src/zoom-query.c

   1 /* This file is part of the YAZ toolkit.
   2  * Copyright (C) 1995-2011 Index Data
   3  * See the file LICENSE for details.
   4  */
   5 /**
   6  * \file zoom-query.c
   7  * \brief Implements ZOOM C query interface.
   8  */
   9 #if HAVE_CONFIG_H
  10 #include <config.h>
  11 #endif
  12
  13 #include <assert.h>
  14 #include <string.h>
  15 #include <errno.h>
  16 #include "zoom-p.h"
  17
  18 #include <yaz/yaz-util.h>
  19 #include <yaz/xmalloc.h>
  20 #include <yaz/log.h>
  21 #include <yaz/pquery.h>
  22 #include <yaz/cql.h>
  23 #include <yaz/ccl.h>
  24 #include <yaz/sortspec.h>
  25
  26 #define SORT_STRATEGY_Z3950 0
  27 #define SORT_STRATEGY_TYPE7 1
  28 #define SORT_STRATEGY_CQL 2
  29 #define SORT_STRATEGY_SRU11 3
  30 #define SORT_STRATEGY_EMBED 4
  31
  32 struct ZOOM_query_p {
  33     Z_Query *z_query;
  34     int sort_strategy;
  35     Z_SortKeySpecList *sort_spec;
  36     int refcount;
  37     ODR odr_sort_spec;
  38     ODR odr_query;
  39     int query_type;
  40     char *query_string;
  41     WRBUF full_query;
  42     WRBUF sru11_sort_spec;
  43 };
  44
  45 static int generate(ZOOM_query s)
  46 {
  47     if (s->query_string)
  48     {
  49         Z_External *ext;
  50
  51         wrbuf_rewind(s->full_query);
  52         wrbuf_puts(s->full_query, s->query_string);
  53         odr_reset(s->odr_query);
  54
  55         if (s->sort_spec && s->sort_strategy == SORT_STRATEGY_SRU11)
  56         {
  57             int r;
  58             wrbuf_rewind(s->sru11_sort_spec);
  59
  60             r = yaz_sort_spec_to_srw_sortkeys(s->sort_spec,
  61                                               s->sru11_sort_spec);
  62             if (r)
  63                 return r;
  64         }
  65         switch (s->query_type)
  66         {
  67         case Z_Query_type_1: /* RPN */
  68             if (s->sort_spec &&
  69                 (s->sort_strategy == SORT_STRATEGY_TYPE7 ||
  70                  s->sort_strategy == SORT_STRATEGY_EMBED))
  71             {
  72                 int r = yaz_sort_spec_to_type7(s->sort_spec, s->full_query);
  73                 if (r)
  74                     return r;
  75             }
  76             s->z_query = (Z_Query *) odr_malloc(s->odr_query,
  77                                                 sizeof(*s->z_query));
  78             s->z_query->which = Z_Query_type_1;
  79             s->z_query->u.type_1 =
  80                 p_query_rpn(s->odr_query, wrbuf_cstr(s->full_query));
  81             if (!s->z_query->u.type_1)
  82             {
  83                 s->z_query = 0;
  84                 return -1;
  85             }
  86             break;
  87         case Z_Query_type_104: /* CQL */
  88             if (s->sort_spec &&
  89                 (s->sort_strategy == SORT_STRATEGY_CQL ||
  90                  s->sort_strategy == SORT_STRATEGY_EMBED))
  91             {
  92                 int r = yaz_sort_spec_to_cql(s->sort_spec, s->full_query);
  93                 if (r)
  94                     return r;
  95             }
  96             ext = (Z_External *) odr_malloc(s->odr_query, sizeof(*ext));
  97             ext->direct_reference = odr_oiddup(s->odr_query,
  98                                                yaz_oid_userinfo_cql);
  99             ext->indirect_reference = 0;
 100             ext->descriptor = 0;
 101             ext->which = Z_External_CQL;
 102             ext->u.cql = odr_strdup(s->odr_query, wrbuf_cstr(s->full_query));
 103
 104             s->z_query = (Z_Query *) odr_malloc(s->odr_query, sizeof(*s->z_query));
 105             s->z_query->which = Z_Query_type_104;
 106             s->z_query->u.type_104 =  ext;
 107
 108             break;
 109         }
 110     }
 111     return 0;
 112 }
 113
 114 const char *ZOOM_query_get_sru11(ZOOM_query s)
 115 {
 116     if (wrbuf_len(s->sru11_sort_spec))
 117         return wrbuf_cstr(s->sru11_sort_spec);
 118     return 0;
 119 }
 120
 121 Z_Query *ZOOM_query_get_Z_Query(ZOOM_query s)
 122 {
 123     return s->z_query;
 124 }
 125
 126 Z_SortKeySpecList *ZOOM_query_get_sortspec(ZOOM_query s)
 127 {
 128     return s->sort_strategy == SORT_STRATEGY_Z3950 ? s->sort_spec : 0;
 129 }
 130
 131 static void cql2pqf_wrbuf_puts(const char *buf, void *client_data)
 132 {
 133     WRBUF wrbuf = (WRBUF) client_data;
 134     wrbuf_puts(wrbuf, buf);
 135 }
 136
 137 const char *ZOOM_query_get_query_string(ZOOM_query s)
 138 {
 139     return wrbuf_cstr(s->full_query);
 140 }
 141
 142 /*
 143  * Returns an xmalloc()d string containing RPN that corresponds to the
 144  * CQL passed in.  On error, sets the Connection object's error state
 145  * and returns a null pointer.
