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     struct _xmlAttr *attr;
 114     struct yaz_retrieval_elem *el = (struct yaz_retrieval_elem *)
 115         nmem_malloc(p->nmem, sizeof(*el));
 116
 117     el->syntax = 0;
 118     el->identifier = 0;
 119     el->name = 0;
 120     el->backend_name = 0;
 121     el->backend_syntax = 0;
 122
 123     el->next = 0;
 124
 125     for (attr = ptr->properties; attr; attr = attr->next)
 126     {
 127         if (!xmlStrcmp(attr->name, BAD_CAST "syntax") &&
 128             attr->children && attr->children->type == XML_TEXT_NODE)
 129         {
 130             el->syntax = yaz_string_to_oid_odr(
 131                 yaz_oid_std(),
 132                 CLASS_RECSYN,
 133                 (const char *) attr->children->content,
 134                 p->odr);
 135             if (!el->syntax)
 136             {
 137                 wrbuf_printf(p->wr_error, "Element <retrieval>: "
 138                              " unknown attribute value syntax='%s'",
 139                              (const char *) attr->children->content);
 140                 return -1;
 141             }
 142         }
 143         else if (!xmlStrcmp(attr->name, BAD_CAST "identifier") &&
 144                  attr->children && attr->children->type == XML_TEXT_NODE)
 145             el->identifier =
 146                 nmem_strdup(p->nmem, (const char *) attr->children->content);
 147         else if (!xmlStrcmp(attr->name, BAD_CAST "name") &&
 148                  attr->children && attr->children->type == XML_TEXT_NODE)
 149             el->name =
 150                 nmem_strdup(p->nmem, (const char *) attr->children->content);
 151         else
 152         {
 153             wrbuf_printf(p->wr_error, "Element <retrieval>: "
 154                          " expected attributes 'syntax', identifier' or "
 155                          "'name', got '%s'", attr->name);
 156             return -1;
 157         }
 158     }
 159
 160     if (!el->syntax)
 161     {
 162         wrbuf_printf(p->wr_error, "Missing 'syntax' attribute");
 163         return -1;
 164     }
 165
 166     /* parsing backend element */
 167
 168     el->record_conv = 0; /* OK to have no 'backend' sub content */
 169     for (ptr = ptr->children; ptr; ptr = ptr->next)
 170     {
 171         if (ptr->type != XML_ELEMENT_NODE)
 172             continue;
 173         if (strcmp((const char *) ptr->name, "backend"))
 174         {
 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         else
 181         {
 182             if (el->record_conv)
 183             {
 184                 wrbuf_printf(p->wr_error, "Element <retrieval>: "
 185                              "only one <backend> allowed");
 186                 yaz_record_conv_destroy(el->record_conv);
 187                 return -1;
 188             }
 189             /* parsing attributees */
 190             struct _xmlAttr *attr;
 191             for (attr = ptr->properties; attr; attr = attr->next)
 192             {
 193                 if (!xmlStrcmp(attr->name, BAD_CAST "name")
 194                          && attr->children
 195                          && attr->children->type == XML_TEXT_NODE)
 196                     el->backend_name
 197                         = nmem_strdup(p->nmem,
 198                                       (const char *) attr->children->content);
 199
 200                 else if (!xmlStrcmp(attr->name, BAD_CAST "syntax")
 201                          && attr->children
 202                          && attr->children->type == XML_TEXT_NODE)
 203                 {
 204                     el->backend_syntax
 205                         = yaz_string_to_oid_odr(
 206                             yaz_oid_std(),
 207                             CLASS_RECSYN,
 208                             (const char *) attr->children->content,
 209                             p->odr);
 210                     if (!el->backend_syntax)
 211                     {
 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                 {
 223                     wrbuf_printf(p->wr_error, "Element <backend>: expected "
 224                                  "attributes 'syntax' or 'name, got '%s'",
 225                                  attr->name);
 226                     return -1;
 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             if (yaz_record_conv_configure(el->record_conv, ptr))
 236             {
 237                 wrbuf_printf(p->wr_error, "%s",
 238                              yaz_record_conv_get_error(el->record_conv));
