cosmopolitan/third_party/lua/lstring.c
Justine Tunney 10fd8bdb70 Unbloat the build
This change resurrects ae5d06dc53
2022-08-11 00:15:29 -07:00

295 lines
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/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╚──────────────────────────────────────────────────────────────────────────────╝
│ │
│ Lua │
│ Copyright © 2004-2021 Lua.org, PUC-Rio. │
│ │
│ Permission is hereby granted, free of charge, to any person obtaining │
│ a copy of this software and associated documentation files (the │
│ "Software"), to deal in the Software without restriction, including │
│ without limitation the rights to use, copy, modify, merge, publish, │
│ distribute, sublicense, and/or sell copies of the Software, and to │
│ permit persons to whom the Software is furnished to do so, subject to │
│ the following conditions: │
│ │
│ The above copyright notice and this permission notice shall be │
│ included in all copies or substantial portions of the Software. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, │
│ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF │
│ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. │
│ IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY │
│ CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, │
│ TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE │
│ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#define lstring_c
#define LUA_CORE
#include "libc/str/str.h"
#include "third_party/lua/ldebug.h"
#include "third_party/lua/ldo.h"
#include "third_party/lua/lmem.h"
#include "third_party/lua/lobject.h"
#include "third_party/lua/lprefix.h"
#include "third_party/lua/lstate.h"
#include "third_party/lua/lstring.h"
#include "third_party/lua/lua.h"
// clang-format off
asm(".ident\t\"\\n\\n\
Lua 5.4.3 (MIT License)\\n\
Copyright 19942021 Lua.org, PUC-Rio.\"");
asm(".include \"libc/disclaimer.inc\"");
/*
** Maximum size for string table.
*/
#define MAXSTRTB cast_int(luaM_limitN(MAX_INT, TString*))
/*
** equality for long strings
*/
int luaS_eqlngstr (TString *a, TString *b) {
size_t len = a->u.lnglen;
lua_assert(a->tt == LUA_VLNGSTR && b->tt == LUA_VLNGSTR);
return (a == b) || /* same instance or... */
((len == b->u.lnglen) && /* equal length and ... */
(memcmp(getstr(a), getstr(b), len) == 0)); /* equal contents */
}
unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) {
unsigned int h = seed ^ cast_uint(l);
for (; l > 0; l--)
h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1]));
return h;
}
unsigned int luaS_hashlongstr (TString *ts) {
lua_assert(ts->tt == LUA_VLNGSTR);
if (ts->extra == 0) { /* no hash? */
size_t len = ts->u.lnglen;
ts->hash = luaS_hash(getstr(ts), len, ts->hash);
ts->extra = 1; /* now it has its hash */
}
return ts->hash;
}
static void tablerehash (TString **vect, int osize, int nsize) {
int i;
for (i = osize; i < nsize; i++) /* clear new elements */
vect[i] = NULL;
for (i = 0; i < osize; i++) { /* rehash old part of the array */
TString *p = vect[i];
vect[i] = NULL;
while (p) { /* for each string in the list */
TString *hnext = p->u.hnext; /* save next */
unsigned int h = lmod(p->hash, nsize); /* new position */
p->u.hnext = vect[h]; /* chain it into array */
vect[h] = p;
p = hnext;
}
}
}
/*
** Resize the string table. If allocation fails, keep the current size.
** (This can degrade performance, but any non-zero size should work
** correctly.)
*/
void luaS_resize (lua_State *L, int nsize) {
stringtable *tb = &G(L)->strt;
int osize = tb->size;
TString **newvect;
if (nsize < osize) /* shrinking table? */
tablerehash(tb->hash, osize, nsize); /* depopulate shrinking part */
newvect = luaM_reallocvector(L, tb->hash, osize, nsize, TString*);
if (l_unlikely(newvect == NULL)) { /* reallocation failed? */
if (nsize < osize) /* was it shrinking table? */
tablerehash(tb->hash, nsize, osize); /* restore to original size */
/* leave table as it was */
}
else { /* allocation succeeded */
tb->hash = newvect;
tb->size = nsize;
if (nsize > osize)
