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