Add Lua source, not compiled yet as libc/libm functions remain unimplemented

1 files changed, 669 insertions, 0 deletions

diff --git a/src/lib/lua/ltable.c b/src/lib/lua/ltable.c
new file mode 100644
index 0000000..7e15b71
--- /dev/null
+++ b/src/lib/lua/ltable.c
@@ -0,0 +1,669 @@
+/*
+** $Id: ltable.c,v 2.117 2015/11/19 19:16:22 roberto Exp $
+** Lua tables (hash)
+** See Copyright Notice in lua.h
+*/
+
+#define ltable_c
+#define LUA_CORE
+
+#include "lprefix.h"
+
+
+/*
+** Implementation of tables (aka arrays, objects, or hash tables).
+** Tables keep its elements in two parts: an array part and a hash part.
+** Non-negative integer keys are all candidates to be kept in the array
+** part. The actual size of the array is the largest 'n' such that
+** more than half the slots between 1 and n are in use.
+** Hash uses a mix of chained scatter table with Brent's variation.
+** A main invariant of these tables is that, if an element is not
+** in its main position (i.e. the 'original' position that its hash gives
+** to it), then the colliding element is in its own main position.
+** Hence even when the load factor reaches 100%, performance remains good.
+*/
+
+#include <math.h>
+#include <limits.h>
+
+#include "lua.h"
+
+#include "ldebug.h"
+#include "ldo.h"
+#include "lgc.h"
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+#include "ltable.h"
+#include "lvm.h"
+
+
+/*
+** Maximum size of array part (MAXASIZE) is 2^MAXABITS. MAXABITS is
+** the largest integer such that MAXASIZE fits in an unsigned int.
+*/
+#define MAXABITS	cast_int(sizeof(int) * CHAR_BIT - 1)
+#define MAXASIZE	(1u << MAXABITS)
+
+/*
+** Maximum size of hash part is 2^MAXHBITS. MAXHBITS is the largest
+** integer such that 2^MAXHBITS fits in a signed int. (Note that the
+** maximum number of elements in a table, 2^MAXABITS + 2^MAXHBITS, still
+** fits comfortably in an unsigned int.)
+*/
+#define MAXHBITS	(MAXABITS - 1)
+
+
+#define hashpow2(t,n)		(gnode(t, lmod((n), sizenode(t))))
+
+#define hashstr(t,str)		hashpow2(t, (str)->hash)
+#define hashboolean(t,p)	hashpow2(t, p)
+#define hashint(t,i)		hashpow2(t, i)
+
+
+/*
+** for some types, it is better to avoid modulus by power of 2, as
+** they tend to have many 2 factors.
+*/
+#define hashmod(t,n)	(gnode(t, ((n) % ((sizenode(t)-1)|1))))
+
+
+#define hashpointer(t,p)	hashmod(t, point2uint(p))
+
+
+#define dummynode		(&dummynode_)
+
+#define isdummy(n)		((n) == dummynode)
+
+static const Node dummynode_ = {
+  {NILCONSTANT},  /* value */
+  {{NILCONSTANT, 0}}  /* key */
+};
+
+
+/*
+** Hash for floating-point numbers.
+** The main computation should be just
+**     n = frexp(n, &i); return (n * INT_MAX) + i
+** but there are some numerical subtleties.
+** In a two-complement representation, INT_MAX does not has an exact
+** representation as a float, but INT_MIN does; because the absolute
+** value of 'frexp' is smaller than 1 (unless 'n' is inf/NaN), the
+** absolute value of the product 'frexp * -INT_MIN' is smaller or equal
+** to INT_MAX. Next, the use of 'unsigned int' avoids overflows when
+** adding 'i'; the use of '~u' (instead of '-u') avoids problems with
+** INT_MIN.