tablerehash(newvect, osize, nsize); /* rehash for new size */
}
}
/*
** Clear API string cache. (Entries cannot be empty, so fill them with
** a non-collectable string.)
*/
void luaS_clearcache (global_State *g) {
int i, j;
for (i = 0; i < STRCACHE_N; i++)
for (j = 0; j < STRCACHE_M; j++) {
if (iswhite(g->strcache[i][j])) /* will entry be collected? */
g->strcache[i][j] = g->memerrmsg; /* replace it with something fixed */
}
}
/*
** Initialize the string table and the string cache
*/
void luaS_init (lua_State *L) {
global_State *g = G(L);
int i, j;
stringtable *tb = &G(L)->strt;
tb->hash = luaM_newvector(L, MINSTRTABSIZE, TString*);
tablerehash(tb->hash, 0, MINSTRTABSIZE); /* clear array */
tb->size = MINSTRTABSIZE;
/* pre-create memory-error message */
g->memerrmsg = luaS_newliteral(L, MEMERRMSG);
luaC_fix(L, obj2gco(g->memerrmsg)); /* it should never be collected */
for (i = 0; i < STRCACHE_N; i++) /* fill cache with valid strings */
for (j = 0; j < STRCACHE_M; j++)
g->strcache[i][j] = g->memerrmsg;
}
/*
** creates a new string object
*/
static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) {
TString *ts;
GCObject *o;
size_t totalsize; /* total size of TString object */
totalsize = sizelstring(l);
o = luaC_newobj(L, tag, totalsize);
ts = gco2ts(o);
ts->hash = h;
ts->extra = 0;
getstr(ts)[l] = '\0'; /* ending 0 */
return ts;
}
TString *luaS_createlngstrobj (lua_State *L, size_t l) {
TString *ts = createstrobj(L, l, LUA_VLNGSTR, G(L)->seed);
ts->u.lnglen = l;
return ts;
}
void luaS_remove (lua_State *L, TString *ts) {
stringtable *tb = &G(L)->strt;
TString **p = &tb->hash[lmod(ts->hash, tb->size)];
while (*p != ts) /* find previous element */
p = &(*p)->u.hnext;
*p = (*p)->u.hnext; /* remove element from its list */
tb->nuse--;
}
static void growstrtab (lua_State *L, stringtable *tb) {
if (l_unlikely(tb->nuse == MAX_INT)) { /* too many strings? */
luaC_fullgc(L, 1); /* try to free some... */
if (tb->nuse == MAX_INT) /* still too many? */
luaM_error(L); /* cannot even create a message... */
}
if (tb->size <= MAXSTRTB / 2) /* can grow string table? */
luaS_resize(L, tb->size * 2);
}
/*
** Checks whether short string exists and reuses it or creates a new one.
*/
static TString *internshrstr (lua_State *L, const char *str, size_t l) {
TString *ts;
global_State *g = G(L);
stringtable *tb = &g->strt;
unsigned int h = luaS_hash(str, l, g->seed);
TString **list = &tb->hash[lmod(h, tb->size)];
lua_assert(str != NULL); /* otherwise 'memcmp'/'memcpy' are undefined */
for (ts = *list; ts != NULL; ts = ts->u.hnext) {
if (l == ts->shrlen && (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) {
/* found! */
if (isdead(g, ts)) /* dead (but not collected yet)? */
changewhite(ts); /* resurrect it */
return ts;
}
}
/* else must create a new string */
if (tb->nuse >= tb->size) { /* need to grow string table? */
growstrtab(L, tb);
list = &tb->hash[lmod(h, tb->size)]; /* rehash with new size */
}
ts = createstrobj(L, l, LUA_VSHRSTR, h);
memcpy(getstr(ts), str, l * sizeof(char));
ts->shrlen = cast_byte(l);
ts->u.hnext = *list;
*list = ts;
tb->nuse++;
return ts;
}
/*
** new string (with explicit length)
*/
TString *luaS_newlstr (lua_State *L, const char *str, size_t l) {
if (l <= LUAI_MAXSHORTLEN) /* short string? */
return internshrstr(L, str, l);
else {
TString *ts;
if (l_unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char)))
luaM_toobig(L);
ts = luaS_createlngstrobj(L, l);
memcpy(getstr(ts), str, l * sizeof(char));
return ts;
}
}
/*
** Create or reuse a zero-terminated string, first checking in the
** cache (using the string address as a key). The cache can contain
** only zero-terminated strings, so it is safe to use 'strcmp' to
** check hits.
*/
TString *luaS_new (lua_State *L, const char *str) {
unsigned int i = point2uint(str) % STRCACHE_N; /* hash */
int j;
TString **p = G(L)->strcache[i];
for (j = 0; j < STRCACHE_M; j++) {
if (strcmp(str, getstr(p[j])) == 0) /* hit? */
return p[j]; /* that is it */
}
/* normal route */
for (j = STRCACHE_M - 1; j > 0; j--)
p[j] = p[j - 1]; /* move out last element */
/* new element is first in the list */
p[0] = luaS_newlstr(L, str, strlen(str));
return p[0];
}
Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue) {
Udata *u;
int i;
GCObject *o;
if (l_unlikely(s > MAX_SIZE - udatamemoffset(nuvalue)))
luaM_toobig(L);
o = luaC_newobj(L, LUA_VUSERDATA, sizeudata(nuvalue, s));
u = gco2u(o);
u->len = s;
u->nuvalue = nuvalue;
u->metatable = NULL;
for (i = 0; i < nuvalue; i++)
setnilvalue(&u->uv[i].uv);
return u;
}