4741aa72 |
1 | /****************************************************************************** |
2 | * |
3 | * LDC2 source code |
4 | * |
8dc281af |
5 | * $Date: 2007/12/23 15:25:11 $ |
4741aa72 |
6 | * $Author: hachti $ |
7 | * |
8 | * $Log: tape_block.cpp,v $ |
8dc281af |
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 |
d65ad4d7 |
13 | * *** empty log message *** |
14 | * |
15 | * Revision 2.0 2007-03-26 01:00:40 hachti |
4741aa72 |
16 | * *** empty log message *** |
17 | * |
18 | * |
19 | ******************************************************************************/ |
7880ae2d |
20 | |
21 | #include <string> |
22 | #include <vector> |
23 | |
97b26985 |
24 | #include <stdlib.h> |
25 | #include <unistd.h> |
26 | #include <string.h> |
09cb0f4f |
27 | #include <stdio.h> |
6c06db96 |
28 | |
97b26985 |
29 | #include "tape_block.hh" |
7880ae2d |
30 | |
31 | #include "silent_code.hh" |
32 | #include "hw_constants.hh" |
33 | |
34 | #include "eot_block.hh" |
97b26985 |
35 | #include "data_block.hh" |
7880ae2d |
36 | #include "broken_block.hh" |
0ec6e042 |
37 | #include "data_block_0.hh" |
09cb0f4f |
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" |
fd9632c0 |
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" |
97b26985 |
59 | |
6c06db96 |
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; |
fed2c751 |
85 | discarded_bytes=org.discarded_bytes; |
6c06db96 |
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 | |
6c06db96 |
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 |
6c06db96 |
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(){ |
6c06db96 |
136 | vector<string> result; |
09cb0f4f |
137 | result.insert(result.end(), |
138 | "***** "+get_typestring()+"Untyped tape block"); |
6c06db96 |
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 | |
fed2c751 |
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 | |
6c06db96 |
161 | /***************************************************************/ |
162 | /*! |
163 | *\brief Access internal raw data buffer |
164 | * |
d65ad4d7 |
165 | * The raw data buffer contains all block data except the |
166 | * block start and end delimiters. |
6c06db96 |
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 | |
874a2bd8 |
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 | |
8dc281af |
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 | |
874a2bd8 |
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 | |
6c06db96 |
256 | /***************************************************************/ |
257 | /*! |
7880ae2d |
258 | *\brief Static factory method for tape blocks. |
6c06db96 |
259 | * |
260 | * This method creates a tape_block by using the private |
09cb0f4f |
261 | * constructor with file descriptor support.\n |
7880ae2d |
262 | * |
6c06db96 |
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 |
09cb0f4f |
271 | * methods not already present in tape_block.\n |
272 | * Objects of the following subclasses are automagically generated:\n |
6c06db96 |
273 | * - eot_block |
274 | * - data_block |
09cb0f4f |
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 |
fd9632c0 |
288 | * - data_block_0_64 |
09cb0f4f |
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 |
6c06db96 |
296 | * |
7880ae2d |
297 | *\return Pointer to an instance of tape_block or a subclass. |
298 | *\param fd A file descriptor where data can be read from. |
6c06db96 |
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 | */ |
0ec6e042 |
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) |
97b26985 |
311 | { |
fd9632c0 |
