src/rpn2cql.c

   1 /* This file is part of the YAZ toolkit.
   2  * Copyright (C) 1995-2009 Index Data
   3  * See the file LICENSE for details.
   4  */
   5
   6 /**
   7  * \file
   8  * \brief Implements RPN to CQL conversion
   9  *
  10  */
  11
  12 #include <assert.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <yaz/rpn2cql.h>
  16 #include <yaz/xmalloc.h>
  17 #include <yaz/diagbib1.h>
  18 #include <yaz/z-core.h>
  19 #include <yaz/wrbuf.h>
  20
  21 static const char *lookup_index_from_string_attr(Z_AttributeList *attributes)
  22 {
  23     int j;
  24     int server_choice = 1;
  25     for (j = 0; j < attributes->num_attributes; j++)
  26     {
  27         Z_AttributeElement *ae = attributes->attributes[j];
  28         if (*ae->attributeType == 1) /* use attribute */
  29         {
  30             if (ae->which == Z_AttributeValue_complex)
  31             {
  32                 Z_ComplexAttribute *ca = ae->value.complex;
  33                 int i;
  34                 for (i = 0; i < ca->num_list; i++)
  35                 {
  36                     Z_StringOrNumeric *son = ca->list[i];
  37                     if (son->which == Z_StringOrNumeric_string)
  38                         return son->u.string;
  39                 }
  40             }
  41             server_choice = 0; /* not serverChoice because we have use attr */
  42         }
  43     }
  44     if (server_choice)
  45         return "cql.serverChoice";
  46     return 0;
  47 }
  48
  49 static const char *lookup_relation_index_from_attr(Z_AttributeList *attributes)
  50 {
  51     int j;
  52     for (j = 0; j < attributes->num_attributes; j++)
  53     {
  54         Z_AttributeElement *ae = attributes->attributes[j];
  55         if (*ae->attributeType == 2) /* relation attribute */
  56         {
  57             if (ae->which == Z_AttributeValue_numeric)
  58             {
  59                 /* Only support for numeric relation */
  60                 Odr_int *relation = ae->value.numeric;
  61                 /* map this numeric to representation in CQL */
  62                 switch (*relation)
  63                 {
  64                     /* Unsure on whether this is the relation attribute constants? */
  65                 case Z_ProximityOperator_Prox_lessThan:
  66                     return "<";
  67                 case Z_ProximityOperator_Prox_lessThanOrEqual:
  68                     return "<=";
  69                 case Z_ProximityOperator_Prox_equal:
  70                     return "=";
  71                 case Z_ProximityOperator_Prox_greaterThanOrEqual:
  72                     return ">=";
  73                 case Z_ProximityOperator_Prox_greaterThan:
  74                     return ">";
  75                 case Z_ProximityOperator_Prox_notEqual:
  76                     return "<>";
  77                 case 100:
  78                     /* phonetic is not supported in CQL */
  79                     return 0;
  80                 case 101:
  81                     /* stem is not supported in CQL */
  82                     return 0;
  83                 case 102:
  84                     /* relevance is supported in CQL, but not implemented yet */
  85                     return 0;
  86                 default:
  87                     /* Invalid relation */
  88                     return 0;
  89                 }
  90             }
  91             else {
  92                 /*  Can we have a complex relation value?
  93                     Should we implement something?
  94                 */
  95             }
  96         }
  97     }
  98     return "=";
  99 }
 100
 101 static int rpn2cql_attr(cql_transform_t ct,
 102                         Z_AttributeList *attributes, WRBUF w)
 103 {
 104     const char *relation = cql_lookup_reverse(ct, "relation.", attributes);
 105     const char *index = cql_lookup_reverse(ct, "index.", attributes);
 106     const char *structure = cql_lookup_reverse(ct, "structure.", attributes);
 107
 108     /* if transform (properties) do not match, we'll just use a USE string attribute (bug #2978) */
 109     if (!index)
 110         index = lookup_index_from_string_attr(attributes);
 111
 112     /* Attempt to fix bug #2978: Look for a relation attribute */
 113     if (!relation)
 114         relation = lookup_relation_index_from_attr(attributes);
 115
 116     if (!index)
 117     {
 118         cql_transform_set_error(ct,
 119                                 YAZ_BIB1_UNSUPP_USE_ATTRIBUTE, 0);
 120         return -1;
 121     }
 122     /* for serverChoice we omit index+relation+structure */
 123     if (strcmp(index, "cql.serverChoice"))
 124     {
 125         wrbuf_puts(w, index);
 126         if (relation)
 127         {
 128             if (!strcmp(relation, "exact"))
 129                 relation = "==";
 130             else if (!strcmp(relation, "eq"))
 131                 relation = "=";
 132             else if (!strcmp(relation, "le"))
 133                 relation = "<=";
 134             else if (!strcmp(relation, "ge"))
 135                 relation = ">=";
 136             /* Missing mapping of not equal, phonetic, stem and relevance */
 137             wrbuf_puts(w, relation);
 138         }
 139         else
 140             wrbuf_puts(w, "=");
 141
 142         if (structure)
 143         {
 144             if (strcmp(structure, "*"))
 145             {
 146                 wrbuf_puts(w, "/");
 147                 wrbuf_puts(w, structure);
 148                 wrbuf_puts(w, " ");
 149             }
 150         }
 151     }
 152     return 0;
 153 }
 154
 155 /* Bug 2878: Currently only support left and right truncation. Specific check for this */