 146  * ### We could cache CQL parser and/or transformer in Connection.
 147  */
 148 static char *cql2pqf(ZOOM_connection c, const char *cql)
 149 {
 150     CQL_parser parser;
 151     int error;
 152     const char *cqlfile;
 153     cql_transform_t trans;
 154     char *result = 0;
 155
 156     parser = cql_parser_create();
 157     if ((error = cql_parser_string(parser, cql)) != 0) {
 158         cql_parser_destroy(parser);
 159         ZOOM_set_error(c, ZOOM_ERROR_CQL_PARSE, cql);
 160         return 0;
 161     }
 162
 163     cqlfile = ZOOM_connection_option_get(c, "cqlfile");
 164     if (cqlfile == 0)
 165     {
 166         ZOOM_set_error(c, ZOOM_ERROR_CQL_TRANSFORM, "no CQL transform file");
 167     }
 168     else if ((trans = cql_transform_open_fname(cqlfile)) == 0)
 169     {
 170         char buf[512];
 171         sprintf(buf, "can't open CQL transform file '%.200s': %.200s",
 172                 cqlfile, strerror(errno));
 173         ZOOM_set_error(c, ZOOM_ERROR_CQL_TRANSFORM, buf);
 174     }
 175     else
 176     {
 177         WRBUF wrbuf_result = wrbuf_alloc();
 178         error = cql_transform(trans, cql_parser_result(parser),
 179                               cql2pqf_wrbuf_puts, wrbuf_result);
 180         if (error != 0) {
 181             char buf[512];
 182             const char *addinfo;
 183             error = cql_transform_error(trans, &addinfo);
 184             sprintf(buf, "%.200s (addinfo=%.200s)",
 185                     cql_strerror(error), addinfo);
 186             ZOOM_set_error(c, ZOOM_ERROR_CQL_TRANSFORM, buf);
 187         }
 188         else
 189         {
 190             result = xstrdup(wrbuf_cstr(wrbuf_result));
 191         }
 192         cql_transform_close(trans);
 193         wrbuf_destroy(wrbuf_result);
 194     }
 195     cql_parser_destroy(parser);
 196     return result;
 197 }
 198
 199
 200 ZOOM_API(ZOOM_query)
 201     ZOOM_query_create(void)
 202 {
 203     ZOOM_query s = (ZOOM_query) xmalloc(sizeof(*s));
 204
 205     s->refcount = 1;
 206     s->z_query = 0;
 207     s->sort_spec = 0;
 208     s->odr_query = odr_createmem(ODR_ENCODE);
 209     s->odr_sort_spec = odr_createmem(ODR_ENCODE);
 210     s->query_string = 0;
 211     s->full_query = wrbuf_alloc();
 212     s->sort_strategy = SORT_STRATEGY_Z3950;
 213     s->sru11_sort_spec = wrbuf_alloc();
 214     return s;
 215 }
 216
 217 ZOOM_API(void)
 218     ZOOM_query_destroy(ZOOM_query s)
 219 {
 220     if (!s)
 221         return;
 222
 223     (s->refcount)--;
 224     if (s->refcount == 0)
 225     {
 226         odr_destroy(s->odr_query);
 227         odr_destroy(s->odr_sort_spec);
 228         xfree(s->query_string);
 229         wrbuf_destroy(s->full_query);
 230         wrbuf_destroy(s->sru11_sort_spec);
 231         xfree(s);
 232     }
 233 }
 234
 235 ZOOM_API(void)
 236     ZOOM_query_addref(ZOOM_query s)
 237 {
 238     s->refcount++;
 239 }
 240
 241
 242 ZOOM_API(int)
 243     ZOOM_query_prefix(ZOOM_query s, const char *str)
 244 {
 245     xfree(s->query_string);
 246     s->query_string = xstrdup(str);
 247     s->query_type = Z_Query_type_1;
 248     return generate(s);
 249 }
 250
 251 ZOOM_API(int)
 252     ZOOM_query_cql(ZOOM_query s, const char *str)
 253 {
 254     xfree(s->query_string);
 255     s->query_string = xstrdup(str);
 256     s->query_type = Z_Query_type_104;
 257     return generate(s);
 258 }
 259
 260 /*
 261  * Translate the CQL string client-side into RPN which is passed to
 262  * the server.  This is useful for server's that don't themselves
 263  * support CQL, for which ZOOM_query_cql() is useless.  `conn' is used
 264  * only as a place to stash diagnostics if compilation fails; if this
 265  * information is not needed, a null pointer may be used.