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; |
7880ae2d |
318 | broken_block * n_broken_block=0; |
319 | |
50c86ded |
320 | //Use the private constructor which reads in the block from a file descriptor |
7880ae2d |
321 | try{ |
fd9632c0 |
322 | n_tape_block=new tape_block(fd,input_start,input_stop,start_stop_arg); |
7880ae2d |
323 | } |
fd9632c0 |
324 | |
7880ae2d |
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 |
fd9632c0 |
332 | switch(n_tape_block->get_type()){ |
333 | case tape_block::TBT_DATA: |
334 | n_data_block = new data_block(*n_tape_block); |
0ec6e042 |
335 | break; |
09cb0f4f |
336 | case tape_block::TBT_EOT: |
fd9632c0 |
337 | n_eot_block=new eot_block(*n_tape_block); |
338 | delete n_tape_block; |
874a2bd8 |
339 | n_eot_block->m_has_known_type=true; |
fd9632c0 |
340 | return n_eot_block; |
50c86ded |
341 | default: // Unknown block, a bad thing! |
342 | return n_tape_block; |
0ec6e042 |
343 | } |
fd9632c0 |
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; |
0ec6e042 |
357 | default: |
fd9632c0 |
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; |
874a2bd8 |
362 | n_data_block_x->m_has_known_type=true; |
fd9632c0 |
363 | return n_data_block_x; |
0ec6e042 |
364 | } |
0ec6e042 |
365 | |
fd9632c0 |
366 | // Here only type 0 left |
fd9632c0 |
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; |
de6b6757 |
372 | case 004: n_data_block_0_x=new data_block_0_4(*n_data_block_0); break; |
fd9632c0 |
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; |
0ec6e042 |
382 | default: |
fd9632c0 |
383 | return n_data_block_0; |
0ec6e042 |
384 | } |
fd9632c0 |
385 | delete n_data_block_0; |
874a2bd8 |
386 | n_data_block_0_x->m_has_known_type=true; |
fd9632c0 |
387 | return n_data_block_0_x; |
97b26985 |
388 | } |
389 | |
6c06db96 |
390 | /***************************************************************/ |
0ec6e042 |
391 | /*! |
392 | *\brief Default constructor. |
393 | */ |
394 | tape_block::tape_block(){} |
395 | |
09cb0f4f |
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 | } |
0ec6e042 |
410 | |
6c06db96 |
411 | /***************************************************************/ |
0ec6e042 |
412 | /*! |
413 | *\brief Automatic constructor with file descriptor support |
414 | * |
7880ae2d |
415 | * This constructor is used to initialise the block read in the |
416 | * block's data via a file descriptor.\n |
0ec6e042 |
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 | */ |
97b26985 |
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 | |
7880ae2d |
444 | block_type= TBT_BROKEN; |
fed2c751 |
445 | discarded_bytes=0; |
97b26985 |
446 | raw_data = 0; |
447 | raw_size = 0; |
448 | word_data = 0; |
449 | word_size = 0; |
fed2c751 |
450 | poolsize = 1024; |
451 | |
452 | // Get initial portion of memory |
453 | raw_data=(unsigned char*)malloc(poolsize); |
454 | |
97b26985 |
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 |
7880ae2d |
461 | free(raw_data); |
462 | throw eof_legal_exception(discarded_bytes); |
97b26985 |
463 | return; |
464 | } |
465 | if (retval == -1){ // Error reading from fd |
7880ae2d |
466 | free(raw_data); |
467 | throw io_error_exception(); |
97b26985 |
468 | return; |
469 | } |
fed2c751 |
470 | discarded_bytes++; |
97b26985 |
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){ |
7880ae2d |
484 | raw_data=(unsigned char*)realloc(raw_data,3); |
97b26985 |
485 | raw_size=3; |
fed2c751 |
486 | discarded_bytes-=3; |
97b26985 |
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; |
97b26985 |
491 | return; |
492 | } |
493 | else eot_needed=EOT_LENGTH; |
