]>
Commit | Line | Data |
---|---|---|
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> |
24 | #include <strings.h> | |
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 | ||
241 | int | |
242 | g_iadb(op, hcon, arg) | |
243 | OPERATION op; | |
244 | HALF_CONNECTION hcon; | |
245 | struct adb_data *arg; | |
246 | { | |
247 | int rc; | |
248 | ||
249 | /* | |
250 | * Figure out how the receipt went | |
251 | */ | |
252 | rc = OP_STATUS(arg->get_retcode); | |
253 | ||
254 | /* | |
255 | * Release all transient data structures. | |
256 | */ | |
257 | if (rc != OP_COMPLETE || op->result != DB_OPEN) | |
258 | g_tear_down(arg->db); | |
259 | else | |
260 | DB_STATUS(arg->db) = DB_OPEN; | |
261 | ||
262 | delete_operation(arg->get_retcode); | |
263 | db_free((char *)arg, sizeof(struct adb_data)); | |
264 | ||
265 | return rc; | |
266 | } | |
267 | \f | |
268 | /************************************************************************/ | |
269 | /* | |
270 | /* g_tear_down | |
271 | /* | |
272 | /* this is called by access_db and perf_db_op when a fatal error | |
273 | /* is reached. It is an attempt to intelligently handle the error, | |
274 | /* and tear down connections and data structures if necessary. | |
275 | /* | |
276 | /* The current version simply tears down everything, perhaps later | |
277 | /* versions should make provision for closing the db as necessary, | |
278 | /* and/or other less drastic ways to handle the errors. | |
279 | /* | |
280 | /************************************************************************/ | |
281 | ||
282 | int | |
283 | g_tear_down (db_handle) | |
284 | DATABASE db_handle; | |
285 | { | |
286 | register DATABASE db = db_handle; | |
287 | ||
288 | /*----------------------------------------------------------*/ | |
289 | /* | |
290 | /* If the db is opened, and the connexn is severed, | |
291 | /* some error handling, closing of the db should be done | |
292 | /* at the server. | |
293 | /* | |
294 | /* Also, at the server, perhaps a return code to indicate | |
295 | /* that user tried to open non-existant db??? | |
296 | /* | |
297 | /*----------------------------------------------------------*/ | |
298 | ||
299 | ||
300 | if (db==NULL) | |
301 | return; | |
302 | ||
303 | ||
304 | (void) sever_connection (db->connection); | |
305 | ||
306 | /* | |
307 | * Free up the separately allocated strings to which the | |
308 | * database descriptor points | |
309 | */ | |
310 | gdb_fstring(db->server); | |
311 | gdb_fstring(db->name); | |
312 | ||
313 | /* | |
314 | * Free the descriptor itself | |
315 | */ | |
316 | db_free ((char *)db,sizeof(struct db_struct)); | |
317 | return; | |
318 | } | |
319 | \f | |
320 | /************************************************************************/ | |
321 | /* | |
322 | /* g_make_db | |
323 | /* | |
324 | /* Allocate and initialize a database descriptor structure. | |
325 | /* | |
326 | /************************************************************************/ | |
327 | ||
328 | DATABASE | |
329 | g_make_db() | |
330 | { | |
331 | register DATABASE db; | |
332 | ||
333 | db = (DATABASE)db_alloc (sizeof(struct db_struct)); | |
334 | db->id = GDB_DB_ID; | |
335 | db->connection = NULL; | |
336 | db->name = NULL; | |
337 | db->server = NULL; | |
338 | DB_STATUS(db) = DB_CLOSED; | |
339 | ||
340 | return db; | |
341 | } | |
342 | \f/************************************************************************/ | |
343 | /* | |
344 | /* access_db (access_db) | |
345 | /* | |
346 | /* Does a start_accessing_db and waits for it to complete. | |
347 | /* | |
348 | /************************************************************************/ | |
349 | ||
350 | int | |
351 | access_db (db_ident, db_handle) | |
352 | char *db_ident; | |
353 | DATABASE *db_handle; | |
354 | { | |
355 | register OPERATION op; | |
356 | register int status; | |
357 | register int result; | |
358 | ||
359 | GDB_INIT_CHECK | |
360 | ||
361 | /* | |
