1

/* $Id$ */

     2

     3

/** @file saveload.cpp

     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

 */

    16

#include "stdafx.h"

    17

#include "openttd.h"

    18

#include "debug.h"

    19

#include "functions.h"

    20

#include "hal.h"

    21

#include "vehicle.h"

    22

#include "station.h"

    23

#include "thread.h"

    24

#include "town.h"

    25

#include "player.h"

    26

#include "saveload.h"

    27

#include "network/network.h"

    28

#include "variables.h"

    29

#include <setjmp.h>

    30

    32

uint16 _sl_version;       ///< the major savegame version identifier

    33

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

    34

    35

typedef void WriterProc(uint len);

    36

typedef uint ReaderProc(void);

    37

    38

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

    39

static struct {

    40

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

    41

	byte need_length;                    ///< ???

    42

	byte block_mode;                     ///< ???

    43

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

    44

    45

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

    46

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

    47

    48

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

    49

    50

	WriterProc *write_bytes;             ///< savegame writer function

    51

	ReaderProc *read_bytes;              ///< savegame loader function

    52

    53

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

    54

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

    55

    56

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

    57

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

    58

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

    59

    60

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

    61

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

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

    63

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

    64

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

    65

    66

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

    67

	const char *excpt_msg;               ///< the error message

    68

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

    69

} _sl;

    70

    71

    72

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

    73

    74

/**

    75

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

    76

 */

    77

static void SlReadFill(void)

    78

{

    79

	uint len = _sl.read_bytes();

    80

	assert(len != 0);

    81

    82

	_sl.bufp = _sl.buf;

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	_sl.bufe = _sl.buf + len;

    84

	_sl.offs_base += len;

    85

}

    86

    87

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

    88

    89

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

    90

 * as it appears in memory. See VarTypes

    91

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

    92

 * @return Return the size of this type in bytes */

    93

static inline byte SlCalcConvMemLen(VarType conv)

    94

{

    95

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

    96

	byte length = GB(conv, 4, 4);

    97

	assert(length < lengthof(conv_mem_size));

    98

	return conv_mem_size[length];

    99

}

   100

   101

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

   102

 * as it appears in a saved game. See VarTypes

   103

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

   104

 * @return Return the size of this type in bytes */

   105

static inline byte SlCalcConvFileLen(VarType conv)

   106

{

   107

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

   108

	byte length = GB(conv, 0, 4);

   109

	assert(length < lengthof(conv_file_size));

   110

	return conv_file_size[length];

   111

}

   112

   113

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

   114

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

   115

   116

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

   117

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

   118

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

   119

 */

   120

static void SlWriteFill(void)

   121

{

   122

	/* flush the buffer to disk (the writer) */

   123

	if (_sl.bufp != NULL) {

   124

		uint len = _sl.bufp - _sl.buf;

   125

		_sl.offs_base += len;

   126

		if (len) _sl.write_bytes(len);

   127

	}

   128

   129

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

   130

	 * to start reading in more data */

   131

	_sl.bufp = _sl.buf;

   132

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

   133

}

   134

   135

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

   136

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

   137

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

   138

static void NORETURN SlError(const char *msg)

   139

{

   140

	_sl.excpt_msg = msg;

   141

	longjmp(_sl.excpt, 0);

   142

}

   143

   144

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

   145

 * flush it to its final destination

   146

 * @return return the read byte from file

   147

 */

   148

static inline byte SlReadByteInternal(void)

   149

{

   150

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

   151

	return *_sl.bufp++;

   152

}

   153

   154

/** Wrapper for SlReadByteInternal */

   155

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

   156

   157

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

   158

 * flush it to its destination (file)

   159

 * @param b the byte that is currently written

   160

 */

   161

static inline void SlWriteByteInternal(byte b)

   162

{

   163

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

   164

	*_sl.bufp++ = b;

   165

}

   166

   167

/** Wrapper for SlWriteByteInternal */

   168

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

   169

   170

static inline int SlReadUint16(void)

   171

{

   172

	int x = SlReadByte() << 8;

   173

	return x | SlReadByte();

   174

}

   175

   176

static inline uint32 SlReadUint32(void)

   177

{

   178

	uint32 x = SlReadUint16() << 16;

   179

	return x | SlReadUint16();

   180

}

   181

   182

static inline uint64 SlReadUint64(void)

   183

{

   184

	uint32 x = SlReadUint32();

   185

	uint32 y = SlReadUint32();

   186

	return (uint64)x << 32 | y;

   187

}

   188

   189

static inline void SlWriteUint16(uint16 v)