+*/
+#if !defined(l_hashfloat)
+static int l_hashfloat (lua_Number n) {
+  int i;
+  lua_Integer ni;
+  n = l_mathop(frexp)(n, &i) * -cast_num(INT_MIN);
+  if (!lua_numbertointeger(n, &ni)) {  /* is 'n' inf/-inf/NaN? */
+    lua_assert(luai_numisnan(n) || l_mathop(fabs)(n) == cast_num(HUGE_VAL));
+    return 0;
+  }
+  else {  /* normal case */
+    unsigned int u = cast(unsigned int, i) + cast(unsigned int, ni);
+    return cast_int(u <= cast(unsigned int, INT_MAX) ? u : ~u);
+  }
+}
+#endif
+
+
+/*
+** returns the 'main' position of an element in a table (that is, the index
+** of its hash value)
+*/
+static Node *mainposition (const Table *t, const TValue *key) {
+  switch (ttype(key)) {
+    case LUA_TNUMINT:
+      return hashint(t, ivalue(key));
+    case LUA_TNUMFLT:
+      return hashmod(t, l_hashfloat(fltvalue(key)));
+    case LUA_TSHRSTR:
+      return hashstr(t, tsvalue(key));
+    case LUA_TLNGSTR:
+      return hashpow2(t, luaS_hashlongstr(tsvalue(key)));
+    case LUA_TBOOLEAN:
+      return hashboolean(t, bvalue(key));
+    case LUA_TLIGHTUSERDATA:
+      return hashpointer(t, pvalue(key));
+    case LUA_TLCF:
+      return hashpointer(t, fvalue(key));
+    default:
+      lua_assert(!ttisdeadkey(key));
+      return hashpointer(t, gcvalue(key));
+  }
+}
+
+
+/*
+** returns the index for 'key' if 'key' is an appropriate key to live in
+** the array part of the table, 0 otherwise.
+*/
+static unsigned int arrayindex (const TValue *key) {
+  if (ttisinteger(key)) {
+    lua_Integer k = ivalue(key);
+    if (0 < k && (lua_Unsigned)k <= MAXASIZE)
+      return cast(unsigned int, k);  /* 'key' is an appropriate array index */
+  }
+  return 0;  /* 'key' did not match some condition */
+}
+
+
+/*
+** returns the index of a 'key' for table traversals. First goes all
+** elements in the array part, then elements in the hash part. The
+** beginning of a traversal is signaled by 0.
+*/
+static unsigned int findindex (lua_State *L, Table *t, StkId key) {
+  unsigned int i;
+  if (ttisnil(key)) return 0;  /* first iteration */
+  i = arrayindex(key);
+  if (i != 0 && i <= t->sizearray)  /* is 'key' inside array part? */
+    return i;  /* yes; that's the index */
+  else {
+    int nx;
+    Node *n = mainposition(t, key);
+    for (;;) {  /* check whether 'key' is somewhere in the chain */
+      /* key may be dead already, but it is ok to use it in 'next' */
+      if (luaV_rawequalobj(gkey(n), key) ||
+            (ttisdeadkey(gkey(n)) && iscollectable(key) &&
+             deadvalue(gkey(n)) == gcvalue(key))) {
+        i = cast_int(n - gnode(t, 0));  /* key index in hash table */
+        /* hash elements are numbered after array ones */
+        return (i + 1) + t->sizearray;
+      }
+      nx = gnext(n);
+      if (nx == 0)
+        luaG_runerror(L, "invalid key to 'next'");  /* key not found */
+      else n += nx;
+    }
+  }
+}
+
+
+int luaH_next (lua_State *L, Table *t, StkId key) {
+  unsigned int i = findindex(L, t, key);  /* find original element */
+  for (; i < t->sizearray; i++) {  /* try first array part */
+    if (!ttisnil(&t->array[i])) {  /* a non-nil value? */
+      setivalue(key, i + 1);
+      setobj2s(L, key+1, &t->array[i]);
+      return 1;
+    }
+  }
+  for (i -= t->sizearray; cast_int(i) < sizenode(t); i++) {  /* hash part */
+    if (!ttisnil(gval(gnode(t, i)))) {  /* a non-nil value? */
+      setobj2s(L, key, gkey(gnode(t, i)));
+      setobj2s(L, key+1, gval(gnode(t, i)));
+      return 1;
+    }
+  }
+  return 0;  /* no more elements */
+}
+
+
+/*
+** {=============================================================
+** Rehash
+** ==============================================================
+*/
+
+/*
+** Compute the optimal size for the array part of table 't'. 'nums' is a
+** "count array" where 'nums[i]' is the number of integers in the table
+** between 2^(i - 1) + 1 and 2^i. 'pna' enters with the total number of
+** integer keys in the table and leaves with the number of keys that
+** will go to the array part; return the optimal size.
