ceph/src/civetweb/src/third_party/lua-5.3.1/src/ltablib.c

   1 /*
   2 ** $Id: ltablib.c,v 1.80 2015/01/13 16:27:29 roberto Exp $
   3 ** Library for Table Manipulation
   4 ** See Copyright Notice in lua.h
   5 */
   6
   7 #define ltablib_c
   8 #define LUA_LIB
   9
  10 #include "lprefix.h"
  11
  12
  13 #include <limits.h>
  14 #include <stddef.h>
  15
  16 #include "lua.h"
  17
  18 #include "lauxlib.h"
  19 #include "lualib.h"
  20
  21
  22
  23 /*
  24 ** Structure with table-access functions
  25 */
  26 typedef struct {
  27   int (*geti) (lua_State *L, int idx, lua_Integer n);
  28   void (*seti) (lua_State *L, int idx, lua_Integer n);
  29 } TabA;
  30
  31
  32 /*
  33 ** Check that 'arg' has a table and set access functions in 'ta' to raw
  34 ** or non-raw according to the presence of corresponding metamethods.
  35 */
  36 static void checktab (lua_State *L, int arg, TabA *ta) {
  37   ta->geti = NULL; ta->seti = NULL;
  38   if (lua_getmetatable(L, arg)) {
  39     lua_pushliteral(L, "__index");  /* 'index' metamethod */
  40     if (lua_rawget(L, -2) != LUA_TNIL)
  41       ta->geti = lua_geti;
  42     lua_pushliteral(L, "__newindex");  /* 'newindex' metamethod */
  43     if (lua_rawget(L, -3) != LUA_TNIL)
  44       ta->seti = lua_seti;
  45     lua_pop(L, 3);  /* pop metatable plus both metamethods */
  46   }
  47   if (ta->geti == NULL || ta->seti == NULL) {
  48     luaL_checktype(L, arg, LUA_TTABLE);  /* must be table for raw methods */
  49     if (ta->geti == NULL) ta->geti = lua_rawgeti;
  50     if (ta->seti == NULL) ta->seti = lua_rawseti;
  51   }
  52 }
  53
  54
  55 #define aux_getn(L,n,ta)        (checktab(L, n, ta), luaL_len(L, n))
  56
  57
  58 #if defined(LUA_COMPAT_MAXN)
  59 static int maxn (lua_State *L) {
  60   lua_Number max = 0;
  61   luaL_checktype(L, 1, LUA_TTABLE);
  62   lua_pushnil(L);  /* first key */
  63   while (lua_next(L, 1)) {
  64     lua_pop(L, 1);  /* remove value */
  65     if (lua_type(L, -1) == LUA_TNUMBER) {
  66       lua_Number v = lua_tonumber(L, -1);
  67       if (v > max) max = v;
  68     }
  69   }
  70   lua_pushnumber(L, max);
  71   return 1;
  72 }
  73 #endif
  74
  75
  76 static int tinsert (lua_State *L) {
  77   TabA ta;
  78   lua_Integer e = aux_getn(L, 1, &ta) + 1;  /* first empty element */
  79   lua_Integer pos;  /* where to insert new element */
  80   switch (lua_gettop(L)) {
  81     case 2: {  /* called with only 2 arguments */
  82       pos = e;  /* insert new element at the end */
  83       break;
  84     }
  85     case 3: {
  86       lua_Integer i;
  87       pos = luaL_checkinteger(L, 2);  /* 2nd argument is the position */
  88       luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
  89       for (i = e; i > pos; i--) {  /* move up elements */
  90         (*ta.geti)(L, 1, i - 1);
  91         (*ta.seti)(L, 1, i);  /* t[i] = t[i - 1] */
  92       }
  93       break;
  94     }
  95     default: {
  96       return luaL_error(L, "wrong number of arguments to 'insert'");
  97     }
  98   }
  99   (*ta.seti)(L, 1, pos);  /* t[pos] = v */
 100   return 0;
 101 }
 102
 103
 104 static int tremove (lua_State *L) {
 105   TabA ta;
 106   lua_Integer size = aux_getn(L, 1, &ta);
 107   lua_Integer pos = luaL_optinteger(L, 2, size);
 108   if (pos != size)  /* validate 'pos' if given */
 109     luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
 110   (*ta.geti)(L, 1, pos);  /* result = t[pos] */
 111   for ( ; pos < size; pos++) {
 112     (*ta.geti)(L, 1, pos + 1);
 113     (*ta.seti)(L, 1, pos);  /* t[pos] = t[pos + 1] */
 114   }
 115   lua_pushnil(L);
 116   (*ta.seti)(L, 1, pos);  /* t[pos] = nil */
 117   return 1;
 118 }
 119
 120
 121 static int tmove (lua_State *L) {
 122   TabA ta;
