git.ozlabs.org Git - ccan/blob - ccan/ttxml/ttxml.c

   1 /* Licensed under GPL - see LICENSE file for details */\r
   2 \r
   3 #include <stdlib.h>\r
   4 #include <string.h>\r
   5 #include <stdio.h>\r
   6 \r
   7 #include "ttxml.h"\r
   8 \r
   9 #ifndef BUFFER\r
  10 #define BUFFER 3264\r
  11 #endif\r
  12 \r
  13 \r
  14 #define XML_LETTER      1\r
  15 #define XML_NUMBER      2\r
  16 #define XML_SPACE       4\r
  17 #define XML_SLASH       8\r
  18 #define XML_OPEN        16\r
  19 #define XML_EQUALS      32\r
  20 #define XML_CLOSE       64\r
  21 #define XML_QUOTE       128\r
  22 #define XML_OTHER       256\r
  23 \r
  24 #define XML_ALL 0xFFFFFFFF\r
  25 \r
  26 \r
  27 typedef struct XMLBUF\r
  28 {\r
  29         FILE * fptr;\r
  30         char * buf;\r
  31         int len;\r
  32         int read_index;\r
  33         int eof;\r
  34 } XMLBUF;\r
  35 \r
  36 \r
  37 /* Allocate a new XmlNode */\r
  38 static XmlNode* xml_new(char * name)\r
  39 {\r
  40         XmlNode * ret = malloc(sizeof(XmlNode));\r
  41         if(!ret)return NULL;\r
  42 \r
  43         ret->attrib = NULL;\r
  44         ret->nattrib = 0;\r
  45         ret->child = ret->next = NULL;\r
  46 \r
  47         ret->name = name;\r
  48         return ret;\r
  49 }\r
  50 \r
  51 /* free a previously allocated XmlNode */\r
  52 void xml_free(XmlNode *target)\r
  53 {\r
  54         int i;\r
  55         for(i=0; i<target->nattrib*2; i++)\r
  56                 if(target->attrib[i])\r
  57                         free(target->attrib[i]);\r
  58 \r
  59         if(target->attrib)free(target->attrib);\r
  60         if(target->child)xml_free(target->child);\r
  61         if(target->next)xml_free(target->next);\r
  62         free(target->name);\r
  63         free(target);\r
  64 }\r
  65 \r
  66 /* Raise flags if we have a character of special meaning.\r
  67  * This is where I've hidden the switch statements :-p\r
  68  */\r
  69 static int is_special(char item)\r
  70 {\r
  71         if((item >= 'a' && item <= 'z') || (item >= 'A' && item <='Z'))\r
  72                 return XML_LETTER;\r
  73         if( item >= '0' && item <='9' )\r
  74                 return XML_NUMBER;\r
  75         if( item == 0x20 || item == '\t' ||     item == 0x0D || item == 0x0A )\r
  76                 return XML_SPACE;\r
  77         if( item == '/' )\r
  78                 return XML_SLASH;\r
  79         if( item == '<' )\r
  80                 return XML_OPEN;\r
  81         if( item == '=' )\r
  82                 return XML_EQUALS;\r
  83         if( item == '>' )\r
  84                 return XML_CLOSE;\r
  85         if( item == '"' || item == '\'' )\r
  86                 return XML_QUOTE;\r
  87         return 128;\r
  88 }\r
  89 \r
  90 /* Refresh the buffer, if possible */\r
  91 static void xml_read_file(XMLBUF *xml)\r
  92 {\r
  93         int size;\r
  94         \r
  95         if(xml->eof)return;\r
  96           \r
  97         size = fread( xml->buf, 1, xml->len, xml->fptr);\r
  98         if( size != xml->len )\r
  99         {\r
 100                 xml->len = size;\r
 101                 xml->buf[size]=0;\r
 102                 xml->eof = 1;\r
 103         }\r
 104 }\r
 105 \r
 106 \r
 107 /* All reading of the XML buffer done through these two functions */\r
 108 /*** read a byte without advancing the offset */\r
 109 static char xml_peek(XMLBUF *xml)\r
 110 {\r
 111         return xml->buf[xml->read_index];\r
 112 }\r
 113 \r
 114 /*** read a byte and advance the offset */\r
 115 static char xml_read_byte(XMLBUF *xml)\r
 116 {\r
 117         char ret = xml_peek(xml);\r
 118         xml->read_index++;\r
 119         if(xml->read_index >= xml->len)\r
 120         {\r
 121                 if(xml->eof)\r
 122                 {\r
 123                   xml->read_index = xml->len;\r
 124                   return ret;\r
 125                 }\r
 126                 xml->read_index = 0 ;\r
 127                 xml_read_file(xml);\r
 128         }\r
 129         return ret;\r
 130 }\r
 131 \r
 132 \r
 133 /* skip over bytes matching the is_special mask */\r
 134 static void xml_skip( XMLBUF *xml, int mask)\r
 135 {\r
 136         while( is_special(xml_peek(xml)) & mask && !(xml->eof && xml->read_index >= xml->len) )\r
 137                 xml_read_byte(xml);\r
 138 }\r
 139 \r
 140 \r
 141 /* character matching tests for the feed functions */\r
 142 static char quotechar = 0;\r
 143 static int test_quote(const char x)\r
 144 {\r
 145         static int escaped=0;\r
 146         if( escaped || '\\' == x )\r
 147         {\r
 148                 escaped = !escaped;\r
 149                 return 1;\r
 150         }\r
 151         if( x != quotechar )\r
 152                 return 1;\r
 153         return 0;\r
