1ODEUM(3) Quick Database Manager ODEUM(3)
2
6 Odeum - the inverted API of QDBM
7
10 #include <depot.h>
11 #include <cabin.h>
12 #include <odeum.h>
13 #include <stdlib.h>
14 typedef struct { int id; int score; } ODPAIR;
16 ODEUM *odopen(const char *name, int omode);
18 int odclose(ODEUM *odeum);
20 int odput(ODEUM *odeum, const ODDOC *doc, int wmax, int over);
22 int odout(ODEUM *odeum, const char *uri);
24 int odoutbyid(ODEUM *odeum, int id);
26 ODDOC *odget(ODEUM *odeum, const char *uri);
28 ODDOC *odgetbyid(ODEUM *odeum, int id);
30 int odgetidbyuri(ODEUM *odeum, const char *uri);
32 int odcheck(ODEUM *odeum, int id);
34 ODPAIR *odsearch(ODEUM *odeum, const char *word, int max, int *np);
36 int odsearchdnum(ODEUM *odeum, const char *word);
38 int oditerinit(ODEUM *odeum);
40 ODDOC *oditernext(ODEUM *odeum);
42 int odsync(ODEUM *odeum);
44 int odoptimize(ODEUM *odeum);
46 char *odname(ODEUM *odeum);
48 double odfsiz(ODEUM *odeum);
50 int odbnum(ODEUM *odeum);
52 int odbusenum(ODEUM *odeum);
54 int oddnum(ODEUM *odeum);
56 int odwnum(ODEUM *odeum);
58 int odwritable(ODEUM *odeum);
60 int odfatalerror(ODEUM *odeum);
62 int odinode(ODEUM *odeum);
64 time_t odmtime(ODEUM *odeum);
66 int odmerge(const char *name, const CBLIST *elemnames);
68 int odremove(const char *name);
70 ODDOC *oddocopen(const char *uri);
72 void oddocclose(ODDOC *doc);
74 void oddocaddattr(ODDOC *doc, const char *name, const char *value);
76 void oddocaddword(ODDOC *doc, const char *normal, const char *asis);
78 int oddocid(const ODDOC *doc);
80 const char *oddocuri(const ODDOC *doc);
82 const char *oddocgetattr(const ODDOC *doc, const char *name);
84 const CBLIST *oddocnwords(const ODDOC *doc);
86 const CBLIST *oddocawords(const ODDOC *doc);
88 CBMAP *oddocscores(const ODDOC *doc, int max, ODEUM *odeum);
90 CBLIST *odbreaktext(const char *text);
92 char *odnormalizeword(const char *asis);
94 ODPAIR *odpairsand(ODPAIR *apairs, int anum, ODPAIR *bpairs, int bnum,
96 int *np);
97 ODPAIR *odpairsor(ODPAIR *apairs, int anum, ODPAIR *bpairs, int bnum,
99 int *np);
100 ODPAIR *odpairsnotand(ODPAIR *apairs, int anum, ODPAIR *bpairs, int
102 bnum, int *np);
103 void odpairssort(ODPAIR *pairs, int pnum);
105 double odlogarithm(double x);
107 double odvectorcosine(const int *avec, const int *bvec, int vnum);
109 void odsettuning(int ibnum, int idnum, int cbnum, int csiz);
111 void odanalyzetext(ODEUM *odeum, const char *text, CBLIST *awords,
113 CBLIST *nwords);
114 void odsetcharclass(ODEUM *odeum, const char *spacechars, const char
116 *delimchars, const char *gluechars);
117 ODPAIR *odquery(ODEUM *odeum, const char *query, int *np, CBLIST
119 *errors);
120
123 Odeum is the API which handles an inverted index. An inverted index is
124 a data structure to retrieve a list of some documents that include one
125 of words which were extracted from a population of documents. It is
126 easy to realize a full-text search system with an inverted index.
127 Odeum provides an abstract data structure which consists of words and
128 attributes of a document. It is used when an application stores a doc‐
129 ument into a database and when an application retrieves some documents
130 from a database.
131 Odeum does not provide methods to extract the text from the original
133 data of a document. It should be implemented by applications.
