| 1 | /****************************************************************************** |
| 2 | * |
| 3 | * LDC2 source code |
| 4 | * |
| 5 | * $Date: 2007/12/23 15:25:11 $ |
| 6 | * $Author: hachti $ |
| 7 | * |
| 8 | * $Log: tape_block.cpp,v $ |
| 9 | * Revision 2.2 2007/12/23 15:25:11 hachti |
| 10 | * *** empty log message *** |
| 11 | * |
| 12 | * Revision 2.1 2007-03-26 03:20:31 hachti |
| 13 | * *** empty log message *** |
| 14 | * |
| 15 | * Revision 2.0 2007-03-26 01:00:40 hachti |
| 16 | * *** empty log message *** |
| 17 | * |
| 18 | * |
| 19 | ******************************************************************************/ |
| 20 | |
| 21 | #include <string> |
| 22 | #include <vector> |
| 23 | |
| 24 | #include <stdlib.h> |
| 25 | #include <unistd.h> |
| 26 | #include <string.h> |
| 27 | #include <stdio.h> |
| 28 | |
| 29 | #include "tape_block.hh" |
| 30 | |
| 31 | #include "silent_code.hh" |
| 32 | #include "hw_constants.hh" |
| 33 | |
| 34 | #include "eot_block.hh" |
| 35 | #include "data_block.hh" |
| 36 | #include "broken_block.hh" |
| 37 | #include "data_block_0.hh" |
| 38 | #include "data_block_0_0.hh" |
| 39 | #include "data_block_0_1.hh" |
| 40 | #include "data_block_0_2.hh" |
| 41 | #include "data_block_0_3.hh" |
| 42 | #include "data_block_0_4.hh" |
| 43 | #include "data_block_0_10.hh" |
| 44 | #include "data_block_0_14.hh" |
| 45 | #include "data_block_0_24.hh" |
| 46 | #include "data_block_0_44.hh" |
| 47 | #include "data_block_0_30.hh" |
| 48 | #include "data_block_0_54.hh" |
| 49 | #include "data_block_0_60.hh" |
| 50 | #include "data_block_0_50.hh" |
| 51 | #include "data_block_0_64.hh" |
| 52 | #include "data_block_1.hh" |
| 53 | #include "data_block_2.hh" |
| 54 | #include "data_block_3.hh" |
| 55 | #include "data_block_4.hh" |
| 56 | #include "data_block_5.hh" |
| 57 | #include "data_block_6.hh" |
| 58 | #include "data_block_7.hh" |
| 59 | |
| 60 | using namespace std; |
| 61 | |
| 62 | /***************************************************************/ |
| 63 | /*! |
| 64 | *\brief Destructor. |
| 65 | */ |
| 66 | tape_block::~tape_block(){ |
| 67 | free(raw_data); |
| 68 | free(word_data); |
| 69 | } |
| 70 | |
| 71 | /***************************************************************/ |
| 72 | /*! |
| 73 | *\brief Copy constructor. |
| 74 | */ |
| 75 | tape_block::tape_block(tape_block & org){ |
| 76 | operator=(org); |
| 77 | } |
| 78 | |
| 79 | /***************************************************************/ |
| 80 | /*! |
| 81 | *\brief Assignment operator. |
| 82 | */ |
| 83 | void tape_block::operator=(tape_block &org){ |
| 84 | block_type=org.block_type; |
| 85 | discarded_bytes=org.discarded_bytes; |
| 86 | raw_data=0; |
| 87 | raw_size=org.raw_size; |
| 88 | word_data=0; |
| 89 | word_size=org.word_size; |
| 90 | if (raw_size){ |
| 91 | raw_data=(unsigned char *)malloc(raw_size); |
| 92 | memcpy(raw_data,org.raw_data,raw_size); |
| 93 | } |
| 94 | if (word_size){ |
| 95 | word_data=(unsigned short *)malloc(word_size*sizeof(unsigned short)); |
| 96 | memcpy(word_data,org.word_data,word_size*sizeof(unsigned short)); |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | /***************************************************************/ |
| 101 | /*! |
| 102 | *\brief Determine the block's type |
| 103 | * |
| 104 | * This routine returns the block's type.\\ |
| 105 | *\retval TBT_DATA if it's a data block |
| 106 | *\retval TBT_EOT if it's an end of tape mark |
| 107 | * |
| 108 | *\note This function is virtual. That means that if the tape block in |
