newsearch/newsearch_ast.c

   1 #include "newsearch.h"
   2 #include "../lib/sstring.h"
   3 #include "../lib/strlfunc.h"
   4 #include "../lib/stringbuf.h"
   5 #include <stdarg.h>
   6 #include <string.h>
   7
   8 /* at least we have some type safety... */
   9 typedef union exprunion {
  10   searchASTExpr *expr;
  11   char *literal;
  12 } exprunion;
  13
  14 typedef struct searchASTCache {
  15   searchASTExpr *tree;
  16   searchASTExpr *cache[AST_RECENT];
  17   int nextpos;
  18 } searchASTCache;
  19
  20 /* comares either a string and a string or an expression and an expression */
  21 static searchASTExpr *compareloc(searchASTExpr *expr, exprunion *loc) {
  22   if(expr->type == AST_NODE_LITERAL) {
  23     if(expr->u.literal == loc->literal)
  24       return expr;
  25   } else if(expr->type == AST_NODE_CHILD) {
  26     if(expr == loc->expr)
  27       return expr;
  28   } else {
  29     parseError = "static_parse_compare: bad node type";
  30     return NULL;
  31   }
  32   return NULL;
  33 }
  34
  35 /* searches the abstract syntax tree for the supplied expression/string */
  36 static searchASTExpr *treesearch(searchASTExpr *expr, exprunion *loc) {
  37   searchASTExpr *ret = compareloc(expr, loc);
  38   if(ret)
  39     return ret;
  40
  41   if(expr->type == AST_NODE_CHILD) {
  42     int i;
  43     for(i=0;i<expr->u.child->argc;i++) {
  44       searchASTExpr *d = treesearch(expr->u.child->argv[i], loc);
  45       if(d)
  46         return d;
  47     }
  48   }
  49   return NULL;
  50 }
  51
  52 /*
  53  * searches the AST cache, if this fails it goes and searches the tree.
  54  * the cache is hit most of the time and I guess makes it nearly O(1) amortised...
  55  */
  56 searchASTExpr *cachesearch(searchASTCache *cache, exprunion *loc) {
  57   searchASTExpr *ret = compareloc(cache->tree, loc);
  58   int i;
  59   if(ret)
  60     return ret;
  61
  62   for(i=0;i<AST_RECENT;i++) {
  63     if(!cache->cache[i])
  64       continue;
  65     ret = compareloc(cache->cache[i], loc);
  66     if(ret)
  67       return ret;
  68   }
  69
  70   return treesearch(cache->tree, loc);
  71 }
  72
  73 /* pushes an item into the cache */
  74 static void cachepush(searchASTCache *cache, searchASTExpr *expr) {
  75   cache->cache[cache->nextpos] = expr;
  76   cache->nextpos = (cache->nextpos + 1) % AST_RECENT;
  77 }
  78
  79 /* ast parser, the way we pass context around is very very hacky... */
  80 searchNode *search_astparse(searchCtx *ctx, int type, char *loc) {
  81   searchASTCache *cache = ctx->arg;
  82   searchASTExpr *expr = cachesearch(cache, (exprunion *)&loc);
  83   searchNode *node;
  84   char **v;
  85   int i;
  86
  87   if(!expr) {
  88     parseError = "WARNING: AST parsing failed";
  89     return NULL;
  90   }
  91
  92   switch(expr->type) {
  93     case AST_NODE_LITERAL:
  94       if (!(node=(searchNode *)malloc(sizeof(searchNode)))) {
  95         parseError = "malloc: could not allocate memory for this search.";
  96         return NULL;
  97       }
  98       node->localdata  = getsstring(expr->u.literal,512);
  99       node->returntype = RETURNTYPE_CONST | RETURNTYPE_STRING;
 100       node->exe        = literal_exe;
 101       node->free       = literal_free;
 102       return node;
 103     case AST_NODE_CHILD:
 104       v = (char **)malloc(expr->u.child->argc * sizeof(char *));
 105       if(!v) {
 106         parseError = "malloc: could not allocate memory for this search.";
 107         return NULL;
 108       }
 109       for(i=0;i<expr->u.child->argc;i++) {
 110         searchASTExpr *child = expr->u.child->argv[i];
 111
 112         cachepush(cache, child);
 113         switch(child->type) {
 114           case AST_NODE_LITERAL:
 115             v[i] = child->u.literal;
 116             break;
 117           case AST_NODE_CHILD:
 118             v[i] = (char *)child;
 119             break;
 120           default:
 121             parseError = "static_parse: bad child node type";
 122             free(v);
 123             return NULL;