134 Although Odeum provides utilities to extract words from a text, it is
135 oriented to such languages whose words are separated with space charac‐
136 ters as English. If an application handles such languages which need
137 morphological analysis or N-gram analysis as Japanese, or if an appli‐
138 cation perform more such rarefied analysis of natural languages as
139 stemming, its own analyzing method can be adopted. Result of search is
140 expressed as an array contains elements which are structures composed
141 of the ID number of documents and its score. In order to search with
142 two or more words, Odeum provides utilities of set operations.
143 Odeum is implemented, based on Curia, Cabin, and Villa. Odeum creates
145 a database with a directory name. Some databases of Curia and Villa
146 are placed in the specified directory. For example, `casket/docs',
147 `casket/index', and `casket/rdocs' are created in the case that a data‐
148 base directory named as `casket'. `docs' is a database directory of
149 Curia. The key of each record is the ID number of a document, and the
150 value is such attributes as URI. `index' is a database directory of
151 Curia. The key of each record is the normalized form of a word, and
152 the value is an array whose element is a pair of the ID number of a
153 document including the word and its score. `rdocs' is a database file
154 of Villa. The key of each record is the URI of a document, and the
155 value is its ID number.
156 In order to use Odeum, you should include `depot.h', `cabin.h',
158 `odeum.h' and `stdlib.h' in the source files. Usually, the following
159 description will be near the beginning of a source file.
160 #include <depot.h>
162 #include <cabin.h>
163 #include <odeum.h>
164 #include <stdlib.h>
165 A pointer to `ODEUM' is used as a database handle. A database handle
167 is opened with the function `odopen' and closed with `odclose'. You
168 should not refer directly to any member of the handle. If a fatal
169 error occurs in a database, any access method via the handle except
170 `odclose' will not work and return error status. Although a process is
171 allowed to use multiple database handles at the same time, handles of
172 the same database file should not be used.
173 A pointer to `ODDOC' is used as a document handle. A document handle
175 is opened with the function `oddocopen' and closed with `oddocclose'.
176 You should not refer directly to any member of the handle. A document
177 consists of attributes and words. Each word is expressed as a pair of
178 a normalized form and a appearance form.
179 Odeum also assign the external variable `dpecode' with the error code.
181 The function `dperrmsg' is used in order to get the message of the
182 error code.
183 Structures of `ODPAIR' type is used in order to handle results of
185 search.
186 typedef struct { int id; int score; } ODPAIR;
188 `id' specifies the ID number of a document. `score' specifies
189 the score calculated from the number of searching words in the
190 document.
191 The function `odopen' is used in order to get a database handle.
193 ODEUM *odopen(const char *name, int omode);
195 `name' specifies the name of a database directory. `omode'
196 specifies the connection mode: `OD_OWRITER' as a writer,
197 `OD_OREADER' as a reader. If the mode is `OD_OWRITER', the fol‐
198 lowing may be added by bitwise or: `OD_OCREAT', which means it
199 creates a new database if not exist, `OD_OTRUNC', which means it
200 creates a new database regardless if one exists. Both of
201 `OD_OREADER' and `OD_OWRITER' can be added to by bitwise or:
202 `OD_ONOLCK', which means it opens a database directory without
203 file locking, or `OD_OLCKNB', which means locking is performed
204 without blocking. The return value is the database handle or
205 `NULL' if it is not successful. While connecting as a writer,
206 an exclusive lock is invoked to the database directory. While
207 connecting as a reader, a shared lock is invoked to the database
208 directory. The thread blocks until the lock is achieved. If
209 `OD_ONOLCK' is used, the application is responsible for exclu‐
210 sion control.
211 The function `odclose' is used in order to close a database handle.
213 int odclose(ODEUM *odeum);
215 `odeum' specifies a database handle. If successful, the return
216 value is true, else, it is false. Because the region of a
217 closed handle is released, it becomes impossible to use the han‐
218 dle. Updating a database is assured to be written when the han‐
219 dle is closed. If a writer opens a database but does not close
220 it appropriately, the database will be broken.
221 The function `odput' is used in order to store a document.
223 int odput(ODEUM *odeum, const ODDOC *doc, int wmax, int over);
225 `odeum' specifies a database handle connected as a writer.
