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 "station.h"

    20

#include "thread.h"

    21

#include "town.h"

    22

#include "saveload.h"

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#include "network/network.h"

    24

#include "variables.h"

    35

#include "table/strings.h"

    36

    37

extern const uint16 SAVEGAME_VERSION = NEWGRF_AIRPORTS_SAVEGAME;

    38

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

    39

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

    40

    41

typedef void WriterProc(uint len);

    42

typedef uint ReaderProc();

    43

    44

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

    45

static struct {

    46

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

    47

	byte need_length;                    ///< ???

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	byte block_mode;                     ///< ???

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

    50

    51

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

    52

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

    53

    54

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

    55

    56

	WriterProc *write_bytes;             ///< savegame writer function

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	ReaderProc *read_bytes;              ///< savegame loader function

    58

    59

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

    60

    61

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

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

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

    64

    65

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

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	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

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

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

    70

    71

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

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

    73

	char *extra_msg;                     ///< the error message

    74

} _sl;

    75

    76

    77

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

    78

    79

/**

    80

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

    81

 */

    82

static void SlReadFill()

    83

{

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	uint len = _sl.read_bytes();

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	assert(len != 0);

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    87

	_sl.bufp = _sl.buf;

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	_sl.bufe = _sl.buf + len;

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	_sl.offs_base += len;

    90

}

    91

    92

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

    93

    94

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

    95

 * as it appears in memory. See VarTypes

    96

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

    97

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

    98

static inline byte SlCalcConvMemLen(VarType conv)

    99

{

   100

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

   101

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

   102

	assert(length < lengthof(conv_mem_size));

   103

	return conv_mem_size[length];

   104

}

   105

   106

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

   107

 * as it appears in a saved game. See VarTypes

   108

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

   109

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

   110

static inline byte SlCalcConvFileLen(VarType conv)

   111

{

   112

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

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

   114

	assert(length < lengthof(conv_file_size));

   115

	return conv_file_size[length];

   116

}

   117

   118

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

   119

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

   120

   121

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

   122

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

   123

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

   124

 */

   125

static void SlWriteFill()

   126

{

   127

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

   128

	if (_sl.bufp != NULL) {

   129

		uint len = _sl.bufp - _sl.buf;

   130

		_sl.offs_base += len;

   131

		if (len) _sl.write_bytes(len);

   132

	}

   133

   134

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

   135

	 * to start reading in more data */

   136

	_sl.bufp = _sl.buf;

   137

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

   138

}

   139

   140

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

   141

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

   142

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

   143

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

   144

{

   145

	_sl.error_str = string;

   146

	free(_sl.extra_msg);

   147

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

   148

	throw std::exception();

   149

}

   150

   151

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

   152

 * flush it to its final destination

   153

 * @return return the read byte from file

   154

 */

   155

static inline byte SlReadByteInternal()

   156

{

   157

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

   158

	return *_sl.bufp++;

   159

}

   160

   161

/** Wrapper for SlReadByteInternal */

   162

byte SlReadByte() {return SlReadByteInternal();}

   163

   164

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

   165

 * flush it to its destination (file)

   166

 * @param b the byte that is currently written

   167

 */

   168

static inline void SlWriteByteInternal(byte b)

   169

{

   170

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

   171

	*_sl.bufp++ = b;

   172

}

   173

   174

/** Wrapper for SlWriteByteInternal */

   175

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

   176

   177

static inline int SlReadUint16()

   178

{

   179

	int x = SlReadByte() << 8;

   180

	return x | SlReadByte();

   181

}

   182

   183

static inline uint32 SlReadUint32()

   184

{

   185

	uint32 x = SlReadUint16() << 16;

   186

	return x | SlReadUint16();

   187

}

   188

   189

static inline uint64 SlReadUint64()

   190

{

   191

	uint32 x = SlReadUint32();

   192

	uint32 y = SlReadUint32();

   193

	return (uint64)x << 32 | y;

   194

}

   195

   196

static inline void SlWriteUint16(uint16 v)

   197

{

   198

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

   199

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

   200

}

   201

   202

static inline void SlWriteUint32(uint32 v)

   203

{

   204

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

   205

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

   206

}

   207

   208

static inline void SlWriteUint64(uint64 x)

   209

{

   210

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

   211

	SlWriteUint32((uint32)x);

   212

}

   213

   214

/**

   215

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

   216

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

   217

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

   218

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

   219

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

   220

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

   221

 * @return Return the value of the index

   222

 */

   223

static uint SlReadSimpleGamma()

   224

{

   225

	uint i = SlReadByte();

   226

	if (HasBit(i, 7)) {

   227

		i &= ~0x80;

   228

		if (HasBit(i, 6)) {

   229

			i &= ~0x40;

   230

			if (HasBit(i, 5)) {

   231

				i &= ~0x20;

   232

				if (HasBit(i, 4))

   233

					SlError(STR_GAME_SAVELOAD_ERROR_BROKEN_SAVEGAME, "Unsupported gamma");

   234

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

   235

			}

   236

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

   237

		}

   238

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

   239

	}

   240

	return i;

   241

}

   242

   243

/**

   244

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

   245

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

   246

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

   247

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

   248

 * 0xxxxxxx

   249

 * 10xxxxxx xxxxxxxx

   250

 * 110xxxxx xxxxxxxx xxxxxxxx

   251

 * 1110xxxx xxxxxxxx xxxxxxxx xxxxxxxx

   252

 * @param i Index being written

   253

 */

   254

   255

static void SlWriteSimpleGamma(uint i)

   256

{

   257

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

   258

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

   259

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

   260

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

   261

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

   262

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

   263

			} else {

   264

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

   265

			}

   266

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

   267

		} else {

   268

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

   269

		}

   270

	}

   271

	SlWriteByte(i);