| 109 | * question is of the subtype data_block which overwrites this method, |
| 110 | * it will return the block type contained in the upper 4 bits of the |
| 111 | * first data word! Try to avoid testing for TBT_DATA. \n |
| 112 | * Blocks generated by gen_from_fd should never have TBT_DATA. |
| 113 | */ |
| 114 | int tape_block::get_type(){ |
| 115 | return block_type; |
| 116 | } |
| 117 | |
| 118 | /***************************************************************/ |
| 119 | /*! |
| 120 | *\brief Determine the block's subtype |
| 121 | * |
| 122 | * Some data block types have a subtype. |
| 123 | *\note This is a virtual method and to be used in derived classes. |
| 124 | *\return Always 0 |
| 125 | */ |
| 126 | int tape_block::get_subtype(){ |
| 127 | return 0; |
| 128 | } |
| 129 | |
| 130 | /***************************************************************/ |
| 131 | /*! |
| 132 | *\brief Get a cleartext description of the block. |
| 133 | *\return ldc style descriptive line for the block |
| 134 | */ |
| 135 | vector<string> tape_block:: get_description(){ |
| 136 | vector<string> result; |
| 137 | result.insert(result.end(), |
| 138 | "***** "+get_typestring()+"Untyped tape block"); |
| 139 | return result; |
| 140 | } |
| 141 | |
| 142 | /***************************************************************/ |
| 143 | /*! |
| 144 | *\brief Get size of the internal raw data buffer |
| 145 | *\return The size of the internal raw data buffer |
| 146 | */ |
| 147 | int tape_block::get_raw_size(){ |
| 148 | return raw_size; |
| 149 | } |
| 150 | |
| 151 | /***************************************************************/ |
| 152 | /*! |
| 153 | *\brief Get amount of bytes discarded before beginning |
| 154 | * of block sensed. |
| 155 | *\return Length of unusable tape before block start delimiter. |
| 156 | */ |
| 157 | int tape_block::get_discarded_bytes(){ |
| 158 | return discarded_bytes; |
| 159 | } |
| 160 | |
| 161 | /***************************************************************/ |
| 162 | /*! |
| 163 | *\brief Access internal raw data buffer |
| 164 | * |
| 165 | * The raw data buffer contains all block data except the |
| 166 | * block start and end delimiters. |
| 167 | *\return Pointer to internal raw data buffer of the block |
| 168 | */ |
| 169 | unsigned char * tape_block::get_raw_data(){ |
| 170 | return raw_data; |
| 171 | } |
| 172 | |
| 173 | /***************************************************************/ |
| 174 | /*! |
| 175 | *\brief Dump contents of the block to a file descriptor. |
| 176 | * |
| 177 | *\param fd A writable file descriptor. |
| 178 | *\return Always zero. |
| 179 | *\throw io_error_exception A write error occured. |
| 180 | */ |
| 181 | int tape_block::dump_to_fd(int fd){ |
| 182 | int to_write=raw_size; |
| 183 | unsigned char * dump_ptr=raw_data; |
| 184 | int written; |
| 185 | while (to_write) { |
| 186 | written=write(fd,dump_ptr,to_write); |
| 187 | if (written < 0) throw io_error_exception(); |
| 188 | to_write-=written; |
| 189 | dump_ptr+=written; |
| 190 | } |
| 191 | return 0; |
| 192 | } |
| 193 | |
| 194 | /***************************************************************/ |
| 195 | /*! |
| 196 | *\brief Determine if the block marks the end of an object |
| 197 | *\retval true The block marks the end of an object. |
| 198 | *\retval false The block does not mark the end of an object. |
| 199 | *\note This is only a virtual method returning always false. |