362 | * Create an operation and use it to asynchronously access | |
363 | * the database | |
364 | */ | |
365 | op = create_operation(); | |
366 | (void) start_accessing_db(op, db_ident, db_handle); | |
367 | ||
368 | /* | |
369 | * Wait for it to complete, note whether the operation completed | |
370 | * at all, and if so, whether it returned a successful result | |
371 | * in accessing the database. Then reclaim the space used for | |
372 | * the operation. | |
373 | */ | |
374 | (void) complete_operation(op); | |
375 | status = OP_STATUS(op); | |
376 | result = OP_RESULT(op); | |
377 | ||
378 | delete_operation(op); | |
379 | ||
380 | /* | |
381 | * Tell the caller either that we were interrupted, or pass | |
382 | * on the actual result of accessing the database. If it | |
383 | * failed, then tear everything down after all. | |
384 | */ | |
385 | if (status==OP_COMPLETE) | |
386 | return result; | |
387 | else | |
388 | return status; | |
389 | } | |
390 | \f/************************************************************************/ | |
391 | /* | |
392 | /* start_performing_db_operation (start_performing_db_operation) | |
393 | /* | |
394 | /* Asynchronously performs any operation except for a query | |
395 | /* on the remote database. | |
396 | /* | |
397 | /* The operation is encoded as a GDB string and sent to the server. | |
398 | /* | |
399 | /* An integer return code is received back and returned to the caller. | |
400 | /* | |
401 | /* Note that this operation executes on both the outbound and inbound | |
402 | /* half connections. Since there is no explicit sync between the two | |
403 | /* directions, operations like this pipeline freely from requestor | |
404 | /* to server, but there is no way to cancel this operation once it | |
405 | /* has started without severing the accompanying connection. | |
406 | /* | |
407 | /************************************************************************/ | |
408 | ||
409 | int g_ipdb(); | |
410 | ||
411 | struct pdb_data { | |
412 | DATABASE db; /* the database we're */ | |
413 | /* working on */ | |
414 | OPERATION send_request; /* used to send the string */ | |
415 | /* containing the db oper. */ | |
416 | /* to be performed */ | |
417 | OPERATION get_retcode; /* used to get back the */ | |
418 | /* response to our request */ | |
419 | STRING s; /* the operation string */ | |
420 | /* itself. This is sent. */ | |
421 | }; | |
422 | ||
423 | #define MIN_REQUEST_LEN 1 /*completely arbitrary */ | |
424 | #undef FAILURE | |
425 | #define FAILURE -1 | |
426 | ||
427 | int | |
428 | start_performing_db_operation (op, db_handle,request) | |
429 | OPERATION op; | |
430 | DATABASE db_handle; | |
431 | char *request; | |
432 | { | |
433 | /*----------------------------------------------------------*/ | |
434 | /* | |
435 | /* Declarations | |
436 | /* | |
437 | /*----------------------------------------------------------*/ | |
438 | ||
439 | register struct pdb_data *arg; /* holds our state */ | |
440 | /* during async operation*/ | |
441 | register DATABASE db = db_handle; /* fast working copy */ | |
442 | ||
443 | /*----------------------------------------------------------*/ | |
444 | /* | |
445 | /* Execution begins here | |
446 | /* | |
447 | /* Make sure parameters are correct, then allocate a | |
448 | /* structure. | |
449 | /* | |
450 | /*----------------------------------------------------------*/ | |
451 | ||
452 | GDB_CHECK_OP(op, "start_performing_db_operation ") | |
453 | if (db==NULL) { | |
454 | fprintf (gdb_log, "gdb: start_performing_db_operation: supplied database is NULL\n"); | |
455 | OP_STATUS(op) = OP_CANCELLED; | |
456 | return OP_CANCELLED; | |
457 | } | |
458 | ||
459 | GDB_CHECK_DB(db, "start_performing_db_operation") | |
460 | ||
461 | if (DB_STATUS(db) != DB_OPEN) { | |
462 | fprintf (gdb_log, "gdb: start_performing_db_operation: request to closed database "); | |
463 | OP_STATUS(op) = OP_CANCELLED; | |
464 | return OP_CANCELLED; | |
