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 "vehicle.h"

    21

#include "station.h"

    22

#include "thread.h"

    23

#include "town.h"

    24

#include "player.h"

    25

#include "saveload.h"

    26

#include "network/network.h"

    27

#include "variables.h"

    28

#include "table/strings.h"

    29

#include "strings.h"

    30

#include <setjmp.h>

    31

#include <list>

    32

    34

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

    35

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

    36

    37

typedef void WriterProc(uint len);

    38

typedef uint ReaderProc();

    39

    40

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

    41

static struct {

    42

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

    43

	byte need_length;                    ///< ???

    44

	byte block_mode;                     ///< ???

    45

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

    46

    47

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

    48

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

    49

    50

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

    51

    52

	WriterProc *write_bytes;             ///< savegame writer function

    53

	ReaderProc *read_bytes;              ///< savegame loader function

    54

    55

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

    56

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

    57

    58

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

    59

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

    60

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

    61

    62

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

    63

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

    64

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

    65

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

    66

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

    67

    68

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

    69

	StringID error_str;                  ///< the translateable error message to show

    70

	char *extra_msg;                     ///< the error message

    71

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

    72

} _sl;

    73

    74

    75

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

    76

    77

/**

    78

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

    79

 */

    80

static void SlReadFill()

    81

{

    82

	uint len = _sl.read_bytes();

    83

	assert(len != 0);

    84

    85

	_sl.bufp = _sl.buf;

    86

	_sl.bufe = _sl.buf + len;

    87

	_sl.offs_base += len;

    88

}

    89

    90

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

    91

    92

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

    93

 * as it appears in memory. See VarTypes

    94

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

    95

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

    96

static inline byte SlCalcConvMemLen(VarType conv)

    97

{

    98

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

    99

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

   100

	assert(length < lengthof(conv_mem_size));

   101

	return conv_mem_size[length];

   102

}

   103

   104

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

   105

 * as it appears in a saved game. See VarTypes

   106

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

   107

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

   108

static inline byte SlCalcConvFileLen(VarType conv)

   109

{

   110

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

   111

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

   112

	assert(length < lengthof(conv_file_size));

   113

	return conv_file_size[length];

   114

}

   115

   116

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

   117

static inline size_t SlCalcRefLen() {return CheckSavegameVersion(69) ? 2 : 4;}

   118

   119

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

   120

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

   121

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

   122

 */

   123

static void SlWriteFill()

   124

{

   125

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

   126

	if (_sl.bufp != NULL) {

   127

		uint len = _sl.bufp - _sl.buf;

   128

		_sl.offs_base += len;

   129

		if (len) _sl.write_bytes(len);

   130

	}

   131

   132

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

   133

	 * to start reading in more data */

   134

	_sl.bufp = _sl.buf;

   135

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

   136

}

   137

   138

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

   139

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

   140

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

   141

static void NORETURN SlError(StringID string, const char *extra_msg = NULL)

   142

{

   143

	_sl.error_str = string;

   144

	free(_sl.extra_msg);

   145

	_sl.extra_msg = (extra_msg == NULL) ? NULL : strdup(extra_msg);

   146

	longjmp(_sl.excpt, 0);

   147

}

   148

   149

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

   150

 * flush it to its final destination

   151

 * @return return the read byte from file

   152

 */

   153

static inline byte SlReadByteInternal()

   154

{

   155

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

   156

	return *_sl.bufp++;

   157

}

   158

   159

/** Wrapper for SlReadByteInternal */

   160

byte SlReadByte() {return SlReadByteInternal();}

   161

   162

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

   163

 * flush it to its destination (file)

   164

 * @param b the byte that is currently written

   165

 */

   166

static inline void SlWriteByteInternal(byte b)

   167

{

   168

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

   169

	*_sl.bufp++ = b;

   170

}

   171

   172

/** Wrapper for SlWriteByteInternal */

   173

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

   174

   175

static inline int SlReadUint16()

   176

{

   177

	int x = SlReadByte() << 8;