226 `doc' specifies a document handle. `wmax' specifies the max
227 number of words to be stored in the document database. If it is
228 negative, the number is unlimited. `over' specifies whether the
229 data of the duplicated document is overwritten or not. If it is
230 false and the URI of the document is duplicated, the function
231 returns as an error. If successful, the return value is true,
232 else, it is false.
233 The function `odout' is used in order to delete a document specified by
235 a URI.
236 int odout(ODEUM *odeum, const char *uri);
238 `odeum' specifies a database handle connected as a writer.
239 `uri' specifies the string of the URI of a document. If suc‐
240 cessful, the return value is true, else, it is false. False is
241 returned when no document corresponds to the specified URI.
242 The function `odoutbyid' is used in order to delete a document speci‐
244 fied by an ID number.
245 int odoutbyid(ODEUM *odeum, int id);
247 `odeum' specifies a database handle connected as a writer. `id'
248 specifies the ID number of a document. If successful, the
249 return value is true, else, it is false. False is returned when
250 no document corresponds to the specified ID number.
251 The function `odget' is used in order to retrieve a document specified
253 by a URI.
254 ODDOC *odget(ODEUM *odeum, const char *uri);
256 `odeum' specifies a database handle. `uri' specifies the string
257 of the URI of a document. If successful, the return value is
258 the handle of the corresponding document, else, it is `NULL'.
259 `NULL' is returned when no document corresponds to the specified
260 URI. Because the handle of the return value is opened with the
261 function `oddocopen', it should be closed with the function
262 `oddocclose'.
263 The function `odgetbyid' is used in order to retrieve a document by an
265 ID number.
266 ODDOC *odgetbyid(ODEUM *odeum, int id);
268 `odeum' specifies a database handle. `id' specifies the ID num‐
269 ber of a document. If successful, the return value is the han‐
270 dle of the corresponding document, else, it is `NULL'. `NULL'
271 is returned when no document corresponds to the specified ID
272 number. Because the handle of the return value is opened with
273 the function `oddocopen', it should be closed with the function
274 `oddocclose'.
275 The function `odgetidbyuri' is used in order to retrieve the ID of the
277 document specified by a URI.
278 int odgetidbyuri(ODEUM *odeum, const char *uri);
280 `odeum' specifies a database handle. `uri' specifies the string
281 the URI of a document. If successful, the return value is the
282 ID number of the document, else, it is -1. -1 is returned when
283 no document corresponds to the specified URI.
284 The function `odcheck' is used in order to check whether the document
286 specified by an ID number exists.
287 int odcheck(ODEUM *odeum, int id);
289 `odeum' specifies a database handle. `id' specifies the ID num‐
290 ber of a document. The return value is true if the document
291 exists, else, it is false.
292 The function `odsearch' is used in order to search the inverted index
294 for documents including a particular word.
295 ODPAIR *odsearch(ODEUM *odeum, const char *word, int max, int *np);
297 `odeum' specifies a database handle. `word' specifies a search‐
298 ing word. `max' specifies the max number of documents to be
299 retrieve. `np' specifies the pointer to a variable to which the
300 number of the elements of the return value is assigned. If suc‐
301 cessful, the return value is the pointer to an array, else, it
302 is `NULL'. Each element of the array is a pair of the ID number
303 and the score of a document, and sorted in descending order of
304 their scores. Even if no document corresponds to the specified
305 word, it is not error but returns an dummy array. Because the
306 region of the return value is allocated with the `malloc' call,
307 it should be released with the `free' call if it is no longer in
308 use. Note that each element of the array of the return value
309 can be data of a deleted document.
310 The function `odsearchnum' is used in order to get the number of docu‐
312 ments including a word.
313 int odsearchdnum(ODEUM *odeum, const char *word);
315 `odeum' specifies a database handle. `word' specifies a search‐
316 ing word. If successful, the return value is the number of doc‐
317 uments including the word, else, it is -1. Because this func‐
318 tion does not read the entity of the inverted index, it is
319 faster than `odsearch'.
320 The function `oditerinit' is used in order to initialize the iterator
322 of a database handle.