| 200 | * Classes which can be the legal last block of an object |
| 201 | * will overwrite this method so that it returns true. |
| 202 | */ |
| 203 | bool tape_block::is_endblock(){ |
| 204 | return false; |
| 205 | } |
| 206 | |
| 207 | /***************************************************************/ |
| 208 | /*! |
| 209 | *\brief Get exported symbols. |
| 210 | *\return A vector containing any symbols exported in this block. |
| 211 | *\note This is only a virtual method returning always an empty |
| 212 | * vector. Classes describing appropriate data blocks |
| 213 | * will override this method. |
| 214 | */ |
| 215 | vector<string> tape_block::get_exported_symbols(){ |
| 216 | vector<string> result; |
| 217 | return result; |
| 218 | } |
| 219 | |
| 220 | /***************************************************************/ |
| 221 | /*! |
| 222 | *\brief Get called symbols. |
| 223 | *\return A vector containing any symbols called in this block. |
| 224 | *\note This is only a virtual method returning always an empty |
| 225 | * vector. Classes describing appropriate data blocks |
| 226 | * will override this method. |
| 227 | */ |
| 228 | vector<string> tape_block::get_called_symbols(){ |
| 229 | vector<string> result; |
| 230 | return result; |
| 231 | } |
| 232 | |
| 233 | /***************************************************************/ |
| 234 | /*! |
| 235 | *\brief Dump block contents |
| 236 | *\return A vector containing Information about the block's |
| 237 | * content. |
| 238 | */ |
| 239 | vector<string> tape_block::dump_contents(){ |
| 240 | vector<string> result; |
| 241 | result.insert(result.end(),"No known contents."); |
| 242 | return result; |
| 243 | } |
| 244 | |
| 245 | /***************************************************************/ |
| 246 | /*! |
| 247 | *\brief Determine if the block has a known type. |
| 248 | *\return true if type and subtype are known. |
| 249 | *\return false if the block type is not one of the valid end |
| 250 | * nodes of the type tree. |
| 251 | */ |
| 252 | bool tape_block::has_known_type(){ |
| 253 | return m_has_known_type; |
| 254 | } |
| 255 | |
| 256 | /***************************************************************/ |
| 257 | /*! |
| 258 | *\brief Static factory method for tape blocks. |
| 259 | * |
| 260 | * This method creates a tape_block by using the private |
| 261 | * constructor with file descriptor support.\n |
| 262 | * |
| 263 | * The factory method tries to determine the block's type and then |
| 264 | * looks for appropriate subclasses. If there's an appropriate |
| 265 | * subclass fitting the newly-created object, an |
| 266 | * object of the subclass will be created and a pointer to this |
| 267 | * object will be returned to the caller.\n |
| 268 | * This allows for easy use of the object using it's virtual |
| 269 | * interface methods or a cast of the pointer to a sub type pointer |
| 270 | * according to the type information, and then using the subtype's |
| 271 | * methods not already present in tape_block.\n |
| 272 | * Objects of the following subclasses are automagically generated:\n |
| 273 | * - eot_block |
| 274 | * - data_block |
| 275 | * - data_block_0 |
| 276 | * - data_block_0_0 |
| 277 | * - data_block_0_1 |
| 278 | * - data_block_0_2 |
| 279 | * - data_block_0_3 |
| 280 | * - data_block_0_4 |
| 281 | * - data_block_0_10 |
| 282 | * - data_block_0_14 |
| 283 | * - data_block_0_24 |
| 284 | * - data_block_0_30 |
| 285 | * - data_block_0_50 |
| 286 | * - data_block_0_54 |