465 | } | |
466 | ||
467 | if (db->connection == NULL) { | |
468 | fprintf (gdb_log, | |
469 | "gdb: start_performing_db_operation: connection severed, request cancelled\n"); | |
470 | OP_STATUS(op) = OP_CANCELLED; | |
471 | return OP_CANCELLED; | |
472 | } | |
473 | ||
474 | if (connection_status(db->connection) != CON_UP ) { | |
475 | fprintf (gdb_log, "gdb: start_performing_db_operation: problems maintaining connection "); | |
476 | connection_perror(db->connection, "Reason for connection failure"); | |
477 | fprintf (gdb_log, "request cancelled \n"); | |
478 | OP_STATUS(op) = OP_CANCELLED; | |
479 | return OP_CANCELLED; | |
480 | } | |
481 | ||
482 | if ((request == NULL) || (strlen (request)<MIN_REQUEST_LEN)) { | |
483 | fprintf (gdb_log, "gdb: start_performing_db_operation: request either missing or too short\n"); | |
484 | OP_STATUS(op) = OP_CANCELLED; | |
485 | return OP_CANCELLED; | |
486 | /*should we disallow empty requests? */ | |
487 | } | |
488 | ||
489 | ||
490 | /*----------------------------------------------------------*/ | |
491 | /* | |
492 | /* Asynchronously send the request to the server | |
493 | /* | |
494 | /*----------------------------------------------------------*/ | |
495 | ||
496 | /* | |
497 | * Allocate a structure to hold our state while we're gone | |
498 | * waiting for this to complete. | |
499 | */ | |
500 | ||
501 | arg = (struct pdb_data *)db_alloc(sizeof(struct pdb_data)); | |
502 | arg->db = db; | |
503 | arg->send_request = create_operation(); | |
504 | ||
505 | /* | |
506 | * Send the request string to the server | |
507 | */ | |
508 | STRING_DATA(arg->s) = request; | |
509 | MAX_STRING_SIZE(arg->s) = strlen (request) +1; | |
510 | start_sending_object (arg->send_request, db->connection, | |
511 | (char *)&(arg->s), STRING_T); | |
512 | if (OP_STATUS(arg->send_request) == OP_CANCELLED) { | |
513 | OP_STATUS(op) = OP_CANCELLED; | |
514 | delete_operation(arg->send_request); | |
515 | db_free((char *)arg, sizeof(struct pdb_data)); | |
516 | return OP_CANCELLED; | |
517 | } | |
518 | ||
519 | /*----------------------------------------------------------*/ | |
520 | /* | |
521 | /* Asynchronously receive the return code (note, we | |
522 | /* really don't know whether the request has even been | |
523 | /* sent yet...doesn't really matter.) | |
524 | /* | |
525 | /*----------------------------------------------------------*/ | |
526 | ||
527 | arg->get_retcode = create_operation(); | |
528 | /* | |
529 | * This must come here as it sets op_result | |
530 | */ | |
531 | initialize_operation(op, g_ipdb, (char *)arg, (int (*)())NULL); | |
532 | ||
533 | start_receiving_object (arg->get_retcode, db->connection, | |
534 | (char *)&(OP_RESULT(op)), INTEGER_T); | |
535 | if (OP_STATUS(arg->get_retcode) == OP_CANCELLED) { | |
536 | OP_STATUS(op) = OP_CANCELLED; | |
537 | (void) cancel_operation(arg->send_request);/* this could be a bug, */ | |
538 | /* because we introduce */ | |
539 | /* indeterminism into */ | |
540 | /* the reply stream, probably */ | |
541 | /* should shutdown the whole */ | |
542 | /* db here */ | |
543 | delete_operation(arg->send_request); | |
544 | delete_operation(arg->get_retcode); | |
545 | db_free((char *)arg, sizeof(struct adb_data)); | |
546 | return OP_CANCELLED; | |
547 | } | |
548 | ||
549 | /* | |
550 | * We've successfully queued the receive of the return code. | |
551 | * That's about all we have to do if things go well, but if the | |
552 | * operation fails later, we have to be there to clean up. To | |
553 | * get control back, we queue ourselves as a second operation | |
554 | * so we can see how the first did, and so we can free up arg. | |
555 | */ | |
556 | (void) queue_operation(db->connection, CON_INPUT, op); | |
557 | return OP_RUNNING; | |
558 | } | |
559 | ||
560 | /*----------------------------------------------------------*/ | |
561 | /* | |
562 | /* g_ipdb | |
563 | /* | |
