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

    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

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

    67

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

    68

	char *extra_msg;                     ///< the error message

    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()

    78

{

    79

	uint len = _sl.read_bytes();

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	assert(len != 0);

    81

    82

	_sl.bufp = _sl.buf;

    83

	_sl.bufe = _sl.buf + len;

    84

	_sl.offs_base += len;

    85

}

    86

    87

static inline uint32 SlGetOffs() {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() {return CheckSavegameVersion(69) ? 2 : 4;}

   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()

   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(StringID string, const char *extra_msg = NULL)

   139

{

   140

	_sl.error_str = string;

   141

	free(_sl.extra_msg);

   142

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

   143

	throw std::exception();

   144

}

   145

   146

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

   147

 * flush it to its final destination

   148

 * @return return the read byte from file

   149

 */

   150

static inline byte SlReadByteInternal()

   151

{

   152

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

   153

	return *_sl.bufp++;

   154

}

   155

   156

/** Wrapper for SlReadByteInternal */

   157

byte SlReadByte() {return SlReadByteInternal();}

   158

   159

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

   160

 * flush it to its destination (file)

   161

 * @param b the byte that is currently written

   162

 */

   163

static inline void SlWriteByteInternal(byte b)

   164

{

   165

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

   166

	*_sl.bufp++ = b;

   167

}

   168

   169

/** Wrapper for SlWriteByteInternal */

   170

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

   171

   172

static inline int SlReadUint16()

   173

{

   174

	int x = SlReadByte() << 8;

   175

	return x | SlReadByte();

   176

}

   177

   178

static inline uint32 SlReadUint32()

   179

{

   180

	uint32 x = SlReadUint16() << 16;

   181

	return x | SlReadUint16();

   182

}

   183

   184

static inline uint64 SlReadUint64()

   185

{

   186

	uint32 x = SlReadUint32();

   187

	uint32 y = SlReadUint32();

   188

	return (uint64)x << 32 | y;

   189

}

   190

   191

static inline void SlWriteUint16(uint16 v)

   192

{

   193

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

   194

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

   195

}

   196

   197

static inline void SlWriteUint32(uint32 v)

   198

{

   199

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

   200

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

   201

}

   202

   203

static inline void SlWriteUint64(uint64 x)

   204

{

   205

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

   206

	SlWriteUint32((uint32)x);

   207

}

   208

   209

/**

   210

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

   211

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

   212

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

   213

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

   214

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

   215

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

   216

 * @return Return the value of the index

   217

 */

   218

static uint SlReadSimpleGamma()

   219

{

   220

	uint i = SlReadByte();

   221

	if (HASBIT(i, 7)) {

   222

		i &= ~0x80;

   223

		if (HASBIT(i, 6)) {

   224

			i &= ~0x40;

   225

			if (HASBIT(i, 5)) {

   226

				i &= ~0x20;

   227

				if (HASBIT(i, 4))

   228

					SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Unsupported gamma");

   229

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

   230

			}

   231

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

   232

		}

   233

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

   234

	}

   235

	return i;

   236

}

   237

   238

/**

   239

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

   240

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

   241

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

   242

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

   243

 * 0xxxxxxx

   244

 * 10xxxxxx xxxxxxxx

   245

 * 110xxxxx xxxxxxxx xxxxxxxx

   246

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   247

 * @param i Index being written

   248

 */

   249

   250

static void SlWriteSimpleGamma(uint i)

   251

{

   252

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

   253

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

   254

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

   255

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

   256

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

   257

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

   258

			} else {

   259

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

   260

			}

   261

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

   262

		} else {

   263

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

   264

		}

   265

	}

   266

	SlWriteByte(i);

   267

}

   268

   269

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

   270

static inline uint SlGetGammaLength(uint i)

   271

{

   272

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

   273

}

   274

   275

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

   276

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

   277

   278

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

   279

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

   280

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

   281

   282

void SlSetArrayIndex(uint index)

   283

{

   284

	_sl.need_length = NL_WANTLENGTH;

   285

	_sl.array_index = index;

   286

}

   287

   288

static uint32 _next_offs;

   289

   290

/**

   291

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

   292

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

   293

 */

   294

int SlIterateArray()

   295

{

   296

	int index;

   297

   298

	/* After reading in the whole array inside the loop

   299

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

   300

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

   301

   302

	while (true) {

   303

		uint length = SlReadArrayLength();

   304

		if (length == 0) {

   305

			_next_offs = 0;

   306

			return -1;

   307

		}

   308

   309

		_sl.obj_len = --length;

   310

		_next_offs = SlGetOffs() + length;

   311

   312

		switch (_sl.block_mode) {

   313

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

   314

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

   315

		default:

   316

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

   317

			return -1; // error

   318

		}

   319

   320

		if (length != 0) return index;

   321

	}

   322

}

   323

   324

/**

   325

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

   326

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

   327

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

   328

 */

   329

void SlSetLength(size_t length)

   330

{

   331

	assert(_sl.save);

   332

   333

	switch (_sl.need_length) {

   334

	case NL_WANTLENGTH:

   335

		_sl.need_length = NL_NONE;

   336

		switch (_sl.block_mode) {

   337

		case CH_RIFF:

   338

			/* Ugly encoding of >16M RIFF chunks

   339

			 * The lower 24 bits are normal

   340

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

   341

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

   342

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

   343

			break;

   344

		case CH_ARRAY:

   345

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

   346

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

   347

				SlWriteArrayLength(1);

   348

			SlWriteArrayLength(length + 1);

   349

			break;

   350

		case CH_SPARSE_ARRAY:

   351

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

   352

			SlWriteSparseIndex(_sl.array_index);

   353

			break;

   354

		default: NOT_REACHED();

   355

		} break;

   356

	case NL_CALCLENGTH:

   357

		_sl.obj_len += length;

   358

		break;

   359

	}

   360

}

   361

   362

/**

   363

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

   364

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

   365

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

   366

 * @param length number of bytes this fast CopyBytes lasts

   367

 */

   368

static void SlCopyBytes(void *ptr, size_t length)

   369

{

   370

	byte *p = (byte*)ptr;

   371

   372

	if (_sl.save) {

   373

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

   374

	} else {

   375

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

   376

	}

   377

}

   378

   379

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

   380

 * anything with them, discarding them in effect

   381

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

   382

 */

   383

static inline void SlSkipBytes(size_t length)

   384

{

   385

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

   386

}

   387

   388

/* Get the length of the current object */

   389

uint SlGetFieldLength() {return _sl.obj_len;}

   390

   391

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

   392

 * @param ptr pointer to the variable

   393

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

   394

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

   395

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

   396

int64 ReadValue(const void *ptr, VarType conv)

   397

{

   398

	switch (GetVarMemType(conv)) {

   399

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

   400

	case SLE_VAR_I8:  return *(int8*  )ptr;

   401

	case SLE_VAR_U8:  return *(byte*  )ptr;

   402

	case SLE_VAR_I16: return *(int16* )ptr;

   403

	case SLE_VAR_U16: return *(uint16*)ptr;

   404

	case SLE_VAR_I32: return *(int32* )ptr;

   405

	case SLE_VAR_U32: return *(uint32*)ptr;

   406

	case SLE_VAR_I64: return *(int64* )ptr;

   407

	case SLE_VAR_U64: return *(uint64*)ptr;

   408

	case SLE_VAR_NULL:return 0;

   409

	default: NOT_REACHED();

   410

	}

   411

   412

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

   413

	return 0;

   414

}

   415

   416

/** Write the value of a setting

   417

 * @param ptr pointer to the variable

   418

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

   419

 *             with other flags. It is parsed upon read

   420

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

   421

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

   422

{

   423

	switch (GetVarMemType(conv)) {

   424

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

   425

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

   426

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

   427

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

   428

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

   429

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

   430

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

   431

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

   432

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

   433

	case SLE_VAR_NULL: break;

   434

	default: NOT_REACHED();

   435

	}

   436

}

   437

   438

/**

   439

 * Handle all conversion and typechecking of variables here.

   440

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

   441

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

   442

 * goes exactly the opposite way

   443

 * @param ptr The object being filled/read

   444

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

   445

 */

   446

static void SlSaveLoadConv(void *ptr, VarType conv)

   447

{

   448

	int64 x = 0;

   449

   450

	if (_sl.save) { // SAVE values

   451

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

   452

		x = ReadValue(ptr, conv);

   453

   454

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

   455

		switch (GetVarFileType(conv)) {

   456

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

   457

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

   458

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

   459

		case SLE_FILE_STRINGID:

   460

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

   461

		case SLE_FILE_I32:

   462

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

   463

		case SLE_FILE_I64:

   464

		case SLE_FILE_U64:                                   SlWriteUint64(x);break;

   465

		default: NOT_REACHED();

   466

		}

   467

	} else { // LOAD values

   468

   469

		/* Read a value from the file */

   470

		switch (GetVarFileType(conv)) {

   471

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

   472

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

   473

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

   474

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

   475

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

   476

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

   477

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

   478

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

   479

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

   480

		default: NOT_REACHED();

   481

		}

   482

   483

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

   484

		WriteValue(ptr, conv, x);

   485

	}

   486

}

   487

   488

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

   489

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

   490

 * resort to the maximum length of the buffer.

   491

 * @param ptr pointer to the stringbuffer