From ba4e59a1d687173ac5cfa74d26d71d6059dc6bc6 Mon Sep 17 00:00:00 2001 From: Alex Auvolat Date: Fri, 15 Jul 2016 22:45:41 +0200 Subject: Move stuff around --- src/lib/lua/ltablib.c | 450 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 450 insertions(+) create mode 100644 src/lib/lua/ltablib.c (limited to 'src/lib/lua/ltablib.c') diff --git a/src/lib/lua/ltablib.c b/src/lib/lua/ltablib.c new file mode 100644 index 0000000..98b2f87 --- /dev/null +++ b/src/lib/lua/ltablib.c @@ -0,0 +1,450 @@ +/* +** $Id: ltablib.c,v 1.93 2016/02/25 19:41:54 roberto Exp $ +** Library for Table Manipulation +** See Copyright Notice in lua.h +*/ + +#define ltablib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include +#include +#include + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** Operations that an object must define to mimic a table +** (some functions only need some of them) +*/ +#define TAB_R 1 /* read */ +#define TAB_W 2 /* write */ +#define TAB_L 4 /* length */ +#define TAB_RW (TAB_R | TAB_W) /* read/write */ + + +#define aux_getn(L,n,w) (checktab(L, n, (w) | TAB_L), luaL_len(L, n)) + + +static int checkfield (lua_State *L, const char *key, int n) { + lua_pushstring(L, key); + return (lua_rawget(L, -n) != LUA_TNIL); +} + + +/* +** Check that 'arg' either is a table or can behave like one (that is, +** has a metatable with the required metamethods) +*/ +static void checktab (lua_State *L, int arg, int what) { + if (lua_type(L, arg) != LUA_TTABLE) { /* is it not a table? */ + int n = 1; /* number of elements to pop */ + if (lua_getmetatable(L, arg) && /* must have metatable */ + (!(what & TAB_R) || checkfield(L, "__index", ++n)) && + (!(what & TAB_W) || checkfield(L, "__newindex", ++n)) && + (!(what & TAB_L) || checkfield(L, "__len", ++n))) { + lua_pop(L, n); /* pop metatable and tested metamethods */ + } + else + luaL_checktype(L, arg, LUA_TTABLE); /* force an error */ + } +} + + +#if defined(LUA_COMPAT_MAXN) +static int maxn (lua_State *L) { + lua_Number max = 0; + luaL_checktype(L, 1, LUA_TTABLE); + lua_pushnil(L); /* first key */ + while (lua_next(L, 1)) { + lua_pop(L, 1); /* remove value */ + if (lua_type(L, -1) == LUA_TNUMBER) { + lua_Number v = lua_tonumber(L, -1); + if (v > max) max = v; + } + } + lua_pushnumber(L, max); + return 1; +} +#endif + + +static int tinsert (lua_State *L) { + lua_Integer e = aux_getn(L, 1, TAB_RW) + 1; /* first empty element */ + lua_Integer pos; /* where to insert new element */ + switch (lua_gettop(L)) { + case 2: { /* called with only 2 arguments */ + pos = e; /* insert new element at the end */ + break; + } + case 3: { + lua_Integer i; + pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */ + luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds"); + for (i = e; i > pos; i--) { /* move up elements */ + lua_geti(L, 1, i - 1); + lua_seti(L, 1, i); /* t[i] = t[i - 1] */ + } + break; + } + default: { + return luaL_error(L, "wrong number of arguments to 'insert'"); + } + } + lua_seti(L, 1, pos); /* t[pos] = v */ + return 0; +} + + +static int tremove (lua_State *L) { + lua_Integer size = aux_getn(L, 1, TAB_RW); + lua_Integer pos = luaL_optinteger(L, 2, size); + if (pos != size) /* validate 'pos' if given */ + luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds"); + lua_geti(L, 1, pos); /* result = t[pos] */ + for ( ; pos < size; pos++) { + lua_geti(L, 