323 int oditerinit(ODEUM *odeum);
325 `odeum' specifies a database handle. If successful, the return
326 value is true, else, it is false. The iterator is used in order
327 to access every document stored in a database.
328 The function `oditernext' is used in order to get the next key of the
330 iterator.
331 ODDOC *oditernext(ODEUM *odeum);
333 `odeum' specifies a database handle. If successful, the return
334 value is the handle of the next document, else, it is `NULL'.
335 `NULL' is returned when no document is to be get out of the
336 iterator. It is possible to access every document by iteration
337 of calling this function. However, it is not assured if updat‐
338 ing the database is occurred while the iteration. Besides, the
339 order of this traversal access method is arbitrary, so it is not
340 assured that the order of string matches the one of the traver‐
341 sal access. Because the handle of the return value is opened
342 with the function `oddocopen', it should be closed with the
343 function `oddocclose'.
344 The function `odsync' is used in order to synchronize updating contents
346 with the files and the devices.
347 int odsync(ODEUM *odeum);
349 `odeum' specifies a database handle connected as a writer. If
350 successful, the return value is true, else, it is false. This
351 function is useful when another process uses the connected data‐
352 base directory.
353 The function `odoptimize' is used in order to optimize a database.
355 int odoptimize(ODEUM *odeum);
357 `odeum' specifies a database handle connected as a writer. If
358 successful, the return value is true, else, it is false. Ele‐
359 ments of the deleted documents in the inverted index are purged.
360 The function `odname' is used in order to get the name of a database.
362 char *odname(ODEUM *odeum);
364 `odeum' specifies a database handle. If successful, the return
365 value is the pointer to the region of the name of the database,
366 else, it is `NULL'. Because the region of the return value is
367 allocated with the `malloc' call, it should be released with the
368 `free' call if it is no longer in use.
369 The function `odfsiz' is used in order to get the total size of data‐
371 base files.
372 double odfsiz(ODEUM *odeum);
374 `odeum' specifies a database handle. If successful, the return
375 value is the total size of the database files, else, it is -1.0.
376 The function `odbnum' is used in order to get the total number of the
378 elements of the bucket arrays in the inverted index.
379 int odbnum(ODEUM *odeum);
381 `odeum' specifies a database handle. If successful, the return
382 value is the total number of the elements of the bucket arrays,
383 else, it is -1.
384 The function `odbusenum' is used in order to get the total number of
386 the used elements of the bucket arrays in the inverted index.
387 int odbusenum(ODEUM *odeum);
389 `odeum' specifies a database handle. If successful, the return
390 value is the total number of the used elements of the bucket
391 arrays, else, it is -1.
392 The function `oddnum' is used in order to get the number of the docu‐
394 ments stored in a database.
395 int oddnum(ODEUM *odeum);
397 `odeum' specifies a database handle. If successful, the return
398 value is the number of the documents stored in the database,
399 else, it is -1.
400 The function `odwnum' is used in order to get the number of the words
402 stored in a database.
403 int odwnum(ODEUM *odeum);
405 `odeum' specifies a database handle. If successful, the return
406 value is the number of the words stored in the database, else,
407 it is -1. Because of the I/O buffer, the return value may be
408 less than the hard number.
409 The function `odwritable' is used in order to check whether a database
411 handle is a writer or not.
412 int odwritable(ODEUM *odeum);
414 `odeum' specifies a database handle. The return value is true
415 if the handle is a writer, false if not.
416 The function `odfatalerror' is used in order to check whether a data‐
418 base has a fatal error or not.
419 int odfatalerror(ODEUM *odeum);
421 `odeum' specifies a database handle. The return value is true
422 if the database has a fatal error, false if not.
423 The function `odinode' is used in order to get the inode number of a
425 database directory.
426 int odinode(ODEUM *odeum);
428 `odeum' specifies a database handle. The return value is the
429 inode number of the database directory.
430 The function `odmtime' is used in order to get the last modified time
432 of a database.
433 time_t odmtime(ODEUM *odeum);
435 `odeum' specifies a database handle. The return value is the
436 last modified time of the database.
437 The function `odmerge' is used in order to merge plural database direc‐
439 tories.
440 int odmerge(const char *name, const CBLIST *elemnames);
442 `name' specifies the name of a database directory to create.
