/[pgswish]/trunk/pgswish.c
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Contents of /trunk/pgswish.c

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Revision 17 - (show annotations)
Sun Feb 20 21:54:39 2005 UTC (19 years, 2 months ago) by dpavlin
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1 /*
2 * integrate swish-e into PostgreSQL
3 *
4 * Dobrica Pavlinusic <dpavlin@rot13.org> 2005-02-18
5 *
6 * TODO:
7 * - check null input using PG_ARGISNULL before using PG_GETARG_xxxx
8 * - support composite type arguments
9 *
10 * NOTES:
11 * - clear structures with memset to support hash indexes (who whould like
12 * to create hash index on table returned from function?)
13 * - number of returned rows is set by PostgreSQL evaluator, see:
14 * http://archives.postgresql.org/pgsql-hackers/2005-02/msg00546.php
15 *
16 * Based on:
17 * - C example from PostgreSQL documentation (BSD licence)
18 * - swish-e example src/libtest.c (GPL)
19 * - _textin/_textout from pgcurl.c (LGPL)
20 *
21 * This code is licenced under GPL
22 */
23
24 #include "postgres.h"
25 #include "fmgr.h"
26 #include "funcapi.h"
27 #include "utils/builtins.h"
28 #include "utils/array.h"
29 #include "miscadmin.h"
30 #include <swish-e.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
38 SW_HANDLE swish_handle = NULL;/* Database handle */
39 SW_SEARCH search = NULL; /* search handle -- holds search parameters */
40 SW_RESULTS swish_results = NULL; /* results handle -- holds list of results */
41 SW_RESULT *sw_res = NULL; /* one row from swish-e results */
42
43 /* define PostgreSQL v1 function */
44 PG_FUNCTION_INFO_V1(pgswish);
45 Datum pgswish(PG_FUNCTION_ARGS) {
46
47 FuncCallContext *funcctx;
48 int call_cntr;
49 int max_calls;
50 TupleDesc tupdesc;
51 TupleTableSlot *slot;
52 AttInMetadata *attinmeta;
53 char *index_path;
54 char *query;
55
56 /* stuff done only on the first call of the function */
57 if (SRF_IS_FIRSTCALL()) {
58 MemoryContext oldcontext;
59
60 /* take arguments from function */
61 //index_path = _textout(PG_GETARG_TEXT_P(0));
62 index_path = _textout(PG_GETARG_TEXT_P(0));
63 query = _textout(PG_GETARG_TEXT_P(1));
64
65 /* create a function context for cross-call persistence */
66 funcctx = SRF_FIRSTCALL_INIT();
67
68 /* switch to memory context appropriate for multiple function calls */
69 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
70
71
72 /* Send any errors or warnings to stderr (default is stdout) */
73 SwishErrorsToStderr();
74
75 elog(INFO, "pgswish: SwishInit(%s)", index_path);
76
77 swish_handle = SwishInit( index_path );
78
79 if (! swish_handle) {
80 elog(ERROR, "pgswish: can't open %s", index_path);
81 SRF_RETURN_DONE(funcctx);
82 }
83
84 error_or_abort( swish_handle );
85 /* set ranking scheme. default is 0 */
86 SwishRankScheme( swish_handle, 0 );
87 error_or_abort( swish_handle );
88
89 elog(INFO, "pgswish: SwishQuery(%s)", query);
90 /* Here's a short-cut to searching that creates a search object and searches at the same time */
91 swish_results = SwishQuery( swish_handle, query);
92 error_or_abort( swish_handle );
93
94 /* total number of tuples to be returned */
95 funcctx->max_calls = SwishHits( swish_results );
96
97 /* check if results exists */
98 if ( 0 == funcctx->max_calls )
99 elog(INFO, "no results for: %s", query );
100
101 elog(INFO, "pgswish: SwishHits = %d", funcctx->max_calls);
102
103 /* Build a tuple description for a __pgswish tuple */
104 tupdesc = RelationNameGetTupleDesc("__pgswish");
105
106 /* allocate a slot for a tuple with this tupdesc */
107 slot = TupleDescGetSlot(tupdesc);
108
109 /* assign slot to function context */
110 funcctx->slot = slot;
111
112 /*
113 * generate attribute metadata needed later to produce tuples from raw
114 * C strings
115 */
116 attinmeta = TupleDescGetAttInMetadata(tupdesc);
117 funcctx->attinmeta = attinmeta;
118
119 MemoryContextSwitchTo(oldcontext);
120
121 elog(INFO, "SRF_IS_FIRSTCALL done");
122 }
123
124 /* stuff done on every call of the function */
125 funcctx = SRF_PERCALL_SETUP();
126
127 call_cntr = funcctx->call_cntr;
128 max_calls = funcctx->max_calls;
129 slot = funcctx->slot;
130 attinmeta = funcctx->attinmeta;
131
132 if (call_cntr < max_calls) {
133 char **values;
134 HeapTuple tuple;
135 Datum result;
136
137 elog(INFO, "pgswish: loop count %d", call_cntr);
138
139 if (! swish_results) {
140 elog(ERROR, "pgswish: no swish-e results");
141 SRF_RETURN_DONE(funcctx);
142 }
143
144 elog(DEBUG1, "pgswish: check for swish-e error");
145 error_or_abort( swish_handle );
146
147 /*
148 * Prepare a values array for storage in our slot.
