diff options
Diffstat (limited to 'plugins/SmartAutoReplier/lualib/ltable.c')
-rw-r--r-- | plugins/SmartAutoReplier/lualib/ltable.c | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/plugins/SmartAutoReplier/lualib/ltable.c b/plugins/SmartAutoReplier/lualib/ltable.c new file mode 100644 index 0000000000..0c64adb10a --- /dev/null +++ b/plugins/SmartAutoReplier/lualib/ltable.c @@ -0,0 +1,509 @@ +/* +** $Id: ltable.c,v 1.132 2003/04/03 13:35:34 roberto Exp $ +** Lua tables (hash) +** See Copyright Notice in lua.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 at +** least half the slots between 0 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. +** In other words, there are collisions only when two elements have the +** same main position (i.e. the same hash values for that table size). +** Because of that, the load factor of these tables can be 100% without +** performance penalties. +*/ + +#include <string.h> + +#define ltable_c + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "ltable.h" + + +/* +** max size of array part is 2^MAXBITS +*/ +#if BITS_INT > 26 +#define MAXBITS 24 +#else +#define MAXBITS (BITS_INT-2) +#endif + +/* check whether `x' < 2^MAXBITS */ +#define toobig(x) ((((x)-1) >> MAXBITS) != 0) + + +/* function to convert a lua_Number to int (with any rounding method) */ +#ifndef lua_number2int +#define lua_number2int(i,n) ((i)=(int)(n)) +#endif + + +#define hashpow2(t,n) (gnode(t, lmod((n), sizenode(t)))) + +#define hashstr(t,str) hashpow2(t, (str)->tsv.hash) +#define hashboolean(t,p) hashpow2(t, p) + + +/* +** 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, IntPoint(p)) + + +/* +** number of ints inside a lua_Number +*/ +#define numints cast(int, sizeof(lua_Number)/sizeof(int)) + + +/* +** hash for lua_Numbers +*/ +static Node *hashnum (const Table *t, lua_Number n) { + unsigned int a[numints]; + int i; + n += 1; /* normalize number (avoid -0) */ + lua_assert(sizeof(a) <= sizeof(n)); + memcpy(a, &n, sizeof(a)); + for (i = 1; i < numints; i++) a[0] += a[i]; + return hashmod(t, cast(lu_hash, a[0])); +} + + + +/* +** returns the `main' position of an element in a table (that is, the index +** of its hash value) +*/ +Node *luaH_mainposition (const Table *t, const TObject *key) { + switch (ttype(key)) { + case LUA_TNUMBER: + return hashnum(t, nvalue(key)); + case LUA_TSTRING: + return hashstr(t, tsvalue(key)); + case LUA_TBOOLEAN: + return hashboolean(t, bvalue(key)); + case LUA_TLIGHTUSERDATA: + return hashpointer(t, pvalue(key)); + default: + 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, -1 otherwise. +*/ +static int arrayindex (const TObject *key) { + if (ttisnumber(key)) { + int k; + lua_number2int(k, (nvalue(key))); + if (cast(lua_Number, k) == nvalue(key) && k >= 1 && !toobig(k)) + return k; + } + return -1; /* `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 and end of a traversal are signalled by -1. +*/ +static int luaH_index (lua_State *L, Table *t, StkId key) { + int i; + if (ttisnil(key)) return -1; /* first iteration */ + i = arrayindex(key); + if (0 <= i && i <= t->sizearray) { /* is `key' inside array part? */ + return i-1; /* yes; that's the index (corrected to C) */ + } + else { + const TObject *v = luaH_get(t, key); + if (v == &luaO_nilobject) + luaG_runerror(L, "invalid key for `next'"); + i = cast(int, (cast(const lu_byte *, v) - + cast(const lu_byte *, gval(gnode(t, 0)))) / sizeof(Node)); + return i + t->sizearray; /* hash elements are numbered after array ones */ + } +} + + +int luaH_next (lua_State *L, Table *t, StkId key) { + int i = luaH_index(L, t, key); /* find original element */ + for (i++; i < t->sizearray; i++) { /* try first array part */ + if (!ttisnil(&t->array[i])) { /* a non-nil value? */ + setnvalue(key, cast(lua_Number, i+1)); + setobj2s(key+1, &t->array[i]); + return 1; + } + } + for (i -= t->sizearray; i < sizenode(t); i++) { /* then hash part */ + if (!ttisnil(gval(gnode(t, i)))) { /* a non-nil value? */ + setobj2s(key, gkey(gnode(t, i))); + setobj2s(key+1, gval(gnode(t, i))); + return 1; + } + } + return 0; /* no more elements */ +} + + +/* +** {============================================================= +** Rehash +** ============================================================== +*/ + + +static void computesizes (int nums[], int ntotal, int *narray, int *nhash) { + int i; + int a = nums[0]; /* number of elements smaller than 2^i */ + int na = a; /* number of elements to go to array part */ + int n = (na == 0) ? -1 : 0; /* (log of) optimal size for array part */ + for (i = 1; a < *narray && *narray >= twoto(i-1); i++) { + if (nums[i] > 0) { + a += nums[i]; + if (a >= twoto(i-1)) { /* more than half elements in use? */ + n = i; + na = a; + } + } + } + lua_assert(na <= *narray && *narray <= ntotal); + *nhash = ntotal - na; + *narray = (n == -1) ? 