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5580185e | 1 | /* |
2 | * $Source$ | |
3 | * $Header$ | |
4 | */ | |
5 | ||
6 | #ifndef lint | |
7 | static char *rcsid_gdb_db_c = "$Header$"; | |
8 | #endif lint | |
9 | ||
10 | /************************************************************************/ | |
11 | /* | |
12 | /* gdb_db.c | |
13 | /* | |
14 | /* Authors: Susan Ryan and Noah Mendelsohn | |
15 | /* | |
16 | /* Copyright: 1986 MIT Project Athena | |
0a5ff702 | 17 | /* For copying and distribution information, please see |
18 | /* the file <mit-copyright.h>. | |
5580185e | 19 | /* |
20 | /************************************************************************/ | |
21 | ||
0a5ff702 | 22 | #include <mit-copyright.h> |
5580185e | 23 | #include <stdio.h> |
f4c08abd | 24 | #include <string.h> |
5580185e | 25 | #include "gdb.h" |
26 | ||
27 | ||
28 | ||
29 | \f/************************************************************************/ | |
30 | /* | |
31 | /* start_accessing_db (start_accessing_db) | |
32 | /* | |
33 | /* 1) Creates a new db structure to describe the database. | |
34 | /* | |
35 | /* 2) Parses the supplied db_ident into a server and a db name | |
36 | /* | |
37 | /* 3) Opens a connection to the server, sending the name of the | |
38 | /* database as an argument | |
39 | /* | |
40 | /* 4) Asynchronously receives a return code from the server | |
41 | /* to indicate whether the database could be accessed | |
42 | /* | |
43 | /* 5) If successful, the handle on the new structure is placed into | |
44 | /* the variable supplied by the caller. Otherwise, the structure | |
45 | /* is de_allocated and failure status is returned to the caller. | |
46 | /* | |
47 | /* Note: this code was adapted from an earlier synchronous | |
48 | /* implementation and there may yet be some loose ends. | |
49 | /* | |
50 | /************************************************************************/ | |
51 | ||
52 | #define MIN_NAME_LEN 1 /*completely arbitrary */ | |
53 | #define FAILURE NULL /*until we decide what it should really be */ | |
54 | /*note if fails returns NULL for the db_handle value*/ | |
55 | /*as per above */ | |
56 | ||
57 | DATABASE g_make_db(); | |
58 | int g_iadb(); | |
59 | ||
60 | struct adb_data { | |
61 | DATABASE db; | |
62 | OPERATION get_retcode; | |
63 | }; | |
64 | ||
65 | int | |
66 | start_accessing_db (op, db_ident, db_handle) | |
67 | OPERATION op; | |
68 | char *db_ident; | |
69 | DATABASE *db_handle; | |
70 | { | |
71 | /*----------------------------------------------------------*/ | |
72 | /* | |
73 | /* Declarations | |
74 | /* | |
75 | /*----------------------------------------------------------*/ | |
76 | ||
77 | register DATABASE db; /* the newly created */ | |
78 | /* structure */ | |
79 | register struct adb_data *arg; /* holds our state */ | |
80 | /* during async operation*/ | |
81 | char *ident, *server, *temp_server; /* loop variables for */ | |
82 | /* parsing*/ | |
83 | char *db_name, *temp_name; | |
84 | int count; /* counts chars during parse */ | |
85 | ||
86 | CONNECTION connexn; /* the connection to the */ | |
87 | /* database server*/ | |
88 | ||
89 | /*----------------------------------------------------------*/ | |
90 | /* | |
91 | /* Execution begins here | |
92 | /* | |
93 | /* Make sure parameters are correct, then allocate a | |
94 | /* structure. | |
95 | /* | |
96 | /*----------------------------------------------------------*/ | |
97 | ||
98 | GDB_INIT_CHECK | |
99 | ||
100 | db_name = NULL; | |
101 | temp_name = NULL; | |
102 | ident = NULL ; | |
103 | server = NULL; | |
104 | ||
105 | GDB_CHECK_OP(op, "start_accessing_db") | |
106 | ||
107 | if ((db_ident == NULL)|| (strlen(db_ident)<MIN_NAME_LEN)) { | |
108 | fprintf (gdb_log,"access_db: correct syntax is db_name@server \n"); | |
109 | *db_handle = NULL; | |
110 | return (OP_CANCELLED); | |
111 | } | |
112 | ||
113 | db = g_make_db(); | |
114 | *db_handle = db; | |
115 | ||
116 | /*----------------------------------------------------------*/ | |
117 | /* | |
118 | /* Loop to count lengths of server and database names | |
119 | /* Allocate space for each and copy them both | |
120 | /* | |
121 | /*----------------------------------------------------------*/ | |
122 | ||
123 | count = 1; | |
124 | ident = db_ident; | |
125 | while (*ident++ != '@') { | |
126 | count++; | |
127 | } | |
128 | ||
129 | db_name = db_alloc (count); /* space for db_name */ | |
130 | /* note: this is cleaned */ | |
131 | /* up by the tear down rtn*/ | |
132 | ||
133 | count = 1; | |
134 | while (*ident++ != '\0') | |
135 | count++; | |
136 | ||
137 | count += strlen(GDB_DB_SERVICE)+1; /* leave room for :service */ | |
138 | server = db_alloc (count); /* space for host:service */ | |
139 | /* note: this is cleaned */ | |
140 | /* up by the tear down rtn*/ | |
141 | ||
142 | /* | |
143 | * copy head of db_ident string from db_name@server to db_name | |
144 | */ | |
145 | temp_name = db_name; | |
146 | while (*db_ident != '@') { | |