+*/
+static unsigned int computesizes (unsigned int nums[], unsigned int *pna) {
+  int i;
+  unsigned int twotoi;  /* 2^i (candidate for optimal size) */
+  unsigned int a = 0;  /* number of elements smaller than 2^i */
+  unsigned int na = 0;  /* number of elements to go to array part */
+  unsigned int optimal = 0;  /* optimal size for array part */
+  /* loop while keys can fill more than half of total size */
+  for (i = 0, twotoi = 1; *pna > twotoi / 2; i++, twotoi *= 2) {
+    if (nums[i] > 0) {
+      a += nums[i];
+      if (a > twotoi/2) {  /* more than half elements present? */
+        optimal = twotoi;  /* optimal size (till now) */
+        na = a;  /* all elements up to 'optimal' will go to array part */
+      }
+    }
+  }
+  lua_assert((optimal == 0 || optimal / 2 < na) && na <= optimal);
+  *pna = na;
+  return optimal;
+}
+
+
+static int countint (const TValue *key, unsigned int *nums) {
+  unsigned int k = arrayindex(key);
+  if (k != 0) {  /* is 'key' an appropriate array index? */
+    nums[luaO_ceillog2(k)]++;  /* count as such */
+    return 1;
+  }
+  else
+    return 0;
+}
+
+
+/*
+** Count keys in array part of table 't': Fill 'nums[i]' with
+** number of keys that will go into corresponding slice and return
+** total number of non-nil keys.
+*/
+static unsigned int numusearray (const Table *t, unsigned int *nums) {
+  int lg;
+  unsigned int ttlg;  /* 2^lg */
+  unsigned int ause = 0;  /* summation of 'nums' */
+  unsigned int i = 1;  /* count to traverse all array keys */
+  /* traverse each slice */
+  for (lg = 0, ttlg = 1; lg <= MAXABITS; lg++, ttlg *= 2) {
+    unsigned int lc = 0;  /* counter */
+    unsigned int lim = ttlg;
+    if (lim > t->sizearray) {
+      lim = t->sizearray;  /* adjust upper limit */
+      if (i > lim)
+        break;  /* no more elements to count */
+    }
+    /* count elements in range (2^(lg - 1), 2^lg] */
+    for (; i <= lim; i++) {
+      if (!ttisnil(&t->array[i-1]))
+        lc++;
+    }
+    nums[lg] += lc;
+    ause += lc;
+  }
+  return ause;
+}
+
+
+static int numusehash (const Table *t, unsigned int *nums, unsigned int *pna) {
+  int totaluse = 0;  /* total number of elements */
+  int ause = 0;  /* elements added to 'nums' (can go to array part) */
+  int i = sizenode(t);
+  while (i--) {
+    Node *n = &t->node[i];
+    if (!ttisnil(gval(n))) {
+      ause += countint(gkey(n), nums);
+      totaluse++;
+    }
+  }
+  *pna += ause;
+  return totaluse;
+}
+
+
+static void setarrayvector (lua_State *L, Table *t, unsigned int size) {
+  unsigned int i;
+  luaM_reallocvector(L, t->array, t->sizearray, size, TValue);
+  for (i=t->sizearray; i<size; i++)
+     setnilvalue(&t->array[i]);
+  t->sizearray = size;
+}
+
+
+static void setnodevector (lua_State *L, Table *t, unsigned int size) {
+  int lsize;
+  if (size == 0) {  /* no elements to hash part? */
+    t->node = cast(Node *, dummynode);  /* use common 'dummynode' */
+    lsize = 0;
+  }
+  else {
+    int i;
+    lsize = luaO_ceillog2(size);
+    if (lsize > MAXHBITS)
+      luaG_runerror(L, "table overflow");
+    size = twoto(lsize);
+    t->node = luaM_newvector(L, size, Node);
+    for (i = 0; i < (int)size; i++) {
+      Node *n = gnode(t, i);
+      gnext(n) = 0;
+      setnilvalue(wgkey(n));
+      setnilvalue(gval(n));
+    }
+  }
+  t->lsizenode = cast_byte(lsize);
+  t->lastfree = gnode(t, size);  /* all positions are free */