   178

	return x | SlReadByte();

   179

}

   180

   181

static inline uint32 SlReadUint32()

   182

{

   183

	uint32 x = SlReadUint16() << 16;

   184

	return x | SlReadUint16();

   185

}

   186

   187

static inline uint64 SlReadUint64()

   188

{

   189

	uint32 x = SlReadUint32();

   190

	uint32 y = SlReadUint32();

   191

	return (uint64)x << 32 | y;

   192

}

   193

   194

static inline void SlWriteUint16(uint16 v)

   195

{

   196

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

   197

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

   198

}

   199

   200

static inline void SlWriteUint32(uint32 v)

   201

{

   202

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

   203

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

   204

}

   205

   206

static inline void SlWriteUint64(uint64 x)

   207

{

   208

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

   209

	SlWriteUint32((uint32)x);

   210

}

   211

   212

/**

   213

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

   214

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

   215

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

   216

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

   217

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

   218

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

   219

 * @return Return the value of the index

   220

 */

   221

static uint SlReadSimpleGamma()

   222

{

   223

	uint i = SlReadByte();

   224

	if (HASBIT(i, 7)) {

   225

		i &= ~0x80;

   226

		if (HASBIT(i, 6)) {

   227

			i &= ~0x40;

   228

			if (HASBIT(i, 5)) {

   229

				i &= ~0x20;

   230

				if (HASBIT(i, 4))

   231

					SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Unsupported gamma");

   232

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

   233

			}

   234

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

   235

		}

   236

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

   237

	}

   238

	return i;

   239

}

   240

   241

/**

   242

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

   243

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

   244

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

   245

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

   246

 * 0xxxxxxx

   247

 * 10xxxxxx xxxxxxxx

   248

 * 110xxxxx xxxxxxxx xxxxxxxx

   249

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   250

 * @param i Index being written

   251

 */

   252

   253

static void SlWriteSimpleGamma(uint i)

   254

{

   255

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

   256

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

   257

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

   258

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

   259

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

   260

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

   261

			} else {

   262

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

   263

			}

   264

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

   265

		} else {

   266

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

   267

		}

   268

	}

   269

	SlWriteByte(i);

   270

}

   271

   272

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

   273

static inline uint SlGetGammaLength(uint i) {

   274

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

   275

}

   276

   277

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

   278

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

   279

   280

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

   281

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

   282

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

   283

   284

void SlSetArrayIndex(uint index)

   285

{

   286

	_sl.need_length = NL_WANTLENGTH;

   287

	_sl.array_index = index;

   288

}

   289

   290

static uint32 _next_offs;

   291

   292

/**

   293

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

   294

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

   295

 */

   296

int SlIterateArray()

   297

{

   298

	int index;

   299

   300

	/* After reading in the whole array inside the loop

   301

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

   302

	if (_next_offs != 0 && SlGetOffs() != _next_offs) SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Invalid chunk size");

   303

   304

	while (true) {

   305

		uint length = SlReadArrayLength();

   306

		if (length == 0) {

   307

			_next_offs = 0;

   308

			return -1;

   309

		}

   310

   311

		_sl.obj_len = --length;

   312

		_next_offs = SlGetOffs() + length;

   313

   314

		switch (_sl.block_mode) {

   315

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

   316

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

   317

		default:

   318

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

   319

			return -1; // error

   320

		}

   321

   322

		if (length != 0) return index;

   323

	}

   324

}

   325

   326

/**

   327

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

   328

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

   329

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

   330

 */

   331

void SlSetLength(size_t length)

   332

{

   333

	assert(_sl.save);

   334

   335

	switch (_sl.need_length) {

   336

	case NL_WANTLENGTH:

   337

		_sl.need_length = NL_NONE;

   338

		switch (_sl.block_mode) {

   339

		case CH_RIFF:

   340

			/* Ugly encoding of >16M RIFF chunks

   341

			 * The lower 24 bits are normal

   342

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

   343

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

   344

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

   345

			break;