| 287 | * - data_block_0_60 |
| 288 | * - data_block_0_64 |
| 289 | * - data_block_1 |
| 290 | * - data_block_2 |
| 291 | * - data_block_3 |
| 292 | * - data_block_4 |
| 293 | * - data_block_5 |
| 294 | * - data_block_6 |
| 295 | * - data_block_7 |
| 296 | * |
| 297 | *\return Pointer to an instance of tape_block or a subclass. |
| 298 | *\param fd A file descriptor where data can be read from. |
| 299 | *\param input_start A pointer to a function |
| 300 | * called before reading data from fd. |
| 301 | *\param input_stop A pointer to a function |
| 302 | * called after reading data from fd. |
| 303 | * |
| 304 | *\param start_stop_arg A pointer passed to input_start |
| 305 | * and input_stop(). Can be anything. |
| 306 | */ |
| 307 | tape_block * tape_block::gen_from_fd(int fd, |
| 308 | void(*input_start)(void *), |
| 309 | void (*input_stop)(void *), |
| 310 | void * start_stop_arg) |
| 311 | { |
| 312 | tape_block * n_tape_block=0; |
| 313 | data_block * n_data_block=0; |
| 314 | data_block * n_data_block_x=0; |
| 315 | data_block_0 * n_data_block_0=0; |
| 316 | data_block_0 * n_data_block_0_x=0; |
| 317 | eot_block * n_eot_block=0; |
| 318 | broken_block * n_broken_block=0; |
| 319 | |
| 320 | //Use the private constructor which reads in the block from a file descriptor |
| 321 | try{ |
| 322 | n_tape_block=new tape_block(fd,input_start,input_stop,start_stop_arg); |
| 323 | } |
| 324 | |
| 325 | catch(checksum_error_exception e){ |
| 326 | n_broken_block=new broken_block(*(e.get_block())); |
| 327 | delete e.get_block(); |
| 328 | throw checksum_error_exception(n_broken_block); |
| 329 | } |
| 330 | |
| 331 | // Retype to data_block, eot_block - if possible |
| 332 | switch(n_tape_block->get_type()){ |
| 333 | case tape_block::TBT_DATA: |
| 334 | n_data_block = new data_block(*n_tape_block); |
| 335 | break; |
| 336 | case tape_block::TBT_EOT: |
| 337 | n_eot_block=new eot_block(*n_tape_block); |
| 338 | delete n_tape_block; |
| 339 | n_eot_block->m_has_known_type=true; |
| 340 | return n_eot_block; |
| 341 | default: // Unknown block, a bad thing! |
| 342 | return n_tape_block; |
| 343 | } |
| 344 | delete n_tape_block; |
| 345 | |
| 346 | // Now only data blocks are left |
| 347 | |
| 348 | switch(n_data_block->get_type()){ |
| 349 | case 00: n_data_block_0=new data_block_0(*n_data_block); break; |
| 350 | case 01: n_data_block_x=new data_block_1(*n_data_block); break; |
| 351 | case 02: n_data_block_x=new data_block_2(*n_data_block); break; |
| 352 | case 03: n_data_block_x=new data_block_3(*n_data_block); break; |
| 353 | case 04: n_data_block_x=new data_block_4(*n_data_block); break; |
| 354 | case 05: n_data_block_x=new data_block_5(*n_data_block); break; |
| 355 | case 06: n_data_block_x=new data_block_6(*n_data_block); break; |
| 356 | case 07: n_data_block_x=new data_block_7(*n_data_block); break; |
| 357 | default: |
| 358 | return n_data_block; |
| 359 | } |
| 360 | if (n_data_block_0==0){ // So we must have found another one |
| 361 | delete n_data_block; |
| 362 | n_data_block_x->m_has_known_type=true; |
| 363 | return n_data_block_x; |
| 364 | } |
| 365 | |
| 366 | // Here only type 0 left |
| 367 | switch(n_data_block_0->get_subtype()){ |
| 368 | case 000: n_data_block_0_x=new data_block_0_0(*n_data_block_0); break; |
| 369 | case 001: n_data_block_0_x=new data_block_0_1(*n_data_block_0); break; |
| 370 | case 002: n_data_block_0_x=new data_block_0_2(*n_data_block_0); break; |
| 371 | case 003: n_data_block_0_x=new data_block_0_3(*n_data_block_0); break; |
