/[pgestraier]/trunk/pgest.c
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Revision 14 - (show annotations)
Thu May 26 00:06:10 2005 UTC (18 years, 11 months ago) by dpavlin
File MIME type: text/plain
File size: 9831 byte(s)
tests and fix for limit and offset bug introduced with null handling

1 /*
2 * integrate Hyper Estraier into PostgreSQL
3 *
4 * Dobrica Pavlinusic <dpavlin@rot13.org> 2005-05-19
5 *
6 * TODO:
7 * - all
8 *
9 * NOTES:
10 * - clear structures with memset to support hash indexes (who whould like
11 * to create hash index on table returned from function?)
12 * - number of returned rows is set by PostgreSQL evaluator, see:
13 * http://archives.postgresql.org/pgsql-hackers/2005-02/msg00546.php
14 *
15 * Based on:
16 * - C example from PostgreSQL documentation (BSD licence)
17 * - example002.c from Hyper Estraier (GPL)
18 * - _textin/_textout from pgcurl.c (LGPL)
19 *
20 * This code is licenced under GPL
21 */
22
23 #include "postgres.h"
24 #include "fmgr.h"
25 #include "funcapi.h"
26 #include "utils/builtins.h"
27 #include "utils/array.h"
28 #include "miscadmin.h"
29 #include <estraier.h>
30 #include <cabin.h>
31
32 #define _textin(str) DirectFunctionCall1(textin, CStringGetDatum(str))
33 #define _textout(str) DatumGetPointer(DirectFunctionCall1(textout, PointerGetDatum(str)))
34 #define GET_STR(textp) DatumGetCString(DirectFunctionCall1(textout, PointerGetDatum(textp)))
35 #define GET_TEXT(cstrp) DatumGetTextP(DirectFunctionCall1(textin, CStringGetDatum(cstrp)))
36
37 /* prototype */
38 char *attr2text(ESTDOC *doc, char *attr);
39
40 ESTDB *db;
41 ESTCOND *cond;
42 ESTDOC *doc;
43 const CBLIST *texts;
44 int ecode, *est_result, resnum, i, j;
45 int limit = 0;
46 int offset = 0;
47
48 /* define PostgreSQL v1 function */
49 PG_FUNCTION_INFO_V1(pgest);
50 Datum pgest(PG_FUNCTION_ARGS) {
51
52 FuncCallContext *funcctx;
53 int call_cntr;
54 int max_calls;
55 TupleDesc tupdesc;
56 TupleTableSlot *slot;
57 AttInMetadata *attinmeta;
58 char *index_path;
59 char *query;
60 char *attr;
61
62 /* stuff done only on the first call of the function */
63 if (SRF_IS_FIRSTCALL()) {
64 MemoryContext oldcontext;
65
66 /* create a function context for cross-call persistence */
67 funcctx = SRF_FIRSTCALL_INIT();
68
69 /* switch to memory context appropriate for multiple function calls */
70 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
71 /* take arguments from function */
72
73 /* index path */
74 if (PG_ARGISNULL(0)) {
75 elog(ERROR, "index path can't be null");
76 SRF_RETURN_DONE(funcctx);
77 }
78 index_path = _textout(PG_GETARG_TEXT_P(0));
79
80 /* query string */
81 if (PG_ARGISNULL(0)) {
82 query = "";
83 } else {
84 query = _textout(PG_GETARG_TEXT_P(1));
85 }
86
87 /* atribute filter */
88 if (PG_ARGISNULL(2)) {
89 attr = "";
90 } else {
91 attr = _textout(PG_GETARG_TEXT_P(2));
92 }
93
94 /* limit */
95 if (PG_ARGISNULL(3)) {
96 limit = 0;
97 } else {
98 limit = PG_GETARG_INT32(3);
99 }
100
101 /* offset */
102 if (PG_ARGISNULL(4)) {
103 offset = 0;
104 } else {
105 offset = PG_GETARG_INT32(4);
106 }
107
108
109 /* open the database */
110 elog(DEBUG1, "pgest: est_db_open(%s)", index_path);
111
112 if(!(db = est_db_open(index_path, ESTDBREADER, &ecode))){
113 elog(ERROR, "est_db_open: can't open %s [%d]: %s", index_path, ecode, est_err_msg(ecode));
114 SRF_RETURN_DONE(funcctx);
115 }
116
117 elog(INFO, "pgest: query[%s] attr[%s] limit %d offset %d", query, (PG_ARGISNULL(2) ? "NULL" : attr), limit, offset);
118
119 /* create a search condition object */
120 if (!(cond = est_cond_new())) {
121 elog(INFO, "pgest: est_cond_new failed");
122 SRF_RETURN_DONE(funcctx);
123 }
124