443 `elemnames' specifies a list of names of element databases. If
444 successful, the return value is true, else, it is false. If two
445 or more documents which have the same URL come in, the first one
446 is adopted and the others are ignored.
447 The function `odremove' is used in order to remove a database direc‐
449 tory.
450 int odremove(const char *name);
452 `name' specifies the name of a database directory. If success‐
453 ful, the return value is true, else, it is false. A database
454 directory can contain databases of other APIs of QDBM, they are
455 also removed by this function.
456 The function `oddocopen' is used in order to get a document handle.
458 ODDOC *oddocopen(const char *uri);
460 `uri' specifies the URI of a document. The return value is a
461 document handle. The ID number of a new document is not
462 defined. It is defined when the document is stored in a data‐
463 base.
464 The function `oddocclose' is used in order to close a document handle.
466 void oddocclose(ODDOC *doc);
468 `doc' specifies a document handle. Because the region of a
469 closed handle is released, it becomes impossible to use the han‐
470 dle.
471 The function `oddocaddattr' is used in order to add an attribute to a
473 document.
474 void oddocaddattr(ODDOC *doc, const char *name, const char *value);
476 `doc' specifies a document handle. `name' specifies the string
477 of the name of an attribute. `value' specifies the string of
478 the value of the attribute.
479 The function `oddocaddword' is used in order to add a word to a docu‐
481 ment.
482 void oddocaddword(ODDOC *doc, const char *normal, const char *asis);
484 `doc' specifies a document handle. `normal' specifies the
485 string of the normalized form of a word. Normalized forms are
486 treated as keys of the inverted index. If the normalized form
487 of a word is an empty string, the word is not reflected in the
488 inverted index. `asis' specifies the string of the appearance
489 form of the word. Appearance forms are used after the document
490 is retrieved by an application.
491 The function `oddocid' is used in order to get the ID number of a docu‐
493 ment.
494 int oddocid(const ODDOC *doc);
496 `doc' specifies a document handle. The return value is the ID
497 number of a document.
498 The function `oddocuri' is used in order to get the URI of a document.
500 const char *oddocuri(const ODDOC *doc);
502 `doc' specifies a document handle. The return value is the
503 string of the URI of a document.
504 The function `oddocgetattr' is used in order to get the value of an
506 attribute of a document.
507 const char *oddocgetattr(const ODDOC *doc, const char *name);
509 `doc' specifies a document handle. `name' specifies the string
510 of the name of an attribute. The return value is the string of
511 the value of the attribute, or `NULL' if no attribute corre‐
512 sponds.
513 The function `oddocnwords' is used in order to get the list handle con‐
515 tains words in normalized form of a document.
516 const CBLIST *oddocnwords(const ODDOC *doc);
518 `doc' specifies a document handle. The return value is the list
519 handle contains words in normalized form.
520 The function `oddocawords' is used in order to get the list handle con‐
522 tains words in appearance form of a document.
523 const CBLIST *oddocawords(const ODDOC *doc);
525 `doc' specifies a document handle. The return value is the list
526 handle contains words in appearance form.
527 The function `oddocscores' is used in order to get the map handle con‐
529 tains keywords in normalized form and their scores.
530 CBMAP *oddocscores(const ODDOC *doc, int max, ODEUM *odeum);
532 `doc' specifies a document handle. `max' specifies the max num‐
533 ber of keywords to get. `odeum' specifies a database handle
534 with which the IDF for weighting is calculate. If it is `NULL',
535 it is not used. The return value is the map handle contains
536 keywords and their scores. Scores are expressed as decimal
537 strings. Because the handle of the return value is opened with
538 the function `cbmapopen', it should be closed with the function
539 `cbmapclose' if it is no longer in use.
540 The function `odbreaktext' is used in order to break a text into words
542 in appearance form.
543 CBLIST *odbreaktext(const char *text);
545 `text' specifies the string of a text. The return value is the
546 list handle contains words in appearance form. Words are sepa‐
547 rated with space characters and such delimiters as period, comma
548 and so on. Because the handle of the return value is opened
549 with the function `cblistopen', it should be closed with the
550 function `cblistclose' if it is no longer in use.
