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

    30

enum {

    32

	SAVEGAME_MINOR_VERSION = 0,

    33

    34

	SAVEGAME_LOADABLE_VERSION = (SAVEGAME_MAJOR_VERSION << 8) + SAVEGAME_MINOR_VERSION

    35

};

    36

    37

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

    38

    39

SaverLoader _sl;

    40

    41

/**

    42

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

    43

 */

    44

static void SlReadFill(void)

    45

{

    46

	uint len = _sl.read_bytes();

    47

	assert(len != 0);

    48

    49

	_sl.bufp = _sl.buf;

    50

	_sl.bufe = _sl.buf + len;

    51

	_sl.offs_base += len;

    52

}

    53

    54

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

    55

    56

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

    57

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

    58

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

    59

 */

    60

static void SlWriteFill(void)

    61

{

    62

	// flush the buffer to disk (the writer)

    63

	if (_sl.bufp != NULL) {

    64

		uint len = _sl.bufp - _sl.buf;

    65

		_sl.offs_base += len;

    66

		if (len) _sl.write_bytes(len);

    67

	}

    68

    69

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

    70

	* to start reading in more data */

    71

	_sl.bufp = _sl.buf;

    72

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

    73

}

    74

    75

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

    76

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

    77

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

    78

static void NORETURN SlError(const char *msg)

    79

{

    80

	_sl.excpt_msg = msg;

    81

	longjmp(_sl.excpt, 0);

    82

}

    83

    84

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

    85

 * flush it to its final destination

    86

 * @return return the read byte from file

    87

 */

    88

static inline int SlReadByteInternal(void)

    89

{

    90

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

    91

	return *_sl.bufp++;

    92

}

    93

    94

/** Wrapper for SlReadByteInternal */

    95

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

    96

    97

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

    98

 * flush it to its destination (file)

    99

 * @param b the byte that is currently written

   100

 */

   101

static inline void SlWriteByteInternal(byte b)

   102

{

   103

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

   104

	*_sl.bufp++ = b;

   105

}

   106

   107

/** Wrapper for SlWriteByteInternal */

   108

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

   109

   110

static inline int SlReadUint16(void)

   111

{

   112

	int x = SlReadByte() << 8;

   113

	return x | SlReadByte();

   114

}

   115

   116

static inline uint32 SlReadUint32(void)

   117

{

   118

	uint32 x = SlReadUint16() << 16;

   119

	return x | SlReadUint16();

   120

}

   121

   122

static inline uint64 SlReadUint64(void)

   123

{

   124

	uint32 x = SlReadUint32();

   125

	uint32 y = SlReadUint32();

   126

	return (uint64)x << 32 | y;

   127

}

   128

   129

static inline void SlWriteUint16(uint16 v)

   130

{

   131

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

   132

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

   133

}

   134

   135

static inline void SlWriteUint32(uint32 v)

   136

{

   137

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

   138

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

   139

}

   140

   141

static inline void SlWriteUint64(uint64 x)

   142

{

   143

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

   144

	SlWriteUint32((uint32)x);

   145

}

   146

   147

/**

   148

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

   149

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

   150

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

   151

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

   152

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

   153

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

   154

 * @return Return the value of the index

   155

 */

   156

static uint SlReadSimpleGamma(void)

   157

{

   158

	uint i = SlReadByte();

   159

	if (HASBIT(i, 7)) {

   160

		i &= ~0x80;

   161

		if (HASBIT(i, 6)) {

   162

			i &= ~0x40;

   163

			if (HASBIT(i, 5)) {

   164

				i &= ~0x20;

   165

				if (HASBIT(i, 4))

   166

					SlError("Unsupported gamma");

   167

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

   168

			}

   169

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

   170

		}

   171

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

   172

	}

   173

	return i;

   174

}

   175

   176

/**

   177

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

   178

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

   179

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

   180

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

   181

 * 0xxxxxxx

   182

 * 10xxxxxx xxxxxxxx

   183

 * 110xxxxx xxxxxxxx xxxxxxxx

   184

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   185

 * @param i Index being written

   186

 */

   187

   188

static void SlWriteSimpleGamma(uint i)

   189

{

   190

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

   191

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

   192

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

   193

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

   194

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

   195

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

   196

			} else {

   197

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

   198

			}

   199

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

   200

		} else {

   201

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

   202

		}

   203

	}

   204

	SlWriteByte(i);

   205

}

   206

   207

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

   208

static inline uint SlGetGammaLength(uint i) {

   209

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

   210

}

   211

   212

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

   213

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

   214

   215

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

   216

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

   217

   218

void SlSetArrayIndex(uint index)

   219

{

   220

	_sl.need_length = NL_WANTLENGTH;

   221

	_sl.array_index = index;

   222

}

   223

   224

/**

   225

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

   226

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

   227

 */

   228

int SlIterateArray(void)

   229

{

   230

	int index;

   231

	static uint32 next_offs;

   232

   233

	/* After reading in the whole array inside the loop

   234

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

   235

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

   236

   237

	while (true) {

   238

		uint length = SlReadArrayLength();

   239

		if (length == 0) {

   240

			next_offs = 0;

   241

			return -1;

   242

		}

   243

   244

		_sl.obj_len = --length;

   245

		next_offs = SlGetOffs() + length;