147 | *temp_name = *db_ident; | |
148 | temp_name++; | |
149 | db_ident++; | |
150 | } | |
151 | *temp_name = '\0'; | |
152 | ||
153 | db->name = db_name; | |
154 | ||
155 | /* | |
156 | * Set up server host name | |
157 | */ | |
158 | temp_server = server; | |
159 | db_ident++; /* skip the '@' */ | |
160 | while (*db_ident!= '\0') { | |
161 | *temp_server = *db_ident; | |
162 | temp_server++; | |
163 | db_ident++; | |
164 | } | |
165 | ||
166 | /* | |
167 | * Append :service id to the server host name | |
168 | */ | |
169 | *temp_server++ = ':'; | |
170 | *temp_server = '\0'; | |
171 | (void) strcat(server, GDB_DB_SERVICE); | |
172 | ||
173 | db->server = server; | |
174 | ||
175 | ||
176 | /*----------------------------------------------------------*/ | |
177 | /* | |
178 | /* Create a connection to the server. | |
179 | /* | |
180 | /*----------------------------------------------------------*/ | |
181 | ||
182 | connexn = start_server_connection (server, db_name); | |
183 | ||
184 | if (connexn==NULL || connection_status(connexn) != CON_UP) { | |
185 | connection_perror(connexn, "Error starting server connection"); | |
186 | fprintf (gdb_log, "gdb:access_db: couldn't connect to server %s \n", server); | |
187 | g_tear_down(*db_handle); | |
188 | OP_STATUS(op) = OP_CANCELLED; | |
189 | return (OP_CANCELLED); | |
190 | } | |
191 | ||
192 | db->connection = connexn; | |
193 | ||
194 | /* | |
195 | * Start asynchronously receiving the return code from the | |
196 | * data base server. May take awhile, since ingres is so | |
197 | * slow to start up. | |
198 | */ | |
199 | ||
200 | arg = (struct adb_data *)db_alloc(sizeof(struct adb_data)); | |
201 | arg->get_retcode = create_operation(); | |
202 | arg->db = db; | |
203 | ||
204 | start_receiving_object (arg->get_retcode, connexn, | |
205 | (char *)&(OP_RESULT(op)), INTEGER_T); | |
206 | /* | |
207 | * Error handling | |
208 | */ | |
209 | if (OP_STATUS(arg->get_retcode) == OP_CANCELLED) { | |
210 | g_tear_down (*db_handle); | |
211 | OP_STATUS(op) = OP_CANCELLED; | |
212 | delete_operation(arg->get_retcode); | |
213 | db_free((char *)arg, sizeof(struct adb_data)); | |
214 | return OP_CANCELLED; | |
215 | } | |
216 | ||
217 | /* | |
218 | * We've successfully queued the receive of the return code. | |
219 | * That's about all we have to do if things go well, but if the | |
220 | * operation fails later, we have to be there to clean up. To | |
221 | * get control back, we queue ourselves as a second operation | |
222 | * so we can see how the first did, and so we can free up arg. | |
223 | */ | |
224 | initialize_operation(op, g_iadb, (char *)arg, (int (*)())NULL); | |
225 | (void) queue_operation(connexn, CON_INPUT, op); | |
226 | ||
227 | return OP_RUNNING; | |
228 | } | |
229 | ||
230 | /*----------------------------------------------------------*/ | |
231 | /* | |
232 | /* g_iadb | |
233 | /* | |
234 | /* Init routine for getting return code on accessing a | |
235 | /* database. If all went well, (or even if it didn't), then | |
236 | /* we are done. All we have to do is clean up the stuff we've | |
237 | /* allocated. | |
238 | /* | |
239 | /*----------------------------------------------------------*/ | |
240 | ||
24582af9 | 241 | /*ARGSUSED*/ |
5580185e | 242 | int |
243 | g_iadb(op, hcon, arg) | |
244 | OPERATION op; | |
245 | HALF_CONNECTION hcon; | |
246 | struct adb_data *arg; | |
247 | { | |
248 | int rc; | |
249 | ||
250 | /* | |
251 | * Figure out how the receipt went | |
252 | */ | |
253 | rc = OP_STATUS(arg->get_retcode); | |
254 | ||
255 | /* | |
256 | * Release all transient data structures. | |
257 | */ | |
258 | if (rc != OP_COMPLETE || op->result != DB_OPEN) | |
259 | g_tear_down(arg->db); | |
260 | else | |
261 | DB_STATUS(arg->db) = DB_OPEN; | |
262 | ||
263 | delete_operation(arg->get_retcode); | |
264 | db_free((char *)arg, sizeof(struct adb_data)); | |
265 | ||
266 | return rc; | |
267 | } | |
268 | \f | |
269 | /************************************************************************/ | |
270 | /* | |
271 | /* g_tear_down | |
272 | /* | |
273 | /* this is called by access_db and perf_db_op when a fatal error | |
274 | /* is reached. It is an attempt to intelligently handle the error, | |
275 | /* and tear down connections and data structures if necessary. | |
276 | /* | |
277 | /* The current version simply tears down everything, perhaps later | |
278 | /* versions should make provision for closing the db as necessary, | |
279 | /* and/or other less drastic ways to handle the errors. | |
280 | /* | |
281 | /************************************************************************/ | |
282 | ||
283 | int | |
284 | g_tear_down (db_handle) | |
285 | DATABASE db_handle; | |
286 | { | |
287 | register DATABASE db = db_handle; | |
288 | ||
289 | /*----------------------------------------------------------*/ | |
290 | /* | |
291 | /* If the db is opened, and the connexn is severed, | |
