src/rpn2cql.c

   1 /* This file is part of the YAZ toolkit.
   2  * Copyright (C) 1995-2010 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 void wrbuf_vputs(const char *buf, void *client_data)
  22 {
  23     wrbuf_write((WRBUF) client_data, buf, strlen(buf));
  24 }
  25
  26 static const char *lookup_index_from_string_attr(Z_AttributeList *attributes)
  27 {
  28     int j;
  29     int server_choice = 1;
  30     for (j = 0; j < attributes->num_attributes; j++)
  31     {
  32         Z_AttributeElement *ae = attributes->attributes[j];
  33         if (*ae->attributeType == 1) /* use attribute */
  34         {
  35             if (ae->which == Z_AttributeValue_complex)
  36             {
  37                 Z_ComplexAttribute *ca = ae->value.complex;
  38                 int i;
  39                 for (i = 0; i < ca->num_list; i++)
  40                 {
  41                     Z_StringOrNumeric *son = ca->list[i];
  42                     if (son->which == Z_StringOrNumeric_string)
  43                         return son->u.string;
  44                 }
  45             }
  46             server_choice = 0; /* not serverChoice because we have use attr */
  47         }
  48     }
  49     if (server_choice)
  50         return "cql.serverChoice";
  51     return 0;
  52 }
  53
  54 static const char *lookup_relation_index_from_attr(Z_AttributeList *attributes)
  55 {
  56     int j;
  57     for (j = 0; j < attributes->num_attributes; j++)
  58     {
  59         Z_AttributeElement *ae = attributes->attributes[j];
  60         if (*ae->attributeType == 2) /* relation attribute */
  61         {
  62             if (ae->which == Z_AttributeValue_numeric)
  63             {
  64                 /* Only support for numeric relation */
  65                 Odr_int *relation = ae->value.numeric;
  66                 /* map this numeric to representation in CQL */
  67                 switch (*relation)
  68                 {
  69                     /* Unsure on whether this is the relation attribute constants? */
  70                 case Z_ProximityOperator_Prox_lessThan:
  71                     return "<";
  72                 case Z_ProximityOperator_Prox_lessThanOrEqual:
  73                     return "<=";
  74                 case Z_ProximityOperator_Prox_equal:
  75                     return "=";
  76                 case Z_ProximityOperator_Prox_greaterThanOrEqual:
  77                     return ">=";
  78                 case Z_ProximityOperator_Prox_greaterThan:
  79                     return ">";
  80                 case Z_ProximityOperator_Prox_notEqual:
  81                     return "<>";
  82                 case 100:
  83                     /* phonetic is not supported in CQL */
  84                     return 0;
  85                 case 101:
  86                     /* stem is not supported in CQL */
  87                     return 0;
  88                 case 102:
  89                     /* relevance is supported in CQL, but not implemented yet */
  90                     return 0;
  91                 default:
  92                     /* Invalid relation */
  93                     return 0;
  94                 }
  95             }
  96             else {
  97                 /*  Can we have a complex relation value?
  98                     Should we implement something?
  99                 */
 100             }
 101         }
 102     }
 103     return "=";
 104 }
 105
 106 static int rpn2cql_attr(cql_transform_t ct,
 107                         Z_AttributeList *attributes, WRBUF w)
 108 {
 109     const char *relation = cql_lookup_reverse(ct, "relation.", attributes);
 110     const char *index = cql_lookup_reverse(ct, "index.", attributes);
 111     const char *structure = cql_lookup_reverse(ct, "structure.", attributes);
 112
 113     /* if transform (properties) do not match, we'll just use a USE string attribute (bug #2978) */
 114     if (!index)
 115         index = lookup_index_from_string_attr(attributes);
 116
 117     /* Attempt to fix bug #2978: Look for a relation attribute */
 118     if (!relation)
 119         relation = lookup_relation_index_from_attr(attributes);
 120
 121     if (!index)
 122     {
 123         cql_transform_set_error(ct,
 124                                 YAZ_BIB1_UNSUPP_USE_ATTRIBUTE, 0);
 125         return -1;
 126     }
 127     /* for serverChoice we omit index+relation+structure */
 128     if (strcmp(index, "cql.serverChoice"))
 129     {
 130         wrbuf_puts(w, index);
 131         if (relation)
 132         {
 133             if (!strcmp(relation, "exact"))
 134                 relation = "==";
 135             else if (!strcmp(relation, "eq"))
 136                 relation = "=";
 137             else if (!strcmp(relation, "le"))
 138                 relation = "<=";
 139             else if (!strcmp(relation, "ge"))
 140                 relation = ">=";
 141             /* Missing mapping of not equal, phonetic, stem and relevance */
 142             wrbuf_puts(w, relation);
 143         }
 144         else
 145             wrbuf_puts(w, "=");
 146
 147         if (structure)
 148         {
 149             if (strcmp(structure, "*"))
 150             {
 151                 wrbuf_puts(w, "/");
 152                 wrbuf_puts(w, structure);
 153                 wrbuf_puts(w, " ");
 154             }
 155         }
 156     }
 157     return 0;
 158 }
 159
 160 /* Bug 2878: Currently only support left and right truncation. Specific check for this */
 161 static int checkForTruncation(int flag, Z_AttributeList *attributes)
 162 {
 163     int j;