   346

		case CH_ARRAY:

   347

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

   348

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

   349

				SlWriteArrayLength(1);

   350

			SlWriteArrayLength(length + 1);

   351

			break;

   352

		case CH_SPARSE_ARRAY:

   353

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

   354

			SlWriteSparseIndex(_sl.array_index);

   355

			break;

   356

		default: NOT_REACHED();

   357

		} break;

   358

	case NL_CALCLENGTH:

   359

		_sl.obj_len += length;

   360

		break;

   361

	}

   362

}

   363

   364

/**

   365

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

   366

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

   367

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

   368

 * @param length number of bytes this fast CopyBytes lasts

   369

 */

   370

static void SlCopyBytes(void *ptr, size_t length)

   371

{

   372

	byte *p = (byte*)ptr;

   373

   374

	if (_sl.save) {

   375

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

   376

	} else {

   377

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

   378

	}

   379

}

   380

   381

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

   382

 * anything with them, discarding them in effect

   383

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

   384

 */

   385

static inline void SlSkipBytes(size_t length)

   386

{

   387

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

   388

}

   389

   390

/* Get the length of the current object */

   391

uint SlGetFieldLength() {return _sl.obj_len;}

   392

   393

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

   394

 * @param ptr pointer to the variable

   395

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

   396

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

   397

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

   398

int64 ReadValue(const void *ptr, VarType conv)

   399

{

   400

	switch (GetVarMemType(conv)) {

   401

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

   402

	case SLE_VAR_I8:  return *(int8*  )ptr;

   403

	case SLE_VAR_U8:  return *(byte*  )ptr;

   404

	case SLE_VAR_I16: return *(int16* )ptr;

   405

	case SLE_VAR_U16: return *(uint16*)ptr;

   406

	case SLE_VAR_I32: return *(int32* )ptr;

   407

	case SLE_VAR_U32: return *(uint32*)ptr;

   408

	case SLE_VAR_I64: return *(int64* )ptr;

   409

	case SLE_VAR_U64: return *(uint64*)ptr;

   410

	case SLE_VAR_NULL:return 0;

   411

	default: NOT_REACHED();

   412

	}

   413

   414

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

   415

	return 0;

   416

}

   417

   418

/** Write the value of a setting

   419

 * @param ptr pointer to the variable

   420

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

   421

 *             with other flags. It is parsed upon read

   422

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

   423

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

   424

{

   425

	switch (GetVarMemType(conv)) {

   426

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

   427

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

   428

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

   429

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

   430

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

   431

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

   432

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

   433

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

   434

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

   435

	case SLE_VAR_NULL: break;

   436

	default: NOT_REACHED();

   437

	}

   438

}

   439

   440

/**

   441

 * Handle all conversion and typechecking of variables here.

   442

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

   443

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

   444

 * goes exactly the opposite way

   445

 * @param ptr The object being filled/read

   446

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

   447

 */

   448

static void SlSaveLoadConv(void *ptr, VarType conv)

   449

{

   450

	int64 x = 0;

   451

   452

	if (_sl.save) { // SAVE values

   453

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

   454

		x = ReadValue(ptr, conv);

   455

   456

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

   457

		switch (GetVarFileType(conv)) {

   458

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

   459

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

   460

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

   461

		case SLE_FILE_STRINGID:

   462

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

   463

		case SLE_FILE_I32:

   464

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

   465

		case SLE_FILE_I64:

   466

		case SLE_FILE_U64:                                   SlWriteUint64(x);break;

   467

		default: NOT_REACHED();

   468

		}

   469

	} else { // LOAD values

   470

   471

		/* Read a value from the file */

   472

		switch (GetVarFileType(conv)) {

   473

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

   474

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

   475

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

   476

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

   477

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

   478

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

   479

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

   480

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

   481

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

   482

		default: NOT_REACHED();

   483

		}

   484

   485

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

   486

		WriteValue(ptr, conv, x);

   487

	}

   488

}

   489

   490

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

   491

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