292 | /* some error handling, closing of the db should be done | |
293 | /* at the server. | |
294 | /* | |
295 | /* Also, at the server, perhaps a return code to indicate | |
296 | /* that user tried to open non-existant db??? | |
297 | /* | |
298 | /*----------------------------------------------------------*/ | |
299 | ||
300 | ||
301 | if (db==NULL) | |
302 | return; | |
303 | ||
304 | ||
305 | (void) sever_connection (db->connection); | |
306 | ||
307 | /* | |
308 | * Free up the separately allocated strings to which the | |
309 | * database descriptor points | |
310 | */ | |
311 | gdb_fstring(db->server); | |
312 | gdb_fstring(db->name); | |
313 | ||
314 | /* | |
315 | * Free the descriptor itself | |
316 | */ | |
317 | db_free ((char *)db,sizeof(struct db_struct)); | |
318 | return; | |
319 | } | |
320 | \f | |
321 | /************************************************************************/ | |
322 | /* | |
323 | /* g_make_db | |
324 | /* | |
325 | /* Allocate and initialize a database descriptor structure. | |
326 | /* | |
327 | /************************************************************************/ | |
328 | ||
329 | DATABASE | |
330 | g_make_db() | |
331 | { | |
332 | register DATABASE db; | |
333 | ||
334 | db = (DATABASE)db_alloc (sizeof(struct db_struct)); | |
335 | db->id = GDB_DB_ID; | |
336 | db->connection = NULL; | |
337 | db->name = NULL; | |
338 | db->server = NULL; | |
339 | DB_STATUS(db) = DB_CLOSED; | |
340 | ||
341 | return db; | |
342 | } | |
343 | \f/************************************************************************/ | |
344 | /* | |
345 | /* access_db (access_db) | |
346 | /* | |
347 | /* Does a start_accessing_db and waits for it to complete. | |
348 | /* | |
349 | /************************************************************************/ | |
350 | ||
351 | int | |
352 | access_db (db_ident, db_handle) | |
353 | char *db_ident; | |
354 | DATABASE *db_handle; | |
355 | { | |
356 | register OPERATION op; | |
357 | register int status; | |
358 | register int result; | |
359 | ||
360 | GDB_INIT_CHECK | |
361 | ||
362 | /* | |
363 | * Create an operation and use it to asynchronously access | |
364 | * the database | |
365 | */ | |
366 | op = create_operation(); | |
367 | (void) start_accessing_db(op, db_ident, db_handle); | |
368 | ||
369 | /* | |
370 | * Wait for it to complete, note whether the operation completed | |
371 | * at all, and if so, whether it returned a successful result | |
372 | * in accessing the database. Then reclaim the space used for | |
373 | * the operation. | |
374 | */ | |
375 | (void) complete_operation(op); | |
376 | status = OP_STATUS(op); | |
377 | result = OP_RESULT(op); | |
378 | ||
379 | delete_operation(op); | |
380 | ||
381 | /* | |
382 | * Tell the caller either that we were interrupted, or pass | |
383 | * on the actual result of accessing the database. If it | |
384 | * failed, then tear everything down after all. | |
385 | */ | |
386 | if (status==OP_COMPLETE) | |
387 | return result; | |
388 | else | |
389 | return status; | |
390 | } | |
391 | \f/************************************************************************/ | |
392 | /* | |
393 | /* start_performing_db_operation (start_performing_db_operation) | |
394 | /* | |
395 | /* Asynchronously performs any operation except for a query | |
396 | /* on the remote database. | |
397 | /* | |
398 | /* The operation is encoded as a GDB string and sent to the server. | |
399 | /* | |
400 | /* An integer return code is received back and returned to the caller. | |
401 | /* | |
402 | /* Note that this operation executes on both the outbound and inbound | |
403 | /* half connections. Since there is no explicit sync between the two | |
404 | /* directions, operations like this pipeline freely from requestor | |
405 | /* to server, but there is no way to cancel this operation once it | |
406 | /* has started without severing the accompanying connection. | |
407 | /* | |
408 | /************************************************************************/ | |
409 | ||
410 | int g_ipdb(); | |
411 | ||
412 | struct pdb_data { | |
413 | DATABASE db; /* the database we're */ | |
414 | /* working on */ | |
415 | OPERATION send_request; /* used to send the string */ | |
416 | /* containing the db oper. */ | |
417 | /* to be performed */ | |
418 | OPERATION get_retcode; /* used to get back the */ | |
419 | /* response to our request */ | |
420 | STRING s; /* the operation string */ | |
421 | /* itself. This is sent. */ | |
422 | }; | |
423 | ||
424 | #define MIN_REQUEST_LEN 1 /*completely arbitrary */ | |
425 | #undef FAILURE | |
426 | #define FAILURE -1 | |
427 | ||
428 | int | |
429 | start_performing_db_operation (op, db_handle,request) | |
430 | OPERATION op; | |
431 | DATABASE db_handle; | |
432 | char *request; | |
433 | { | |
434 | /*----------------------------------------------------------*/ | |
435 | /* | |
436 | /* Declarations | |
437 | /* | |
438 | /*----------------------------------------------------------*/ | |
439 | ||