 164     for (j = 0; j < attributes->num_attributes; j++)
 165     {
 166         Z_AttributeElement *ae = attributes->attributes[j];
 167         if (*ae->attributeType == 5) /* truncation attribute */
 168         {
 169             if (ae->which == Z_AttributeValue_numeric)
 170             {
 171                 Odr_int truncation = *(ae->value.numeric);
 172                 /* This logic only works for Left, right and both. eg. 1,2,3 */
 173                 if (truncation <= 3)
 174                     return ((int) truncation & flag);
 175             }
 176             /* Complex: Shouldn't happen */
 177         }
 178     }
 179     /* No truncation or unsupported */
 180     return 0;
 181 };
 182
 183 static int checkForLeftTruncation(Z_AttributeList *attributes) {
 184         return checkForTruncation(1, attributes);
 185 }
 186
 187 static int checkForRightTruncation(Z_AttributeList *attributes) {
 188         return checkForTruncation(2, attributes);
 189 };
 190
 191 static int rpn2cql_simple(cql_transform_t ct,
 192                           void (*pr)(const char *buf, void *client_data),
 193                           void *client_data,
 194                           Z_Operand *q, WRBUF w)
 195 {
 196     int ret = 0;
 197     if (q->which != Z_Operand_APT)
 198     {
 199         ret = -1;
 200         cql_transform_set_error(ct, YAZ_BIB1_RESULT_SET_UNSUPP_AS_A_SEARCH_TERM, 0);
 201     }
 202     else
 203     {
 204         Z_AttributesPlusTerm *apt = q->u.attributesPlusTerm;
 205         Z_Term *term = apt->term;
 206         const char *sterm = 0;
 207         size_t lterm = 0;
 208
 209         wrbuf_rewind(w);
 210         ret = rpn2cql_attr(ct, apt->attributes, w);
 211
 212         switch(term->which)
 213         {
 214         case Z_Term_general:
 215             lterm = term->u.general->len;
 216             sterm = (const char *) term->u.general->buf;
 217             break;
 218         case Z_Term_numeric:
 219             wrbuf_printf(w, ODR_INT_PRINTF, *term->u.numeric);
 220             break;
 221         case Z_Term_characterString:
 222             sterm = term->u.characterString;
 223             lterm = strlen(sterm);
 224             break;
 225         default:
 226             ret = -1;
 227             cql_transform_set_error(ct, YAZ_BIB1_TERM_TYPE_UNSUPP, 0);
 228         }
 229
 230         if (term)
 231         {
 232             size_t i;
 233             int must_quote = 0;
 234             for (i = 0 ; i < lterm; i++)
 235                 if (sterm[i] == ' ')
 236                     must_quote = 1;
 237             if (must_quote)
 238                 wrbuf_puts(w, "\"");
 239             /* Bug 2878: Check and add Truncation */
 240                         if (checkForLeftTruncation(apt->attributes))
 241                 wrbuf_puts(w, "*");
 242             wrbuf_write(w, sterm, lterm);
 243             /* Bug 2878: Check and add Truncation */
 244                         if (checkForRightTruncation(apt->attributes))
 245                 wrbuf_puts(w, "*");
 246             if (must_quote)
 247                 wrbuf_puts(w, "\"");
 248         }
 249         if (ret == 0)
 250             pr(wrbuf_cstr(w), client_data);
 251     }
 252     return ret;
 253 }
 254
 255
 256 static int rpn2cql_structure(cql_transform_t ct,
 257                              void (*pr)(const char *buf, void *client_data),
 258                              void *client_data,
 259                              Z_RPNStructure *q, int nested,
 260                              WRBUF w)
 261 {
 262     if (q->which == Z_RPNStructure_simple)
 263         return rpn2cql_simple(ct, pr, client_data, q->u.simple, w);
 264     else
 265     {
 266         Z_Operator *op = q->u.complex->roperator;
 267         int r;
 268
 269         if (nested)
 270             pr("(", client_data);
 271
 272         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s1, 1, w);
 273         if (r)
 274             return r;
 275         switch(op->which)
 276         {
 277         case  Z_Operator_and:
 278             pr(" and ", client_data);
 279             break;
 280         case  Z_Operator_or:
 281             pr(" or ", client_data);
 282             break;
 283         case  Z_Operator_and_not:
 284             pr(" not ", client_data);
 285             break;
 286         case  Z_Operator_prox:
 287             cql_transform_set_error(ct, YAZ_BIB1_UNSUPP_SEARCH, 0);
 288             return -1;
 289         }
 290         r = rpn2cql_structure(ct, pr, client_data, q->u.complex->s2, 1, w);
 291         if (nested)
 292             pr(")", client_data);
 293         return r;
 294     }
 295 }
 296
 297 int cql_transform_rpn2cql_stream(cql_transform_t ct,
 298                                  void (*pr)(const char *buf, void *client_data),
 299                                  void *client_data,
 300                                  Z_RPNQuery *q)
 301 {
 302     int r;
 303     WRBUF w = wrbuf_alloc();
 304     cql_transform_set_error(ct, 0, 0);
 305     r = rpn2cql_structure(ct, pr, client_data, q->RPNStructure, 0, w);
 306     wrbuf_destroy(w);
 307     return r;
 308 }
 309
 310
 311 int cql_transform_rpn2cql_wrbuf(cql_transform_t ct,
 312                                 WRBUF w,
 313                                 Z_RPNQuery *q)
 314 {
 315     return cql_transform_rpn2cql_stream(ct, wrbuf_vputs, w, q);
 316 }
 317
 318 /*
 319  * Local variables:
 320  * c-basic-offset: 4
 321  * c-file-style: "Stroustrup"
 322  * indent-tabs-mode: nil
 323  * End:
 324  * vim: shiftwidth=4 tabstop=8 expandtab
 325  */
 326