1, pos + 1); + lua_seti(L, 1, pos); /* t[pos] = t[pos + 1] */ + } + lua_pushnil(L); + lua_seti(L, 1, pos); /* t[pos] = nil */ + return 1; +} + + +/* +** Copy elements (1[f], ..., 1[e]) into (tt[t], tt[t+1], ...). Whenever +** possible, copy in increasing order, which is better for rehashing. +** "possible" means destination after original range, or smaller +** than origin, or copying to another table. +*/ +static int tmove (lua_State *L) { + lua_Integer f = luaL_checkinteger(L, 2); + lua_Integer e = luaL_checkinteger(L, 3); + lua_Integer t = luaL_checkinteger(L, 4); + int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */ + checktab(L, 1, TAB_R); + checktab(L, tt, TAB_W); + if (e >= f) { /* otherwise, nothing to move */ + lua_Integer n, i; + luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3, + "too many elements to move"); + n = e - f + 1; /* number of elements to move */ + luaL_argcheck(L, t <= LUA_MAXINTEGER - n + 1, 4, + "destination wrap around"); + if (t > e || t <= f || (tt != 1 && !lua_compare(L, 1, tt, LUA_OPEQ))) { + for (i = 0; i < n; i++) { + lua_geti(L, 1, f + i); + lua_seti(L, tt, t + i); + } + } + else { + for (i = n - 1; i >= 0; i--) { + lua_geti(L, 1, f + i); + lua_seti(L, tt, t + i); + } + } + } + lua_pushvalue(L, tt); /* return destination table */ + return 1; +} + + +static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) { + lua_geti(L, 1, i); + if (!lua_isstring(L, -1)) + luaL_error(L, "invalid value (%s) at index %d in table for 'concat'", + luaL_typename(L, -1), i); + luaL_addvalue(b); +} + + +static int tconcat (lua_State *L) { + luaL_Buffer b; + lua_Integer last = aux_getn(L, 1, TAB_R); + size_t lsep; + const char *sep = luaL_optlstring(L, 2, "", &lsep); + lua_Integer i = luaL_optinteger(L, 3, 1); + last = luaL_optinteger(L, 4, last); + luaL_buffinit(L, &b); + for (; i < last; i++) { + addfield(L, &b, i); + luaL_addlstring(&b, sep, lsep); + } + if (i == last) /* add last value (if interval was not empty) */ + addfield(L, &b, i); + luaL_pushresult(&b); + return 1; +} + + +/* +** {====================================================== +** Pack/unpack +** ======================================================= +*/ + +static int pack (lua_State *L) { + int i; + int n = lua_gettop(L); /* number of elements to pack */ + lua_createtable(L, n, 1); /* create result table */ + lua_insert(L, 1); /* put it at index 1 */ + for (i = n; i >= 1; i--) /* assign elements */ + lua_seti(L, 1, i); + lua_pushinteger(L, n); + lua_setfield(L, 1, "n"); /* t.n = number of elements */ + return 1; /* return table */ +} + + +static int unpack (lua_State *L) { + lua_Unsigned n; + lua_Integer i = luaL_optinteger(L, 2, 1); + lua_Integer e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1)); + if (i > e) return 0; /* empty range */ + n = (lua_Unsigned)e - i; /* number of elements minus 1 (avoid overflows) */ + if (n >= (unsigned int)INT_MAX || !lua_checkstack(L, (int)(++n))) + return luaL_error(L, "too many results to unpack"); + for (; i < e; i++) { /* push arg[i..e - 1] (to avoid overflows) */ + lua_geti(L, 1, i); + } + lua_geti(L, 1, e); /* push last element */ + return (int)n; +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** Quicksort +** (based on 'Algorithms in MODULA-3', Robert Sedgewick; +** Addison-Wesley, 1993.) +** ======================================================= +*/ + + +/* type for array indices */ +typedef unsigned int IdxT; + + +/* +** Produce a "random" 'unsigned int' to randomize pivot choice. This +** macro is used only when 'sort' detects a big imbalance in the result +** of a partition. (If you don't want/need this "randomness", ~0 is a +** good choice.) +*/ +#if !defined(l_randomizePivot) /* { */ + +#include + +/* size of 'e' measured in number of 'unsigned int's */ +#define sof(e) (sizeof(e) / sizeof(unsigned int)) + +/* +** Use 'time' and 'clock' as sources of "randomness". Because we don't +** know the types 'clock_t' and 'time_t', we cannot cast them to +** anything without risking overflows. A safe way to use their values +** is to copy them to an array of a known type and use the array values. +*/ +static unsigned int l_randomizePivot (void) { + clock_t c = clock(); + time_t t = time(NULL); + unsigned int buff[sof(c) + sof(t)]; + unsigned int i, rnd = 0; + memcpy(buff, &c, sof(c) * sizeof(unsigned int)); + memcpy(buff + sof(c), &t, sof(t) * sizeof(unsigned int)); + for (i = 0; i < sof(buff); i++) + rnd += buff[i]; + return rnd; +} + +#endif /* } */ + + +/* arrays larger than 'RANLIMIT' may use randomized pivots */ +#define RANLIMIT 100u + + +static void set2 (lua_State *L, IdxT i, IdxT j) { + lua_seti(L, 1, i); + lua_seti(L, 1, j); +} + + +/* +** Return true iff value at stack index 'a' is less than the value at +** index 'b' (according to the order of the sort). +*/ +static int sort_comp (lua_State *L, int a, int b) { + if (lua_isnil(L, 2)) /* no function? */ + return lua_compare(L, a, b, LUA_OPLT); /* a < b */ + else { /* function */ + int res; + lua_pushvalue(L, 2); /* push function */ + lua_pushvalue(L, a-1); /* -1 to compensate function */ + lua_pushvalue(L, b-2); /* -2 to compensate function and 'a' */ + lua_call(L, 2, 1); /* call function */ + res = lua_toboolean(L, -1); /* get result */ + lua_pop(L, 1); /* pop result */ + return res; + } +} + + +/* +** Does the partition: Pivot P is at the top of the stack. +** precondition: a[lo] <= P == a[up-1] <= a[up], +** so it only needs to do the partition from lo + 1 to up - 2. +** Pos-condition: a[lo .. i - 1] <= a[i] == P <= a[i + 1 .. up] +** returns 'i'. +*/ +static IdxT partition (lua_State *L, IdxT lo, IdxT up) { + IdxT i = lo; /* will be incremented before first use */ + IdxT j = up - 1; /* will be decremented before first use */ + /* loop invariant: a[lo .. i] <= P <= a[j .. up] */ + for (;;) { + /* next loop: repeat ++i while a[i] < P */ + while (lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) { + if (i == up - 1) /* a[i] < P but a[up - 1] == P ?? */ + luaL_error(L, "invalid order function for sorting"); + lua_pop(L, 1); /* remove a[i] */ + } + /* after the loop, a[i] >= P and a[lo .. i - 1] < P */ + /* next loop: repeat --j while P < a[j] */ + while (lua_geti(L, 1, --j), sort_comp(L, -3, -1)) { + if (j < i) /* j < i but a[j] > P ?? */ + luaL_error(L, "invalid order function for sorting"); + lua_pop(L, 1); /* remove a[j] */ + } + /* after the loop, a[j] <= P and a[j + 1 .. up] >= P */ + if (j < i) { /* no elements out of place? */ + /* a[lo .. i - 1] <= P <= a[j + 1 .. i .. up] */ + lua_pop(L, 1); /* pop a[j] */ + /* swap pivot (a[up - 1]) with a[i] to satisfy pos-condition */ + set2(L, up - 1, i); + return i; + } + /* otherwise, swap a[i] - a[j] to restore invariant and repeat */ + set2(L, i, j); + } +} + + +/* +** Choose an element in the middle (2nd-3th quarters) of [lo,up] +** "randomized" by 'rnd' +*/ +static IdxT choosePivot (IdxT lo, IdxT up, unsigned int rnd) { + IdxT r4 = (up - lo) / 4; /* range/4 */ + IdxT p = rnd % (r4 * 2) + (lo + r4); + lua_assert(lo + r4 <= p && p <= up - r4); + return p; +} + + +/* +** QuickSort algorithm (recursive function) +*/ +static void auxsort (lua_State *L, IdxT lo, IdxT up, + unsigned int rnd) { + while (lo < up) { /* loop for tail recursion */ + IdxT p; /* Pivot index */ + IdxT n; /* to be used later */ + /* sort elements 'lo', 'p', and 'up' */ + lua_geti(L, 1, lo); + lua_geti(L, 1, up); + if (sort_comp(L, -1, -2)) /* a[up] < a[lo]? */ + set2(L, lo, up); /* swap a[lo] - a[up] */ + else + lua_pop(L, 2); /* remove both values */ + if (up - lo == 1) /* only 2 elements? */ + return; /* already sorted */ + if (up - lo < RANLIMIT || rnd == 0) /* small interval or no randomize? */ + p = (lo + up)/2; /* middle element is a good pivot */ + else /* for larger intervals, it is worth a random pivot */ + p = choosePivot(lo, up, rnd); + lua_geti(L, 1, p); + lua_geti(L, 1, lo); + if (sort_comp(L, -2, -1)) /* a[p] < a[lo]? */ + set2(L, p, lo); /* swap a[p] - a[lo] */ + else { + lua_pop(L, 1); /* remove a[lo] */ + lua_geti(L, 1, up); + if (sort_comp(L, -1, -2)) /* a[up] < a[p]? */ + set2(L, p, up); /* swap a[up] - a[p] */ + else + lua_pop(L, 2); + } + if (up - lo == 2) /* only 3 elements? */ + return; /* already sorted */ + lua_geti(L, 1, p); /* get middle element (Pivot) */ + lua_pushvalue(L, -1); /* push Pivot */ + lua_geti(L, 1, up - 1); /* push a[up - 1] */ + set2(L, p, up - 1); /* swap Pivot (a[p]) with a[up - 1] */ + p = partition(L, lo, up); + /* a[lo .. p - 1] <= a[p] == P <= a[p + 1 .. up] */ + if (p - lo < up - p) { /* lower interval is smaller? */ + auxsort(L, lo, p - 1, rnd); /* call recursively for lower interval */ + n = p - lo; /* size of smaller interval */ + lo = p + 1; /* tail call for [p + 1 .. up] (upper interval) */ + } + else { + auxsort(L, p + 1, up, rnd); /* call recursively for upper interval */ + n = up - p; /* size of smaller interval */ + up = p - 1; /* tail call for [lo .. p - 1] (lower interval) */ + } + if ((up - lo) / 128 > n) /* partition too imbalanced? */ + rnd = l_randomizePivot(); /* try a new randomization */ + } /* tail call auxsort(L, lo, up, rnd) */ +} + + +static int sort (lua_State *L) { + lua_Integer n = aux_getn(L, 1, TAB_RW); + if (n > 1) { /* non-trivial interval? */ + luaL_argcheck(L, n < INT_MAX, 1, "array too big"); + if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ + luaL_checktype(L, 2, LUA_TFUNCTION); /* must be a function */ + lua_settop(L, 2); /* make sure there are two arguments */ + auxsort(L, 1, (IdxT)n, 0); + } + return 0; +} + +/* }====================================================== */ + + +static const luaL_Reg tab_funcs[] = { + {"concat", tconcat}, +#if defined(LUA_COMPAT_MAXN) + {"maxn", maxn}, +#endif + {"insert", tinsert}, + {"pack", pack}, + {"unpack", unpack}, + {"remove", tremove}, + {"move", tmove}, + {"sort", sort}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_table (lua_State *L) { + luaL_newlib(L, tab_funcs); +#if defined(LUA_COMPAT_UNPACK) + /* _G.unpack = table.unpack */ + lua_getfield(L, -1, "unpack"); + lua_setglobal(L, "unpack"); +#endif + return 1; +} + -- cgit v1.2.3