440 | register struct pdb_data *arg; /* holds our state */ | |
441 | /* during async operation*/ | |
442 | register DATABASE db = db_handle; /* fast working copy */ | |
443 | ||
444 | /*----------------------------------------------------------*/ | |
445 | /* | |
446 | /* Execution begins here | |
447 | /* | |
448 | /* Make sure parameters are correct, then allocate a | |
449 | /* structure. | |
450 | /* | |
451 | /*----------------------------------------------------------*/ | |
452 | ||
453 | GDB_CHECK_OP(op, "start_performing_db_operation ") | |
454 | if (db==NULL) { | |
455 | fprintf (gdb_log, "gdb: start_performing_db_operation: supplied database is NULL\n"); | |
456 | OP_STATUS(op) = OP_CANCELLED; | |
457 | return OP_CANCELLED; | |
458 | } | |
459 | ||
460 | GDB_CHECK_DB(db, "start_performing_db_operation") | |
461 | ||
462 | if (DB_STATUS(db) != DB_OPEN) { | |
463 | fprintf (gdb_log, "gdb: start_performing_db_operation: request to closed database "); | |
464 | OP_STATUS(op) = OP_CANCELLED; | |
465 | return OP_CANCELLED; | |
466 | } | |
467 | ||
468 | if (db->connection == NULL) { | |
469 | fprintf (gdb_log, | |
470 | "gdb: start_performing_db_operation: connection severed, request cancelled\n"); | |
471 | OP_STATUS(op) = OP_CANCELLED; | |
472 | return OP_CANCELLED; | |
473 | } | |
474 | ||
475 | if (connection_status(db->connection) != CON_UP ) { | |
476 | fprintf (gdb_log, "gdb: start_performing_db_operation: problems maintaining connection "); | |
477 | connection_perror(db->connection, "Reason for connection failure"); | |
478 | fprintf (gdb_log, "request cancelled \n"); | |
479 | OP_STATUS(op) = OP_CANCELLED; | |
480 | return OP_CANCELLED; | |
481 | } | |
482 | ||
483 | if ((request == NULL) || (strlen (request)<MIN_REQUEST_LEN)) { | |
484 | fprintf (gdb_log, "gdb: start_performing_db_operation: request either missing or too short\n"); | |
485 | OP_STATUS(op) = OP_CANCELLED; | |
486 | return OP_CANCELLED; | |
487 | /*should we disallow empty requests? */ | |
488 | } | |
489 | ||
490 | ||
491 | /*----------------------------------------------------------*/ | |
492 | /* | |
493 | /* Asynchronously send the request to the server | |
494 | /* | |
495 | /*----------------------------------------------------------*/ | |
496 | ||
497 | /* | |
498 | * Allocate a structure to hold our state while we're gone | |
499 | * waiting for this to complete. | |
500 | */ | |
501 | ||
502 | arg = (struct pdb_data *)db_alloc(sizeof(struct pdb_data)); | |
503 | arg->db = db; | |
504 | arg->send_request = create_operation(); | |
505 | ||
506 | /* | |
507 | * Send the request string to the server | |
508 | */ | |
509 | STRING_DATA(arg->s) = request; | |
510 | MAX_STRING_SIZE(arg->s) = strlen (request) +1; | |
511 | start_sending_object (arg->send_request, db->connection, | |
512 | (char *)&(arg->s), STRING_T); | |
513 | if (OP_STATUS(arg->send_request) == OP_CANCELLED) { | |
514 | OP_STATUS(op) = OP_CANCELLED; | |
515 | delete_operation(arg->send_request); | |
516 | db_free((char *)arg, sizeof(struct pdb_data)); | |
517 | return OP_CANCELLED; | |
518 | } | |
519 | ||
520 | /*----------------------------------------------------------*/ | |
521 | /* | |
522 | /* Asynchronously receive the return code (note, we | |
523 | /* really don't know whether the request has even been | |
524 | /* sent yet...doesn't really matter.) | |
525 | /* | |
526 | /*----------------------------------------------------------*/ | |
527 | ||
528 | arg->get_retcode = create_operation(); | |
529 | /* | |
530 | * This must come here as it sets op_result | |
531 | */ | |
532 | initialize_operation(op, g_ipdb, (char *)arg, (int (*)())NULL); | |
533 | ||
534 | start_receiving_object (arg->get_retcode, db->connection, | |
535 | (char *)&(OP_RESULT(op)), INTEGER_T); | |
536 | if (OP_STATUS(arg->get_retcode) == OP_CANCELLED) { | |
537 | OP_STATUS(op) = OP_CANCELLED; | |
538 | (void) cancel_operation(arg->send_request);/* this could be a bug, */ | |
539 | /* because we introduce */ | |
540 | /* indeterminism into */ | |
541 | /* the reply stream, probably */ | |
542 | /* should shutdown the whole */ | |
543 | /* db here */ | |
544 | delete_operation(arg->send_request); | |
545 | delete_operation(arg->get_retcode); | |
546 | db_free((char *)arg, sizeof(struct adb_data)); | |
547 | return OP_CANCELLED; | |
548 | } | |
549 | ||
550 | /* | |
551 | * We've successfully queued the receive of the return code. | |
552 | * That's about all we have to do if things go well, but if the | |
553 | * operation fails later, we have to be there to clean up. To | |
554 | * get control back, we queue ourselves as a second operation | |
555 | * so we can see how the first did, and so we can free up arg. | |
556 | */ | |
557 | (void) queue_operation(db->connection, CON_INPUT, op); | |
558 | return OP_RUNNING; | |
559 | } | |
560 | ||
561 | /*----------------------------------------------------------*/ | |
562 | /* | |
563 | /* g_ipdb | |
564 | /* | |
