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 <list>

    31

    32

extern const uint16 SAVEGAME_VERSION = 73;

    33

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

    34

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

    35

    36

typedef void WriterProc(uint len);

    37

typedef uint ReaderProc();

    38

    39

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

    40

static struct {

    41

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

    42

	byte need_length;                    ///< ???

    43

	byte block_mode;                     ///< ???

    44

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

    45

    46

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

    47

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

    48

    49

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

    50

    51

	WriterProc *write_bytes;             ///< savegame writer function

    52

	ReaderProc *read_bytes;              ///< savegame loader function

    53

    54

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

    55

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

    56

    57

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

    58

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

    59

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

    60

    61

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

    62

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

    63

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

    64

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

    65

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

    66

    67

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

    68

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

    69

	char *extra_msg;                     ///< the error message

    70

} _sl;

    71

    72

    73

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

    74

    75

/**

    76

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

    77

 */

    78

static void SlReadFill()

    79

{

    80

	uint len = _sl.read_bytes();

    81

	assert(len != 0);

    82

    83

	_sl.bufp = _sl.buf;

    84

	_sl.bufe = _sl.buf + len;

    85

	_sl.offs_base += len;

    86

}

    87

    88

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

    89

    90

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

    91

 * as it appears in memory. See VarTypes

    92

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

    93

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

    94

static inline byte SlCalcConvMemLen(VarType conv)

    95

{

    96

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

    97

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

    98

	assert(length < lengthof(conv_mem_size));

    99

	return conv_mem_size[length];

   100

}

   101

   102

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

   103

 * as it appears in a saved game. See VarTypes

   104

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

   105

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

   106

static inline byte SlCalcConvFileLen(VarType conv)

   107

{

   108

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

   109

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

   110

	assert(length < lengthof(conv_file_size));

   111

	return conv_file_size[length];

   112

}

   113

   114

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

   115

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

   116

   117

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

   118

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

   119

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

   120

 */

   121

static void SlWriteFill()

   122

{

   123

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

   124

	if (_sl.bufp != NULL) {

   125

		uint len = _sl.bufp - _sl.buf;

   126

		_sl.offs_base += len;

   127

		if (len) _sl.write_bytes(len);

   128

	}

   129

   130

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

   131

	 * to start reading in more data */

   132

	_sl.bufp = _sl.buf;

   133

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

   134

}

   135

   136

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

   137

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

   138

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

   139

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

   140

{

   141

	_sl.error_str = string;

   142

	free(_sl.extra_msg);

   143

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

   145

}

   146

   147

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

   148

 * flush it to its final destination

   149

 * @return return the read byte from file

   150

 */

   151

static inline byte SlReadByteInternal()

   152

{

   153

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

   154

	return *_sl.bufp++;

   155

}

   156

   157

/** Wrapper for SlReadByteInternal */

   158

byte SlReadByte() {return SlReadByteInternal();}

   159

   160

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

   161

 * flush it to its destination (file)

   162

 * @param b the byte that is currently written

   163

 */

   164

static inline void SlWriteByteInternal(byte b)

   165

{

   166

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

   167

	*_sl.bufp++ = b;

   168

}

   169

   170

/** Wrapper for SlWriteByteInternal */

   171

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

   172

   173

static inline int SlReadUint16()

   174

{

   175

	int x = SlReadByte() << 8;

   176

	return x | SlReadByte();

   177

}

   178

   179

static inline uint32 SlReadUint32()

   180

{

   181

	uint32 x = SlReadUint16() << 16;

   182

	return x | SlReadUint16();

   183

}

   184

   185

static inline uint64 SlReadUint64()

   186

{

   187

	uint32 x = SlReadUint32();

   188

	uint32 y = SlReadUint32();

   189

	return (uint64)x << 32 | y;

   190

}

   191

   192

static inline void SlWriteUint16(uint16 v)

   193

{

   194

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

   195

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

   196

}

   197

   198

static inline void SlWriteUint32(uint32 v)

   199

{

   200

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

   201

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

   202

}

   203

   204

static inline void SlWriteUint64(uint64 x)

   205

{

   206

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

   207

	SlWriteUint32((uint32)x);

   208

}

   209

   210

/**

   211

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

   212

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

   213

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

   214

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

   215

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

   216

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

   217

 * @return Return the value of the index

   218

 */

   219

static uint SlReadSimpleGamma()

   220

{

   221

	uint i = SlReadByte();

   222

	if (HASBIT(i, 7)) {

   223

		i &= ~0x80;

   224

		if (HASBIT(i, 6)) {

   225

			i &= ~0x40;

   226

			if (HASBIT(i, 5)) {

   227

				i &= ~0x20;

   228

				if (HASBIT(i, 4))

   229

					SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Unsupported gamma");

   230

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

   231

			}

   232

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

   233

		}

   234

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

   235

	}

   236

	return i;

   237

}

   238

   239

/**

   240

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

   241

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

   242

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

   243

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

   244

 * 0xxxxxxx

   245

 * 10xxxxxx xxxxxxxx

   246

 * 110xxxxx xxxxxxxx xxxxxxxx

   247

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   248

 * @param i Index being written

   249

 */

   250

   251

static void SlWriteSimpleGamma(uint i)

   252

{

   253

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

   254

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

   255

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

   256

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

   257

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

   258

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

   259

			} else {

   260

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

   261

			}

   262

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

   263

		} else {

   264

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

   265

		}

   266

	}

   267

	SlWriteByte(i);

   268

}

   269

   270

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

   271

static inline uint SlGetGammaLength(uint i)

