length;

   244

		next_offs = SlGetOffs() + length;

   245

   246

		switch (_sl.block_mode) {

   247

		case CH_SPARSE_ARRAY: index = SlReadSparseIndex(); break;

   248

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

   249

		default:

   250

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

   251

			return -1; // error

   252

		}

   253

   254

		if (length != 0) return index;

   255

	}

   256

}

   257

   258

/**

   259

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

   260

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

   261

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

   262

 */

   263

void SlSetLength(size_t length)

   264

{

   265

	switch (_sl.need_length) {

   266

	case NL_WANTLENGTH:

   267

		_sl.need_length = NL_NONE;

   268

		switch (_sl.block_mode) {

   269

		case CH_RIFF:

   270

			// Ugly encoding of >16M RIFF chunks

   271

			// The lower 24 bits are normal

   272

			// The uppermost 4 bits are bits 24:27

   273

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

   274

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

   275

			break;

   276

		case CH_ARRAY:

   277

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

   278

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

   279

				SlWriteArrayLength(1);

   280

			SlWriteArrayLength(length + 1);

   281

			break;

   282

		case CH_SPARSE_ARRAY:

   283

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

   284

			SlWriteSparseIndex(_sl.array_index);

   285

			break;

   286

		default: NOT_REACHED();

   287

		} break;

   288

	case NL_CALCLENGTH:

   289

		_sl.obj_len += length;

   290

		break;

   291

	}

   292

}

   293

   294

/**

   295

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

   296

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

   297

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

   298

 * @param length number of bytes this fast CopyBytes lasts

   299

 */

   300

static void SlCopyBytes(void *ptr, size_t length)

   301

{

   302

	byte *p = (byte*)ptr;

   303

   304

	if (_sl.save) {

   305

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

   306

	} else {

   307

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

   308

	}

   309

}

   310

   311

#if 0

   312

/**

   313

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

   314

 * anything with them

   315

 * NOTICE: currently unused

   316

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

   317

 */

   318

static inline void SlSkipBytes(size_t length)

   319

{

   320

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

   321

		SlReadByte();

   322

}

   323

#endif

   324

   325

/* Get the length of the current object */

   326

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

   327

   328

/**

   329

 * Handle all conversion and typechecking of variables here.

   330

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

   331

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

   332

 * goes exactly the opposite way

   333

 * @param ptr The object being filled/read

   334

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

   335

 */

   336

static void SlSaveLoadConv(void *ptr, VarType conv)

   337

{

   338

	int64 x = 0;

   339

   340

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

   341

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

   342

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

   343

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

   344

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

   345

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

   346

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

   347

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

   348

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

   349

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

   350

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

   351

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

   352

		default: NOT_REACHED();

   353

		}

   354

   355

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

   356

		switch (conv & 0xF) {

   357

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

   358

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

   359

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

   360

		case SLE_FILE_STRINGID:

   361

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

   362

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

   363

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

   364

		default: NOT_REACHED();

   365

		}

   366

	} else { /* LOAD values */

   367

   368

		// Read a value from the file

   369

		switch (conv & 0xF) {

   370

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

   371

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

   372

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

   373

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

   374

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

   375

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

   376

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

   377

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

   378

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

   379

		default: NOT_REACHED();

   380

		}

   381

   382

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

   383

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

   384

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

   385

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

   386

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

   387

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

   388

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

   389

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

   390

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

   391

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

   392

		case SLE_VAR_NULL >> 4: break;

   393

		default: NOT_REACHED();

   394

		}

   395

	}

   396

}

   397

   398

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

   399

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

   400

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

   401

   402

/**

   403

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

   404

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

   405

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

   406

 * @return Return the size of this type in byes

   407

 */

   408

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

   409

   410

/**

   411

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

   412

 */

   413

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

   414

   415

/**

   416

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

   417

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

   418

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

   419

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

   420

 */

   421

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

   422

   423

/**

   424

 * Save/Load an array.

   425

 * @param array The array being manipulated

   426

 * @param length The length of the array in elements

   427

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

   428

 */

   429

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

   430

{

   431

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

   432

   433

	// Automatically calculate the length?

   434

	if (_sl.need_length != NL_NONE) {

   435

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

   436

		// Determine length only?

   437

		if (_sl.need_length == NL_CALCLENGTH)

   438

			return;

   439

	}

   440

   441

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

   442

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

   443

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

   444

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

   445

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

   446

			conv = SLE_INT8;

   447

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

   448

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

   449

			conv = SLE_INT8;

   450

		}

   451

	}

   452

   453

	/* If the size of elements is 1 byte, no special conversion is needed,

   454

	 * use specialized copy-to-copy function to speed up things */

   455

	if (conv == SLE_INT8 || conv == SLE_UINT8) {

   456

		SlCopyBytes(array, length);

   457

	} else {

   458

		byte *a = (byte*)array;

   459

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

   460

			SlSaveLoadConv(a, conv);

   461

			a += conv_mem_size[(conv >> 4) & 0xF]; // get size

   462

		}

   463

	}

   464

}

   465

   466

/**

   467

 * Calculate the size of an object.

   468

 * @param object Object that needs its length calculated

   469

 * @param sld The @SaveLoad description of the object so we know how to manipulate it

   470

 */

   471

static size_t SlCalcObjLength(void *object, const SaveLoad *sld)

   472

{

   473

	size_t length = 0;

   474

   475

	// Need to determine the length and write a length tag.

   476

	for (; sld->cmd != SL_END; sld++) {

   477

		if (sld->cmd < SL_WRITEBYTE) {

   478

			if (HASBIT(sld->cmd, 2)) {

   479

				// check if the field is used in the current savegame version

   480

				if (_sl.version < sld->version_from || _sl.version > sld->version_to)

   481

					continue;

   482

			}

   483

   484

			switch (sld->cmd) {

   485

			case SL_VAR: case SL_CONDVAR: /* Normal Variable */

   486

				length += SlCalcConvLen(NULL, sld->type); break;

   487

			case SL_REF: case SL_CONDREF:  /* Reference variable */

   488

				length += SlCalcRefLen(); break;

   489

			case SL_ARR: case SL_CONDARR: /* Array */

   490

				length += SlCalcArrayLen(NULL, sld->length, sld->type); break;

   491

			default: NOT_REACHED();

   492

			}

   493

		} else if (sld->cmd == SL_WRITEBYTE) {

   494

			length++; // a byte is logically of size 1

   495

		} else if (sld->cmd == SL_INCLUDE) {

   496

			length += SlCalcObjLength(NULL, _sl.includes[sld->version_from]);

   497

		} else