565 | /* Init routine for getting return code on performin a db | |
566 | /* operation. If all went well, (or even if it didn't), | |
567 | /* then we are done. All we have to do is clean up the | |
568 | /* stuff we've allocated. | |
569 | /* | |
570 | /*----------------------------------------------------------*/ | |
571 | ||
24582af9 | 572 | /*ARGSUSED*/ |
5580185e | 573 | int |
574 | g_ipdb(op, hcon, arg) | |
575 | OPERATION op; | |
576 | HALF_CONNECTION hcon; | |
577 | struct pdb_data *arg; | |
578 | { | |
579 | int rc1, rc2; | |
580 | ||
581 | /* | |
582 | * Figure out how the receipt went | |
583 | */ | |
584 | rc1 = OP_STATUS(arg->send_request); | |
585 | rc2 = OP_STATUS(arg->get_retcode); | |
586 | ||
587 | /* | |
588 | * Release all transient data structures. | |
589 | */ | |
590 | if (rc1 != OP_COMPLETE || rc2 != OP_COMPLETE) | |
591 | g_tear_down(arg->db); | |
592 | ||
593 | delete_operation(arg->send_request); | |
594 | delete_operation(arg->get_retcode); | |
595 | db_free((char *)arg, sizeof(struct pdb_data)); | |
596 | ||
597 | return rc2; | |
598 | } | |
599 | \f | |
600 | /************************************************************************/ | |
601 | /* | |
602 | /* perform_db_operation (perform_db_operation) | |
603 | /* | |
604 | /* Do a database operation synchronously. This just calls | |
605 | /* the async routine and waits for it to complete. | |
606 | /* | |
607 | /************************************************************************/ | |
608 | ||
609 | perform_db_operation (db_handle,request) | |
610 | DATABASE db_handle; | |
611 | char *request; | |
612 | { | |
613 | register OPERATION op; | |
614 | register int status; | |
615 | register int result; | |
616 | ||
617 | /* | |
618 | * Create an operation and use it to asynchronously perform | |
619 | * the operation | |
620 | */ | |
621 | op = create_operation(); | |
622 | (void) start_performing_db_operation(op, db_handle, request); | |
623 | ||
624 | /* | |
625 | * Wait for it to complete, note whether the operation | |
626 | * completed at all, and if so, whether it returned a | |
627 | * successful result. Then reclaim the space used for the | |
628 | * operation. | |
629 | */ | |
630 | (void) complete_operation(op); | |
631 | status = OP_STATUS(op); | |
632 | result = OP_RESULT(op); | |
633 | ||
634 | delete_operation(op); | |
635 | ||
636 | /* | |
637 | * Tell the caller either that we were interrupted, or pass | |
638 | * on the actual result of accessing the database. If it | |
639 | * failed, then tear everything down after all. | |
640 | */ | |
641 | if (status==OP_COMPLETE) | |
642 | return result; | |
643 | else | |
644 | return status; | |
645 | } | |
646 | \f/************************************************************************/ | |
647 | /* | |
648 | /* start_db_query (start_db_query) | |
649 | /* | |
650 | /* Asynchronously performs a database query on the remote | |
651 | /* database. | |
652 | /* | |
653 | /* The operation is encoded as a GDB string and sent to the server. | |
654 | /* | |
655 | /* An integer return code is received back and returned to the caller. | |
656 | /* | |
657 | /* If the return code indicates success, then we go into a loop | |
658 | /* receiving the retrieved data. Each returned tuple is preceeded by | |
659 | /* a so-called yes/no flag, which indicates whether tuple data is really | |
660 | /* to follow. Last tuple is followed by a NO flag. | |
661 | /* | |
662 | /* Note that this operation executes on both the outbound and inbound | |
663 | /* half connections. Since there is no explicit sync between the two | |
664 | /* directions, operations like this pipeline freely from requestor | |
665 | /* to server, but there is no way to cancel this operation once it | |
666 | /* has started without severing the accompanying connection. | |
667 | /* | |
668 | /************************************************************************/ | |
669 | ||
670 | int g_idbq(); | |
671 | int g_cdbq(); | |
672 | ||
673 | struct dbq_data { | |
674 | /* | |
675 | * Following may be used throughout processing | |
676 | */ | |
677 | DATABASE db; /* the database we're */ | |
678 | /* working on */ | |
679 | RELATION rel; | |
680 | TUPLE_DESCRIPTOR tpd; | |
681 | /* | |
682 | * used primarily in first phase for sending query and getting | |
683 | * return code | |
684 | */ | |
685 | OPERATION send_query; /* used to send the string */ | |
686 | /* containing the query */ | |
687 | /* to be performed */ | |
688 | OPERATION send_descriptor; /* used to send the tuple */ | |
689 | /* descriptor to the server */ | |
690 | OPERATION get_retcode; /* used to get back the */ | |
691 | /* response to our request */ | |
692 | STRING s; /* the operation string */ | |
693 | /* itself. This is sent. */ | |
694 | /* | |
695 | * Following are used during later phase to receive the tuples | |
696 | */ | |
697 | int state; /* are we expecting a yes/no */ | |
698 | /* or a tuple next? */ | |
699 | #define YESNO 1 | |