0 : twoto(n); + lua_assert(na <= *narray && na >= *narray/2); +} + + +static void numuse (const Table *t, int *narray, int *nhash) { + int nums[MAXBITS+1]; + int i, lg; + int totaluse = 0; + /* count elements in array part */ + for (i=0, lg=0; lg<=MAXBITS; lg++) { /* for each slice [2^(lg-1) to 2^lg) */ + int ttlg = twoto(lg); /* 2^lg */ + if (ttlg > t->sizearray) { + ttlg = t->sizearray; + if (i >= ttlg) break; + } + nums[lg] = 0; + for (; i<ttlg; i++) { + if (!ttisnil(&t->array[i])) { + nums[lg]++; + totaluse++; + } + } + } + for (; lg<=MAXBITS; lg++) nums[lg] = 0; /* reset other counts */ + *narray = totaluse; /* all previous uses were in array part */ + /* count elements in hash part */ + i = sizenode(t); + while (i--) { + Node *n = &t->node[i]; + if (!ttisnil(gval(n))) { + int k = arrayindex(gkey(n)); + if (k >= 0) { /* is `key' an appropriate array index? */ + nums[luaO_log2(k-1)+1]++; /* count as such */ + (*narray)++; + } + totaluse++; + } + } + computesizes(nums, totaluse, narray, nhash); +} + + +static void setarrayvector (lua_State *L, Table *t, int size) { + int i; + luaM_reallocvector(L, t->array, t->sizearray, size, TObject); + for (i=t->sizearray; i<size; i++) + setnilvalue(&t->array[i]); + t->sizearray = size; +} + + +static void setnodevector (lua_State *L, Table *t, int lsize) { + int i; + int size = twoto(lsize); + if (lsize > MAXBITS) + luaG_runerror(L, "table overflow"); + if (lsize == 0) { /* no elements to hash part? */ + t->node = G(L)->dummynode; /* use common `dummynode' */ + lua_assert(ttisnil(gkey(t->node))); /* assert invariants: */ + lua_assert(ttisnil(gval(t->node))); + lua_assert(t->node->next == NULL); /* (`dummynode' must be empty) */ + } + else { + t->node = luaM_newvector(L, size, Node); + for (i=0; i<size; i++) { + t->node[i].next = NULL; + setnilvalue(gkey(gnode(t, i))); + setnilvalue(gval(gnode(t, i))); + } + } + t->lsizenode = cast(lu_byte, lsize); + t->firstfree = gnode(t, size-1); /* first free position to be used */ +} + + +static void resize (lua_State *L, Table *t, int nasize, int nhsize) { + int i; + int oldasize = t->sizearray; + int oldhsize = t->lsizenode; + Node *nold; + Node temp[1]; + if (oldhsize) + nold = t->node; /* save old hash ... */ + else { /* old hash is `dummynode' */ + lua_assert(t->node == G(L)->dummynode); + temp[0] = t->node[0]; /* copy it to `temp' */ + nold = temp; + setnilvalue(gkey(G(L)->dummynode)); /* restate invariant */ + setnilvalue(gval(G(L)->dummynode)); + lua_assert(G(L)->dummynode->next == NULL); + } + if (nasize > oldasize) /* array part must grow? */ + setarrayvector(L, t, nasize); + /* create new hash part with appropriate size */ + setnodevector(L, t, nhsize); + /* re-insert elements */ + 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])) + setobjt2t(luaH_setnum(L, t, i+1), &t->array[i]); + } + /* shrink array */ + luaM_reallocvector(L, t->array, oldasize, nasize, TObject); + } + /* re-insert elements in hash part */ + for (i = twoto(oldhsize) - 1; i >= 0; i--) { + Node *old = nold+i; + if (!ttisnil(gval(old))) + setobjt2t(luaH_set(L, t, gkey(old)), gval(old)); + } + if (oldhsize) + luaM_freearray(L, nold, twoto(oldhsize), Node); /* free old array */ +} + + +static void rehash (lua_State *L, Table *t) { + int nasize, nhsize; + numuse(t, &nasize, &nhsize); /* compute new sizes for array and hash parts */ + resize(L, t, nasize, luaO_log2(nhsize)+1); +} + + + +/* +** }============================================================= +*/ + + +Table *luaH_new (lua_State *L, int narray, int lnhash) { + Table *t = luaM_new(L, Table); + luaC_link(L, valtogco(t), LUA_TTABLE); + t->metatable = hvalue(defaultmeta(L)); + t->flags = cast(lu_byte, ~0); + /* temporary values (kept only if some malloc fails) */ + t->array = NULL; + t->sizearray = 0; + t->lsizenode = 0; + t->node = NULL; + setarrayvector(L, t, narray); + setnodevector(L, t, lnhash); + return t; +} + + +void luaH_free (lua_State *L, Table *t) { + if (t->lsizenode) + luaM_freearray(L, t->node, sizenode(t), Node); + luaM_freearray(L, t->array, t->sizearray, TObject); + luaM_freelem(L, t); +} + + +#if 