 124         }
 125       }
 126
 127       node = expr->u.child->fn(ctx, type, expr->u.child->argc, v);
 128       free(v);
 129       return node;
 130    default:
 131       parseError = "static_parse: bad node type";
 132       return NULL;
 133   }
 134 }
 135
 136 int ast_nicksearch(searchASTExpr *tree, replyFunc reply, void *sender, wallFunc wall, NickDisplayFunc display, int limit) {
 137   searchCtx ctx;
 138   searchASTCache cache;
 139   searchNode *search;
 140   char buf[1024];
 141
 142   memset(&cache, 0, sizeof(cache));
 143   cache.tree = tree;
 144
 145   ctx.reply = reply;
 146   ctx.wall = wall;
 147   ctx.parser = search_astparse;
 148   ctx.arg = (void *)&cache;
 149
 150   buf[0] = '\0';
 151   reply(sender, "Parsing: %s", ast_printtree(buf, sizeof(buf), tree));
 152   search = ctx.parser(&ctx, SEARCHTYPE_NICK, (char *)tree);
 153   if(!search) {
 154     reply(sender, "Parse error: %s", parseError);
 155     return CMD_ERROR;
 156   }
 157
 158   reply(sender, "Executing...");
 159   nicksearch_exe(search, &ctx, sender, display, limit);
 160
 161   (search->free)(&ctx, search);
 162
 163   return CMD_OK;
 164 }
 165
 166 int ast_chansearch(searchASTExpr *tree, replyFunc reply, void *sender, wallFunc wall, ChanDisplayFunc display, int limit) {
 167   searchCtx ctx;
 168   searchASTCache cache;
 169   searchNode *search;
 170   char buf[1024];
 171
 172   ctx.reply = reply;
 173   ctx.wall = wall;
 174   ctx.parser = search_astparse;
 175   ctx.arg = (void *)&cache;
 176
 177   buf[0] = '\0';
 178   reply(sender, "Parsing: %s", ast_printtree(buf, sizeof(buf), tree));
 179   search = ctx.parser(&ctx, SEARCHTYPE_CHANNEL, (char *)tree);
 180   if(!search) {
 181     reply(sender, "Parse error: %s", parseError);
 182     return CMD_ERROR;
 183   }
 184
 185   reply(sender, "Executing...");
 186   chansearch_exe(search, &ctx, sender, display, limit);
 187
 188   (search->free)(&ctx, search);
 189
 190   return CMD_OK;
 191 }
 192
 193 int ast_usersearch(searchASTExpr *tree, replyFunc reply, void *sender, wallFunc wall, UserDisplayFunc display, int limit) {
 194   searchCtx ctx;
 195   searchASTCache cache;
 196   searchNode *search;
 197   char buf[1024];
 198
 199   memset(&cache, 0, sizeof(cache));
 200   cache.tree = tree;
 201
 202   ctx.reply = reply;
 203   ctx.wall = wall;
 204   ctx.parser = search_astparse;
 205   ctx.arg = (void *)&cache;
 206
 207   buf[0] = '\0';
 208   reply(sender, "Parsing: %s", ast_printtree(buf, sizeof(buf), tree));
 209   search = ctx.parser(&ctx, SEARCHTYPE_USER, (char *)tree);
 210   if(!search) {
 211     reply(sender, "Parse error: %s", parseError);
 212     return CMD_ERROR;
 213   }
 214
 215   reply(sender, "Executing...");
 216   usersearch_exe(search, &ctx, sender, display, limit);
 217
 218   (search->free)(&ctx, search);
 219
 220   return CMD_OK;
 221 }
 222
 223
 224 /* horribly inefficient -- don't call me very often! */
 225 static char *ast_printtree_real(StringBuf *buf, searchASTExpr *expr) {
 226   char lbuf[256];
 227   if(expr->type == AST_NODE_CHILD) {
 228     int i;
 229     sstring *command = getcommandname(searchTree, (void *)expr->u.child->fn);
 230
 231     if(command) {
 232       snprintf(lbuf, sizeof(lbuf), "(%s", command->content);
 233     } else {
 234       snprintf(lbuf, sizeof(lbuf), "(%p", expr->u.child->fn);
 235     }
 236     sbaddstr(buf, lbuf);
 237
 238     for(i=0;i<expr->u.child->argc;i++) {
 239       sbaddchar(buf, ' ');
 240       ast_printtree_real(buf, expr->u.child->argv[i]);
 241     }
 242     sbaddchar(buf, ')');
 243
 244   } else if(expr->type == AST_NODE_LITERAL) {
 245     sbaddstr(buf, expr->u.literal);
 246   } else {
 247     sbaddstr(buf, "???");
 248   }
 249
 250   return buf->buf;
 251 }
 252
 253 char *ast_printtree(char *buf, size_t bufsize, searchASTExpr *expr) {
 254   StringBuf b;
 255   char *p;
 256
 257   b.capacity = bufsize;
 258   b.len = 0;
 259   b.buf = buf;
 260
 261   p = ast_printtree_real(&b, expr);
 262
 263   sbterminate(&b);
 264   return p;
 265 }