564 | /* Init routine for getting return code on performin a db | |
565 | /* operation. If all went well, (or even if it didn't), | |
566 | /* then we are done. All we have to do is clean up the | |
567 | /* stuff we've allocated. | |
568 | /* | |
569 | /*----------------------------------------------------------*/ | |
570 | ||
571 | int | |
572 | g_ipdb(op, hcon, arg) | |
573 | OPERATION op; | |
574 | HALF_CONNECTION hcon; | |
575 | struct pdb_data *arg; | |
576 | { | |
577 | int rc1, rc2; | |
578 | ||
579 | /* | |
580 | * Figure out how the receipt went | |
581 | */ | |
582 | rc1 = OP_STATUS(arg->send_request); | |
583 | rc2 = OP_STATUS(arg->get_retcode); | |
584 | ||
585 | /* | |
586 | * Release all transient data structures. | |
587 | */ | |
588 | if (rc1 != OP_COMPLETE || rc2 != OP_COMPLETE) | |
589 | g_tear_down(arg->db); | |
590 | ||
591 | delete_operation(arg->send_request); | |
592 | delete_operation(arg->get_retcode); | |
593 | db_free((char *)arg, sizeof(struct pdb_data)); | |
594 | ||
595 | return rc2; | |
596 | } | |
597 | \f | |
598 | /************************************************************************/ | |
599 | /* | |
600 | /* perform_db_operation (perform_db_operation) | |
601 | /* | |
602 | /* Do a database operation synchronously. This just calls | |
603 | /* the async routine and waits for it to complete. | |
604 | /* | |
605 | /************************************************************************/ | |
606 | ||
607 | perform_db_operation (db_handle,request) | |
608 | DATABASE db_handle; | |
609 | char *request; | |
610 | { | |
611 | register OPERATION op; | |
612 | register int status; | |
613 | register int result; | |
614 | ||
615 | /* | |
616 | * Create an operation and use it to asynchronously perform | |
617 | * the operation | |
618 | */ | |
619 | op = create_operation(); | |
620 | (void) start_performing_db_operation(op, db_handle, request); | |
621 | ||
622 | /* | |
623 | * Wait for it to complete, note whether the operation | |
624 | * completed at all, and if so, whether it returned a | |
625 | * successful result. Then reclaim the space used for the | |
626 | * operation. | |
627 | */ | |
628 | (void) complete_operation(op); | |
629 | status = OP_STATUS(op); | |
630 | result = OP_RESULT(op); | |
631 | ||
632 | delete_operation(op); | |
633 | ||
634 | /* | |
635 | * Tell the caller either that we were interrupted, or pass | |
636 | * on the actual result of accessing the database. If it | |
637 | * failed, then tear everything down after all. | |
638 | */ | |
639 | if (status==OP_COMPLETE) | |
640 | return result; | |
641 | else | |
642 | return status; | |
643 | } | |
644 | \f/************************************************************************/ | |
645 | /* | |
646 | /* start_db_query (start_db_query) | |
647 | /* | |
648 | /* Asynchronously performs a database query on the remote | |
649 | /* database. | |
650 | /* | |
651 | /* The operation is encoded as a GDB string and sent to the server. | |
652 | /* | |
653 | /* An integer return code is received back and returned to the caller. | |
654 | /* | |
655 | /* If the return code indicates success, then we go into a loop | |
656 | /* receiving the retrieved data. Each returned tuple is preceeded by | |
657 | /* a so-called yes/no flag, which indicates whether tuple data is really | |
658 | /* to follow. Last tuple is followed by a NO flag. | |
659 | /* | |
660 | /* Note that this operation executes on both the outbound and inbound | |
661 | /* half connections. Since there is no explicit sync between the two | |
662 | /* directions, operations like this pipeline freely from requestor | |
663 | /* to server, but there is no way to cancel this operation once it | |
664 | /* has started without severing the accompanying connection. | |
665 | /* | |
666 | /************************************************************************/ | |
667 | ||
668 | int g_idbq(); | |
669 | int g_cdbq(); | |
670 | ||
671 | struct dbq_data { | |
672 | /* | |