494 | break; |
495 | } |
496 | } while (buffer != (unsigned char) BLOCK_START_DELIMITER); |
874a2bd8 |
497 | discarded_bytes--; // Don't want to declare the start delimiter discarded! |
fed2c751 |
498 | raw_size=1; // But we want to account it here! |
874a2bd8 |
499 | |
97b26985 |
500 | /* Now input the block data */ |
501 | block_complete = 0; |
874a2bd8 |
502 | |
503 | raw_data[0]=buffer; // Put the start delimiter in! |
504 | |
97b26985 |
505 | do { |
506 | retval = read (fd, &buffer, 1); |
507 | |
508 | if (retval == 0){ // End of file |
7880ae2d |
509 | broken_block * b_block=new broken_block(*this); |
510 | free(raw_data); |
511 | throw eof_illegal_exception(b_block); |
97b26985 |
512 | } |
513 | if (retval == -1){ // Error reading from fd |
7880ae2d |
514 | free(raw_data); |
515 | throw io_error_exception(); |
97b26985 |
516 | } |
97b26985 |
517 | |
518 | /* sort in the new byte */ |
519 | raw_size++; |
fed2c751 |
520 | // Need more memory?? |
874a2bd8 |
521 | if (raw_size>poolsize){ |
fed2c751 |
522 | poolsize+=1024; |
523 | raw_data=(unsigned char*)realloc(raw_data,poolsize); |
524 | } |
525 | |
874a2bd8 |
526 | raw_data[raw_size-1]=buffer; |
97b26985 |
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){ |
97b26985 |
536 | block_complete=1; |
537 | } |
538 | else eob_needed=EOB_LENGTH; |
539 | break; |
540 | } |
541 | }while (!block_complete); |
7880ae2d |
542 | |
97b26985 |
543 | if (input_stop) input_stop (start_stop_arg); |
544 | |
7880ae2d |
545 | |
97b26985 |
546 | /* Now we have the data in. */ |
547 | |
548 | if (init_words()!=0){ |
7880ae2d |
549 | broken_block * b_block=new broken_block(*this); |
550 | free(raw_data); |
551 | free(word_data); |
552 | throw checksum_error_exception(b_block); |
97b26985 |
553 | } |
7880ae2d |
554 | |
97b26985 |
555 | if (test_checksum()!=0){ |
7880ae2d |
556 | broken_block * b_block=new broken_block(*this); |
557 | free(raw_data); |
558 | free(word_data); |
559 | throw checksum_error_exception(b_block); |
97b26985 |
560 | } |
97b26985 |
561 | block_type=TBT_DATA; |
97b26985 |
562 | } |
563 | |
97b26985 |
564 | |
6c06db96 |
565 | /***************************************************************/ |
0ec6e042 |
566 | /*! |
6c06db96 |
567 | *\brief Initialize word representation of data. |
568 | *\retval 0 on success. |
569 | *\retval 1 on error. |
0ec6e042 |
570 | */ |
97b26985 |
571 | int tape_block::init_words(){ |
874a2bd8 |
572 | word_size=(raw_size-EOB_LENGTH-1)/3; |
97b26985 |
573 | if (word_size<MINIMUM_DATA_BLOCK_WORDSIZE) return 1; // Block too short! |
7880ae2d |
574 | word_data=(unsigned short *)malloc(word_size*sizeof(unsigned short)); |
97b26985 |
575 | for (int pos=0; pos<word_size; pos++) |
874a2bd8 |
576 | word_data[pos]=combine466(raw_data+1+3*pos); |
97b26985 |
577 | return 0; |
578 | } |
579 | |
6c06db96 |
580 | /***************************************************************/ |
0ec6e042 |
581 | /*! |
6c06db96 |
582 | *\brief Calculate and check checksum. |
583 | *\retval 0 on success. |
584 | *\retval 1 on error. |
0ec6e042 |
585 | */ |
97b26985 |
586 | int tape_block::test_checksum(){ |
587 | unsigned short sum=0; |
588 | for (int pos=0; pos<word_size-1;pos++) |
0ec6e042 |
589 | sum^=word_data[pos]; |
97b26985 |
590 | if (sum==word_data[word_size-1]) return 0; |
591 | else return 1; |
592 | } |
6c06db96 |
593 | |
7880ae2d |
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. |
d65ad4d7 |
652 | *\return Amount of bytes read from fd while looking for |
7880ae2d |
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 | |