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invariant tests over tables performed externally, through a built-in

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function (when DEBUG is ion).
This commit is contained in:
Roberto Ierusalimschy
1999-10-26 08:53:40 -02:00
parent bbab974717
commit 5a48255c9f
3 changed files with 29 additions and 56 deletions
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45
ltable.c
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@@ -1,5 +1,5 @@
/*
** $Id: ltable.c,v 1.26 1999/10/14 19:13:31 roberto Exp roberto $
** $Id: ltable.c,v 1.27 1999/10/19 13:33:22 roberto Exp roberto $
** Lua tables (hash)
** See Copyright Notice in lua.h
*/
@@ -38,7 +38,7 @@
** returns the `main' position of an element in a table (that is, the index
** of its hash value)
*/
static Node *luaH_mainposition (const Hash *t, const TObject *key) {
Node *luaH_mainposition (const Hash *t, const TObject *key) {
unsigned long h;
switch (ttype(key)) {
case LUA_T_NUMBER:
@@ -90,7 +90,7 @@ static Node *hashnodecreate (int nhash) {
Node *v = luaM_newvector(nhash, Node);
int i;
for (i=0; i<nhash; i++) {
ttype(key(&v[i])) = ttype(val(&v[i])) = LUA_T_NIL;
ttype(&v[i].key) = ttype(&v[i].val) = LUA_T_NIL;
v[i].next = NULL;
}
return v;
@@ -129,48 +129,13 @@ static int newsize (const Hash *t) {
int realuse = 0;
int i;
for (i=0; i<size; i++) {
if (ttype(val(v+i)) != LUA_T_NIL)
if (ttype(&v[i].val) != LUA_T_NIL)
realuse++;
}
return luaO_redimension(realuse*2);
}
#ifdef DEBUG
/* check invariant of a table */
static int listfind (const Node *m, const Node *n) {
do {
if (m==n) return 1;
m = m->next;
} while (m);
return 0;
}
static int check_invariant (const Hash *t, int filled) {
Node *n;
for (n=t->node; n<t->firstfree; n++) {
TObject *key = &n->key;
LUA_ASSERT(ttype(key) == LUA_T_NIL || n == luaH_mainposition(t, key),
"all elements before firstfree are empty or in their main positions");
}
if (!filled)
LUA_ASSERT(ttype(&(n++)->key) == LUA_T_NIL, "firstfree must be empty");
else
LUA_ASSERT(n == t->node, "table cannot have empty places");
for (; n<t->node+t->size; n++) {
TObject *key = &n->key;
Node *mp = luaH_mainposition(t, key);
LUA_ASSERT(ttype(key) != LUA_T_NIL,
"cannot exist empty elements after firstfree");
LUA_ASSERT(n == mp || luaH_mainposition(t, &mp->key) == mp,
"either an element or its colliding element is in its main position");
LUA_ASSERT(listfind(mp,n), "element is in its main position list");
}
return 1;
}
#endif
/*
** the rehash is done in two stages: first, we insert only the elements whose
** main position is free, to avoid needless collisions. In the second stage,
@@ -180,7 +145,6 @@ static void rehash (Hash *t) {
int oldsize = t->size;
Node *nold = t->node;
int i;
LUA_ASSERT(check_invariant(t, 1), "invalid table");
L->nblocks -= gcsize(oldsize);
setnodevector(t, newsize(t)); /* create new array of nodes */
/* first loop; set only elements that can go in their main positions */
@@ -216,7 +180,6 @@ static void rehash (Hash *t) {
} while (ttype(&t->firstfree->key) != LUA_T_NIL);
}
}
LUA_ASSERT(check_invariant(t, 0), "invalid table");
luaM_free(nold); /* free old array */
}