 154 }\r
 155 \r
 156 static int feed_mask = 0;\r
 157 static int test_mask(const char x)\r
 158 {\r
 159         return !(is_special(x) & feed_mask);\r
 160 }\r
 161 \r
 162 /*\r
 163  * char* xml_feed(x, test)\r
 164  *\r
 165  * Reads as many contiguous chars that pass test() into a newly allocated\r
 166  * string.\r
 167  *\r
 168  * Instead of calling xml_read_byte and flogging realloc() for each byte,\r
 169  * it checks the buffer itself.\r
 170 */\r
 171 static char* xml_feed( XMLBUF *xml, int (*test)(char) )\r
 172 {\r
 173         int offset = xml->read_index;\r
 174         int delta;\r
 175         char *ret = NULL;\r
 176         int size = 0;\r
 177 \r
 178         /* perform first and N middle realloc()'s */\r
 179         while( test(xml->buf[offset]) )\r
 180         {\r
 181                 offset ++;\r
 182 \r
 183                 if(offset >= xml->len)\r
 184                 {\r
 185                         delta = offset - xml->read_index;\r
 186                         ret = realloc(ret, size + delta + 1);\r
 187                         memcpy(ret+size, xml->buf + xml->read_index, delta);\r
 188                         size += delta;\r
 189                         ret[size]=0;\r
 190                         if(xml->eof)return ret;\r
 191                         xml_read_file(xml);\r
 192                         xml->read_index = 0;\r
 193                         offset = 0;\r
 194                 }\r
 195         }\r
 196         /* perform final realloc() if needed */\r
 197         if(offset > xml->read_index)\r
 198         {\r
 199                 delta = offset - xml->read_index;\r
 200                 ret = realloc(ret, size + delta + 1);\r
 201                 memcpy(ret+size, xml->buf + xml->read_index, delta);\r
 202                 xml->read_index = offset;\r
 203                 size += delta;\r
 204                 ret[size]=0;\r
 205         }\r
 206         return ret;\r
 207 }\r
 208 \r
 209 /* this reads attributes from tags, of the form...\r
 210  *\r
 211  * <tag attr1="some arguments" attr2=argument>\r
 212  *\r
 213  * It is aware of quotes, and will allow anything inside quoted arguments\r
 214  */\r
 215 static void xml_read_attr(struct XMLBUF *xml, XmlNode *node)\r
 216 {\r
 217         int n=0;\r
 218 \r
 219         // how does this tag finish?\r
 220         while(xml->len)\r
 221         {\r
 222                 if( is_special(xml_peek(xml)) & (XML_CLOSE | XML_SLASH) )\r
 223                         return;\r
 224 \r
 225                 n = ++node->nattrib;\r
 226                 node->attrib = realloc(node->attrib, n * 2 * sizeof(char*) );\r
 227                 node->attrib[--n*2+1] = 0;\r
 228                 \r
 229                 feed_mask = XML_EQUALS | XML_SPACE | XML_CLOSE | XML_SLASH;\r
 230                 node->attrib[n*2] = xml_feed(xml, test_mask );\r
 231                 if( xml_peek(xml) == '=' )\r
 232                 {\r
 233                         xml_read_byte(xml);\r
 234                         if( is_special(xml_peek(xml)) & XML_QUOTE )\r
 235                         {\r
 236                                 quotechar = xml_read_byte(xml);\r
 237                                 node->attrib[n*2+1] = xml_feed(xml, test_quote);\r
 238                                 xml_read_byte(xml);\r
 239                         }\r
 240                         else\r
 241                         {\r
 242                                 feed_mask = XML_SPACE | XML_CLOSE | XML_SLASH;\r
 243                                 node->attrib[n*2+1] = xml_feed(xml, test_mask);\r
 244                         }\r
 245                 }\r
 246                 xml_skip(xml, XML_SPACE);\r
 247         }\r
 248 }\r
 249 \r
 250 /* The big decision maker, is it a regular node, or a text node.\r
 251  * If it's a node, it will check if it should have children, and if so\r
 252  * will recurse over them.\r
 253  * Text nodes don't have children, so no recursing.\r
 254  */\r
 255 static XmlNode* xml_parse(struct XMLBUF *xml)\r
 256 {\r
 257         int offset;\r
 258         int toff;\r
 259         char *tmp;\r
 260         XmlNode **this, *ret = NULL;\r
 261         \r
 262         this = &ret;\r
 263 \r
 264         xml_skip(xml, XML_SPACE);       // skip whitespace\r
 265         offset=0;\r
 266         while( (xml->read_index < xml->len) || !xml->eof )\r
 267         {\r
 268                 switch(is_special(xml_peek(xml)))\r
 269                 {\r
 270                         case XML_OPEN:\r
 271                                 xml_read_byte(xml);\r
 272                                 if(xml_peek(xml) == '/')\r
 273                                         return ret;             // parents close tag\r