149 * This should be an array of C strings which will
150 * be processed later by the type input functions.
151 */
152
153 sw_res = SwishNextResult( swish_results );
154 if (! sw_res) {
155 elog(ERROR, "pgswish: swish-e sort result list: %d rows expected %d", call_cntr, max_calls - 1);
156 SRF_RETURN_DONE(funcctx);
157 }
158
159 elog(INFO, "Path: %s\n Rank: %lu\n Size: %lu\n Title: %s\n Index: %s\n Modified: %s\n Record #: %lu\n File #: %lu\n\n",
160 SwishResultPropertyStr ( sw_res, "swishdocpath" ),
161 SwishResultPropertyULong ( sw_res, "swishrank" ),
162 SwishResultPropertyULong ( sw_res, "swishdocsize" ),
163 SwishResultPropertyStr ( sw_res, "swishtitle"),
164 SwishResultPropertyStr ( sw_res, "swishdbfile" ),
165 SwishResultPropertyStr ( sw_res, "swishlastmodified" ),
166 SwishResultPropertyULong ( sw_res, "swishreccount" ), /* can figure this out in loop, of course */
167 SwishResultPropertyULong ( sw_res, "swishfilenum" )
168 );
169
170 values = (char **) palloc(4 * sizeof(char *));
171
172 values[0] = prop2int( sw_res, "swishrank" );
173 values[1] = prop2text( sw_res, "swishdocpath" );
174 values[2] = prop2text( sw_res, "swishtitle" );
175 values[3] = prop2int( sw_res, "swishdocsize" );
176
177 /*
178 values[0] = (char *) palloc(16 * sizeof(char));
179 snprintf(values[0], 16, "%d", 1);
180 values[1] = (char *) palloc(16 * sizeof(char));
181 snprintf(values[1], 16, "%d", 2);
182 values[2] = (char *) palloc(16 * sizeof(char));
183 snprintf(values[2], 16, "%d", 3);
184 values[3] = (char *) palloc(16 * sizeof(char));
185 snprintf(values[3], 16, "%d", 4);
186 */
187
188 /* build a tuple */
189 tuple = BuildTupleFromCStrings(attinmeta, values);
190
191 /* make the tuple into a datum */
192 result = TupleGetDatum(slot, tuple);
193
194 /* clean up ? */
195 pfree(values[0]);
196 pfree(values[1]);
197 pfree(values[2]);
198 pfree(values[3]);
199 pfree(values);
200
201 elog(DEBUG1, "row: %s|%s|%s|%s",values[0],values[1],values[2],values[3]);
202
203 SRF_RETURN_NEXT(funcctx, result);
204 } else {
205 elog(INFO, "loop over");
206
207 /* free swish object and close */
208 Free_Search_Object( search );
209 SwishClose( swish_handle );
210
211 /* do when there is no more left */
212 SRF_RETURN_DONE(funcctx);
213 }
214 }
215
216 /* work in progress */
217 PG_FUNCTION_INFO_V1(pgswish2);
218 Datum pgswish2(PG_FUNCTION_ARGS)
219 {
220 int ncols = 2;
221 int nrows = 3;
222 int16 typlen;
223 bool typbyval;
224 char typalign;
225 ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
226 AttInMetadata *attinmeta;
227 TupleDesc tupdesc;
228 Tuplestorestate *tupstore = NULL;
229 HeapTuple tuple;
230 MemoryContext per_query_ctx;
231 MemoryContext oldcontext;
232 Datum dvalue;
233 char **values;
234 int rsinfo_ncols;
235 int i, j;
236
237 /* check to see if caller supports us returning a tuplestore */
238 if (!rsinfo || !(rsinfo->allowedModes & SFRM_Materialize))
239 ereport(ERROR,
240 (errcode(ERRCODE_SYNTAX_ERROR),
241 errmsg("materialize mode required, but it is not " \
242 "allowed in this context")));
243
244 /* get the requested return tuple description */
245 tupdesc = rsinfo->expectedDesc;
246 rsinfo_ncols = tupdesc->natts;
247
248 /*
249 * The requested tuple description better match up with the array
250 * we were given.