   246

   247

		switch (_sl.block_mode) {

   248

		case CH_SPARSE_ARRAY: index = SlReadSparseIndex(); break;

   249

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

   250

		default:

   251

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

   252

			return -1; // error

   253

		}

   254

   255

		if (length != 0) return index;

   256

	}

   257

}

   258

   259

/**

   260

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

   261

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

   262

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

   263

 */

   264

void SlSetLength(size_t length)

   265

{

   266

	switch (_sl.need_length) {

   267

	case NL_WANTLENGTH:

   268

		_sl.need_length = NL_NONE;

   269

		switch (_sl.block_mode) {

   270

		case CH_RIFF:

   271

			// Ugly encoding of >16M RIFF chunks

   272

			// The lower 24 bits are normal

   273

			// The uppermost 4 bits are bits 24:27

   274

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

   275

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

   276

			break;

   277

		case CH_ARRAY:

   278

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

   279

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

   280

				SlWriteArrayLength(1);

   281

			SlWriteArrayLength(length + 1);

   282

			break;

   283

		case CH_SPARSE_ARRAY:

   284

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

   285

			SlWriteSparseIndex(_sl.array_index);

   286

			break;

   287

		default: NOT_REACHED();

   288

		} break;

   289

	case NL_CALCLENGTH:

   290

		_sl.obj_len += length;

   291

		break;

   292

	}

   293

}

   294

   295

/**

   296

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

   297

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

   298

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

   299

 * @param length number of bytes this fast CopyBytes lasts

   300

 */

   301

static void SlCopyBytes(void *ptr, size_t length)

   302

{

   303

	byte *p = (byte*)ptr;

   304

   305

	if (_sl.save) {

   306

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

   307

	} else {

   308

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

   309

	}

   310

}

   311

   312

#if 0

   313

/**

   314

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

   315

 * anything with them

   316

 * NOTICE: currently unused

   317

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

   318

 */

   319

static inline void SlSkipBytes(size_t length)

   320

{

   321

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

   322

		SlReadByte();

   323

}

   324

#endif

   325

   326

/* Get the length of the current object */

   327

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

   328

   329

/**

   330

 * Handle all conversion and typechecking of variables here.

   331

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

   332

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

   333

 * goes exactly the opposite way

   334

 * @param ptr The object being filled/read

   335

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

   336

 */

   337

static void SlSaveLoadConv(void *ptr, VarType conv)

   338

{

   339

	int64 x = 0;

   340

   341

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

   342

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

   343

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

   344

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

   345

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

   346

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

   347

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

   348

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

   349

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

   350

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

   351

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

   352

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

   353

		default: NOT_REACHED();

   354

		}

   355

   356

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

   357

		switch (conv & 0xF) {

   358

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

   359

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

   360

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

   361

		case SLE_FILE_STRINGID:

   362

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

   363

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

   364

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

   365

		default: NOT_REACHED();

   366

		}

   367

	} else { /* LOAD values */

   368

   369

		// Read a value from the file

   370

		switch (conv & 0xF) {

   371

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

   372

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

   373

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

   374

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

   375

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

   376

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

   377

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

   378

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

   379

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

   380

		default: NOT_REACHED();

   381

		}

   382

   383

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

   384

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

   385

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

   386

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

   387

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

   388

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

   389

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

   390

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

   391

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

   392

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

   393

		case SLE_VAR_NULL >> 4: break;

   394

		default: NOT_REACHED();

   395

		}

   396

	}

   397

}

   398

   399

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

   400

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

   401

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

   402

   403

/**

   404

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

   405

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

   406

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

   407

 * @return Return the size of this type in byes

   408

 */

   409

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

   410

   411

/**

   412

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

   413

 */

   414

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

   415

   416

/**

   417

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

   418

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

   419

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

   420

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

   421

 */

   422

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

   423

   424

/**

   425

 * Save/Load an array.

   426

 * @param array The array being manipulated

   427

 * @param length The length of the array in elements

   428

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

   429

 */

   430

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

   431

{

   432

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

   433

   434

	// Automatically calculate the length?

   435

	if (_sl.need_length != NL_NONE) {

   436

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

   437

		// Determine length only?

   438

		if (_sl.need_length == NL_CALCLENGTH)

   439

			return;

   440

	}

   441

   442

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

   443

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

   444

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

   445

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

   446

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

   447

			conv = SLE_INT8;

   448

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

   449

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

   450

			conv = SLE_INT8;

   451

		}

   452

	}

   453

   454

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

   455

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

   456

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

   457

		SlCopyBytes(array, length);

   458

	} else {

   459

		byte *a = (byte*)array;

   460

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

   461

			SlSaveLoadConv(a, conv);

   462

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

   463

		}

   464

	}

   465

}

   466

   467

/**

   468

 * Calculate the size of an object.

   469

 * @param object Object that needs its length calculated

   470

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

   471

 */

   472

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

   473

{

   474

	size_t length = 0;

   475

   476

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

   477

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

   478

		if (sld->cmd < SL_WRITEBYTE) {

   479

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

   480

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

   481

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

   482

					continue;

   483

			}

   484

   485

			switch (sld->cmd) {

   486

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

   487

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

   488

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

   489

				length += SlCalcRefLen(); break;

   490

			case SL_ARR: case SL_CONDARR: /* Array */

   491

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

   492

			default: NOT_REACHED();

   493

			}

   494

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

   495

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

   496

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

   497

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