551 The function `odnormalizeword' is used in order to make the normalized
553 form of a word.
554 char *odnormalizeword(const char *asis);
556 `asis' specifies the string of the appearance form of a word.
557 The return value is is the string of the normalized form of the
558 word. Alphabets of the ASCII code are unified into lower cases.
559 Words composed of only delimiters are treated as empty strings.
560 Because the region of the return value is allocated with the
561 `malloc' call, it should be released with the `free' call if it
562 is no longer in use.
563 The function `odpairsand' is used in order to get the common elements
565 of two sets of documents.
566 ODPAIR *odpairsand(ODPAIR *apairs, int anum, ODPAIR *bpairs, int bnum,
568 int *np);
569 `apairs' specifies the pointer to the former document array.
570 `anum' specifies the number of the elements of the former docu‐
571 ment array. `bpairs' specifies the pointer to the latter docu‐
572 ment array. `bnum' specifies the number of the elements of the
573 latter document array. `np' specifies the pointer to a variable
574 to which the number of the elements of the return value is
575 assigned. The return value is the pointer to a new document
576 array whose elements commonly belong to the specified two sets.
577 Elements of the array are sorted in descending order of their
578 scores. Because the region of the return value is allocated
579 with the `malloc' call, it should be released with the `free'
580 call if it is no longer in use.
581 The function `odpairsor' is used in order to get the sum of elements of
583 two sets of documents.
584 ODPAIR *odpairsor(ODPAIR *apairs, int anum, ODPAIR *bpairs, int bnum,
586 int *np);
587 `apairs' specifies the pointer to the former document array.
588 `anum' specifies the number of the elements of the former docu‐
589 ment array. `bpairs' specifies the pointer to the latter docu‐
590 ment array. `bnum' specifies the number of the elements of the
591 latter document array. `np' specifies the pointer to a variable
592 to which the number of the elements of the return value is
593 assigned. The return value is the pointer to a new document
594 array whose elements belong to both or either of the specified
595 two sets. Elements of the array are sorted in descending order
596 of their scores. Because the region of the return value is
597 allocated with the `malloc' call, it should be released with the
598 `free' call if it is no longer in use.
599 The function `odpairsnotand' is used in order to get the difference set
601 of documents.
602 ODPAIR *odpairsnotand(ODPAIR *apairs, int anum, ODPAIR *bpairs, int
604 bnum, int *np);
605 `apairs' specifies the pointer to the former document array.
606 `anum' specifies the number of the elements of the former docu‐
607 ment array. `bpairs' specifies the pointer to the latter docu‐
608 ment array of the sum of elements. `bnum' specifies the number
609 of the elements of the latter document array. `np' specifies
610 the pointer to a variable to which the number of the elements of
611 the return value is assigned. The return value is the pointer
612 to a new document array whose elements belong to the former set
613 but not to the latter set. Elements of the array are sorted in
614 descending order of their scores. Because the region of the
615 return value is allocated with the `malloc' call, it should be
616 released with the `free' call if it is no longer in use.
617 The function `odpairssort' is used in order to sort a set of documents
619 in descending order of scores.
620 void odpairssort(ODPAIR *pairs, int pnum);
622 `pairs' specifies the pointer to a document array. `pnum' spec‐
623 ifies the number of the elements of the document array.
624 The function `odlogarithm' is used in order to get the natural loga‐
626 rithm of a number.
627 double odlogarithm(double x);
629 `x' specifies a number. The return value is the natural loga‐
630 rithm of the number. If the number is equal to or less than
631 1.0, the return value is 0.0. This function is useful when an
632 application calculates the IDF of search results.
633 The function `odvectorcosine' is used in order to get the cosine of the
635 angle of two vectors.
636 double odvectorcosine(const int *avec, const int *bvec, int vnum);
638 `avec' specifies the pointer to one array of numbers. `bvec'
639 specifies the pointer to the other array of numbers. `vnum'
640 specifies the number of elements of each array. The return
641 value is the cosine of the angle of two vectors. This function
642 is useful when an application calculates similarity of docu‐
643 ments.
644 The function `odsettuning' is used in order to set the global tuning
646 parameters.
