lua/luadb.c

   1 #include "lua.h"
   2 #include "luabot.h"
   3
   4 #include "../dbapi2/dbapi2.h"
   5
   6 static DBAPIConn *luadb;
   7
   8 typedef struct lua_callback {
   9   lua_list *l;
  10   long handler, args;
  11 } lua_callback;
  12
  13 static int lua_dbcreatequery(lua_State *ps) {
  14   char *s = (char *)lua_tostring(ps, 1);
  15
  16   if(!luadb)
  17     LUA_RETURN(ps, LUA_FAIL);
  18
  19   if(!s)
  20     LUA_RETURN(ps, LUA_FAIL);
  21
  22   luadb->unsafecreatetable(luadb, NULL, NULL, "%s", s);
  23   LUA_RETURN(ps, LUA_OK);
  24 }
  25
  26 static int lua_dbtablename(lua_State *ps) {
  27   char *s = (char *)lua_tostring(ps, 1);
  28
  29   if(!luadb)
  30     LUA_RETURN(ps, LUA_FAIL);
  31
  32   if(!s)
  33     LUA_RETURN(ps, LUA_FAIL);
  34
  35   char *tablename = luadb->tablename(luadb, s);
  36   if(!tablename)
  37     LUA_RETURN(ps, LUA_FAIL);
  38
  39   lua_pushstring(ps, tablename);
  40   return 1;
  41 }
  42
  43 const static DBAPIResult *active_result;
  44 static void lua_dbcallback(const DBAPIResult *result, void *tag) {
  45   lua_callback *c = (lua_callback *)tag;
  46
  47   if(!lua_listexists(c->l)) {
  48     luafree(c);
  49     return;
  50   }
  51
  52   active_result = result;
  53   _lua_vpcall(c->l->l, (void *)c->handler, LUA_POINTERMODE, "bR", result && result->success ? 1 : 0, c->args);
  54   active_result = NULL;
  55
  56   if(result)
  57     result->clear(result);
  58
  59   luaL_unref(c->l->l, LUA_REGISTRYINDEX, c->handler);
  60   luaL_unref(c->l->l, LUA_REGISTRYINDEX, c->args);
  61   luafree(c);
  62 }
  63
  64 static int lua_dbnumfields(lua_State *ps) {
  65   if(!luadb)
  66     return 0;
  67
  68   if(!active_result)
  69     return 0;
  70
  71   lua_pushint(ps, active_result->fields);
  72   return 1;
  73 }
  74
  75 static int lua_dbgetvalue(lua_State *ps) {
  76   if(!luadb)
  77     return 0;
  78
  79   if(!active_result)
  80     return 0;
  81
  82   if(!lua_isint(ps, 1))
  83     return 0;
  84
  85   int field = lua_toint(ps, 1);
  86   if(field < 0 || field >= active_result->fields)
  87     return 0;
  88
  89   char *value = active_result->get(active_result, field);
  90   /* bit rubbish, no way to get the length... binary data is out then */
  91   lua_pushstring(ps, value);
  92
  93   return 1;
  94 }
  95
  96 static int lua_dbnextrow(lua_State *ps) {
  97   if(!luadb)
  98     return 0;
  99
 100   if(!active_result)
 101     return 0;
 102
 103   int r = active_result->next(active_result);
 104   lua_pushboolean(ps, r?1:0);
 105   return 1;
 106 }
 107
 108 static int lua_dbquery(lua_State *ps) {
 109   lua_list *l = lua_listfromstate(ps);
 110   char *q = (char *)lua_tostring(ps, 1);
 111   lua_callback *cb;
 112
 113   if(!luadb)
 114     LUA_RETURN(ps, LUA_FAIL);
 115
 116   /* what happens if 3 isn't there? */
 117   if(!l || !q)
 118     LUA_RETURN(ps, LUA_FAIL);
 119
 120   if(!lua_isfunction(ps, 2)) {
 121     luadb->unsafesquery(luadb, "%s", q);
 122     LUA_RETURN(ps, LUA_OK);
 123   }
 124
 125   cb = (lua_callback *)luamalloc(sizeof(lua_callback));
 126   if(!cb)
 127     LUA_RETURN(ps, LUA_FAIL);
 128
 129   cb->l = l;
 130   cb->args = luaL_ref(ps, LUA_REGISTRYINDEX);
 131   cb->handler = luaL_ref(ps, LUA_REGISTRYINDEX);
 132
 133   luadb->unsafequery(luadb, lua_dbcallback, cb, "%s", q);
 134
 135   LUA_RETURN(ps, LUA_OK);
 136 }
 137
 138 static int lua_dbescape(lua_State *ps) {
 139   char ebuf[8192 * 2 + 1];
 140   char *s = (char *)lua_tostring(ps, 1);
 141   int len;
 142
 143   if(!luadb)
 144     return 0;
 145
 146   if(!s)
 147     return 0;
 148
 149   len = lua_strlen(ps, 1);
 150   if(len > sizeof(ebuf) / 2 - 5)
 151     return 0;
 152
 153   luadb->escapestring(luadb, ebuf, s, len);
 154   lua_pushstring(ps, ebuf);
 155
 156   return 1;
 157 }
 158
 159 void lua_registerdbcommands(lua_State *l) {
 160   lua_register(l, "db_tablename", lua_dbtablename);
 161
 162   lua_register(l, "db_createquery", lua_dbcreatequery);
 163   lua_register(l, "db_query", lua_dbquery);
 164   lua_register(l, "db_escape", lua_dbescape);
 165
 166   lua_register(l, "db_numfields", lua_dbnumfields);
 167   lua_register(l, "db_getvalue", lua_dbgetvalue);
 168   lua_register(l, "db_nextrow", lua_dbnextrow);
 169
 170   luadb = dbapi2open(NULL, "lua");
 171
 172   /* TODO */
 173   /* open gets you a unique db */
 174   /* parameterised queries (huge pain due to no va_args in dbapi2) */
 175   /* loadtable */
 176   /* getrow */
 177 }
 178
 179 void lua_destroydb(void) {
 180   if(luadb)
 181     luadb->close(luadb);
 182 }