700 | #define TUPDATA 2 | |
701 | int yesno; /* an indicator of whether */ | |
702 | /* another tuple is to follow*/ | |
703 | #define YES 1 | |
704 | OPERATION receive_yesno_or_data; | |
705 | TUPLE tup; /* a place to put */ | |
706 | /* the next tuple */ | |
707 | }; | |
708 | ||
709 | int | |
710 | start_db_query (op, db_handle,rel, query) | |
711 | OPERATION op; | |
712 | DATABASE db_handle; | |
713 | RELATION rel; | |
714 | char *query; | |
715 | { | |
716 | /*----------------------------------------------------------*/ | |
717 | /* | |
718 | /* Declarations | |
719 | /* | |
720 | /*----------------------------------------------------------*/ | |
721 | ||
722 | register struct dbq_data *arg; /* holds our state */ | |
723 | /* during async operation*/ | |
724 | register DATABASE db = db_handle; /* fast working copy */ | |
725 | ||
726 | /*----------------------------------------------------------*/ | |
727 | /* | |
728 | /* Execution begins here | |
729 | /* | |
730 | /* Make sure parameters are correct, then allocate a | |
731 | /* structure. | |
732 | /* | |
733 | /*----------------------------------------------------------*/ | |
734 | ||
735 | GDB_CHECK_OP(op, "start_db_query ") | |
736 | ||
737 | if (rel ==NULL) { | |
738 | fprintf (gdb_log, "gdb: query_db: input rel is null \n"); | |
739 | OP_STATUS(op) = OP_CANCELLED; | |
740 | return OP_CANCELLED; | |
741 | } | |
742 | ||
743 | if (db==NULL) { | |
744 | fprintf (gdb_log, "gdb: start_db_query: supplied database is NULL\n"); | |
745 | OP_STATUS(op) = OP_CANCELLED; | |
746 | return OP_CANCELLED; | |
747 | } | |
748 | ||
749 | GDB_CHECK_DB(db, "start_db_query") | |
750 | ||
751 | if (DB_STATUS(db) != DB_OPEN) { | |
752 | fprintf (gdb_log, "gdb: start_db_query: request to closed database "); | |
753 | OP_STATUS(op) = OP_CANCELLED; | |
754 | return OP_CANCELLED; | |
755 | } | |
756 | ||
757 | if (db->connection == NULL) { | |
758 | fprintf (gdb_log,"gdb: start_db_query: connection severed, request cancelled\n"); | |
759 | OP_STATUS(op) = OP_CANCELLED; | |
760 | return OP_CANCELLED; | |
761 | } | |
762 | ||
763 | if (connection_status(db->connection) != CON_UP ) { | |
764 | fprintf (gdb_log,"gdb: start_db_query: problems maintaining connection "); | |
765 | connection_perror(db->connection, "Reason for connection failure"); | |
766 | fprintf (gdb_log,"request cancelled \n"); | |
767 | OP_STATUS(op) = OP_CANCELLED; | |
768 | return OP_CANCELLED; | |
769 | } | |
770 | ||
771 | if (query == NULL || *query == '\0') { | |
772 | fprintf (gdb_log, "gdb: start_db_query: request string is null\n"); | |
773 | OP_STATUS(op) = OP_CANCELLED; | |
774 | return OP_CANCELLED; | |
775 | } | |
776 | ||
777 | ||
778 | /*----------------------------------------------------------*/ | |
779 | /* | |
780 | /* Asynchronously send the query to the server | |
781 | /* | |
782 | /*----------------------------------------------------------*/ | |
783 | ||
784 | /* | |
785 | * Allocate a structure to hold our state while we're gone | |
786 | * waiting for this to complete. | |
787 | */ | |
788 | ||
789 | arg = (struct dbq_data *)db_alloc(sizeof(struct dbq_data)); | |
790 | arg->db = db; | |
791 | arg->rel = rel; | |
792 | arg->send_query = create_operation(); | |
793 | ||
794 | /* | |
795 | * Send the query string to the server | |
796 | */ | |
797 | (void) string_alloc(&(arg->s), strlen(query)+11); | |
798 | (void) strcpy(STRING_DATA(arg->s), "retrieve "); | |
799 | (void) strcat(STRING_DATA(arg->s), query); | |
800 | MAX_STRING_SIZE(arg->s) = strlen (query) +11; | |
801 | start_sending_object (arg->send_query, db->connection, | |
802 | (char *)&(arg->s), STRING_T); | |
803 | if (OP_STATUS(arg->send_query) == OP_CANCELLED) { | |
804 | OP_STATUS(op) = OP_CANCELLED; | |
805 | delete_operation(arg->send_query); | |
806 | string_free(&(arg->s)); | |
807 | db_free((char *)arg, sizeof(struct dbq_data)); | |
808 | return OP_CANCELLED; | |
809 | } | |
810 | ||
811 | /* | |
812 | * Send the tuple descriptor to the server | |
813 | */ | |
814 | ||
815 | arg->send_descriptor = create_operation(); | |
816 | arg->tpd = DESCRIPTOR_FROM_RELATION(arg->rel); | |
817 | ||
818 | start_sending_object (arg->send_descriptor, db->connection, | |
819 | (char *)&(arg->tpd), TUPLE_DESCRIPTOR_T); | |
820 | if (OP_STATUS(arg->send_descriptor) == OP_CANCELLED) { | |
821 | OP_STATUS(op) = OP_CANCELLED; | |
822 | (void) cancel_operation(arg->send_query);/* this could be a bug, */ | |
823 | /* because we introduce */ | |
824 | /* indeterminism into */ | |
825 | /* the reply stream, probably */ | |
826 | /* should shutdown the whole */ | |
827 | /* db here */ | |
828 | delete_operation(arg->send_query); | |
829 | delete_operation(arg->send_descriptor); | |
830 | string_free(&(arg->s)); | |
831 | db_free((char *)arg, sizeof(struct dbq_data)); | |
832 | return OP_CANCELLED; | |
833 | } | |
834 | ||
835 | /*----------------------------------------------------------*/ | |
836 | /* | |
837 | /* Asynchronously receive the return code (note, we | |
