src/rpn2cql.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
   7  * \brief Implements RPN to CQL conversion
   8  */
   9 #if HAVE_CONFIG_H
  10 #include <config.h>
  11 #endif
  12
  13 #include <assert.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <yaz/rpn2cql.h>
  17 #include <yaz/xmalloc.h>
  18 #include <yaz/diagbib1.h>
  19 #include <yaz/z-core.h>
  20 #include <yaz/wrbuf.h>
  21
  22 static void wrbuf_vputs(const char *buf, void *client_data)
  23 {
  24     wrbuf_write((WRBUF) client_data, buf, strlen(buf));
  25 }
  26
  27 static const char *lookup_index_from_string_attr(Z_AttributeList *attributes)
  28 {
  29     int j;
  30     int server_choice = 1;
  31     for (j = 0; j < attributes->num_attributes; j++)
  32     {
  33         Z_AttributeElement *ae = attributes->attributes[j];
  34         if (*ae->attributeType == 1) /* use attribute */
  35         {
  36             if (ae->which == Z_AttributeValue_complex)
  37             {
  38                 Z_ComplexAttribute *ca = ae->value.complex;
  39                 int i;
  40                 for (i = 0; i < ca->num_list; i++)
  41                 {
  42                     Z_StringOrNumeric *son = ca->list[i];
  43                     if (son->which == Z_StringOrNumeric_string)
  44                         return son->u.string;
  45                 }
  46             }
  47             server_choice = 0; /* not serverChoice because we have use attr */
  48         }
  49     }
  50     if (server_choice)
  51         return "cql.serverChoice";
  52     return 0;
  53 }
  54
  55 static const char *lookup_relation_index_from_attr(Z_AttributeList *attributes)
  56 {
  57     int j;
  58     for (j = 0; j < attributes->num_attributes; j++)
  59     {
  60         Z_AttributeElement *ae = attributes->attributes[j];
  61         if (*ae->attributeType == 2) /* relation attribute */
  62         {
  63             if (ae->which == Z_AttributeValue_numeric)
  64             {
  65                 /* Only support for numeric relation */
  66                 Odr_int *relation = ae->value.numeric;
  67                 /* map this numeric to representation in CQL */
  68                 switch (*relation)
  69                 {
  70                     /* Unsure on whether this is the relation attribute constants? */
  71                 case Z_ProximityOperator_Prox_lessThan:
  72                     return "<";
  73                 case Z_ProximityOperator_Prox_lessThanOrEqual:
  74                     return "<=";
  75                 case Z_ProximityOperator_Prox_equal:
  76                     return "=";
  77                 case Z_ProximityOperator_Prox_greaterThanOrEqual:
  78                     return ">=";
  79                 case Z_ProximityOperator_Prox_greaterThan:
  80                     return ">";
  81                 case Z_ProximityOperator_Prox_notEqual:
  82                     return "<>";
  83                 case 100:
  84                     /* phonetic is not supported in CQL */
  85                     return 0;
  86                 case 101:
  87                     /* stem is not supported in CQL */
  88                     return 0;
  89                 case 102:
  90                     /* relevance is supported in CQL, but not implemented yet */
  91                     return 0;
  92                 default:
  93                     /* Invalid relation */
  94                     return 0;
  95                 }
  96             }
  97             else {
  98                 /*  Can we have a complex relation value?
  99                     Should we implement something?
 100                 */
 101             }
 102         }
 103     }
 104     return "=";
 105 }
 106
 107 static int rpn2cql_attr(cql_transform_t ct,
 108                         Z_AttributeList *attributes, WRBUF w)
 109 {
 110     const char *relation = cql_lookup_reverse(ct, "relation.", attributes);
 111     const char *index = cql_lookup_reverse(ct, "index.", attributes);
 112     const char *structure = cql_lookup_reverse(ct, "structure.", attributes);
 113
 114     /* if transform (properties) do not match, we'll just use a USE string attribute (bug #2978) */
 115     if (!index)
 116         index = lookup_index_from_string_attr(attributes);
 117
 118     /* Attempt to fix bug #2978: Look for a relation attribute */
 119     if (!relation)
 120         relation = lookup_relation_index_from_attr(attributes);
 121
 122     if (!index)
 123     {
 124         cql_transform_set_error(ct,
 125                                 YAZ_BIB1_UNSUPP_USE_ATTRIBUTE, 0);
 126         return -1;
 127     }
 128     /* for serverChoice we omit index+relation+structure */
 129     if (strcmp(index, "cql.serverChoice"))
 130     {
 131         wrbuf_puts(w, index);
 132         if (relation)
 133         {
 134             if (!strcmp(relation, "exact"))
 135                 relation = "==";
 136             else if (!strcmp(relation, "eq"))
 137                 relation = "=";
 138             else if (!strcmp(relation, "le"))
 139                 relation = "<=";
 140             else if (!strcmp(relation, "ge"))
 141                 relation = ">=";
 142             /* Missing mapping of not equal, phonetic, stem and relevance */
 143             wrbuf_puts(w, relation);
 144         }
 145         else
 146             wrbuf_puts(w, "=");
 147
 148         if (structure)
 149         {
 150             if (strcmp(structure, "*"))
 151             {
 152                 wrbuf_puts(w, "/");
 153                 wrbuf_puts(w, structure);
 154                 wrbuf_puts(w, " ");
 155             }
 156         }
 157     }
 158     return 0;
 159 }
 160
 161 /* Bug 2878: Currently only support left and right truncation. Specific check for this */