| 372 | case 004: n_data_block_0_x=new data_block_0_4(*n_data_block_0); break; |
| 373 | case 010: n_data_block_0_x=new data_block_0_10(*n_data_block_0); break; |
| 374 | case 014: n_data_block_0_x=new data_block_0_14(*n_data_block_0); break; |
| 375 | case 024: n_data_block_0_x=new data_block_0_24(*n_data_block_0); break; |
| 376 | case 044: n_data_block_0_x=new data_block_0_44(*n_data_block_0); break; |
| 377 | case 030: n_data_block_0_x=new data_block_0_30(*n_data_block_0); break; |
| 378 | case 054: n_data_block_0_x=new data_block_0_54(*n_data_block_0); break; |
| 379 | case 060: n_data_block_0_x=new data_block_0_60(*n_data_block_0); break; |
| 380 | case 064: n_data_block_0_x=new data_block_0_64(*n_data_block_0); break; |
| 381 | case 050: n_data_block_0_x=new data_block_0_50(*n_data_block_0); break; |
| 382 | default: |
| 383 | return n_data_block_0; |
| 384 | } |
| 385 | delete n_data_block_0; |
| 386 | n_data_block_0_x->m_has_known_type=true; |
| 387 | return n_data_block_0_x; |
| 388 | } |
| 389 | |
| 390 | /***************************************************************/ |
| 391 | /*! |
| 392 | *\brief Default constructor. |
| 393 | */ |
| 394 | tape_block::tape_block(){} |
| 395 | |
| 396 | /***************************************************************/ |
| 397 | /*! |
| 398 | *\brief get a short type description string. |
| 399 | *\return A small string to be used in description methods. |
| 400 | * |
| 401 | * The string is always 19 characters long.\n |
| 402 | * An example is "(99-99) ". |
| 403 | */ |
| 404 | string tape_block::get_typestring(){ |
| 405 | char buffer[13]; |
| 406 | sprintf(buffer,"(%o-%o) ",get_type(),get_subtype()); |
| 407 | buffer[10]=0; |
| 408 | return string(buffer); |
| 409 | } |
| 410 | |
| 411 | /***************************************************************/ |
| 412 | /*! |
| 413 | *\brief Automatic constructor with file descriptor support |
| 414 | * |
| 415 | * This constructor is used to initialise the block read in the |
| 416 | * block's data via a file descriptor.\n |
| 417 | * This is done in the following way: |
| 418 | * - input_start() is called. |
| 419 | * - Data is read from fd. Stops on end of file or end of block |
| 420 | * or IO error. On EOF or IO error input_stop() is NOT called. |
| 421 | * - If there was no IO error the block's checksum is calculated |
| 422 | * and checked. |
| 423 | * - The block's type field is initialised. |
| 424 | * - input_stop() is called. |
| 425 | * |
| 426 | *\param fd A file descriptor where the read is taken from |
| 427 | *\param input_stop A pointer to a function called at the end of input |
| 428 | *\param input_start A pointer to a function called at the beginning |
| 429 | * of input |
| 430 | *\param start_stop_arg A pointer passed to input_start and input_stop(). |
| 431 | */ |
| 432 | tape_block::tape_block (int fd, |
| 433 | void(*input_start)(void *), |
| 434 | void (*input_stop)(void *), |
| 435 | void * start_stop_arg |
| 436 | ) |
| 437 | { |
| 438 | unsigned char buffer; |
| 439 | int retval; |
| 440 | int eot_needed=EOT_LENGTH; |
| 441 | int eob_needed=EOB_LENGTH; |
| 442 | int block_complete=0; |
| 443 | |
| 444 | block_type= TBT_BROKEN; |
| 445 | discarded_bytes=0; |
| 446 | raw_data = 0; |
| 447 | raw_size = 0; |
| 448 | word_data = 0; |
| 449 | word_size = 0; |
| 450 | poolsize = 1024; |
| 451 | |
| 452 | // Get initial portion of memory |
| 453 | raw_data=(unsigned char*)malloc(poolsize); |
| 454 | |