838 | /* really don't know whether the query/and the descriptor | |
839 | /* have even been sent yet...doesn't really matter.) | |
840 | /* | |
841 | /*----------------------------------------------------------*/ | |
842 | ||
843 | arg->get_retcode = create_operation(); | |
844 | start_receiving_object (arg->get_retcode, db->connection, | |
845 | (char *)&(OP_RESULT(op)), INTEGER_T); | |
846 | if (OP_STATUS(arg->get_retcode) == OP_CANCELLED) { | |
847 | OP_STATUS(op) = OP_CANCELLED; | |
848 | (void) cancel_operation(arg->send_query);/* this could be a bug, */ | |
849 | /* because we introduce */ | |
850 | /* indeterminism into */ | |
851 | /* the reply stream, probably */ | |
852 | /* should shutdown the whole */ | |
853 | /* db here */ | |
854 | (void) cancel_operation(arg->send_descriptor); | |
855 | string_free(&(arg->s)); | |
856 | delete_operation(arg->send_query); | |
857 | delete_operation(arg->send_descriptor); | |
858 | delete_operation(arg->get_retcode); | |
859 | db_free((char *)arg, sizeof(struct adb_data)); | |
860 | return OP_CANCELLED; | |
861 | } | |
862 | ||
863 | /* | |
864 | * We've successfully queued the receive of the return code. | |
865 | * That's about all we have to do if things go well, but if the | |
866 | * operation fails later, we have to be there to clean up. To | |
867 | * get control back, we queue ourselves as a second operation | |
868 | * so we can see how the first did, and so we can free up arg. | |
869 | */ | |
870 | initialize_operation(op, g_idbq, (char *)arg, (int (*)())NULL); | |
871 | (void) queue_operation(db->connection, CON_INPUT, op); | |
872 | ||
873 | return OP_RUNNING; | |
874 | } | |
875 | ||
876 | /*----------------------------------------------------------*/ | |
877 | /* | |
878 | /* g_idbq | |
879 | /* | |
880 | /* Init routine for getting return code on performing a | |
881 | /* bd query. If there was an error, then we are done except for | |
882 | /* cleaning up all the dynamic memory we allocated. | |
883 | /* If the return code was 0,then we must asynchronously | |
884 | /* do the following iteratively until a no is received: | |
885 | /* | |
886 | /* while (async_receive(yes/no) == yes) { | |
887 | /* async receive new tuple | |
888 | /* add it to the relation | |
889 | /* } | |
890 | /* | |
891 | /*----------------------------------------------------------*/ | |
892 | ||
24582af9 | 893 | /*ARGSUSED*/ |
5580185e | 894 | int |
895 | g_idbq(op, hcon, arg) | |
896 | OPERATION op; | |
897 | HALF_CONNECTION hcon; | |
898 | struct dbq_data *arg; | |
899 | { | |
900 | int rc1, rc2, rc3; | |
901 | ||
902 | /*----------------------------------------------------------*/ | |
903 | /* | |
904 | /* See how the three asynchronous operations went,and | |
905 | /* clean up after them. | |
906 | /* | |
907 | /*----------------------------------------------------------*/ | |
908 | ||
909 | /* | |
910 | * Figure out how the receipt went | |
911 | */ | |
912 | rc1 = OP_STATUS(arg->send_query); | |
913 | rc2 = OP_STATUS(arg->send_descriptor); | |
914 | rc3 = OP_STATUS(arg->get_retcode); | |
915 | ||
916 | /* | |
917 | * Release all transient data structures which were used in the | |
918 | * preliminary operations. | |
919 | */ | |
920 | delete_operation(arg->send_query); | |
921 | delete_operation(arg->get_retcode); | |
922 | string_free(&(arg->s)); | |
923 | /* | |
924 | * If we've failed for any reason, then mark ourselves complete and | |
925 | * return. | |
926 | */ | |
927 | if (rc1 != OP_COMPLETE || rc2 != OP_COMPLETE|| rc3 != OP_COMPLETE | |
928 | || OP_RESULT(op) != OP_SUCCESS) { | |
929 | OP_STATUS(op) = rc3; /* we must have done */ | |
930 | /* about as well as */ | |
931 | /* the last one */ | |
932 | ||
933 | db_free((char *)arg, sizeof(struct dbq_data)); | |
934 | return rc3; /* tell the dispatcher */ | |
935 | /* that we're either */ | |
936 | /* cancelled or complete */ | |
937 | } | |
938 | ||
939 | /*----------------------------------------------------------*/ | |
940 | /* | |
941 | /* We've successfully received a return code of 0 from | |
942 | /* Ingres, which means we are now going to begin the | |
943 | /* yes/no loop. | |
944 | /* | |
945 | /*----------------------------------------------------------*/ | |
946 | ||
947 | op->fcn.cont = g_cdbq; /* after the preempting */ | |
948 | /* receive completes, the */ | |
949 | /* dispatcher will call */ | |
950 | /* this routine. */ | |
951 | arg->state = YESNO; /* tell continuation routine */ | |
952 | /* that we're receiving */ | |
953 | /* a yes/no */ | |
954 | arg->tup = NULL; /* so we won't try to clean */ | |
955 | /* it up */ | |
956 | arg->receive_yesno_or_data = create_operation(); | |
957 | ||
958 | preempt_and_start_receiving_object(arg->receive_yesno_or_data, | |
959 | op, | |
960 | (char *)&(arg->yesno), | |
961 | INTEGER_T); | |
962 | return OP_PREEMPTED; | |
963 | } | |
964 | ||
965 | /*----------------------------------------------------------*/ | |
966 | /* | |