 162 static int checkForTruncation(int flag, Z_AttributeList *attributes)
 163 {
 164     int j;
 165     for (j = 0; j < attributes->num_attributes; j++)
 166     {
 167         Z_AttributeElement *ae = attributes->attributes[j];
 168         if (*ae->attributeType == 5) /* truncation attribute */
 169         {
 170             if (ae->which == Z_AttributeValue_numeric)
 171             {
 172                 Odr_int truncation = *(ae->value.numeric);
 173                 /* This logic only works for Left, right and both. eg. 1,2,3 */
 174                 if (truncation <= 3)
 175                     return ((int) truncation & flag);
 176             }
 177             /* Complex: Shouldn't happen */
 178         }
 179     }
 180     /* No truncation or unsupported */
 181     return 0;
 182 };
 183
 184 static int checkForLeftTruncation(Z_AttributeList *attributes) {
 185         return checkForTruncation(2, attributes);
 186 }
 187
 188 static int checkForRightTruncation(Z_AttributeList *attributes) {
 189         return checkForTruncation(1, attributes);
 190 };
 191
 192 static int rpn2cql_simple(cql_transform_t ct,
 193                           void (*pr)(const char *buf, void *client_data),
 194                           void *client_data,
 195                           Z_Operand *q, WRBUF w)
 196 {
 197     int ret = 0;
 198     if (q->which != Z_Operand_APT)
 199     {
 200         ret = -1;
 201         cql_transform_set_error(ct, YAZ_BIB1_RESULT_SET_UNSUPP_AS_A_SEARCH_TERM, 0);
 202     }
 203     else
 204     {
 205         Z_AttributesPlusTerm *apt = q->u.attributesPlusTerm;
 206         Z_Term *term = apt->term;
 207         const char *sterm = 0;
 208         size_t lterm = 0;
 209
 210         wrbuf_rewind(w);
 211         ret = rpn2cql_attr(ct, apt->attributes, w);
 212
 213         switch(term->which)
 214         {
 215         case Z_Term_general:
 216             lterm = term->u.general->len;
 217             sterm = (const char *) term->u.general->buf;
 218             break;
 219         case Z_Term_numeric:
 220             wrbuf_printf(w, ODR_INT_PRINTF, *term->u.numeric);
 221             break;
 222         case Z_Term_characterString:
 223             sterm = term->u.characterString;
 224             lterm = strlen(sterm);
 225             break;
 226         default:
 227             ret = -1;
 228             cql_transform_set_error(ct, YAZ_BIB1_TERM_TYPE_UNSUPP, 0);
 229         }
 230
 231         if (term)
 232         {
 233             size_t i;
 234             int must_quote = 0;
 235             for (i = 0 ; i < lterm; i++)
 236                 if (sterm[i] == ' ')
 237                     must_quote = 1;
 238             if (must_quote)
 239                 wrbuf_puts(w, "\"");
 240             /* Bug 2878: Check and add Truncation */
 241                         if (checkForLeftTruncation(apt->attributes))
 242                 wrbuf_puts(w, "*");
 243             wrbuf_write(w, sterm, lterm);
 244             /* Bug 2878: Check and add Truncation */
 245                         if (checkForRightTruncation(apt->attributes))
 246                 wrbuf_puts(w, "*");
 247             if (must_quote)
 248                 wrbuf_puts(w, "\"");
 249         }
 250         if (ret == 0)
 251             pr(wrbuf_cstr(w), client_data);
 252     }
 253     return ret;
 254 }
 255
 256
 257 static int rpn2cql_structure(cql_transform_t ct,
 258                              void (*pr)(const char *buf, void *client_data),
 259                              void *client_data,
 260                              Z_RPNStructure *q, int nested,
 261                              WRBUF w)
 262 {
 263     if (q->which == Z_RPNStructure_simple)
 264         return rpn2cql_simple(ct, pr, client_data, q->u.simple, w);
 265     else
 266     {
 267         Z_Operator *op = q->u.complex->roperator;
 268         int r;
 269
 270         if (nested)
 271             pr("(", client_data);
 272
 273         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s1, 1, w);
 274         if (r)
 275             return r;
 276         switch(op->which)
 277         {
 278         case  Z_Operator_and:
 279             pr(" and ", client_data);
 280             break;
 281         case  Z_Operator_or:
 282             pr(" or ", client_data);
 283             break;
 284         case  Z_Operator_and_not:
 285             pr(" not ", client_data);
 286             break;
 287         case  Z_Operator_prox:
 288             cql_transform_set_error(ct, YAZ_BIB1_UNSUPP_SEARCH, 0);
 289             return -1;
 290         }
 291         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s2, 1, w);
 292         if (nested)
 293             pr(")", client_data);
 294         return r;
 295     }
 296 }
 297
 298 int cql_transform_rpn2cql_stream(cql_transform_t ct,
 299                                  void (*pr)(const char *buf, void *client_data),
 300                                  void *client_data,
 301                                  Z_RPNQuery *q)
 302 {
 303     int r;
 304     WRBUF w = wrbuf_alloc();
 305     cql_transform_set_error(ct, 0, 0);
 306     r = rpn2cql_structure(ct, pr, client_data, q->RPNStructure, 0, w);
 307     wrbuf_destroy(w);
 308     return r;
 309 }
 310
 311
 312 int cql_transform_rpn2cql_wrbuf(cql_transform_t ct,
 313                                 WRBUF w,
 314                                 Z_RPNQuery *q)
 315 {
 316     return cql_transform_rpn2cql_stream(ct, wrbuf_vputs, w, q);
 317 }
 318
 319 /*
 320  * Local variables:
 321  * c-basic-offset: 4
 322  * c-file-style: "Stroustrup"
 323  * indent-tabs-mode: nil
 324  * End:
 325  * vim: shiftwidth=4 tabstop=8 expandtab
 326  */
 327