673 | * Following may be used throughout processing | |
674 | */ | |
675 | DATABASE db; /* the database we're */ | |
676 | /* working on */ | |
677 | RELATION rel; | |
678 | TUPLE_DESCRIPTOR tpd; | |
679 | /* | |
680 | * used primarily in first phase for sending query and getting | |
681 | * return code | |
682 | */ | |
683 | OPERATION send_query; /* used to send the string */ | |
684 | /* containing the query */ | |
685 | /* to be performed */ | |
686 | OPERATION send_descriptor; /* used to send the tuple */ | |
687 | /* descriptor to the server */ | |
688 | OPERATION get_retcode; /* used to get back the */ | |
689 | /* response to our request */ | |
690 | STRING s; /* the operation string */ | |
691 | /* itself. This is sent. */ | |
692 | /* | |
693 | * Following are used during later phase to receive the tuples | |
694 | */ | |
695 | int state; /* are we expecting a yes/no */ | |
696 | /* or a tuple next? */ | |
697 | #define YESNO 1 | |
698 | #define TUPDATA 2 | |
699 | int yesno; /* an indicator of whether */ | |
700 | /* another tuple is to follow*/ | |
701 | #define YES 1 | |
702 | OPERATION receive_yesno_or_data; | |
703 | TUPLE tup; /* a place to put */ | |
704 | /* the next tuple */ | |
705 | }; | |
706 | ||
707 | int | |
708 | start_db_query (op, db_handle,rel, query) | |
709 | OPERATION op; | |
710 | DATABASE db_handle; | |
711 | RELATION rel; | |
712 | char *query; | |
713 | { | |
714 | /*----------------------------------------------------------*/ | |
715 | /* | |
716 | /* Declarations | |
717 | /* | |
718 | /*----------------------------------------------------------*/ | |
719 | ||
720 | register struct dbq_data *arg; /* holds our state */ | |
721 | /* during async operation*/ | |
722 | register DATABASE db = db_handle; /* fast working copy */ | |
723 | ||
724 | /*----------------------------------------------------------*/ | |
725 | /* | |
726 | /* Execution begins here | |
727 | /* | |
728 | /* Make sure parameters are correct, then allocate a | |
729 | /* structure. | |
730 | /* | |
731 | /*----------------------------------------------------------*/ | |
732 | ||
733 | GDB_CHECK_OP(op, "start_db_query ") | |
734 | ||
735 | if (rel ==NULL) { | |
736 | fprintf (gdb_log, "gdb: query_db: input rel is null \n"); | |
737 | OP_STATUS(op) = OP_CANCELLED; | |
738 | return OP_CANCELLED; | |
739 | } | |
740 | ||
741 | if (db==NULL) { | |
742 | fprintf (gdb_log, "gdb: start_db_query: supplied database is NULL\n"); | |
743 | OP_STATUS(op) = OP_CANCELLED; | |
744 | return OP_CANCELLED; | |
745 | } | |
746 | ||
747 | GDB_CHECK_DB(db, "start_db_query") | |
748 | ||
749 | if (DB_STATUS(db) != DB_OPEN) { | |
750 | fprintf (gdb_log, "gdb: start_db_query: request to closed database "); | |
751 | OP_STATUS(op) = OP_CANCELLED; | |
752 | return OP_CANCELLED; | |
753 | } | |
754 | ||
755 | if (db->connection == NULL) { | |
756 | fprintf (gdb_log,"gdb: start_db_query: connection severed, request cancelled\n"); | |
757 | OP_STATUS(op) = OP_CANCELLED; | |
758 | return OP_CANCELLED; | |
759 | } | |
760 | ||
761 | if (connection_status(db->connection) != CON_UP ) { | |
762 | fprintf (gdb_log,"gdb: start_db_query: problems maintaining connection "); | |
763 | connection_perror(db->connection, "Reason for connection failure"); | |
764 | fprintf (gdb_log,"request cancelled \n"); | |
765 | OP_STATUS(op) = OP_CANCELLED; | |
766 | return OP_CANCELLED; | |
767 | } | |
768 | ||
769 | if (query == NULL || *query == '\0') { | |
770 | fprintf (gdb_log, "gdb: start_db_query: request string is null\n"); | |
771 | OP_STATUS(op) = OP_CANCELLED; | |
772 | return OP_CANCELLED; | |
773 | } | |
774 | ||
775 | ||
776 | /*----------------------------------------------------------*/ | |
777 | /* | |
778 | /* Asynchronously send the query to the server | |
779 | /* | |
780 | /*----------------------------------------------------------*/ | |
781 | ||
782 | /* | |
783 | * Allocate a structure to hold our state while we're gone | |