+}
+
+
+void luaH_resize (lua_State *L, Table *t, unsigned int nasize,
+                                          unsigned int nhsize) {
+  unsigned int i;
+  int j;
+  unsigned int oldasize = t->sizearray;
+  int oldhsize = t->lsizenode;
+  Node *nold = t->node;  /* save old hash ... */
+  if (nasize > oldasize)  /* array part must grow? */
+    setarrayvector(L, t, nasize);
+  /* create new hash part with appropriate size */
+  setnodevector(L, t, nhsize);
+  if (nasize < oldasize) {  /* array part must shrink? */
+    t->sizearray = nasize;
+    /* re-insert elements from vanishing slice */
+    for (i=nasize; i<oldasize; i++) {
+      if (!ttisnil(&t->array[i]))
+        luaH_setint(L, t, i + 1, &t->array[i]);
+    }
+    /* shrink array */
+    luaM_reallocvector(L, t->array, oldasize, nasize, TValue);
+  }
+  /* re-insert elements from hash part */
+  for (j = twoto(oldhsize) - 1; j >= 0; j--) {
+    Node *old = nold + j;
+    if (!ttisnil(gval(old))) {
+      /* doesn't need barrier/invalidate cache, as entry was
+         already present in the table */
+      setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old));
+    }
+  }
+  if (!isdummy(nold))
+    luaM_freearray(L, nold, cast(size_t, twoto(oldhsize))); /* free old hash */
+}
+
+
+void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) {
+  int nsize = isdummy(t->node) ? 0 : sizenode(t);
+  luaH_resize(L, t, nasize, nsize);
+}
+
+/*
+** nums[i] = number of keys 'k' where 2^(i - 1) < k <= 2^i
+*/
+static void rehash (lua_State *L, Table *t, const TValue *ek) {
+  unsigned int asize;  /* optimal size for array part */
+  unsigned int na;  /* number of keys in the array part */
+  unsigned int nums[MAXABITS + 1];
+  int i;
+  int totaluse;
+  for (i = 0; i <= MAXABITS; i++) nums[i] = 0;  /* reset counts */
+  na = numusearray(t, nums);  /* count keys in array part */
+  totaluse = na;  /* all those keys are integer keys */
+  totaluse += numusehash(t, nums, &na);  /* count keys in hash part */
+  /* count extra key */
+  na += countint(ek, nums);
+  totaluse++;
+  /* compute new size for array part */
+  asize = computesizes(nums, &na);
+  /* resize the table to new computed sizes */
+  luaH_resize(L, t, asize, totaluse - na);
+}
+
+
+
+/*
+** }=============================================================
+*/
+
+
+Table *luaH_new (lua_State *L) {
+  GCObject *o = luaC_newobj(L, LUA_TTABLE, sizeof(Table));
+  Table *t = gco2t(o);
+  t->metatable = NULL;
+  t->flags = cast_byte(~0);
+  t->array = NULL;
+  t->sizearray = 0;
+  setnodevector(L, t, 0);
+  return t;
+}
+
+
+void luaH_free (lua_State *L, Table *t) {
+  if (!isdummy(t->node))
+    luaM_freearray(L, t->node, cast(size_t, sizenode(t)));
+  luaM_freearray(L, t->array, t->sizearray);
+  luaM_free(L, t);
+}
+
+
+static Node *getfreepos (Table *t) {
+  while (t->lastfree > t->node) {
+    t->lastfree--;
+    if (ttisnil(gkey(t->lastfree)))
+      return t->lastfree;
+  }
+  return NULL;  /* could not find a free place */
+}
+
+
+
+/*
+** inserts a new key into a hash table; first, check whether key's main
+** position is free. If not, check whether colliding node is in its main
+** position or not: if it is not, move colliding node to an empty place and
+** put new key in its main position; otherwise (colliding node is in its main
+** position), new key goes to an empty position.