   272

{

   273

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

   274

}

   275

   276

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

   277

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

   278

   279

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

   280

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

   281

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

   282

   283

void SlSetArrayIndex(uint index)

   284

{

   285

	_sl.need_length = NL_WANTLENGTH;

   286

	_sl.array_index = index;

   287

}

   288

   289

static uint32 _next_offs;

   290

   291

/**

   292

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

   293

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

   294

 */

   295

int SlIterateArray()

   296

{

   297

	int index;

   298

   299

	/* After reading in the whole array inside the loop

   300

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

   301

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

   302

   303

	while (true) {

   304

		uint length = SlReadArrayLength();

   305

		if (length == 0) {

   306

			_next_offs = 0;

   307

			return -1;

   308

		}

   309

   310

		_sl.obj_len = --length;

   311

		_next_offs = SlGetOffs() + length;

   312

   313

		switch (_sl.block_mode) {

   314

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

   315

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

   316

		default:

   317

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

   318

			return -1; // error

   319

		}

   320

   321

		if (length != 0) return index;

   322

	}

   323

}

   324

   325

/**

   326

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

   327

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

   328

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

   329

 */

   330

void SlSetLength(size_t length)

   331

{

   332

	assert(_sl.save);

   333

   334

	switch (_sl.need_length) {

   335

	case NL_WANTLENGTH:

   336

		_sl.need_length = NL_NONE;

   337

		switch (_sl.block_mode) {

   338

		case CH_RIFF:

   339

			/* Ugly encoding of >16M RIFF chunks

   340

			 * The lower 24 bits are normal

   341

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

   342

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

   343

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

   344

			break;

   345

		case CH_ARRAY:

   346

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

   347

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

   348

				SlWriteArrayLength(1);

   349

			SlWriteArrayLength(length + 1);

   350

			break;

   351

		case CH_SPARSE_ARRAY:

   352

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

   353

			SlWriteSparseIndex(_sl.array_index);

   354

			break;

   355

		default: NOT_REACHED();

   356

		} break;

   357

	case NL_CALCLENGTH:

   358

		_sl.obj_len += length;

   359

		break;

   360

	}

   361

}

   362

   363

/**

   364

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

   365

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

   366

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

   367

 * @param length number of bytes this fast CopyBytes lasts

   368

 */

   369

static void SlCopyBytes(void *ptr, size_t length)

   370

{

   371

	byte *p = (byte*)ptr;

   372

   373

	if (_sl.save) {

   374

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

   375

	} else {

   376

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

   377

	}

   378

}

   379

   380

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

   381

 * anything with them, discarding them in effect

   382

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

   383

 */

   384

static inline void SlSkipBytes(size_t length)

   385

{

   386

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

   387

}

   388

   389

/* Get the length of the current object */

   390

uint SlGetFieldLength() {return _sl.obj_len;}

   391

   392

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

   393

 * @param ptr pointer to the variable

   394

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

   395

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

   396

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

   397

int64 ReadValue(const void *ptr, VarType conv)

   398

{

   399

	switch (GetVarMemType(conv)) {

   400

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

   401

	case SLE_VAR_I8:  return *(int8*  )ptr;

   402

	case SLE_VAR_U8:  return *(byte*  )ptr;

   403

	case SLE_VAR_I16: return *(int16* )ptr;

   404

	case SLE_VAR_U16: return *(uint16*)ptr;

   405

	case SLE_VAR_I32: return *(int32* )ptr;

   406

	case SLE_VAR_U32: return *(uint32*)ptr;

   407

	case SLE_VAR_I64: return *(int64* )ptr;

   408

	case SLE_VAR_U64: return *(uint64*)ptr;

   409

	case SLE_VAR_NULL:return 0;

   410

	default: NOT_REACHED();

   411

	}

   412

   413

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

   414

	return 0;

   415

}

   416

   417

/** Write the value of a setting

   418

 * @param ptr pointer to the variable

   419

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

   420

 *             with other flags. It is parsed upon read

   421

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

   422

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

   423

{

   424

	switch (GetVarMemType(conv)) {

   425

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

   426

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

   427

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

   428

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

   429

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

   430

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

   431

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

   432

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

   433

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

   434

	case SLE_VAR_NULL: break;

   435

	default: NOT_REACHED();

   436

	}

   437

}

   438

   439

/**

   440

 * Handle all conversion and typechecking of variables here.

   441

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

   442

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

   443

 * goes exactly the opposite way

   444

 * @param ptr The object being filled/read

   445

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

   446

 */

   447

static void SlSaveLoadConv(void *ptr, VarType conv)

   448

{

   449

	int64 x = 0;

   450

   451

	if (_sl.save) { // SAVE values

   452

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

   453

		x = ReadValue(ptr, conv);

   454

   455

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

   456

		switch (GetVarFileType(conv)) {

   457

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

   458

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

   459

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

   460

		case SLE_FILE_STRINGID:

   461

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

   462

		case SLE_FILE_I32:

   463

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

   464

		case SLE_FILE_I64:

   465

		case SLE_FILE_U64:                                   SlWriteUint64(x);break;

   466

		default: NOT_REACHED();

   467

		}

   468

	} else { // LOAD values

   469

   470

		/* Read a value from the file */

   471

		switch (GetVarFileType(conv)) {

   472

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

   473

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

   474

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

   475

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

   476

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

   477

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

   478

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

   479

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

   480

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

   481

		default: NOT_REACHED();

   482

		}

   483

   484

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

   485

		WriteValue(ptr, conv, x);

   486

	}

   487

}

   488

   489

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

   490

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

   491

 * resort to the maximum length of the buffer.