125 /* set the search phrase to the search condition object */
126 if (! PG_ARGISNULL(1) && strlen(query) > 0)
127 est_cond_set_phrase(cond, query);
128
129 /* minimum valid attribute length is 10: @a STREQ a */
130 if (! PG_ARGISNULL(2) && strlen(attr) >= 10) {
131 elog(INFO,"est_cond_add_attr(%s)", attr);
132 est_cond_add_attr(cond, attr);
133 }
134
135 /* get the result of search */
136 est_result = est_db_search(db, cond, &resnum, NULL);
137
138 /* total number of tuples to be returned */
139 if (limit && limit < resnum) {
140 funcctx->max_calls = limit - offset;
141 } else {
142 funcctx->max_calls = resnum - offset;
143 }
144
145 /* check if results exists */
146 if ( 0 == funcctx->max_calls )
147 elog(INFO, "pgest: no results for: %s", query );
148
149 elog(DEBUG1, "pgest: found %d hits for %s", resnum, query);
150
151 /* Build a tuple description for a __pgest tuple */
152 tupdesc = RelationNameGetTupleDesc("__pgest");
153
154 /* allocate a slot for a tuple with this tupdesc */
155 slot = TupleDescGetSlot(tupdesc);
156
157 /* assign slot to function context */
158 funcctx->slot = slot;
159
160 /*
161 * generate attribute metadata needed later to produce tuples from raw
162 * C strings
163 */
164 attinmeta = TupleDescGetAttInMetadata(tupdesc);
165 funcctx->attinmeta = attinmeta;
166
167 MemoryContextSwitchTo(oldcontext);
168
169 elog(DEBUG1, "SRF_IS_FIRSTCALL done");
170 }
171
172 /* stuff done on every call of the function */
173 funcctx = SRF_PERCALL_SETUP();
174
175 call_cntr = funcctx->call_cntr;
176 max_calls = funcctx->max_calls;
177 slot = funcctx->slot;
178 attinmeta = funcctx->attinmeta;
179
180 if (limit && call_cntr > limit - 1) {
181 elog(INFO, "call_cntr: %d limit: %d", call_cntr, limit);
182 SRF_RETURN_DONE(funcctx);
183 }
184
185 if (call_cntr < max_calls) {
186 char **values;
187 HeapTuple tuple;
188 Datum result;
189
190 elog(DEBUG1, "pgest: loop count %d", call_cntr);
191
192 if (! est_result) {
193 elog(ERROR, "pgest: no estraier results");
194 SRF_RETURN_DONE(funcctx);
195 }
196
197 /*
198 * Prepare a values array for storage in our slot.
199 * This should be an array of C strings which will
200 * be processed later by the type input functions.
201 */
202
203 if (doc = est_db_get_doc(db, est_result[call_cntr + offset], 0)) {
204
205 elog(DEBUG1, "URI: %s\n Title: %s\n",
206 est_doc_attr(doc, "@uri"),
207 est_doc_attr(doc, "@title")
208 );
209
210 values = (char **) palloc(4 * sizeof(char *));
211
212 // values[0] = (char *) palloc(strlen(_estval) * sizeof(char));
213
214 values[0] = (char *) attr2text(doc,"@id");
215 values[1] = (char *) attr2text(doc,"@uri");
216 values[2] = (char *) attr2text(doc,"@title");
217 values[3] = (char *) attr2text(doc,"@type");
218
219 /* destloy the document object */
220 elog(DEBUG2, "est_doc_delete");
221 est_doc_delete(doc);
222 } else {
223 elog(INFO, "no result from estraier");
224 values[0] = DatumGetCString( "" );
225 values[1] = DatumGetCString( "" );
226 values[2] = DatumGetCString( "" );
227 values[3] = DatumGetCString( "" );
228 }
229
230
231 elog(DEBUG2, "build tuple");
232 /* build a tuple */
233 tuple = BuildTupleFromCStrings(attinmeta, values);
234
235 elog(DEBUG2, "make tuple into datum");
236 /* make the tuple into a datum */
237 result = TupleGetDatum(slot, tuple);
238
239 elog(DEBUG2, "cleanup");
240 /* clean up ? */
241 /*
242 pfree(values[0]);
243 pfree(values[1]);
244 pfree(values[2]);
245 pfree(values[3]);
246 pfree(values);
247 */
248
249 elog(DEBUG2, "cleanup over");
250
251 SRF_RETURN_NEXT(funcctx, result);
252 } else {
253 elog(DEBUG1, "loop over");
254
255 if(!est_db_close(db, &ecode)){
256 elog(INFO, "est_db_close error: %s", est_err_msg(ecode));