+*/
+TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) {
+  Node *mp;
+  TValue aux;
+  if (ttisnil(key)) luaG_runerror(L, "table index is nil");
+  else if (ttisfloat(key)) {
+    lua_Integer k;
+    if (luaV_tointeger(key, &k, 0)) {  /* index is int? */
+      setivalue(&aux, k);
+      key = &aux;  /* insert it as an integer */
+    }
+    else if (luai_numisnan(fltvalue(key)))
+      luaG_runerror(L, "table index is NaN");
+  }
+  mp = mainposition(t, key);
+  if (!ttisnil(gval(mp)) || isdummy(mp)) {  /* main position is taken? */
+    Node *othern;
+    Node *f = getfreepos(t);  /* get a free place */
+    if (f == NULL) {  /* cannot find a free place? */
+      rehash(L, t, key);  /* grow table */
+      /* whatever called 'newkey' takes care of TM cache */
+      return luaH_set(L, t, key);  /* insert key into grown table */
+    }
+    lua_assert(!isdummy(f));
+    othern = mainposition(t, gkey(mp));
+    if (othern != mp) {  /* is colliding node out of its main position? */
+      /* yes; move colliding node into free position */
+      while (othern + gnext(othern) != mp)  /* find previous */
+        othern += gnext(othern);
+      gnext(othern) = cast_int(f - othern);  /* rechain to point to 'f' */
+      *f = *mp;  /* copy colliding node into free pos. (mp->next also goes) */
+      if (gnext(mp) != 0) {
+        gnext(f) += cast_int(mp - f);  /* correct 'next' */
+        gnext(mp) = 0;  /* now 'mp' is free */
+      }
+      setnilvalue(gval(mp));
+    }
+    else {  /* colliding node is in its own main position */
+      /* new node will go into free position */
+      if (gnext(mp) != 0)
+        gnext(f) = cast_int((mp + gnext(mp)) - f);  /* chain new position */
+      else lua_assert(gnext(f) == 0);
+      gnext(mp) = cast_int(f - mp);
+      mp = f;
+    }
+  }
+  setnodekey(L, &mp->i_key, key);
+  luaC_barrierback(L, t, key);
+  lua_assert(ttisnil(gval(mp)));
+  return gval(mp);
+}
+
+
+/*
+** search function for integers
+*/
+const TValue *luaH_getint (Table *t, lua_Integer key) {
+  /* (1 <= key && key <= t->sizearray) */
+  if (l_castS2U(key) - 1 < t->sizearray)
+    return &t->array[key - 1];
+  else {
+    Node *n = hashint(t, key);
+    for (;;) {  /* check whether 'key' is somewhere in the chain */
+      if (ttisinteger(gkey(n)) && ivalue(gkey(n)) == key)
+        return gval(n);  /* that's it */
+      else {
+        int nx = gnext(n);
+        if (nx == 0) break;
+        n += nx;
+      }
+    }
+    return luaO_nilobject;
+  }
+}
+
+
+/*
+** search function for short strings
+*/
+const TValue *luaH_getshortstr (Table *t, TString *key) {
+  Node *n = hashstr(t, key);
+  lua_assert(key->tt == LUA_TSHRSTR);
+  for (;;) {  /* check whether 'key' is somewhere in the chain */
+    const TValue *k = gkey(n);
+    if (ttisshrstring(k) && eqshrstr(tsvalue(k), key))
+      return gval(n);  /* that's it */
+    else {
+      int nx = gnext(n);
+      if (nx == 0)
+        return luaO_nilobject;  /* not found */
+      n += nx;
+    }
+  }
+}
+
+
+/*
+** "Generic" get version. (Not that generic: not valid for integers,
+** which may be in array part, nor for floats with integral values.)