647 void odsettuning(int ibnum, int idnum, int cbnum, int csiz);
649 `ibnum' specifies the number of buckets for inverted indexes.
650 `idnum' specifies the division number of inverted index.
651 `cbnum' specifies the number of buckets for dirty buffers.
652 `csiz' specifies the maximum bytes to use memory for dirty buf‐
653 fers. The default setting is equivalent to `odsettuning(32749,
654 7, 262139, 8388608)'. This function should be called before
655 opening a handle.
656 The function `odanalyzetext' is used in order to break a text into
658 words and store appearance forms and normalized form into lists.
659 void odanalyzetext(ODEUM *odeum, const char *text, CBLIST *awords,
661 CBLIST *nwords);
662 `odeum' specifies a database handle. `text' specifies the
663 string of a text. `awords' specifies a list handle into which
664 appearance form is store. `nwords' specifies a list handle into
665 which normalized form is store. If it is `NULL', it is ignored.
666 Words are separated with space characters and such delimiters as
667 period, comma and so on.
668 The function `odsetcharclass' is used in order to set the classes of
670 characters used by `odanalyzetext'.
671 void odsetcharclass(ODEUM *odeum, const char *spacechars, const char
673 *delimchars, const char *gluechars);
674 `odeum' specifies a database handle. `spacechars' spacifies a
675 string contains space characters. `delimchars' spacifies a
676 string contains delimiter characters. `gluechars' spacifies a
677 string contains glue characters.
678 The function `odquery' is used in order to query a database using a
680 small boolean query language.
681 ODPAIR *odquery(ODEUM *odeum, const char *query, int *np, CBLIST
683 *errors);
684 `odeum' specifies a database handle. 'query' specifies the text
685 of the query. `np' specifies the pointer to a variable to which
686 the number of the elements of the return value is assigned.
687 `errors' specifies a list handle into which error messages are
688 stored. If it is `NULL', it is ignored. If successful, the
689 return value is the pointer to an array, else, it is `NULL'.
690 Each element of the array is a pair of the ID number and the
691 score of a document, and sorted in descending order of their
692 scores. Even if no document corresponds to the specified condi‐
693 tion, it is not error but returns an dummy array. Because the
694 region of the return value is allocated with the `malloc' call,
695 it should be released with the `free' call if it is no longer in
696 use. Note that each element of the array of the return value
697 can be data of a deleted document.
698 If QDBM was built with POSIX thread enabled, the global variable
700 `dpecode' is treated as thread specific data, and functions of Odeum
701 are reentrant. In that case, they are thread-safe as long as a handle
702 is not accessed by threads at the same time, on the assumption that
703 `errno', `malloc', and so on are thread-safe.
704 If QDBM was built with ZLIB enabled, records in the database for docu‐
706 ment attributes are compressed. In that case, the size of the database
707 is reduced to 30% or less. Thus, you should enable ZLIB if you use
708 Odeum. A database of Odeum created without ZLIB enabled is not avail‐
709 able on environment with ZLIB enabled, and vice versa. If ZLIB was not
710 enabled but LZO, LZO is used instead.
711 The query language of the function `odquery' is a basic language fol‐
713 lowing this grammar:
714 expr ::= subexpr ( op subexpr )*
716 subexpr ::= WORD
717 subexpr ::= LPAREN expr RPAREN
718 Operators are "&" (AND), "|" (OR), and "!" (NOTAND). You can use
720 parenthesis to group sub-expressions together in order to change order
721 of operations. The given query is broken up using the function `odana‐
722 lyzetext', so if you want to specify different text breaking rules,
723 then make sure that you at least set "&", "|", "!", "(", and ")" to be
724 delimiter characters. Consecutive words are treated as having an
725 implicit "&" operator between them, so "zed shaw" is actually "zed &
726 shaw".
727 The encoding of the query text should be the same with the encoding of
729 target documents. Moreover, each of space characters, delimiter char‐
730 acters, and glue characters should be single byte.
731
734 qdbm(3), depot(3), curia(3), relic(3), hovel(3), cabin(3), villa(3),
735 ndbm(3), gdbm(3)
736Man Page 2004-04-22 ODEUM(3)