 123   lua_Integer f = luaL_checkinteger(L, 2);
 124   lua_Integer e = luaL_checkinteger(L, 3);
 125   lua_Integer t = luaL_checkinteger(L, 4);
 126   int tt = !lua_isnoneornil(L, 5) ? 5 : 1;  /* destination table */
 127   if (e >= f) {  /* otherwise, nothing to move */
 128     lua_Integer n, i;
 129     ta.geti = (luaL_getmetafield(L, 1, "__index") == LUA_TNIL)
 130       ? (luaL_checktype(L, 1, LUA_TTABLE), lua_rawgeti)
 131       : lua_geti;
 132     ta.seti = (luaL_getmetafield(L, tt, "__newindex") == LUA_TNIL)
 133       ? (luaL_checktype(L, tt, LUA_TTABLE), lua_rawseti)
 134       : lua_seti;
 135     luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3,
 136                   "too many elements to move");
 137     n = e - f + 1;  /* number of elements to move */
 138     luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4,
 139                   "destination wrap around");
 140     if (t > f) {
 141       for (i = n - 1; i >= 0; i--) {
 142         (*ta.geti)(L, 1, f + i);
 143         (*ta.seti)(L, tt, t + i);
 144       }
 145     }
 146     else {
 147       for (i = 0; i < n; i++) {
 148         (*ta.geti)(L, 1, f + i);
 149         (*ta.seti)(L, tt, t + i);
 150       }
 151     }
 152   }
 153   lua_pushvalue(L, tt);  /* return "to table" */
 154   return 1;
 155 }
 156
 157
 158 static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) {
 159   (*ta->geti)(L, 1, i);
 160   if (!lua_isstring(L, -1))
 161     luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
 162                   luaL_typename(L, -1), i);
 163   luaL_addvalue(b);
 164 }
 165
 166
 167 static int tconcat (lua_State *L) {
 168   TabA ta;
 169   luaL_Buffer b;
 170   size_t lsep;
 171   lua_Integer i, last;
 172   const char *sep = luaL_optlstring(L, 2, "", &lsep);
 173   checktab(L, 1, &ta);
 174   i = luaL_optinteger(L, 3, 1);
 175   last = luaL_opt(L, luaL_checkinteger, 4, luaL_len(L, 1));
 176   luaL_buffinit(L, &b);
 177   for (; i < last; i++) {
 178     addfield(L, &b, &ta, i);
 179     luaL_addlstring(&b, sep, lsep);
 180   }
 181   if (i == last)  /* add last value (if interval was not empty) */
 182     addfield(L, &b, &ta, i);
 183   luaL_pushresult(&b);
 184   return 1;
 185 }
 186
 187
 188 /*
 189 ** {======================================================
 190 ** Pack/unpack
 191 ** =======================================================
 192 */
 193
 194 static int pack (lua_State *L) {
 195   int i;
 196   int n = lua_gettop(L);  /* number of elements to pack */
 197   lua_createtable(L, n, 1);  /* create result table */
 198   lua_insert(L, 1);  /* put it at index 1 */
 199   for (i = n; i >= 1; i--)  /* assign elements */
 200     lua_rawseti(L, 1, i);
 201   lua_pushinteger(L, n);
 202   lua_setfield(L, 1, "n");  /* t.n = number of elements */
 203   return 1;  /* return table */
 204 }
 205
 206
 207 static int unpack (lua_State *L) {
 208   TabA ta;
 209   lua_Integer i, e;
 210   lua_Unsigned n;
 211   checktab(L, 1, &ta);
 212   i = luaL_optinteger(L, 2, 1);
 213   e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
 214   if (i > e) return 0;  /* empty range */
 215   n = (lua_Unsigned)e - i;  /* number of elements minus 1 (avoid overflows) */
 216   if (n >= (unsigned int)INT_MAX  || !lua_checkstack(L, (int)(++n)))
 217     return luaL_error(L, "too many results to unpack");
 218   do {  /* must have at least one element */
 219     (*ta.geti)(L, 1, i);  /* push arg[i..e] */
 220   } while (i++ < e);
 221
 222   return (int)n;
 223 }
 224
 225 /* }====================================================== */
 226
 227
 228
 229 /*
 230 ** {======================================================
 231 ** Quicksort
 232 ** (based on 'Algorithms in MODULA-3', Robert Sedgewick;
 233 **  Addison-Wesley, 1993.)