967 | /* g_cdbq | |
968 | /* | |
969 | /* Continuation routine for receiving results of a query. | |
970 | /* Tbis is called repeatedly each time either a yes/no or | |
971 | /* a new tuple is received. It repeatedly preempts itself | |
972 | /* to receive the next yes/no or tuple until a 'no' | |
973 | /* is finally received. | |
974 | /* | |
975 | /*----------------------------------------------------------*/ | |
976 | ||
24582af9 | 977 | /*ARGSUSED*/ |
5580185e | 978 | int |
979 | g_cdbq(op, hcon, arg) | |
980 | OPERATION op; | |
981 | HALF_CONNECTION hcon; | |
982 | struct dbq_data *arg; | |
983 | { | |
984 | /*----------------------------------------------------------*/ | |
985 | /* | |
986 | /* See whether the preempting operation completed | |
987 | /* successfully. If not, we just clean up and cancel | |
988 | /* | |
989 | /*----------------------------------------------------------*/ | |
990 | ||
991 | if (OP_STATUS(arg->receive_yesno_or_data) != OP_COMPLETE) { | |
992 | delete_operation(arg->receive_yesno_or_data); | |
993 | if (arg->tup != NULL) | |
994 | delete_tuple(arg->tup); | |
995 | db_free((char *)arg, sizeof(struct dbq_data)); | |
996 | OP_STATUS(op) = OP_CANCELLED; | |
997 | return OP_CANCELLED; | |
998 | } | |
999 | ||
1000 | /*----------------------------------------------------------*/ | |
1001 | /* | |
1002 | /* Whatever it was, we received it cleanly. If it | |
1003 | /* was tuple data, then accept it and prepare to receive | |
1004 | /* a yesno. If it was a yes, then prepare to receive | |
1005 | /* the tuple data. If it was a NO, then we're all done. | |
1006 | /* | |
1007 | /* Note that g_cdbg will be recalled by the dispatcher | |
1008 | /* after the preempting routines have completed. | |
1009 | /* | |
1010 | /*----------------------------------------------------------*/ | |
1011 | ||
1012 | /* | |
1013 | * New TUPLE DATA | |
1014 | */ | |
1015 | ||
1016 | if (arg->state == TUPDATA) { | |
1017 | ADD_TUPLE_TO_RELATION(arg->rel, arg->tup); | |
1018 | arg->tup = NULL; /* so we won't try to */ | |
1019 | /* delete it in case of error*/ | |
1020 | reset_operation(arg->receive_yesno_or_data); | |
1021 | arg->state = YESNO; | |
1022 | preempt_and_start_receiving_object(arg->receive_yesno_or_data, | |
1023 | op, | |
1024 | (char *)&(arg->yesno), | |
1025 | INTEGER_T); | |
1026 | return OP_PREEMPTED; | |
1027 | } | |
1028 | ||
1029 | /* | |
1030 | * We just received a yes or no. If it's a YES, prepare to | |
1031 | * receive some more tuple data. | |
1032 | */ | |
1033 | if (arg->yesno == YES) { | |
1034 | arg->tup = create_tuple(arg->tpd); | |
1035 | reset_operation(arg->receive_yesno_or_data); | |
1036 | arg->state = TUPDATA; | |
1037 | preempt_and_start_receiving_object(arg->receive_yesno_or_data, | |
1038 | op, | |
1039 | (char *)arg->tup, | |
1040 | TUPLE_DATA_T); | |
1041 | return OP_PREEMPTED; | |
1042 | } | |
1043 | /* | |
1044 | * We just received a NO. Looks like we're all done cleanly. | |
1045 | */ | |
1046 | delete_operation(arg->receive_yesno_or_data); | |
1047 | if (arg->tup != NULL) | |
1048 | delete_tuple(arg->tup); | |
1049 | db_free((char *)arg, sizeof(struct dbq_data)); | |
1050 | OP_STATUS(op) = OP_COMPLETE; | |
1051 | return OP_COMPLETE; | |
1052 | ||
1053 | } | |
1054 | \f | |
1055 | /************************************************************************/ | |
1056 | /* | |
1057 | /* db_query (db_query) | |
1058 | /* | |
1059 | /* Perform a relational query on the specified database. | |
1060 | /* | |
1061 | /* This just calls the asynchronous form of doing a query and | |
1062 | /* waits for it to complete. | |
1063 | /* | |
1064 | /* | |
1065 | /************************************************************************/ | |
1066 | ||
1067 | int | |
1068 | db_query(db_handle, rel, query) | |
1069 | DATABASE db_handle; | |
1070 | RELATION rel; | |
1071 | char *query; | |
1072 | { | |
1073 | register OPERATION op; | |
1074 | register int status; | |
1075 | register int result; | |
1076 | ||
1077 | /* | |
1078 | * Create an operation and use it to asynchronously perform | |
1079 | * the operation | |
1080 | */ | |
1081 | op = create_operation(); | |
1082 | (void) start_db_query(op, db_handle, rel, query); | |
1083 | ||
1084 | /* | |
1085 | * Wait for it to complete, note whether the operation | |
1086 | * completed at all, and if so, whether it returned a | |
1087 | * successful result. Then reclaim the space used for the | |
1088 | * operation. | |
1089 | */ | |
1090 | (void) complete_operation(op); | |
1091 | status = OP_STATUS(op); | |
1092 | result = OP_RESULT(op); | |
1093 | ||
1094 | delete_operation(op); | |
1095 | ||
1096 | /* | |
1097 | * Tell the caller either that we were interrupted, or pass | |
1098 | * on the actual result of accessing the database. If it | |
1099 | * failed, then tear everything down after all. | |
1100 | */ | |
1101 | if (status==OP_COMPLETE) | |
1102 | return result; | |
1103 | else | |
1104 | return status; | |
1105 | } |