+*/
+static const TValue *getgeneric (Table *t, const TValue *key) {
+  Node *n = mainposition(t, key);
+  for (;;) {  /* check whether 'key' is somewhere in the chain */
+    if (luaV_rawequalobj(gkey(n), key))
+      return gval(n);  /* that's it */
+    else {
+      int nx = gnext(n);
+      if (nx == 0)
+        return luaO_nilobject;  /* not found */
+      n += nx;
+    }
+  }
+}
+
+
+const TValue *luaH_getstr (Table *t, TString *key) {
+  if (key->tt == LUA_TSHRSTR)
+    return luaH_getshortstr(t, key);
+  else {  /* for long strings, use generic case */
+    TValue ko;
+    setsvalue(cast(lua_State *, NULL), &ko, key);
+    return getgeneric(t, &ko);
+  }
+}
+
+
+/*
+** main search function
+*/
+const TValue *luaH_get (Table *t, const TValue *key) {
+  switch (ttype(key)) {
+    case LUA_TSHRSTR: return luaH_getshortstr(t, tsvalue(key));
+    case LUA_TNUMINT: return luaH_getint(t, ivalue(key));
+    case LUA_TNIL: return luaO_nilobject;
+    case LUA_TNUMFLT: {
+      lua_Integer k;
+      if (luaV_tointeger(key, &k, 0)) /* index is int? */
+        return luaH_getint(t, k);  /* use specialized version */
+      /* else... */
+    }  /* FALLTHROUGH */
+    default:
+      return getgeneric(t, key);
+  }
+}
+
+
+/*
+** beware: when using this function you probably need to check a GC
+** barrier and invalidate the TM cache.
+*/
+TValue *luaH_set (lua_State *L, Table *t, const TValue *key) {
+  const TValue *p = luaH_get(t, key);
+  if (p != luaO_nilobject)
+    return cast(TValue *, p);
+  else return luaH_newkey(L, t, key);
+}
+
+
+void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) {
+  const TValue *p = luaH_getint(t, key);
+  TValue *cell;
+  if (p != luaO_nilobject)
+    cell = cast(TValue *, p);
+  else {
+    TValue k;
+    setivalue(&k, key);
+    cell = luaH_newkey(L, t, &k);
+  }
+  setobj2t(L, cell, value);
+}
+
+
+static int unbound_search (Table *t, unsigned int j) {
+  unsigned int i = j;  /* i is zero or a present index */
+  j++;
+  /* find 'i' and 'j' such that i is present and j is not */
+  while (!ttisnil(luaH_getint(t, j))) {
+    i = j;
+    if (j > cast(unsigned int, MAX_INT)/2) {  /* overflow? */
+      /* table was built with bad purposes: resort to linear search */
+      i = 1;
+      while (!ttisnil(luaH_getint(t, i))) i++;
+      return i - 1;
+    }
+    j *= 2;
+  }
+  /* now do a binary search between them */
+  while (j - i > 1) {
+    unsigned int m = (i+j)/2;
+    if (ttisnil(luaH_getint(t, m))) j = m;
+    else i = m;
+  }
+  return i;
+}
+
+
+/*
+** Try to find a boundary in table 't'. A 'boundary' is an integer index
+** such that t[i] is non-nil and t[i+1] is nil (and 0 if t[1] is nil).
+*/
+int luaH_getn (Table *t) {
+  unsigned int j = t->sizearray;
+  if (j > 0 && ttisnil(&t->array[j - 1])) {
+    /* there is a boundary in the array part: (binary) search for it */
+    unsigned int i = 0;
+    while (j - i > 1) {
+      unsigned int m = (i+j)/2;
+      if (ttisnil(&t->array[m - 1])) j = m;
+      else i = m;
+    }
+    return i;
+  }
+  /* else must find a boundary in hash part */
+  else if (isdummy(t->node))  /* hash part is empty? */
+    return j;  /* that is easy... */
+  else return unbound_search(t, j);
+}
+
+
+
+#if defined(LUA_DEBUG)
+
+Node *luaH_mainposition (const Table *t, const TValue *key) {
+  return mainposition(t, key);
+}
+
+int luaH_isdummy (Node *n) { return isdummy(n); }
+
+#endif