From 08496eea8b277d37c4de9cf75a011715ad6a4100 Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Wed, 10 Jan 2001 15:41:50 -0200
Subject: small changes in lstring

---
 lstring.c | 44 ++++++++++++++------------------------------
 1 file changed, 14 insertions(+), 30 deletions(-)

(limited to 'lstring.c')

diff --git a/lstring.c b/lstring.c
index c8cd17b1..a8c57cd9 100644
--- a/lstring.c
+++ b/lstring.c
@@ -1,5 +1,5 @@
 /*
-** $Id: lstring.c,v 1.47 2000/12/22 16:57:46 roberto Exp roberto $
+** $Id: lstring.c,v 1.48 2000/12/28 12:55:41 roberto Exp roberto $
 ** String table (keeps all strings handled by Lua)
 ** See Copyright Notice in lua.h
 */
@@ -15,6 +15,8 @@
 #include "lstring.h"
 
 
+#define lmod(s,size)	((int)((s) & ((size)-1)))
+
 
 void luaS_init (lua_State *L) {
   luaS_resize(L, &L->strt, MINPOWER2);
@@ -30,15 +32,6 @@ void luaS_freeall (lua_State *L) {
 }
 
 
-static luint32 hash_s (const char *s, size_t l) {
-  luint32 h = l;  /* seed */
-  size_t step = (l>>5)|1;  /* if string is too long, don't hash all its chars */
-  for (; l>=step; l-=step)
-    h = h ^ ((h<<5)+(h>>2)+(unsigned char)*(s++));
-  return h;
-}
-
-
 void luaS_resize (lua_State *L, stringtable *tb, int newsize) {
   TString **newhash = luaM_newvector(L, newsize, TString *);
   int i;
@@ -49,8 +42,8 @@ void luaS_resize (lua_State *L, stringtable *tb, int newsize) {
     while (p) {  /* for each node in the list */
       TString *next = p->nexthash;  /* save next */
       luint32 h = (tb == &L->strt) ? p->u.s.hash : IntPoint(p->u.d.value);
-      int h1 = h&(newsize-1);  /* new position */
-      LUA_ASSERT(h%newsize == (h&(newsize-1)),
+      int h1 = lmod(h, newsize);  /* new position */
+      LUA_ASSERT(h%newsize == lmod(h, newsize),
                     "a&(x-1) == a%x, for x power of 2");
       p->nexthash = newhash[h1];  /* chain it in new position */
       newhash[h1] = p;
@@ -74,10 +67,13 @@ static void newentry (lua_State *L, stringtable *tb, TString *ts, int h) {
 
 
 TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
-  luint32 h = hash_s(str, l);
-  int h1 = h & (L->strt.size-1);
   TString *ts;
-  for (ts = L->strt.hash[h1]; ts; ts = ts->nexthash) {
+  luint32 h = l;  /* seed */
+  size_t step = (l>>5)+1;  /* if string is too long, don't hash all its chars */
+  size_t l1;
+  for (l1=l; l1>=step; l1-=step)  /* compute hash */
+    h = h ^ ((h<<5)+(h>>2)+(unsigned char)str[l1-1]);
+  for (ts = L->strt.hash[lmod(h, L->strt.size)]; ts; ts = ts->nexthash) {
     if (ts->len == l && (memcmp(str, ts->str, l) == 0))
       return ts;
   }
@@ -90,7 +86,7 @@ TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
   ts->u.s.constindex = 0;
   memcpy(ts->str, str, l);
   ts->str[l] = 0;  /* ending 0 */
-  newentry(L, &L->strt, ts, h1);  /* insert it on table */
+  newentry(L, &L->strt, ts, lmod(h, L->strt.size));  /* insert it on table */
   return ts;
 }
 
@@ -104,13 +100,13 @@ TString *luaS_newudata (lua_State *L, size_t s, void *udata) {
   ts->u.d.tag = 0;
   ts->u.d.value = (udata == NULL) ? uts+1 : udata;
   /* insert it on table */
-  newentry(L, &L->udt, ts, IntPoint(ts->u.d.value) & (L->udt.size-1));
+  newentry(L, &L->udt, ts, lmod(IntPoint(ts->u.d.value), L->udt.size));
   return ts;
 }
 
 
 TString *luaS_createudata (lua_State *L, void *udata, int tag) {
-  int h1 = IntPoint(udata) & (L->udt.size-1);
+  int h1 = lmod(IntPoint(udata), L->udt.size);
   TString *ts;
   for (ts = L->udt.hash[h1]; ts; ts = ts->nexthash) {
     if (udata == ts->u.d.value && (tag == ts->u.d.tag || tag == LUA_ANYTAG))
@@ -123,15 +119,3 @@ TString *luaS_createudata (lua_State *L, void *udata, int tag) {
   return ts;
 }
 
-
-TString *luaS_new (lua_State *L, const char *str) {
-  return luaS_newlstr(L, str, strlen(str));
-}
-
-
-TString *luaS_newfixed (lua_State *L, const char *str) {
-  TString *ts = luaS_new(L, str);
-  if (ts->marked == 0) ts->marked = FIXMARK;  /* avoid GC */
-  return ts;
-}
-
-- 
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