   190

{

   191

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

   192

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

   193

}

   194

   195

static inline void SlWriteUint32(uint32 v)

   196

{

   197

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

   198

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

   199

}

   200

   201

static inline void SlWriteUint64(uint64 x)

   202

{

   203

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

   204

	SlWriteUint32((uint32)x);

   205

}

   206

   207

/**

   208

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

   209

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

   210

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

   211

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

   212

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

   213

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

   214

 * @return Return the value of the index

   215

 */

   216

static uint SlReadSimpleGamma(void)

   217

{

   218

	uint i = SlReadByte();

   219

	if (HASBIT(i, 7)) {

   220

		i &= ~0x80;

   221

		if (HASBIT(i, 6)) {

   222

			i &= ~0x40;

   223

			if (HASBIT(i, 5)) {

   224

				i &= ~0x20;

   225

				if (HASBIT(i, 4))

   226

					SlError("Unsupported gamma");

   227

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

   228

			}

   229

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

   230

		}

   231

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

   232

	}

   233

	return i;

   234

}

   235

   236

/**

   237

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

   238

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

   239

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

   240

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

   241

 * 0xxxxxxx

   242

 * 10xxxxxx xxxxxxxx

   243

 * 110xxxxx xxxxxxxx xxxxxxxx

   244

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   245

 * @param i Index being written

   246

 */

   247

   248

static void SlWriteSimpleGamma(uint i)

   249

{

   250

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

   251

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

   252

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

   253

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

   254

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

   255

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

   256

			} else {

   257

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

   258

			}

   259

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

   260

		} else {

   261

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

   262

		}

   263

	}

   264

	SlWriteByte(i);

   265

}

   266

   267

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

   268

static inline uint SlGetGammaLength(uint i) {

   269

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

   270

}

   271

   272

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

   273

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

   274

   275

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

   276

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

   277

static inline uint SlGetArrayLength(uint length) {return SlGetGammaLength(length);}

   278

   279

void SlSetArrayIndex(uint index)

   280

{

   281

	_sl.need_length = NL_WANTLENGTH;

   282

	_sl.array_index = index;

   283

}

   284

   285

/**

   286

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

   287

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

   288

 */

   289

int SlIterateArray(void)

   290

{

   291

	int index;

   292

	static uint32 next_offs;

   293

   294

	/* After reading in the whole array inside the loop

   295

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

   296

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

   297

   298

	while (true) {

   299

		uint length = SlReadArrayLength();

   300

		if (length == 0) {

   301

			next_offs = 0;

   302

			return -1;

   303

		}

   304

   305

		_sl.obj_len = --length;

   306

		next_offs = SlGetOffs() + length;

   307

   308

		switch (_sl.block_mode) {

   309

		case CH_SPARSE_ARRAY: index = (int)SlReadSparseIndex(); break;

   310

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

   311

		default:

   312

			DEBUG(sl, 0, "SlIterateArray error");

   313

			return -1; // error

   314

		}

   315

   316

		if (length != 0) return index;

   317

	}

   318

}

   319

   320

/**

   321

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

   322

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

   323

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

   324

 */

   325

void SlSetLength(size_t length)

   326

{

   327

	assert(_sl.save);

   328

   329

	switch (_sl.need_length) {

   330

	case NL_WANTLENGTH:

   331

		_sl.need_length = NL_NONE;

   332

		switch (_sl.block_mode) {

   333

		case CH_RIFF:

   334

			/* Ugly encoding of >16M RIFF chunks

   335

			 * The lower 24 bits are normal

   336

			 * The uppermost 4 bits are bits 24:27 */

   337

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

   338

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

   339

			break;

   340

		case CH_ARRAY:

   341

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

   342

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

   343

				SlWriteArrayLength(1);

   344

			SlWriteArrayLength(length + 1);

   345

			break;

   346

		case CH_SPARSE_ARRAY:

   347

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

   348

			SlWriteSparseIndex(_sl.array_index);

   349

			break;

   350

		default: NOT_REACHED();

   351

		} break;

   352

	case NL_CALCLENGTH:

   353

		_sl.obj_len += length;

   354

		break;

   355

	}

   356

}

   357

   358

/**

   359

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

   360

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

   361

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

   362

 * @param length number of bytes this fast CopyBytes lasts

   363

 */

   364

static void SlCopyBytes(void *ptr, size_t length)

   365

{

   366

	byte *p = (byte*)ptr;