784 | * waiting for this to complete. | |
785 | */ | |
786 | ||
787 | arg = (struct dbq_data *)db_alloc(sizeof(struct dbq_data)); | |
788 | arg->db = db; | |
789 | arg->rel = rel; | |
790 | arg->send_query = create_operation(); | |
791 | ||
792 | /* | |
793 | * Send the query string to the server | |
794 | */ | |
795 | (void) string_alloc(&(arg->s), strlen(query)+11); | |
796 | (void) strcpy(STRING_DATA(arg->s), "retrieve "); | |
797 | (void) strcat(STRING_DATA(arg->s), query); | |
798 | MAX_STRING_SIZE(arg->s) = strlen (query) +11; | |
799 | start_sending_object (arg->send_query, db->connection, | |
800 | (char *)&(arg->s), STRING_T); | |
801 | if (OP_STATUS(arg->send_query) == OP_CANCELLED) { | |
802 | OP_STATUS(op) = OP_CANCELLED; | |
803 | delete_operation(arg->send_query); | |
804 | string_free(&(arg->s)); | |
805 | db_free((char *)arg, sizeof(struct dbq_data)); | |
806 | return OP_CANCELLED; | |
807 | } | |
808 | ||
809 | /* | |
810 | * Send the tuple descriptor to the server | |
811 | */ | |
812 | ||
813 | arg->send_descriptor = create_operation(); | |
814 | arg->tpd = DESCRIPTOR_FROM_RELATION(arg->rel); | |
815 | ||
816 | start_sending_object (arg->send_descriptor, db->connection, | |
817 | (char *)&(arg->tpd), TUPLE_DESCRIPTOR_T); | |
818 | if (OP_STATUS(arg->send_descriptor) == OP_CANCELLED) { | |
819 | OP_STATUS(op) = OP_CANCELLED; | |
820 | (void) cancel_operation(arg->send_query);/* this could be a bug, */ | |
821 | /* because we introduce */ | |
822 | /* indeterminism into */ | |
823 | /* the reply stream, probably */ | |
824 | /* should shutdown the whole */ | |
825 | /* db here */ | |
826 | delete_operation(arg->send_query); | |
827 | delete_operation(arg->send_descriptor); | |
828 | string_free(&(arg->s)); | |
829 | db_free((char *)arg, sizeof(struct dbq_data)); | |
830 | return OP_CANCELLED; | |
831 | } | |
832 | ||
833 | /*----------------------------------------------------------*/ | |
834 | /* | |
835 | /* Asynchronously receive the return code (note, we | |
836 | /* really don't know whether the query/and the descriptor | |
837 | /* have even been sent yet...doesn't really matter.) | |
838 | /* | |
839 | /*----------------------------------------------------------*/ | |
840 | ||
841 | arg->get_retcode = create_operation(); | |
842 | start_receiving_object (arg->get_retcode, db->connection, | |
843 | (char *)&(OP_RESULT(op)), INTEGER_T); | |
844 | if (OP_STATUS(arg->get_retcode) == OP_CANCELLED) { | |
845 | OP_STATUS(op) = OP_CANCELLED; | |
846 | (void) cancel_operation(arg->send_query);/* this could be a bug, */ | |
847 | /* because we introduce */ | |
848 | /* indeterminism into */ | |
849 | /* the reply stream, probably */ | |
850 | /* should shutdown the whole */ | |
851 | /* db here */ | |
852 | (void) cancel_operation(arg->send_descriptor); | |
853 | string_free(&(arg->s)); | |
854 | delete_operation(arg->send_query); | |
855 | delete_operation(arg->send_descriptor); | |
856 | delete_operation(arg->get_retcode); | |
857 | db_free((char *)arg, sizeof(struct adb_data)); | |
858 | return OP_CANCELLED; | |
859 | } | |
860 | ||
861 | /* | |
862 | * We've successfully queued the receive of the return code. | |
863 | * That's about all we have to do if things go well, but if the | |
864 | * operation fails later, we have to be there to clean up. To | |
865 | * get control back, we queue ourselves as a second operation | |
866 | * so we can see how the first did, and so we can free up arg. | |
867 | */ | |
868 | initialize_operation(op, g_idbq, (char *)arg, (int (*)())NULL); | |
869 | (void) queue_operation(db->connection, CON_INPUT, op); | |
870 | ||
871 | return OP_RUNNING; | |
872 | } | |
873 | ||
874 | /*----------------------------------------------------------*/ | |
875 | /* | |
876 | /* g_idbq | |
877 | /* | |
878 | /* Init routine for getting return code on performing a | |
879 | /* bd query. If there was an error, then we are done except for | |