 239                 yaz_record_conv_destroy(el->record_conv);
 240                 return -1;
 241             }
 242         }
 243     }
 244
 245     *p->list_p = el;
 246     p->list_p = &el->next;
 247     return 0;
 248 }
 249
 250 int yaz_retrieval_configure(yaz_retrieval_t p, const xmlNode *ptr)
 251 {
 252     yaz_retrieval_reset(p);
 253
 254     if (ptr && ptr->type == XML_ELEMENT_NODE &&
 255         !strcmp((const char *) ptr->name, "retrievalinfo"))
 256     {
 257         for (ptr = ptr->children; ptr; ptr = ptr->next)
 258         {
 259             if (ptr->type != XML_ELEMENT_NODE)
 260                 continue;
 261             if (!strcmp((const char *) ptr->name, "retrieval"))
 262             {
 263                 if (conf_retrieval(p, ptr))
 264                     return -1;
 265             }
 266             else
 267             {
 268                 wrbuf_printf(p->wr_error, "Element <retrievalinfo>: "
 269                              "expected element <retrieval>, got <%s>",
 270                              ptr->name);
 271                 return -1;
 272             }
 273         }
 274     }
 275     else
 276     {
 277         wrbuf_printf(p->wr_error, "Expected element <retrievalinfo>");
 278         return -1;
 279     }
 280     return 0;
 281 }
 282
 283 int yaz_retrieval_request(yaz_retrieval_t p,
 284                           const char *schema, Odr_oid *syntax,
 285                           const char **match_schema, Odr_oid **match_syntax,
 286                           yaz_record_conv_t *rc,
 287                           const char **backend_schema,
 288                           Odr_oid **backend_syntax)
 289 {
 290     struct yaz_retrieval_elem *el = p->list;
 291     int syntax_matches = 0;
 292     int schema_matches = 0;
 293
 294     wrbuf_rewind(p->wr_error);
 295     if (!el)
 296         return 0;
 297     for(; el; el = el->next)
 298     {
 299         int schema_ok = 0;
 300         int syntax_ok = 0;
 301
 302         if (!schema)
 303             schema_ok = 1;
 304         else
 305         {
 306             if (el->name && yaz_match_glob(el->name, schema))
 307                 schema_ok = 1;
 308             if (el->identifier && !strcmp(schema, el->identifier))
 309                 schema_ok = 1;
 310             if (!el->name && !el->identifier)
 311                 schema_ok = 1;
 312         }
 313
 314         if (syntax && el->syntax && !oid_oidcmp(syntax, el->syntax))
 315             syntax_ok = 1;
 316         if (!syntax)
 317             syntax_ok = 1;
 318
 319         if (syntax_ok)
 320             syntax_matches++;
 321         if (schema_ok)
 322             schema_matches++;
 323         if (syntax_ok && schema_ok)
 324         {
 325             *match_syntax = el->syntax;
 326             if (el->identifier)
 327                 *match_schema = el->identifier;
 328             else
 329                 *match_schema = 0;
 330             if (backend_schema)
 331             {
 332                 if (el->backend_name)
 333                     *backend_schema = el->backend_name;
 334                 else if (el->name)
 335                     *backend_schema = el->name;
 336                 else
 337                     *backend_schema = schema;
 338             }
 339             if (backend_syntax)
 340             {
 341                 if (el->backend_syntax)
 342                     *backend_syntax = el->backend_syntax;
 343                 else
 344                     *backend_syntax = el->syntax;
 345             }
 346             if (rc)
 347                 *rc = el->record_conv;
 348             return 0;
 349         }
 350     }
 351     if (!syntax_matches && syntax)
 352     {
 353         char buf[OID_STR_MAX];
 354         wrbuf_printf(p->wr_error, "%s", oid_oid_to_dotstring(syntax, buf));
 355         return 2;
 356     }
 357     if (schema)
 358         wrbuf_printf(p->wr_error, "%s", schema);
 359     if (!schema_matches)
 360         return 1;
 361     return 3;
 362 }
 363
 364 const char *yaz_retrieval_get_error(yaz_retrieval_t p)
 365 {
 366     return wrbuf_cstr(p->wr_error);
 367 }
 368
 369 void yaz_retrieval_set_path(yaz_retrieval_t p, const char *path)
 370 {
 371     xfree(p->path);
 372     p->path = 0;
 373     if (path)
 374         p->path = xstrdup(path);
 375 }
 376
 377 #endif
 378
 379 /*
 380  * Local variables:
 381  * c-basic-offset: 4
 382  * c-file-style: "Stroustrup"
 383  * indent-tabs-mode: nil
 384  * End:
 385  * vim: shiftwidth=4 tabstop=8 expandtab
 386  */
 387