| 455 | if (input_start) input_start (start_stop_arg); |
| 456 | |
| 457 | /* Look for block start in input stream */ |
| 458 | do { |
| 459 | retval=read(fd, &buffer, 1); |
| 460 | if (retval == 0){ // End of file |
| 461 | free(raw_data); |
| 462 | throw eof_legal_exception(discarded_bytes); |
| 463 | return; |
| 464 | } |
| 465 | if (retval == -1){ // Error reading from fd |
| 466 | free(raw_data); |
| 467 | throw io_error_exception(); |
| 468 | return; |
| 469 | } |
| 470 | discarded_bytes++; |
| 471 | |
| 472 | /* Look for end ot tape sequence */ |
| 473 | switch(eot_needed){ |
| 474 | case 3: |
| 475 | if (buffer==EOT_SEQ_1) eot_needed--; |
| 476 | else eot_needed=EOT_LENGTH; |
| 477 | break; |
| 478 | case 2: |
| 479 | if (buffer==EOT_SEQ_2) eot_needed--; |
| 480 | else eot_needed=EOT_LENGTH; |
| 481 | break; |
| 482 | case 1: |
| 483 | if (buffer==EOT_SEQ_3){ |
| 484 | raw_data=(unsigned char*)realloc(raw_data,3); |
| 485 | raw_size=3; |
| 486 | discarded_bytes-=3; |
| 487 | raw_data[0]=EOT_SEQ_1; |
| 488 | raw_data[1]=EOT_SEQ_2; |
| 489 | raw_data[2]=EOT_SEQ_3; |
| 490 | block_type =TBT_EOT; |
| 491 | return; |
| 492 | } |
| 493 | else eot_needed=EOT_LENGTH; |
| 494 | break; |
| 495 | } |
| 496 | } while (buffer != (unsigned char) BLOCK_START_DELIMITER); |
| 497 | discarded_bytes--; // Don't want to declare the start delimiter discarded! |
| 498 | raw_size=1; // But we want to account it here! |
| 499 | |
| 500 | /* Now input the block data */ |
| 501 | block_complete = 0; |
| 502 | |
| 503 | raw_data[0]=buffer; // Put the start delimiter in! |
| 504 | |
| 505 | do { |
| 506 | retval = read (fd, &buffer, 1); |
| 507 | |
| 508 | if (retval == 0){ // End of file |
| 509 | broken_block * b_block=new broken_block(*this); |
| 510 | free(raw_data); |
| 511 | throw eof_illegal_exception(b_block); |
| 512 | } |
| 513 | if (retval == -1){ // Error reading from fd |
| 514 | free(raw_data); |
| 515 | throw io_error_exception(); |
| 516 | } |
| 517 | |
| 518 | /* sort in the new byte */ |
| 519 | raw_size++; |
| 520 | // Need more memory?? |
| 521 | if (raw_size>poolsize){ |
| 522 | poolsize+=1024; |
| 523 | raw_data=(unsigned char*)realloc(raw_data,poolsize); |
| 524 | } |
| 525 | |
| 526 | raw_data[raw_size-1]=buffer; |
| 527 | |
| 528 | /* Look for end ot block sequence */ |
| 529 | switch(eob_needed){ |
| 530 | case 2: |
| 531 | if (buffer==BLOCK_END_DELIMITER_1) eob_needed--; |
| 532 | else eob_needed=EOB_LENGTH; |
| 533 | break; |
| 534 | case 1: |
| 535 | if (buffer==BLOCK_END_DELIMITER_2){ |
| 536 | block_complete=1; |
| 537 | } |
| 538 | else eob_needed=EOB_LENGTH; |
| 539 | break; |
| 540 | } |
| 541 | }while (!block_complete); |
| 542 | |
| 543 | if (input_stop) input_stop (start_stop_arg); |
| 544 | |
| 545 | |
| 546 | /* Now we have the data in. */ |
| 547 | |
| 548 | if (init_words()!=0){ |
| 549 | broken_block * b_block=new broken_block(*this); |
| 550 | free(raw_data); |
| 551 | free(word_data); |
| 552 | throw checksum_error_exception(b_block); |
| 553 | } |
| 554 | |
| 555 | if (test_checksum()!=0){ |
| 556 | broken_block * b_block=new broken_block(*this); |
| 557 | free(raw_data); |
| 558 | free(word_data); |
| 559 | throw checksum_error_exception(b_block); |
| 560 | } |
| 561 | block_type=TBT_DATA; |
| 562 | } |
| 563 | |
| 564 | |
| 565 | /***************************************************************/ |
| 566 | /*! |
| 567 | *\brief Initialize word representation of data. |
| 568 | *\retval 0 on success. |
| 569 | *\retval 1 on error. |
| 570 | */ |