880 | /* cleaning up all the dynamic memory we allocated. | |
881 | /* If the return code was 0,then we must asynchronously | |
882 | /* do the following iteratively until a no is received: | |
883 | /* | |
884 | /* while (async_receive(yes/no) == yes) { | |
885 | /* async receive new tuple | |
886 | /* add it to the relation | |
887 | /* } | |
888 | /* | |
889 | /*----------------------------------------------------------*/ | |
890 | ||
891 | int | |
892 | g_idbq(op, hcon, arg) | |
893 | OPERATION op; | |
894 | HALF_CONNECTION hcon; | |
895 | struct dbq_data *arg; | |
896 | { | |
897 | int rc1, rc2, rc3; | |
898 | ||
899 | /*----------------------------------------------------------*/ | |
900 | /* | |
901 | /* See how the three asynchronous operations went,and | |
902 | /* clean up after them. | |
903 | /* | |
904 | /*----------------------------------------------------------*/ | |
905 | ||
906 | /* | |
907 | * Figure out how the receipt went | |
908 | */ | |
909 | rc1 = OP_STATUS(arg->send_query); | |
910 | rc2 = OP_STATUS(arg->send_descriptor); | |
911 | rc3 = OP_STATUS(arg->get_retcode); | |
912 | ||
913 | /* | |
914 | * Release all transient data structures which were used in the | |
915 | * preliminary operations. | |
916 | */ | |
917 | delete_operation(arg->send_query); | |
918 | delete_operation(arg->get_retcode); | |
919 | string_free(&(arg->s)); | |
920 | /* | |
921 | * If we've failed for any reason, then mark ourselves complete and | |
922 | * return. | |
923 | */ | |
924 | if (rc1 != OP_COMPLETE || rc2 != OP_COMPLETE|| rc3 != OP_COMPLETE | |
925 | || OP_RESULT(op) != OP_SUCCESS) { | |
926 | OP_STATUS(op) = rc3; /* we must have done */ | |
927 | /* about as well as */ | |
928 | /* the last one */ | |
929 | ||
930 | db_free((char *)arg, sizeof(struct dbq_data)); | |
931 | return rc3; /* tell the dispatcher */ | |
932 | /* that we're either */ | |
933 | /* cancelled or complete */ | |
934 | } | |
935 | ||
936 | /*----------------------------------------------------------*/ | |
937 | /* | |
938 | /* We've successfully received a return code of 0 from | |
939 | /* Ingres, which means we are now going to begin the | |
940 | /* yes/no loop. | |
941 | /* | |
942 | /*----------------------------------------------------------*/ | |
943 | ||
944 | op->fcn.cont = g_cdbq; /* after the preempting */ | |
945 | /* receive completes, the */ | |
946 | /* dispatcher will call */ | |
947 | /* this routine. */ | |
948 | arg->state = YESNO; /* tell continuation routine */ | |
949 | /* that we're receiving */ | |
950 | /* a yes/no */ | |
951 | arg->tup = NULL; /* so we won't try to clean */ | |
952 | /* it up */ | |
953 | arg->receive_yesno_or_data = create_operation(); | |
954 | ||
955 | preempt_and_start_receiving_object(arg->receive_yesno_or_data, | |
956 | op, | |
957 | (char *)&(arg->yesno), | |
958 | INTEGER_T); | |
959 | return OP_PREEMPTED; | |
960 | } | |
961 | ||
962 | /*----------------------------------------------------------*/ | |
963 | /* | |
964 | /* g_cdbq | |
965 | /* | |
966 | /* Continuation routine for receiving results of a query. | |
967 | /* Tbis is called repeatedly each time either a yes/no or | |
968 | /* a new tuple is received. It repeatedly preempts itself | |
969 | /* to receive the next yes/no or tuple until a 'no' | |
970 | /* is finally received. | |
971 | /* | |
972 | /*----------------------------------------------------------*/ | |
973 | ||
974 | int | |
975 | g_cdbq(op, hcon, arg) | |
976 | OPERATION op; | |
977 | HALF_CONNECTION hcon; | |
978 | struct dbq_data *arg; | |
979 | { | |
980 | /*----------------------------------------------------------*/ | |
981 | /* | |
982 | /* See whether the preempting operation completed | |
983 | /* successfully. If not, we just clean up and cancel | |
984 | /* | |
985 | /*----------------------------------------------------------*/ | |
986 | ||
987 | if (OP_STATUS(arg->receive_yesno_or_data) != OP_COMPLETE) { | |
988 | delete_operation(arg->receive_yesno_or_data); | |
