src/retrieval.c

   1 /* This file is part of the YAZ toolkit.
   2  * Copyright (C) 1995-2012 Index Data
   3  * See the file LICENSE for details.
   4  */
   5 /**
   6  * \file retrieval.c
   7  * \brief Retrieval utility
   8  */
   9
  10 #if HAVE_CONFIG_H
  11 #include <config.h>
  12 #endif
  13
  14 #include <string.h>
  15 #include <yaz/retrieval.h>
  16 #include <yaz/wrbuf.h>
  17 #include <yaz/xmalloc.h>
  18 #include <yaz/nmem.h>
  19 #include <yaz/tpath.h>
  20 #include <yaz/match_glob.h>
  21 #include <yaz/proto.h>
  22 #include <yaz/oid_db.h>
  23
  24 #if YAZ_HAVE_XML2
  25 #include <libxml/parser.h>
  26 #include <libxml/tree.h>
  27 #include <libxml/xinclude.h>
  28
  29 /** \brief The internal structure for yaz_retrieval_t */
  30 struct yaz_retrieval_struct {
  31     /** \brief ODR memory for configuration */
  32     ODR odr;
  33
  34     /** \brief odr's NMEM memory (odr->mem) */
  35     NMEM nmem;
  36
  37     /** \brief string buffer for error messages */
  38     WRBUF wr_error;
  39
  40     /** \brief path for opening files  */
  41     char *path;
  42
  43     /** \brief retrieval list */
  44     struct yaz_retrieval_elem *list;
  45
  46     /** \brief last pointer in retrieval list */
  47     struct yaz_retrieval_elem **list_p;
  48 };
  49
  50 /** \brief information per 'retrieval' construct */
  51 struct yaz_retrieval_elem {
  52     /** \brief schema identifier */
  53     const char *identifier;
  54     /** \brief schema name , short-hand such as "dc" */
  55     const char *name;
  56     /** \brief record syntax */
  57     Odr_oid *syntax;
  58
  59     /** \brief backend name */
  60     const char *backend_name;
  61     /** \brief backend syntax */
  62     Odr_oid *backend_syntax;
  63
  64     /** \brief record conversion */
  65     yaz_record_conv_t record_conv;
  66
  67     /** \brief next element in list */
  68     struct yaz_retrieval_elem *next;
  69 };
  70
  71 static void yaz_retrieval_reset(yaz_retrieval_t p);
  72
  73 yaz_retrieval_t yaz_retrieval_create()
  74 {
  75     yaz_retrieval_t p = (yaz_retrieval_t) xmalloc(sizeof(*p));
  76     p->odr = odr_createmem(ODR_ENCODE);
  77     p->nmem = odr_getmem(p->odr);
  78     p->wr_error = wrbuf_alloc();
  79     p->list = 0;
  80     p->path = 0;
  81     yaz_retrieval_reset(p);
  82     return p;
  83 }
  84
  85 void yaz_retrieval_destroy(yaz_retrieval_t p)
  86 {
  87     if (p)
  88     {
  89         yaz_retrieval_reset(p);
  90         odr_destroy(p->odr);
  91         wrbuf_destroy(p->wr_error);
  92         xfree(p->path);
  93         xfree(p);
  94     }
  95 }
  96
  97 void yaz_retrieval_reset(yaz_retrieval_t p)
  98 {
  99     struct yaz_retrieval_elem *el = p->list;
 100     for(; el; el = el->next)
 101         yaz_record_conv_destroy(el->record_conv);
 102
 103     wrbuf_rewind(p->wr_error);
 104     odr_reset(p->odr);
 105
 106     p->list = 0;
 107     p->list_p = &p->list;
 108 }
 109
 110 /** \brief parse retrieval XML config */
 111 static int conf_retrieval(yaz_retrieval_t p, const xmlNode *ptr)
 112 {
 113
 114     struct _xmlAttr *attr;
 115     struct yaz_retrieval_elem *el = (struct yaz_retrieval_elem *)
 116         nmem_malloc(p->nmem, sizeof(*el));
 117
 118     el->syntax = 0;
 119     el->identifier = 0;
 120     el->name = 0;
 121     el->backend_name = 0;
 122     el->backend_syntax = 0;
 123
 124     el->next = 0;
 125
 126     for (attr = ptr->properties; attr; attr = attr->next)
 127     {
 128         if (!xmlStrcmp(attr->name, BAD_CAST "syntax") &&
 129             attr->children && attr->children->type == XML_TEXT_NODE)
 130         {
 131             el->syntax = yaz_string_to_oid_odr(
 132                 yaz_oid_std(),
 133                 CLASS_RECSYN,
 134                 (const char *) attr->children->content,
 135                 p->odr);
 136             if (!el->syntax)
 137             {
 138                 wrbuf_printf(p->wr_error, "Element <retrieval>: "
 139                              " unknown attribute value syntax='%s'",
 140                              (const char *) attr->children->content);
 141                 return -1;
 142             }
 143         }
 144         else if (!xmlStrcmp(attr->name, BAD_CAST "identifier") &&
 145                  attr->children && attr->children->type == XML_TEXT_NODE)