   272

}

   273

   274

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

   275

static inline uint SlGetGammaLength(uint i)

   276

{

   277

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

   278

}

   279

   280

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

   281

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

   282

   283

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

   284

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

   285

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

   286

   287

void SlSetArrayIndex(uint index)

   288

{

   289

	_sl.need_length = NL_WANTLENGTH;

   290

	_sl.array_index = index;

   291

}

   292

   293

static uint32 _next_offs;

   294

   295

/**

   296

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

   297

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

   298

 */

   299

int SlIterateArray()

   300

{

   301

	int index;

   302

   303

	/* After reading in the whole array inside the loop

   304

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

   305

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

   306

   307

	while (true) {

   308

		uint length = SlReadArrayLength();

   309

		if (length == 0) {

   310

			_next_offs = 0;

   311

			return -1;

   312

		}

   313

   314

		_sl.obj_len = --length;

   315

		_next_offs = SlGetOffs() + length;

   316

   317

		switch (_sl.block_mode) {

   318

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

   319

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

   320

		default:

   321

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

   322

			return -1; // error

   323

		}

   324

   325

		if (length != 0) return index;

   326

	}

   327

}

   328

   329

/**

   330

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

   331

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

   332

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

   333

 */

   334

void SlSetLength(size_t length)

   335

{

   336

	assert(_sl.save);

   337

   338

	switch (_sl.need_length) {

   339

	case NL_WANTLENGTH:

   340

		_sl.need_length = NL_NONE;

   341

		switch (_sl.block_mode) {

   342

		case CH_RIFF:

   343

			/* Ugly encoding of >16M RIFF chunks

   344

			 * The lower 24 bits are normal

   345

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

   346

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

   347

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

   348

			break;

   349

		case CH_ARRAY:

   350

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

   351

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

   352

				SlWriteArrayLength(1);

   353

			SlWriteArrayLength(length + 1);

   354

			break;

   355

		case CH_SPARSE_ARRAY:

   356

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

   357

			SlWriteSparseIndex(_sl.array_index);

   358

			break;

   359

		default: NOT_REACHED();

   360

		} break;

   361

	case NL_CALCLENGTH:

   362

		_sl.obj_len += length;

   363

		break;

   364

	}

   365

}

   366

   367

/**

   368

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

   369

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

   370

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

   371

 * @param length number of bytes this fast CopyBytes lasts

   372

 */

   373

static void SlCopyBytes(void *ptr, size_t length)

   374

{

   375

	byte *p = (byte*)ptr;

   376

   377

	if (_sl.save) {

   378

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

   379

	} else {

   380

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

   381

	}

   382

}

   383

   384

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

   385

 * anything with them, discarding them in effect

   386

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

   387

 */

   388

static inline void SlSkipBytes(size_t length)

   389

{

   390

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

   391

}

   392

   393

/* Get the length of the current object */

   394

uint SlGetFieldLength() {return _sl.obj_len;}

   395

   396

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

   397

 * @param ptr pointer to the variable

   398

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

   399

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

   400

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

   401

int64 ReadValue(const void *ptr, VarType conv)

   402

{

   403

	switch (GetVarMemType(conv)) {

   404

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

   405

	case SLE_VAR_I8:  return *(int8*  )ptr;

   406

	case SLE_VAR_U8:  return *(byte*  )ptr;

   407

	case SLE_VAR_I16: return *(int16* )ptr;

   408

	case SLE_VAR_U16: return *(uint16*)ptr;

   409

	case SLE_VAR_I32: return *(int32* )ptr;

   410

	case SLE_VAR_U32: return *(uint32*)ptr;

   411

	case SLE_VAR_I64: return *(int64* )ptr;

   412

	case SLE_VAR_U64: return *(uint64*)ptr;

   413

	case SLE_VAR_NULL:return 0;

   414

	default: NOT_REACHED();

   415

	}

   416

   417

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

   418

	return 0;

   419

}

   420

   421

/** Write the value of a setting

   422

 * @param ptr pointer to the variable

   423

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

   424

 *             with other flags. It is parsed upon read

   425

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

   426

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

   427

{

   428

	switch (GetVarMemType(conv)) {

   429

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

   430

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

   431

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

   432

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

   433

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

   434

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

   435

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

   436

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

   437

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

   439

	case SLE_VAR_NULL: break;

   440

	default: NOT_REACHED();

   441

	}

   442

}

   443

   444

/**

   445

 * Handle all conversion and typechecking of variables here.

   446

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

   447

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

   448

 * goes exactly the opposite way

   449

 * @param ptr The object being filled/read

   450

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

   451

 */

   452

static void SlSaveLoadConv(void *ptr, VarType conv)

   453

{

   454

	int64 x = 0;

   455

   456

	if (_sl.save) { // SAVE values

   457

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

   458

		x = ReadValue(ptr, conv);

   459

   460

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

   461

		switch (GetVarFileType(conv)) {

   462

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

   463

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

   464

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

   465

		case SLE_FILE_STRINGID:

   466

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

   467

		case SLE_FILE_I32:

   468

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

   469

		case SLE_FILE_I64:

   470

		case SLE_FILE_U64:                                   SlWriteUint64(x);break;

   471

		default: NOT_REACHED();

   472

		}

   473

	} else { // LOAD values

   474

   475

		/* Read a value from the file */

   476

		switch (GetVarFileType(conv)) {

   477

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

   478

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

   479

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

   480

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

   481

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

   482

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

   483

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

   484

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

   485

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

   486

		default: NOT_REACHED();

   487

		}

   488

   489

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

   490

		WriteValue(ptr, conv, x);