 274                                 // read the tag name\r
 275                                 feed_mask = XML_SPACE | XML_SLASH | XML_CLOSE;\r
 276                                 *this = xml_new( xml_feed(xml, test_mask));\r
 277                                 xml_skip(xml, XML_SPACE);       // skip any whitespace\r
 278 \r
 279                                 xml_read_attr(xml, *this);      // read attributes\r
 280 \r
 281                                 // how does this tag finish?\r
 282                                 switch(is_special(xml_peek(xml)))\r
 283                                 {\r
 284                                         case XML_CLOSE:         // child-nodes ahead\r
 285                                                 xml_read_byte(xml);\r
 286                                                 (*this)->child = xml_parse(xml);\r
 287                                                 xml_skip(xml, XML_ALL ^ XML_CLOSE);\r
 288                                                 xml_read_byte(xml);\r
 289                                                 break;\r
 290                                         case XML_SLASH:         // self closing tag\r
 291                                                 xml_read_byte(xml);\r
 292                                                 xml_read_byte(xml);\r
 293                                                 break;\r
 294                                 }\r
 295                                 break;\r
 296 \r
 297                         default:        // text node\r
 298                                 *this = xml_new(0);\r
 299                                 xml_skip(xml, XML_SPACE);       // skip any whitespace\r
 300                                 feed_mask = XML_OPEN;\r
 301                                 (*this)->nattrib=1;\r
 302                                 (*this)->attrib = malloc(sizeof(char*)*2);\r
 303                                 (*this)->attrib[1] = NULL;\r
 304                                 tmp = (*this)->attrib[0] = xml_feed(xml, test_mask);\r
 305 \r
 306                                 /* trim the whitespace off the end of text nodes,\r
 307                                  * by overwriting the spaces will null termination. */\r
 308                                 toff = strlen(tmp)-1;\r
 309                                 while( ( is_special(tmp[toff]) & XML_SPACE ) )\r
 310                                 {\r
 311                                         tmp[toff] = 0;\r
 312                                         toff --;\r
 313                                 }\r
 314 \r
 315                                 break;\r
 316                 }\r
 317                 this = &(*this)->next; \r
 318                 xml_skip(xml, XML_SPACE);       // skip whitespace\r
 319         }       \r
 320 \r
 321         return ret;\r
 322 }\r
 323 \r
 324 \r
 325 /* bootstrap the structures for xml_parse() to be able to get started */\r
 326 XmlNode* xml_load(const char * filename)\r
 327 {\r
 328         struct XMLBUF xml;\r
 329         XmlNode *ret = NULL;\r
 330 \r
 331 //      printf("xml_load(\"%s\");\n", filename);\r
 332 \r
 333         xml.eof = 0;\r
 334         xml.read_index = 0;\r
 335         xml.fptr = fopen(filename, "rb");\r
 336         if(!xml.fptr)\r
 337                 return NULL;\r
 338 \r
 339         xml.buf = malloc(BUFFER+1);\r
 340         xml.buf[BUFFER]=0;\r
 341         xml.len = BUFFER;\r
 342         if(!xml.buf)\r
 343                 goto xml_load_fail_malloc_buf;\r
 344         \r
 345         xml_read_file(&xml);\r
 346 \r
 347         ret = xml_parse(&xml);\r
 348 \r
 349         free(xml.buf);\r
 350 xml_load_fail_malloc_buf:\r
 351         fclose(xml.fptr);\r
 352         return ret;\r
 353 }\r
 354 \r
 355 /* very basic function that will get you the first node with a given name */\r
 356 XmlNode * xml_find(XmlNode *xml, const char *name)\r
 357 {\r
 358         XmlNode * ret;\r
 359         if(xml->name)if(!strcmp(xml->name, name))return xml;\r
 360         if(xml->child)\r
 361         {\r
 362                 ret = xml_find(xml->child, name);\r
 363                 if(ret)return ret;\r
 364         }\r
 365         if(xml->next)\r
 366         {\r
 367                 ret = xml_find(xml->next, name);\r
 368                 if(ret)return ret;\r
 369         }\r
 370         return NULL;\r
 371 }\r
 372 \r
 373 /* very basic attribute lookup function */\r
 374 char* xml_attr(XmlNode *x, const char *name)\r
 375 {\r
 376         int i;\r
 377         for(i=0; i<x->nattrib; i++)\r
 378                 if(x->attrib[i*2])\r
 379                         if(!strcmp(x->attrib[i*2], name))\r
 380                                 return x->attrib[i*2+1];\r
 381         return 0;\r
 382 }\r
 383 \r
 384 \r