 146             el->identifier =
 147                 nmem_strdup(p->nmem, (const char *) attr->children->content);
 148         else if (!xmlStrcmp(attr->name, BAD_CAST "name") &&
 149                  attr->children && attr->children->type == XML_TEXT_NODE)
 150             el->name =
 151                 nmem_strdup(p->nmem, (const char *) attr->children->content);
 152         else
 153         {
 154             wrbuf_printf(p->wr_error, "Element <retrieval>: "
 155                          " expected attributes 'syntax', identifier' or "
 156                          "'name', got '%s'", attr->name);
 157             return -1;
 158         }
 159     }
 160
 161     if (!el->syntax)
 162     {
 163         wrbuf_printf(p->wr_error, "Missing 'syntax' attribute");
 164         return -1;
 165     }
 166
 167     /* parsing backend element */
 168
 169     el->record_conv = 0; /* OK to have no 'backend' sub content */
 170     for (ptr = ptr->children; ptr; ptr = ptr->next)
 171     {
 172         if (ptr->type != XML_ELEMENT_NODE)
 173             continue;
 174         if (strcmp((const char *) ptr->name, "backend")){
 175             wrbuf_printf(p->wr_error, "Element <retrieval>: expected"
 176                          " zero or one element <backend>, got <%s>",
 177                          (const char *) ptr->name);
 178             return -1;
 179         }
 180
 181         else {
 182
 183             if (el->record_conv)
 184             {
 185                 wrbuf_printf(p->wr_error, "Element <retrieval>: "
 186                              "only one <backend> allowed");
 187                 yaz_record_conv_destroy(el->record_conv);
 188                 return -1;
 189             }
 190
 191             /* parsing attributees */
 192             struct _xmlAttr *attr;
 193             for (attr = ptr->properties; attr; attr = attr->next){
 194
 195                 if (!xmlStrcmp(attr->name, BAD_CAST "name")
 196                          && attr->children
 197                          && attr->children->type == XML_TEXT_NODE)
 198                     el->backend_name
 199                         = nmem_strdup(p->nmem,
 200                                       (const char *) attr->children->content);
 201
 202                 else if (!xmlStrcmp(attr->name, BAD_CAST "syntax")
 203                          && attr->children
 204                          && attr->children->type == XML_TEXT_NODE){
 205                     el->backend_syntax
 206                         = yaz_string_to_oid_odr(
 207                             yaz_oid_std(),
 208                             CLASS_RECSYN,
 209                             (const char *) attr->children->content,
 210                             p->odr);
 211                     if (!el->backend_syntax){
 212                         wrbuf_printf(p->wr_error,
 213                                      "Element <backend syntax='%s'>: "
 214                                      "attribute 'syntax' has invalid "
 215                                      "value '%s'",
 216                                      attr->children->content,
 217                                      attr->children->content);
 218                         return -1;
 219                     }
 220                 }
 221                 else {
 222                     wrbuf_printf(p->wr_error, "Element <backend>: expected "
 223                                  "attributes 'syntax' or 'name, got '%s'",
 224                                  attr->name);
 225                     return -1;
 226                 }
 227             }
 228
 229
 230             /* parsing internal of record conv */
 231             el->record_conv = yaz_record_conv_create();
 232
 233             yaz_record_conv_set_path(el->record_conv, p->path);
 234
 235
 236             if (yaz_record_conv_configure(el->record_conv, ptr))
 237             {
 238                 wrbuf_printf(p->wr_error, "%s",
 239                              yaz_record_conv_get_error(el->record_conv));
 240                 yaz_record_conv_destroy(el->record_conv);
 241                 return -1;
 242             }
 243         }
 244     }
 245
 246     *p->list_p = el;
 247     p->list_p = &el->next;
 248     return 0;
 249 }
 250
