1 files changed, 155 insertions, 0 deletions
diff --git a/src/lua/lstring.c b/src/lua/lstring.c
new file mode 100644
index 00000000..7293e195
--- /dev/null
+++ b/src/lua/lstring.c
@@ -0,0 +1,155 @@
+/*
+** $Id: lstring.c,v 1.3 2001/11/26 23:00:26 darkgod Exp $
+** String table (keeps all strings handled by Lua)
+** See Copyright Notice in lua.h
+*/
+
+
+#include <string.h>
+
+#include "lua.h"
+
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#include "lstring.h"
+
+
+/*
+** type equivalent to TString, but with maximum alignment requirements
+*/
+union L_UTString {
+  TString ts;
+  union L_Umaxalign dummy;  /* ensures maximum alignment for `local' udata */
+};
+
+
+
+void luaS_init (lua_State *L) {
+  L->strt.hash = luaM_newvector(L, 1, TString *);
+  L->udt.hash = luaM_newvector(L, 1, TString *);
+  L->nblocks += 2*sizeof(TString *);
+  L->strt.size = L->udt.size = 1;
+  L->strt.nuse = L->udt.nuse = 0;
+  L->strt.hash[0] = L->udt.hash[0] = NULL;
+}
+
+
+void luaS_freeall (lua_State *L) {
+  LUA_ASSERT(L->strt.nuse==0, "non-empty string table");
+  L->nblocks -= (L->strt.size + L->udt.size)*sizeof(TString *);
+  luaM_free(L, L->strt.hash);
+  LUA_ASSERT(L->udt.nuse==0, "non-empty udata table");
+  luaM_free(L, L->udt.hash);
+}
+
+
+static unsigned long hash_s (const char *s, size_t l) {
+  unsigned long 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;
+  for (i=0; i<newsize; i++) newhash[i] = NULL;
+  /* rehash */
+  for (i=0; i<tb->size; i++) {
+    TString *p = tb->hash[i];
+    while (p) {  /* for each node in the list */
+      TString *next = p->nexthash;  /* save next */
+      unsigned long 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)),
+                    "a&(x-1) == a%x, for x power of 2");
+      p->nexthash = newhash[h1];  /* chain it in new position */
+      newhash[h1] = p;
+      p = next;
+    }
+  }
+  luaM_free(L, tb->hash);
+  L->nblocks += (newsize - tb->size)*sizeof(TString *);
+  tb->size = newsize;
+  tb->hash = newhash;
+}
+
+
+static void newentry (lua_State *L, stringtable *tb, TString *ts, int h) {
+  ts->nexthash = tb->hash[h];  /* chain new entry */
+  tb->hash[h] = ts;
+  tb->nuse++;
+  if (tb->nuse > (lint32)tb->size && tb->size < MAX_INT/2)  /* too crowded? */
+    luaS_resize(L, tb, tb->size*2);
+}
+
+
+
+TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
+  unsigned long h = hash_s(str, l);
+  int h1 = h & (L->strt.size-1);
+  TString *ts;
+  for (ts = L->strt.hash[h1]; ts; ts = ts->nexthash) {
+    if (ts->len == l && (memcmp(str, ts->str, l) == 0))
+      return ts;
+  }
+  /* not found */
+  ts = (TString *)luaM_malloc(L, sizestring(l));
+  ts->marked = 0;
+  ts->nexthash = NULL;
+  ts->len = l;
+  ts->u.s.hash = h;
+  ts->u.s.constindex = 0;
+  memcpy(ts->str, str, l);
+  ts->str[l] = 0;  /* ending 0 */
+  L->nblocks += sizestring(l);
+  newentry(L, &L->strt, ts, h1);  /* insert it on table */
+  return ts;
+}
+
+
+TString *luaS_newudata (lua_State *L, size_t s, void *udata) {
+  union L_UTString *uts = (union L_UTString *)luaM_malloc(L,
+                                (lint32)sizeof(union L_UTString)+s);
+  TString *ts = &uts->ts;
+  ts->marked = 0;
+  ts->nexthash = NULL;
+  ts->len = s;
+  ts->u.d.tag = 0;
+  ts->u.d.value = (udata == NULL) ? uts+1 : udata;
+  L->nblocks += sizestring(s);
+ /* insert it on table */
+  newentry(L, &L->udt, ts, IntPoint(ts->u.d.value) & (L->udt.size-1));
+  return ts;
+}
+
+
+TString *luaS_createudata (lua_State *L, void *udata, int tag) {
+  int h1 = IntPoint(udata) & (L->udt.size-1);
+  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))
+      return ts;
+  }
+  /* not found */
+  ts = luaS_newudata(L, 0, udata);
+  if (tag != LUA_ANYTAG)
+    ts->u.d.tag = 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;
+}
+