989 | if (arg->tup != NULL) | |
990 | delete_tuple(arg->tup); | |
991 | db_free((char *)arg, sizeof(struct dbq_data)); | |
992 | OP_STATUS(op) = OP_CANCELLED; | |
993 | return OP_CANCELLED; | |
994 | } | |
995 | ||
996 | /*----------------------------------------------------------*/ | |
997 | /* | |
998 | /* Whatever it was, we received it cleanly. If it | |
999 | /* was tuple data, then accept it and prepare to receive | |
1000 | /* a yesno. If it was a yes, then prepare to receive | |
1001 | /* the tuple data. If it was a NO, then we're all done. | |
1002 | /* | |
1003 | /* Note that g_cdbg will be recalled by the dispatcher | |
1004 | /* after the preempting routines have completed. | |
1005 | /* | |
1006 | /*----------------------------------------------------------*/ | |
1007 | ||
1008 | /* | |
1009 | * New TUPLE DATA | |
1010 | */ | |
1011 | ||
1012 | if (arg->state == TUPDATA) { | |
1013 | ADD_TUPLE_TO_RELATION(arg->rel, arg->tup); | |
1014 | arg->tup = NULL; /* so we won't try to */ | |
1015 | /* delete it in case of error*/ | |
1016 | reset_operation(arg->receive_yesno_or_data); | |
1017 | arg->state = YESNO; | |
1018 | preempt_and_start_receiving_object(arg->receive_yesno_or_data, | |
1019 | op, | |
1020 | (char *)&(arg->yesno), | |
1021 | INTEGER_T); | |
1022 | return OP_PREEMPTED; | |
1023 | } | |
1024 | ||
1025 | /* | |
1026 | * We just received a yes or no. If it's a YES, prepare to | |
1027 | * receive some more tuple data. | |
1028 | */ | |
1029 | if (arg->yesno == YES) { | |
1030 | arg->tup = create_tuple(arg->tpd); | |
1031 | reset_operation(arg->receive_yesno_or_data); | |
1032 | arg->state = TUPDATA; | |
1033 | preempt_and_start_receiving_object(arg->receive_yesno_or_data, | |
1034 | op, | |
1035 | (char *)arg->tup, | |
1036 | TUPLE_DATA_T); | |
1037 | return OP_PREEMPTED; | |
1038 | } | |
1039 | /* | |
1040 | * We just received a NO. Looks like we're all done cleanly. | |
1041 | */ | |
1042 | delete_operation(arg->receive_yesno_or_data); | |
1043 | if (arg->tup != NULL) | |
1044 | delete_tuple(arg->tup); | |
1045 | db_free((char *)arg, sizeof(struct dbq_data)); | |
1046 | OP_STATUS(op) = OP_COMPLETE; | |
1047 | return OP_COMPLETE; | |
1048 | ||
1049 | } | |
1050 | \f | |
1051 | /************************************************************************/ | |
1052 | /* | |
1053 | /* db_query (db_query) | |
1054 | /* | |
1055 | /* Perform a relational query on the specified database. | |
1056 | /* | |
1057 | /* This just calls the asynchronous form of doing a query and | |
1058 | /* waits for it to complete. | |
1059 | /* | |
1060 | /* | |
1061 | /************************************************************************/ | |
1062 | ||
1063 | int | |
1064 | db_query(db_handle, rel, query) | |
1065 | DATABASE db_handle; | |
1066 | RELATION rel; | |
1067 | char *query; | |
1068 | { | |
1069 | register OPERATION op; | |
1070 | register int status; | |
1071 | register int result; | |
1072 | ||
1073 | /* | |
1074 | * Create an operation and use it to asynchronously perform | |
1075 | * the operation | |
1076 | */ | |
1077 | op = create_operation(); | |
1078 | (void) start_db_query(op, db_handle, rel, query); | |
1079 | ||
1080 | /* | |
1081 | * Wait for it to complete, note whether the operation | |
1082 | * completed at all, and if so, whether it returned a | |
1083 | * successful result. Then reclaim the space used for the | |
1084 | * operation. | |
1085 | */ | |
1086 | (void) complete_operation(op); | |
1087 | status = OP_STATUS(op); | |
1088 | result = OP_RESULT(op); | |
1089 | ||
1090 | delete_operation(op); | |
1091 | ||
1092 | /* | |
1093 | * Tell the caller either that we were interrupted, or pass | |
1094 | * on the actual result of accessing the database. If it | |
1095 | * failed, then tear everything down after all. | |
1096 | */ | |
1097 | if (status==OP_COMPLETE) | |
1098 | return result; | |
1099 | else | |
1100 | return status; | |
1101 | } |