257 }
258
259 /* do when there is no more left */
260 SRF_RETURN_DONE(funcctx);
261 }
262 }
263
264 /* work in progress */
265 PG_FUNCTION_INFO_V1(pgest2);
266 Datum pgest2(PG_FUNCTION_ARGS)
267 {
268 int nrows = 3;
269 int16 typlen;
270 bool typbyval;
271 char typalign;
272 ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
273 AttInMetadata *attinmeta;
274 TupleDesc tupdesc;
275 Tuplestorestate *tupstore = NULL;
276 HeapTuple tuple;
277 MemoryContext per_query_ctx;
278 MemoryContext oldcontext;
279 Datum dvalue;
280 char **values;
281 int ncols;
282 int i, j;
283
284 /* check to see if caller supports us returning a tuplestore */
285 if (!rsinfo || !(rsinfo->allowedModes & SFRM_Materialize))
286 ereport(ERROR,
287 (errcode(ERRCODE_SYNTAX_ERROR),
288 errmsg("materialize mode required, but it is not " \
289 "allowed in this context")));
290
291 /* get the requested return tuple description */
292 tupdesc = rsinfo->expectedDesc;
293 ncols = tupdesc->natts;
294
295 /*
296 * The requested tuple description better match up with the array
297 * we were given.
298 */
299 /* OK, use it */
300 attinmeta = TupleDescGetAttInMetadata(tupdesc);
301
302 /* Now go to work */
303 rsinfo->returnMode = SFRM_Materialize;
304
305 per_query_ctx = fcinfo->flinfo->fn_mcxt;
306 oldcontext = MemoryContextSwitchTo(per_query_ctx);
307
308 /* initialize our tuplestore */
309 tupstore = tuplestore_begin_heap(true, false, SortMem);
310
311 values = (char **) palloc(ncols * sizeof(char *));
312
313 for (i = 0; i < nrows; i++)
314 {
315 for (j = 0; j < ncols; j++)
316 {
317 values[j] = DatumGetCString( "foo" );
318 }
319 /* construct the tuple */
320 tuple = BuildTupleFromCStrings(attinmeta, values);
321
322 /* now store it */
323 tuplestore_puttuple(tupstore, tuple);
324 }
325
326 tuplestore_donestoring(tupstore);
327 rsinfo->setResult = tupstore;
328
329 /*
330 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
331 * tuples are in our tuplestore and passed back through
332 * rsinfo->setResult. rsinfo->setDesc is set to the tuple description
333 * that we actually used to build our tuples with, so the caller can
334 * verify we did what it was expecting.
335 */
336 rsinfo->setDesc = tupdesc;
337 MemoryContextSwitchTo(oldcontext);
338
339 return (Datum) 0;
340 }
341
342
343 /* make text var from attr */
344 char *attr2text(ESTDOC *doc, char *attr) {
345 char *val;
346 const char *attrval;
347 int len;
348 int attrlen;
349
350 elog(DEBUG1, "doc: %08x, attr: %s", doc, attr);
351
352 if ( (attrval = est_doc_attr(doc, attr)) && (attrlen = strlen(attrval)) ) {
353 val = (char *) palloc(attrlen * sizeof(char));
354 } else {
355 return (Datum) NULL;
356 }
357
358 len = strlen(attrval);
359 elog(DEBUG1, "attr2text(%s) = '%s' %d bytes", attr, attrval, len);
360
361 len++;
362 len *= sizeof(char);
363
364 elog(DEBUG2, "palloc(%d)", len);
365
366 val = palloc(len);
367
368 memset(val, 0, len);
369 strncpy(val, attrval, len);
370
371 elog(DEBUG2, "val=%s", val);
372
373 return val;
374 }
375
376 /* make integer variable from property */
377 /*
378 char *prop2int(SW_RESULT sw_res, char *propname) {
379 char *val;
380 unsigned long prop;
381 int len;
382
383 elog(DEBUG2, "prop2int(%s)", propname);
384
385 prop = estResultPropertyULong( sw_res, propname );
386 if (error_or_abort( est_handle )) return NULL;
387
388 elog(DEBUG1, "prop2int(%s) = %lu", propname, prop);
389
390 len = 128 * sizeof(char);
391 elog(DEBUG2, "palloc(%d)", len);
392
393 val = palloc(len);
394 memset(val, 0, len);
395
396 snprintf(val, len, "%lu", prop);
397
398 elog(DEBUG2, "val=%s", val);
399
400 return val;
401 }
402 */

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