251 */
252 elog(INFO, "rsinfo_ncols = %d, ncols = %d", rsinfo_ncols, ncols);
253
254 /* OK, use it */
255 attinmeta = TupleDescGetAttInMetadata(tupdesc);
256
257 /* Now go to work */
258 rsinfo->returnMode = SFRM_Materialize;
259
260 per_query_ctx = fcinfo->flinfo->fn_mcxt;
261 oldcontext = MemoryContextSwitchTo(per_query_ctx);
262
263 /* initialize our tuplestore */
264 tupstore = tuplestore_begin_heap(true, false, SortMem);
265
266 values = (char **) palloc(ncols * sizeof(char *));
267
268 for (i = 0; i < nrows; i++)
269 {
270 for (j = 0; j < ncols; j++)
271 {
272 values[j] = DatumGetCString( "foo" );
273 }
274 /* construct the tuple */
275 tuple = BuildTupleFromCStrings(attinmeta, values);
276
277 /* now store it */
278 tuplestore_puttuple(tupstore, tuple);
279 }
280
281 tuplestore_donestoring(tupstore);
282 rsinfo->setResult = tupstore;
283
284 /*
285 * SFRM_Materialize mode expects us to return a NULL Datum. The actual
286 * tuples are in our tuplestore and passed back through
287 * rsinfo->setResult. rsinfo->setDesc is set to the tuple description
288 * that we actually used to build our tuples with, so the caller can
289 * verify we did what it was expecting.
290 */
291 rsinfo->setDesc = tupdesc;
292 MemoryContextSwitchTo(oldcontext);
293
294 return (Datum) 0;
295 }
296
297
298 /* make text var prom property */
299 char *prop2text(SW_RESULT sw_res, char *propname) {
300 char *val;
301 char *prop;
302 int len;
303
304 elog(DEBUG2, "prop2text(%s)", propname);
305
306 prop = SwishResultPropertyStr( sw_res, propname );
307 error_or_abort( swish_handle );
308
309 len = strlen(prop);
310 elog(DEBUG1, "prop2text(%s) = '%s' %d bytes", propname, prop, len);
311
312 len++;
313 len *= sizeof(char);
314
315 elog(DEBUG2, "palloc(%d)", len);
316
317 val = palloc(len);
318
319 memset(val, 0, len);
320 strncpy(val, prop, len);
321
322 elog(DEBUG2, "val=%s", val);
323
324 return val;
325 }
326
327 /* make integer variable from property */
328 char *prop2int(SW_RESULT sw_res, char *propname) {
329 char *val;
330 unsigned long prop;
331 int len;
332
333 elog(DEBUG2, "prop2int(%s)", propname);
334
335 prop = SwishResultPropertyULong( sw_res, propname );
336 error_or_abort( swish_handle );
337
338 elog(DEBUG1, "prop2int(%s) = %lu", propname, prop);
339
340 len = 128 * sizeof(char);
341 elog(DEBUG2, "palloc(%d)", len);
342
343 val = palloc(len);
344 memset(val, 0, len);
345
346 snprintf(val, len, "%lu", prop);
347
348 elog(DEBUG2, "val=%s", val);
349
350 return val;
351 }
352
353
354 /*
355 * check if swish has returned error, and elog it.
356 */
357 static void error_or_abort( SW_HANDLE swish_handle ) {
358 if ( !SwishError( swish_handle ) )
359 return;
360
361 /* print a message */
362 elog(ERROR,
363 "pgswish error: Number [%d], Type [%s], Optional Message: [%s]\n",
364 SwishError( swish_handle ),
365 SwishErrorString( swish_handle ),
366 SwishLastErrorMsg( swish_handle )
367 );
368 if ( search ) Free_Search_Object( search );
369 SwishClose( swish_handle );
370 }
371

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