| 571 | int tape_block::init_words(){ |
| 572 | word_size=(raw_size-EOB_LENGTH-1)/3; |
| 573 | if (word_size<MINIMUM_DATA_BLOCK_WORDSIZE) return 1; // Block too short! |
| 574 | word_data=(unsigned short *)malloc(word_size*sizeof(unsigned short)); |
| 575 | for (int pos=0; pos<word_size; pos++) |
| 576 | word_data[pos]=combine466(raw_data+1+3*pos); |
| 577 | return 0; |
| 578 | } |
| 579 | |
| 580 | /***************************************************************/ |
| 581 | /*! |
| 582 | *\brief Calculate and check checksum. |
| 583 | *\retval 0 on success. |
| 584 | *\retval 1 on error. |
| 585 | */ |
| 586 | int tape_block::test_checksum(){ |
| 587 | unsigned short sum=0; |
| 588 | for (int pos=0; pos<word_size-1;pos++) |
| 589 | sum^=word_data[pos]; |
| 590 | if (sum==word_data[word_size-1]) return 0; |
| 591 | else return 1; |
| 592 | } |
| 593 | |
| 594 | /***************************************************************/ |
| 595 | /*! |
| 596 | *\brief Standard constructor of exception base class. |
| 597 | */ |
| 598 | tape_block::exception::exception(){ |
| 599 | } |
| 600 | |
| 601 | /***************************************************************/ |
| 602 | /*! |
| 603 | *\brief Standard desctructor. |
| 604 | */ |
| 605 | tape_block::exception::~exception(){ |
| 606 | } |
| 607 | |
| 608 | /***************************************************************/ |
| 609 | /*! |
| 610 | *\brief Get pointer to erroneous tape_block |
| 611 | *\return A pointer to a tape_block instance. |
| 612 | *\note The user has to take care to free the instance contained |
| 613 | * in objects of classes supporting this method. |
| 614 | */ |
| 615 | tape_block * tape_block::exception::get_block(){ |
| 616 | return m_broken_block; |
| 617 | } |
| 618 | |
| 619 | /***************************************************************/ |
| 620 | /*! |
| 621 | *\brief Constructor |
| 622 | */ |
| 623 | tape_block::checksum_error_exception:: |
| 624 | checksum_error_exception (tape_block * broken_block){ |
| 625 | this->m_broken_block=broken_block; |
| 626 | } |
| 627 | |
| 628 | /***************************************************************/ |
| 629 | /*! |
| 630 | *\brief Constructor |
| 631 | */ |
| 632 | tape_block::eof_illegal_exception:: |
| 633 | eof_illegal_exception (tape_block * broken_block){ |
| 634 | this->m_broken_block=broken_block; |
| 635 | } |
| 636 | |
| 637 | /***************************************************************/ |
| 638 | /*! |
| 639 | *\brief Constructor |
| 640 | *\param bytes_consumed Amount of bytes read while looking |
| 641 | * for a block. |
| 642 | */ |
| 643 | tape_block::eof_legal_exception:: |
| 644 | eof_legal_exception(int bytes_consumed){ |
| 645 | this->m_broken_block=NULL; |
| 646 | this->bytes_consumed=bytes_consumed; |
| 647 | } |
| 648 | |
| 649 | /***************************************************************/ |
| 650 | /*! |
| 651 | *\brief Get amount of consumed data before EOF came along. |
| 652 | *\return Amount of bytes read from fd while looking for |
| 653 | * new block or EOF. |
| 654 | */ |
| 655 | int tape_block::eof_legal_exception::get_consumed(){ |
| 656 | return bytes_consumed; |
| 657 | } |
| 658 | |
| 659 | /***************************************************************/ |
| 660 | /*! |
| 661 | *\brief Constructor |
| 662 | */ |
| 663 | tape_block::io_error_exception:: |
| 664 | io_error_exception(){ |
| 665 | this->m_broken_block=NULL; |
| 666 | } |
| 667 | |
| 668 | |
| 669 | |
| 670 | |
| 671 | |
| 672 | |