   367

   368

	if (_sl.save) {

   369

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

   370

	} else {

   371

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

   372

	}

   373

}

   374

   375

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

   376

 * anything with them, discarding them in effect

   377

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

   378

 */

   379

static inline void SlSkipBytes(size_t length)

   380

{

   381

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

   382

}

   383

   384

/* Get the length of the current object */

   385

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

   386

   387

/** Return a signed-long version of the value of a setting

   388

 * @param ptr pointer to the variable

   389

 * @param conv type of variable, can be a non-clean

   390

 * type, eg one with other flags because it is parsed

   391

 * @return returns the value of the pointer-setting */

   392

int64 ReadValue(const void *ptr, VarType conv)

   393

{

   394

	switch (GetVarMemType(conv)) {

   395

	case SLE_VAR_BL:  return (*(bool*)ptr != 0);

   396

	case SLE_VAR_I8:  return *(int8*  )ptr;

   397

	case SLE_VAR_U8:  return *(byte*  )ptr;

   398

	case SLE_VAR_I16: return *(int16* )ptr;

   399

	case SLE_VAR_U16: return *(uint16*)ptr;

   400

	case SLE_VAR_I32: return *(int32* )ptr;

   401

	case SLE_VAR_U32: return *(uint32*)ptr;

   402

	case SLE_VAR_I64: return *(int64* )ptr;

   403

	case SLE_VAR_U64: return *(uint64*)ptr;

   404

	case SLE_VAR_NULL:return 0;

   405

	default: NOT_REACHED();

   406

	}

   407

   408

	/* useless, but avoids compiler warning this way */

   409

	return 0;

   410

}

   411

   412

/** Write the value of a setting

   413

 * @param ptr pointer to the variable

   414

 * @param conv type of variable, can be a non-clean type, eg

   415

 * with other flags. It is parsed upon read

   416

 * @param var the new value being given to the variable */

   417

void WriteValue(void *ptr, VarType conv, int64 val)

   418

{

   419

	switch (GetVarMemType(conv)) {

   420

	case SLE_VAR_BL:  *(bool  *)ptr = (val != 0);  break;

   421

	case SLE_VAR_I8:  *(int8  *)ptr = val; break;

   422

	case SLE_VAR_U8:  *(byte  *)ptr = val; break;

   423

	case SLE_VAR_I16: *(int16 *)ptr = val; break;

   424

	case SLE_VAR_U16: *(uint16*)ptr = val; break;

   425

	case SLE_VAR_I32: *(int32 *)ptr = val; break;

   426

	case SLE_VAR_U32: *(uint32*)ptr = val; break;

   427

	case SLE_VAR_I64: *(int64 *)ptr = val; break;

   428

	case SLE_VAR_U64: *(uint64*)ptr = val; break;

   429

	case SLE_VAR_NULL: break;

   430

	default: NOT_REACHED();

   431

	}

   432

}

   433

   434

/**

   435

 * Handle all conversion and typechecking of variables here.

   436

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

   437

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

   438

 * goes exactly the opposite way

   439

 * @param ptr The object being filled/read

   440

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

   441

 */

   442

static void SlSaveLoadConv(void *ptr, VarType conv)

   443

{

   444

	int64 x = 0;

   445

   446

	if (_sl.save) { // SAVE values

   447

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

   448

		x = ReadValue(ptr, conv);

   449

   450

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

   451

		switch (GetVarFileType(conv)) {

   452

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

   453

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

   454

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

   455

		case SLE_FILE_STRINGID:

   456

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

   457

		case SLE_FILE_I32:

   458

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

   459

		case SLE_FILE_I64:

   460

		case SLE_FILE_U64:                                   SlWriteUint64(x);break;

   461

		default: NOT_REACHED();

   462

		}

   463

	} else { // LOAD values

   464

   465

		/* Read a value from the file */

   466

		switch (GetVarFileType(conv)) {

   467

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

   468

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

   469

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

   470

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

   471

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

   472

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

   473

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

   474

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

   475

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

   476

		default: NOT_REACHED();

   477

		}

   478

   479

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

   480

		WriteValue(ptr, conv, x);

   481

	}

   482

}

   483

   484

/** Calculate the net length of a string. This is in almost all cases

   485

 * just strlen(), but if the string is not properly terminated, we'll

   486

 * resort to the maximum length of the buffer.

   487

 * @param ptr pointer to the stringbuffer

   488

 * @param length maximum length of the string (buffer). If -1 we don't care

   489

 * about a maximum length, but take string length as it is.

   490

 * @return return the net length of the string */

   491

static inline size_t SlCalcNetStringLen(const char *ptr, size_t length)

   492

{

   493