0 +/* +** try to remove an element from a hash table; cannot move any element +** (because gc can call `remove' during a table traversal) +*/ +void luaH_remove (Table *t, Node *e) { + Node *mp = luaH_mainposition(t, gkey(e)); + if (e != mp) { /* element not in its main position? */ + while (mp->next != e) mp = mp->next; /* find previous */ + mp->next = e->next; /* remove `e' from its list */ + } + else { + if (e->next != NULL) ?? + } + lua_assert(ttisnil(gval(node))); + setnilvalue(gkey(e)); /* clear node `e' */ + e->next = NULL; +} +#endif + + +/* +** 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. +*/ +static TObject *newkey (lua_State *L, Table *t, const TObject *key) { + TObject *val; + Node *mp = luaH_mainposition(t, key); + if (!ttisnil(gval(mp))) { /* main position is not free? */ + Node *othern = luaH_mainposition(t, gkey(mp)); /* `mp' of colliding node */ + Node *n = t->firstfree; /* get a free place */ + if (othern != mp) { /* is colliding node out of its main position? */ + /* yes; move colliding node into free position */ + while (othern->next != mp) othern = othern->next; /* find previous */ + othern->next = n; /* redo the chain with `n' in place of `mp' */ + *n = *mp; /* copy colliding node into free pos. (mp->next also goes) */ + mp->next = NULL; /* now `mp' is free */ + setnilvalue(gval(mp)); + } + else { /* colliding node is in its own main position */ + /* new node will go into free position */ + n->next = mp->next; /* chain new position */ + mp->next = n; + mp = n; + } + } + setobj2t(gkey(mp), key); /* write barrier */ + lua_assert(ttisnil(gval(mp))); + for (;;) { /* correct `firstfree' */ + if (ttisnil(gkey(t->firstfree))) + return gval(mp); /* OK; table still has a free place */ + else if (t->firstfree == t->node) break; /* cannot decrement from here */ + else (t->firstfree)--; + } + /* no more free places; must create one */ + setbvalue(gval(mp), 0); /* avoid new key being removed */ + rehash(L, t); /* grow table */ + val = cast(TObject *, luaH_get(t, key)); /* get new position */ + lua_assert(ttisboolean(val)); + setnilvalue(val); + return val; +} + + +/* +** generic search function +*/ +static const TObject *luaH_getany (Table *t, const TObject *key) { + if (ttisnil(key)) return &luaO_nilobject; + else { + Node *n = luaH_mainposition(t, key); + do { /* check whether `key' is somewhere in the chain */ + if (luaO_rawequalObj(gkey(n), key)) return gval(n); /* that's it */ + else n = n->next; + } while (n); + return &luaO_nilobject; + } +} + + +/* +** search function for integers +*/ +const TObject *luaH_getnum (Table *t, int key) { + if (1 <= key && key <= t->sizearray) + return &t->array[key-1]; + else { + lua_Number nk = cast(lua_Number, key); + Node *n = hashnum(t, nk); + do { /* check whether `key' is somewhere in the chain */ + if (ttisnumber(gkey(n)) && nvalue(gkey(n)) == nk) + return gval(n); /* that's it */ + else n = n->next; + } while (n); + return &luaO_nilobject; + } +} + + +/* +** search function for strings +*/ +const TObject *luaH_getstr (Table *t, TString *key) { + Node *n = hashstr(t, key); + do { /* check whether `key' is somewhere in the chain */ + if (ttisstring(gkey(n)) && tsvalue(gkey(n)) == key) + return gval(n); /* that's it */ + else n = n->next; + } while (n); + return &luaO_nilobject; +} + + +/* +** main search function +*/ +const TObject *luaH_get (Table *t, const TObject *key) { + switch (ttype(key)) { + case LUA_TSTRING: return luaH_getstr(t, tsvalue(key)); + case LUA_TNUMBER: { + int k; + lua_number2int(k, (nvalue(key))); + if (cast(lua_Number, k) == nvalue(key)) /* is an integer index? */ + return luaH_getnum(t, k); /* use specialized version */ + /* else go through */ + } + default: return luaH_getany(t, key); + } +} + + +TObject *luaH_set (lua_State *L, Table *t, const TObject *key) { + const TObject *p = luaH_get(t, key); + t->flags = 0; + if (p != &luaO_nilobject) + return cast(TObject *, p); + else { + if (ttisnil(key)) luaG_runerror(L, "table index is nil"); + else if (ttisnumber(key) && nvalue(key) != nvalue(key)) + luaG_runerror(L, "table index is NaN"); + return newkey(L, t, key); + } +} + + +TObject *luaH_setnum (lua_State *L, Table *t, int key) { + const TObject *p = luaH_getnum(t, key); + if (p != &luaO_nilobject) + return cast(TObject *, p); + else { + TObject k; + setnvalue(&k, cast(lua_Number, key)); + return newkey(L, t, &k); + } +} + |