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, 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, 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, HeaderFunc header, void *headerarg, 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   newsearch_ctxinit(&ctx, search_astparse, reply, wall, &cache, reg_nicksearch);
 146
 147   buf[0] = '\0';
 148   reply(sender, "Parsing: %s", ast_printtree(buf, sizeof(buf), tree, reg_nicksearch));
 149   search = ctx.parser(&ctx, (char *)tree);
 150   if(!search) {
 151     reply(sender, "Parse error: %s", parseError);
 152     return CMD_ERROR;
 153   }
 154
 155   reply(sender, "Executing...");
 156   if(header)
 157     header(sender, headerarg);
 158   nicksearch_exe(search, &ctx, sender, display, limit);
 159
 160   (search->free)(&ctx, search);
 161
 162   return CMD_OK;
 163 }
 164
 165 int ast_chansearch(searchASTExpr *tree, replyFunc reply, void *sender, wallFunc wall, ChanDisplayFunc display, HeaderFunc header, void *headerarg, int limit) {
 166   searchCtx ctx;
 167   searchASTCache cache;
 168   searchNode *search;
 169   char buf[1024];
 170
 171   newsearch_ctxinit(&ctx, search_astparse, reply, wall, &cache, reg_chansearch);
 172
 173   buf[0] = '\0';
 174   reply(sender, "Parsing: %s", ast_printtree(buf, sizeof(buf), tree, reg_chansearch));
 175   search = ctx.parser(&ctx, (char *)tree);
 176   if(!search) {
 177     reply(sender, "Parse error: %s", parseError);
 178     return CMD_ERROR;
 179   }
 180
 181   reply(sender, "Executing...");
 182   if(header)
 183     header(sender, headerarg);
 184   chansearch_exe(search, &ctx, sender, display, limit);
 185
 186   (search->free)(&ctx, search);
 187
 188   return CMD_OK;
 189 }
 190
 191 int ast_usersearch(searchASTExpr *tree, replyFunc reply, void *sender, wallFunc wall, UserDisplayFunc display, HeaderFunc header, void *headerarg, int limit) {
 192   searchCtx ctx;
 193   searchASTCache cache;
 194   searchNode *search;
 195   char buf[1024];
 196
 197   memset(&cache, 0, sizeof(cache));
 198   cache.tree = tree;
 199
 200   newsearch_ctxinit(&ctx, search_astparse, reply, wall, &cache, reg_usersearch);
 201
 202   buf[0] = '\0';
 203   reply(sender, "Parsing: %s", ast_printtree(buf, sizeof(buf), tree, reg_usersearch));
 204   search = ctx.parser(&ctx, (char *)tree);
 205   if(!search) {
 206     reply(sender, "Parse error: %s", parseError);
 207     return CMD_ERROR;
 208   }
 209
 210   reply(sender, "Executing...");
 211   if(header)
 212     header(sender, headerarg);
 213   usersearch_exe(search, &ctx, sender, display, limit);
 214
 215   (search->free)(&ctx, search);
 216
 217   return CMD_OK;
 218 }
 219
 220
 221 /* horribly inefficient -- don't call me very often! */
 222 static char *ast_printtree_real(StringBuf *buf, searchASTExpr *expr, searchCmd *cmd) {
 223   char lbuf[256];
 224   if(expr->type == AST_NODE_CHILD) {
 225     int i;
 226     sstring *command = getcommandname(cmd->searchtree, (void *)expr->u.child->fn);
 227
 228     if(command) {
 229       snprintf(lbuf, sizeof(lbuf), "(%s", command->content);
 230     } else {
 231       snprintf(lbuf, sizeof(lbuf), "(%p", expr->u.child->fn);
 232     }
 233     sbaddstr(buf, lbuf);
 234
 235     for(i=0;i<expr->u.child->argc;i++) {
 236       sbaddchar(buf, ' ');
 237       ast_printtree_real(buf, expr->u.child->argv[i], cmd);
 238     }
 239     sbaddchar(buf, ')');
 240
 241   } else if(expr->type == AST_NODE_LITERAL) {
 242     sbaddstr(buf, expr->u.literal);
 243   } else {
 244     sbaddstr(buf, "???");
 245   }
 246
 247   return buf->buf;
 248 }
 249
 250 char *ast_printtree(char *buf, size_t bufsize, searchASTExpr *expr, searchCmd *cmd) {
 251   StringBuf b;
 252   char *p;
 253
 254   b.capacity = bufsize;
 255   b.len = 0;
 256   b.buf = buf;
 257
 258   p = ast_printtree_real(&b, expr, cmd);
 259
 260   sbterminate(&b);
 261   return p;
 262 }