 251 int yaz_retrieval_configure(yaz_retrieval_t p, const xmlNode *ptr)
 252 {
 253     yaz_retrieval_reset(p);
 254
 255     if (ptr && ptr->type == XML_ELEMENT_NODE &&
 256         !strcmp((const char *) ptr->name, "retrievalinfo"))
 257     {
 258         for (ptr = ptr->children; ptr; ptr = ptr->next)
 259         {
 260             if (ptr->type != XML_ELEMENT_NODE)
 261                 continue;
 262             if (!strcmp((const char *) ptr->name, "retrieval"))
 263             {
 264                 if (conf_retrieval(p, ptr))
 265                     return -1;
 266             }
 267             else
 268             {
 269                 wrbuf_printf(p->wr_error, "Element <retrievalinfo>: "
 270                              "expected element <retrieval>, got <%s>",
 271                              ptr->name);
 272                 return -1;
 273             }
 274         }
 275     }
 276     else
 277     {
 278         wrbuf_printf(p->wr_error, "Expected element <retrievalinfo>");
 279         return -1;
 280     }
 281     return 0;
 282 }
 283
 284 int yaz_retrieval_request(yaz_retrieval_t p,
 285                           const char *schema, Odr_oid *syntax,
 286                           const char **match_schema, Odr_oid **match_syntax,
 287                           yaz_record_conv_t *rc,
 288                           const char **backend_schema,
 289                           Odr_oid **backend_syntax)
 290 {
 291     struct yaz_retrieval_elem *el = p->list;
 292     int syntax_matches = 0;
 293     int schema_matches = 0;
 294
 295     wrbuf_rewind(p->wr_error);
 296     if (!el)
 297         return 0;
 298     for(; el; el = el->next)
 299     {
 300         int schema_ok = 0;
 301         int syntax_ok = 0;
 302
 303         if (!schema)
 304             schema_ok = 1;
 305         else
 306         {
 307             if (el->name && yaz_match_glob(el->name, schema))
 308                 schema_ok = 1;
 309             if (el->identifier && !strcmp(schema, el->identifier))
 310                 schema_ok = 1;
 311             if (!el->name && !el->identifier)
 312                 schema_ok = 1;
 313         }
 314
 315         if (syntax && el->syntax && !oid_oidcmp(syntax, el->syntax))
 316             syntax_ok = 1;
 317         if (!syntax)
 318             syntax_ok = 1;
 319
 320         if (syntax_ok)
 321             syntax_matches++;
 322         if (schema_ok)
 323             schema_matches++;
 324         if (syntax_ok && schema_ok)
 325         {
 326             *match_syntax = el->syntax;
 327             if (el->identifier)
 328                 *match_schema = el->identifier;
 329             else
 330                 *match_schema = 0;
 331             if (backend_schema)
 332             {
 333                 if (el->backend_name)
 334                     *backend_schema = el->backend_name;
 335                 else if (el->name)
 336                     *backend_schema = el->name;
 337                 else
 338                     *backend_schema = schema;
 339             }
 340             if (backend_syntax)
 341             {
 342                 if (el->backend_syntax)
 343                     *backend_syntax = el->backend_syntax;
 344                 else
 345                     *backend_syntax = el->syntax;
 346             }
 347             if (rc)
 348                 *rc = el->record_conv;
 349             return 0;
 350         }
 351     }
 352     if (!syntax_matches && syntax)
 353     {
 354         char buf[OID_STR_MAX];
 355         wrbuf_printf(p->wr_error, "%s", oid_oid_to_dotstring(syntax, buf));
 356         return 2;
 357     }
 358     if (schema)
 359         wrbuf_printf(p->wr_error, "%s", schema);
 360     if (!schema_matches)
 361         return 1;
 362     return 3;
 363 }
 364
 365 const char *yaz_retrieval_get_error(yaz_retrieval_t p)
 366 {
 367     return wrbuf_cstr(p->wr_error);
 368 }
 369
 370 void yaz_retrieval_set_path(yaz_retrieval_t p, const char *path)
 371 {
 372     xfree(p->path);
 373     p->path = 0;
 374     if (path)
 375         p->path = xstrdup(path);
 376 }
 377
 378 #endif
 379
 380 /*
 381  * Local variables:
 382  * c-basic-offset: 4
 383  * c-file-style: "Stroustrup"
 384  * indent-tabs-mode: nil
 385  * End:
 386  * vim: shiftwidth=4 tabstop=8 expandtab
 387  */
 388