 156 static int checkForTruncation(int flag, Z_AttributeList *attributes)
 157 {
 158     int j;
 159     for (j = 0; j < attributes->num_attributes; j++)
 160     {
 161         Z_AttributeElement *ae = attributes->attributes[j];
 162         if (*ae->attributeType == 5) /* truncation attribute */
 163         {
 164             if (ae->which == Z_AttributeValue_numeric)
 165             {
 166                 int truncation = *(ae->value.numeric);
 167                 /* This logic only works for Left, right and both. eg. 1,2,3 */
 168                 if (truncation <= 3)
 169                     return (int) (truncation & flag);
 170             }
 171             /* Complex: Shouldn't happen */
 172         }
 173     }
 174     /* No truncation or unsupported */
 175     return 0;
 176 };
 177
 178 static int checkForLeftTruncation(Z_AttributeList *attributes) {
 179         return checkForTruncation(1, attributes);
 180 }
 181
 182 static int checkForRightTruncation(Z_AttributeList *attributes) {
 183         return checkForTruncation(2, attributes);
 184 };
 185
 186 static int rpn2cql_simple(cql_transform_t ct,
 187                           void (*pr)(const char *buf, void *client_data),
 188                           void *client_data,
 189                           Z_Operand *q, WRBUF w)
 190 {
 191     int ret = 0;
 192     if (q->which != Z_Operand_APT)
 193     {
 194         ret = -1;
 195         cql_transform_set_error(ct, YAZ_BIB1_RESULT_SET_UNSUPP_AS_A_SEARCH_TERM, 0);
 196     }
 197     else
 198     {
 199         Z_AttributesPlusTerm *apt = q->u.attributesPlusTerm;
 200         Z_Term *term = apt->term;
 201         const char *sterm = 0;
 202         size_t lterm = 0;
 203
 204         wrbuf_rewind(w);
 205         ret = rpn2cql_attr(ct, apt->attributes, w);
 206
 207         switch(term->which)
 208         {
 209         case Z_Term_general:
 210             lterm = term->u.general->len;
 211             sterm = (const char *) term->u.general->buf;
 212             break;
 213         case Z_Term_numeric:
 214             wrbuf_printf(w, ODR_INT_PRINTF, *term->u.numeric);
 215             break;
 216         case Z_Term_characterString:
 217             sterm = term->u.characterString;
 218             lterm = strlen(sterm);
 219             break;
 220         default:
 221             ret = -1;
 222             cql_transform_set_error(ct, YAZ_BIB1_TERM_TYPE_UNSUPP, 0);
 223         }
 224
 225         if (term)
 226         {
 227             size_t i;
 228             int must_quote = 0;
 229             for (i = 0 ; i < lterm; i++)
 230                 if (sterm[i] == ' ')
 231                     must_quote = 1;
 232             if (must_quote)
 233                 wrbuf_puts(w, "\"");
 234             /* Bug 2878: Check and add Truncation */
 235                         if (checkForLeftTruncation(apt->attributes))
 236                 wrbuf_puts(w, "*");
 237             wrbuf_write(w, sterm, lterm);
 238             /* Bug 2878: Check and add Truncation */
 239                         if (checkForRightTruncation(apt->attributes))
 240                 wrbuf_puts(w, "*");
 241             if (must_quote)
 242                 wrbuf_puts(w, "\"");
 243         }
 244         if (ret == 0)
 245             pr(wrbuf_cstr(w), client_data);
 246     }
 247     return ret;
 248 }
 249
 250
 251 static int rpn2cql_structure(cql_transform_t ct,
 252                              void (*pr)(const char *buf, void *client_data),
 253                              void *client_data,
 254                              Z_RPNStructure *q, int nested,
 255                              WRBUF w)
 256 {
 257     if (q->which == Z_RPNStructure_simple)
 258         return rpn2cql_simple(ct, pr, client_data, q->u.simple, w);
 259     else
 260     {
 261         Z_Operator *op = q->u.complex->roperator;
 262         int r;
 263
 264         if (nested)
 265             pr("(", client_data);
 266
 267         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s1, 1, w);
 268         if (r)
 269             return r;
 270         switch(op->which)
 271         {
 272         case  Z_Operator_and:
 273             pr(" and ", client_data);
 274             break;
 275         case  Z_Operator_or:
 276             pr(" or ", client_data);
 277             break;
 278         case  Z_Operator_and_not:
 279             pr(" not ", client_data);
 280             break;
 281         case  Z_Operator_prox:
 282             cql_transform_set_error(ct, YAZ_BIB1_UNSUPP_SEARCH, 0);
 283             return -1;
 284         }
 285         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s2, 1, w);
 286         if (nested)
 287             pr(")", client_data);
 288         return r;
 289     }
 290 }
 291
 292 int cql_transform_rpn2cql_stream(cql_transform_t ct,
 293                                  void (*pr)(const char *buf, void *client_data),
 294                                  void *client_data,
 295                                  Z_RPNQuery *q)
 296 {
 297     int r;
 298     WRBUF w = wrbuf_alloc();
 299     cql_transform_set_error(ct, 0, 0);
 300     r = rpn2cql_structure(ct, pr, client_data, q->RPNStructure, 0, w);
 301     wrbuf_destroy(w);
 302     return r;
 303 }
 304
 305
 306 int cql_transform_rpn2cql_wrbuf(cql_transform_t ct,
 307                                 WRBUF w,
 308                                 Z_RPNQuery *q)
 309 {
 310     return cql_transform_rpn2cql_stream(ct, wrbuf_vputs, w, q);
 311 }
 312
 313 /*
 314  * Local variables:
 315  * c-basic-offset: 4
 316  * c-file-style: "Stroustrup"
 317  * indent-tabs-mode: nil
 318  * End:
 319  * vim: shiftwidth=4 tabstop=8 expandtab
 320  */
 321