 266  */
 267 ZOOM_API(int)
 268     ZOOM_query_cql2rpn(ZOOM_query s, const char *str, ZOOM_connection conn)
 269 {
 270     char *rpn;
 271     int ret;
 272     ZOOM_connection freeme = 0;
 273
 274     if (conn == 0)
 275         conn = freeme = ZOOM_connection_create(0);
 276
 277     rpn = cql2pqf(conn, str);
 278     if (freeme != 0)
 279         ZOOM_connection_destroy(freeme);
 280     if (rpn == 0)
 281         return -1;
 282
 283     ret = ZOOM_query_prefix(s, rpn);
 284     xfree(rpn);
 285     return ret;
 286 }
 287
 288 /*
 289  * Analogous in every way to ZOOM_query_cql2rpn(), except that there
 290  * is no analogous ZOOM_query_ccl() that just sends uninterpreted CCL
 291  * to the server, as the YAZ GFS doesn't know how to handle this.
 292  */
 293 ZOOM_API(int)
 294     ZOOM_query_ccl2rpn(ZOOM_query s, const char *str, const char *config,
 295                        int *ccl_error, const char **error_string,
 296                        int *error_pos)
 297 {
 298     int ret;
 299     struct ccl_rpn_node *rpn;
 300     CCL_bibset bibset = ccl_qual_mk();
 301
 302     if (config)
 303         ccl_qual_buf(bibset, config);
 304
 305     rpn = ccl_find_str(bibset, str, ccl_error, error_pos);
 306     if (!rpn)
 307     {
 308         *error_string = ccl_err_msg(*ccl_error);
 309         ret = -1;
 310     }
 311     else
 312     {
 313         WRBUF wr = wrbuf_alloc();
 314         ccl_pquery(wr, rpn);
 315         ccl_rpn_delete(rpn);
 316         ret = ZOOM_query_prefix(s, wrbuf_cstr(wr));
 317         wrbuf_destroy(wr);
 318     }
 319     ccl_qual_rm(&bibset);
 320     return ret;
 321 }
 322
 323 ZOOM_API(int)
 324     ZOOM_query_sortby(ZOOM_query s, const char *criteria)
 325 {
 326     return ZOOM_query_sortby2(s, "z3950", criteria);
 327 }
 328
 329 ZOOM_API(int)
 330 ZOOM_query_sortby2(ZOOM_query s, const char *strategy, const char *criteria)
 331 {
 332     if (!strcmp(strategy, "z3950"))
 333     {
 334         s->sort_strategy = SORT_STRATEGY_Z3950;
 335     }
 336     else if (!strcmp(strategy, "type7"))
 337     {
 338         s->sort_strategy = SORT_STRATEGY_TYPE7;
 339     }
 340     else if (!strcmp(strategy, "cql"))
 341     {
 342         s->sort_strategy = SORT_STRATEGY_CQL;
 343     }
 344     else if (!strcmp(strategy, "sru11"))
 345     {
 346         s->sort_strategy = SORT_STRATEGY_SRU11;
 347     }
 348     else if (!strcmp(strategy, "embed"))
 349     {
 350         s->sort_strategy = SORT_STRATEGY_EMBED;
 351     }
 352     else
 353         return -1;
 354
 355     odr_reset(s->odr_sort_spec);
 356     s->sort_spec = yaz_sort_spec(s->odr_sort_spec, criteria);
 357     if (!s->sort_spec)
 358         return -1;
 359     return generate(s);
 360 }
 361
 362 /*
 363  * Local variables:
 364  * c-basic-offset: 4
 365  * c-file-style: "Stroustrup"
 366  * indent-tabs-mode: nil
 367  * End:
 368  * vim: shiftwidth=4 tabstop=8 expandtab
 369  */
 370