 234 ** =======================================================
 235 */
 236
 237
 238 static void set2 (lua_State *L, TabA *ta, int i, int j) {
 239   (*ta->seti)(L, 1, i);
 240   (*ta->seti)(L, 1, j);
 241 }
 242
 243 static int sort_comp (lua_State *L, int a, int b) {
 244   if (!lua_isnil(L, 2)) {  /* function? */
 245     int res;
 246     lua_pushvalue(L, 2);
 247     lua_pushvalue(L, a-1);  /* -1 to compensate function */
 248     lua_pushvalue(L, b-2);  /* -2 to compensate function and 'a' */
 249     lua_call(L, 2, 1);
 250     res = lua_toboolean(L, -1);
 251     lua_pop(L, 1);
 252     return res;
 253   }
 254   else  /* a < b? */
 255     return lua_compare(L, a, b, LUA_OPLT);
 256 }
 257
 258 static void auxsort (lua_State *L, TabA *ta, int l, int u) {
 259   while (l < u) {  /* for tail recursion */
 260     int i, j;
 261     /* sort elements a[l], a[(l+u)/2] and a[u] */
 262     (*ta->geti)(L, 1, l);
 263     (*ta->geti)(L, 1, u);
 264     if (sort_comp(L, -1, -2))  /* a[u] < a[l]? */
 265       set2(L, ta, l, u);  /* swap a[l] - a[u] */
 266     else
 267       lua_pop(L, 2);
 268     if (u-l == 1) break;  /* only 2 elements */
 269     i = (l+u)/2;
 270     (*ta->geti)(L, 1, i);
 271     (*ta->geti)(L, 1, l);
 272     if (sort_comp(L, -2, -1))  /* a[i]<a[l]? */
 273       set2(L, ta, i, l);
 274     else {
 275       lua_pop(L, 1);  /* remove a[l] */
 276       (*ta->geti)(L, 1, u);
 277       if (sort_comp(L, -1, -2))  /* a[u]<a[i]? */
 278         set2(L, ta, i, u);
 279       else
 280         lua_pop(L, 2);
 281     }
 282     if (u-l == 2) break;  /* only 3 elements */
 283     (*ta->geti)(L, 1, i);  /* Pivot */
 284     lua_pushvalue(L, -1);
 285     (*ta->geti)(L, 1, u-1);
 286     set2(L, ta, i, u-1);
 287     /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
 288     i = l; j = u-1;
 289     for (;;) {  /* invariant: a[l..i] <= P <= a[j..u] */
 290       /* repeat ++i until a[i] >= P */
 291       while ((*ta->geti)(L, 1, ++i), sort_comp(L, -1, -2)) {
 292         if (i>=u) luaL_error(L, "invalid order function for sorting");
 293         lua_pop(L, 1);  /* remove a[i] */
 294       }
 295       /* repeat --j until a[j] <= P */
 296       while ((*ta->geti)(L, 1, --j), sort_comp(L, -3, -1)) {
 297         if (j<=l) luaL_error(L, "invalid order function for sorting");
 298         lua_pop(L, 1);  /* remove a[j] */
 299       }
 300       if (j<i) {
 301         lua_pop(L, 3);  /* pop pivot, a[i], a[j] */
 302         break;
 303       }
 304       set2(L, ta, i, j);
 305     }
 306     (*ta->geti)(L, 1, u-1);
 307     (*ta->geti)(L, 1, i);
 308     set2(L, ta, u-1, i);  /* swap pivot (a[u-1]) with a[i] */
 309     /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
 310     /* adjust so that smaller half is in [j..i] and larger one in [l..u] */
 311     if (i-l < u-i) {
 312       j=l; i=i-1; l=i+2;
 313     }
 314     else {
 315       j=i+1; i=u; u=j-2;
 316     }
 317     auxsort(L, ta, j, i);  /* call recursively the smaller one */
 318   }  /* repeat the routine for the larger one */
 319 }
 320
 321 static int sort (lua_State *L) {
 322   TabA ta;
 323   int n = (int)aux_getn(L, 1, &ta);
 324   luaL_checkstack(L, 50, "");  /* assume array is smaller than 2^50 */
 325   if (!lua_isnoneornil(L, 2))  /* is there a 2nd argument? */
 326     luaL_checktype(L, 2, LUA_TFUNCTION);
 327   lua_settop(L, 2);  /* make sure there are two arguments */
 328   auxsort(L, &ta, 1, n);
 329   return 0;
 330 }
 331
 332 /* }====================================================== */
 333
 334
 335 static const luaL_Reg tab_funcs[] = {
 336   {"concat", tconcat},
 337 #if defined(LUA_COMPAT_MAXN)
 338   {"maxn", maxn},
 339 #endif
 340   {"insert", tinsert},
 341   {"pack", pack},
 342   {"unpack", unpack},
 343   {"remove", tremove},
 344   {"move", tmove},
 345   {"sort", sort},
 346   {NULL, NULL}
 347 };
 348
 349
 350 LUAMOD_API int luaopen_table (lua_State *L) {
 351   luaL_newlib(L, tab_funcs);
 352 #if defined(LUA_COMPAT_UNPACK)
 353   /* _G.unpack = table.unpack */
 354   lua_getfield(L, -1, "unpack");
 355   lua_setglobal(L, "unpack");
 356 #endif
 357   return 1;
 358 }
 359