diff options
Diffstat (limited to 'apps/plugins/lua/lstring.c')
| -rw-r--r-- | apps/plugins/lua/lstring.c | 174 |
1 files changed, 50 insertions, 124 deletions
diff --git a/apps/plugins/lua/lstring.c b/apps/plugins/lua/lstring.c index af96c89..4911315 100644 --- a/apps/plugins/lua/lstring.c +++ b/apps/plugins/lua/lstring.c @@ -1,5 +1,5 @@ /* -** $Id: lstring.c,v 2.26.1.1 2013/04/12 18:48:47 roberto Exp $ +** $Id: lstring.c,v 2.8.1.1 2007/12/27 13:02:25 roberto Exp $ ** String table (keeps all strings handled by Lua) ** See Copyright Notice in lua.h */ @@ -18,157 +18,78 @@ #include "lstring.h" -/* -** Lua will use at most ~(2^LUAI_HASHLIMIT) bytes from a string to -** compute its hash -*/ -#if !defined(LUAI_HASHLIMIT) -#define LUAI_HASHLIMIT 5 -#endif - - -/* -** equality for long strings -*/ -int luaS_eqlngstr (TString *a, TString *b) { - size_t len = a->tsv.len; - lua_assert(a->tsv.tt == LUA_TLNGSTR && b->tsv.tt == LUA_TLNGSTR); - return (a == b) || /* same instance or... */ - ((len == b->tsv.len) && /* equal length and ... */ - (memcmp(getstr(a), getstr(b), len) == 0)); /* equal contents */ -} - - -/* -** equality for strings -*/ -int luaS_eqstr (TString *a, TString *b) { - return (a->tsv.tt == b->tsv.tt) && - (a->tsv.tt == LUA_TSHRSTR ? eqshrstr(a, b) : luaS_eqlngstr(a, b)); -} - -unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) { - unsigned int h = seed ^ cast(unsigned int, l); - size_t l1; - size_t step = (l >> LUAI_HASHLIMIT) + 1; - for (l1 = l; l1 >= step; l1 -= step) - h = h ^ ((h<<5) + (h>>2) + cast_byte(str[l1 - 1])); - return h; -} - - -/* -** resizes the string table -*/ void luaS_resize (lua_State *L, int newsize) { + GCObject **newhash; + stringtable *tb; int i; - stringtable *tb = &G(L)->strt; - /* cannot resize while GC is traversing strings */ - luaC_runtilstate(L, ~bitmask(GCSsweepstring)); - if (newsize > tb->size) { - luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *); - for (i = tb->size; i < newsize; i++) tb->hash[i] = NULL; - } + if (G(L)->gcstate == GCSsweepstring) + return; /* cannot resize during GC traverse */ + newhash = luaM_newvector(L, newsize, GCObject *); + tb = &G(L)->strt; + for (i=0; i<newsize; i++) newhash[i] = NULL; /* rehash */ for (i=0; i<tb->size; i++) { GCObject *p = tb->hash[i]; - tb->hash[i] = NULL; while (p) { /* for each node in the list */ - GCObject *next = gch(p)->next; /* save next */ - unsigned int h = lmod(gco2ts(p)->hash, newsize); /* new position */ - gch(p)->next = tb->hash[h]; /* chain it */ - tb->hash[h] = p; - resetoldbit(p); /* see MOVE OLD rule */ + GCObject *next = p->gch.next; /* save next */ + unsigned int h = gco2ts(p)->hash; + int h1 = lmod(h, newsize); /* new position */ + lua_assert(cast_int(h%newsize) == lmod(h, newsize)); + p->gch.next = newhash[h1]; /* chain it */ + newhash[h1] = p; p = next; } } - if (newsize < tb->size) { - /* shrinking slice must be empty */ - lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL); - luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *); - } + luaM_freearray(L, tb->hash, tb->size, TString *); tb->size = newsize; + tb->hash = newhash; } -/* -** creates a new string object -*/ -static TString *createstrobj (lua_State *L, const char *str, size_t l, - int tag, unsigned int h, GCObject **list) { +static TString *newlstr (lua_State *L, const char *str, size_t l, + unsigned int h) { TString *ts; - size_t totalsize; /* total size of TString object */ - totalsize = sizeof(TString) + ((l + 1) * sizeof(char)); - ts = &luaC_newobj(L, tag, totalsize, list, 0)->ts; + stringtable *tb; + if (l+1 > (MAX_SIZET - sizeof(TString))/sizeof(char)) + luaM_toobig(L); + ts = cast(TString *, luaM_malloc(L, (l+1)*sizeof(char)+sizeof(TString))); ts->tsv.len = l; ts->tsv.hash = h; - ts->tsv.extra = 0; + ts->tsv.marked = luaC_white(G(L)); + ts->tsv.tt = LUA_TSTRING; + ts->tsv.reserved = 0; memcpy(ts+1, str, l*sizeof(char)); ((char *)(ts+1))[l] = '\0'; /* ending 0 */ - return ts; -} - - -/* -** creates a new short string, inserting it into string table -*/ -static TString *newshrstr (lua_State *L, const char *str, size_t l, - unsigned int h) { - GCObject **list; /* (pointer to) list where it will be inserted */ - stringtable *tb = &G(L)->strt; - TString *s; - if (tb->nuse >= cast(lu_int32, tb->size) && tb->size <= MAX_INT/2) - luaS_resize(L, tb->size*2); /* too crowded */ - list = &tb->hash[lmod(h, tb->size)]; - s = createstrobj(L, str, l, LUA_TSHRSTR, h, list); + tb = &G(L)->strt; + h = lmod(h, tb->size); + ts->tsv.next = tb->hash[h]; /* chain new entry */ + tb->hash[h] = obj2gco(ts); tb->nuse++; - return s; + if (tb->nuse > cast(lu_int32, tb->size) && tb->size <= MAX_INT/2) + luaS_resize(L, tb->size*2); /* too crowded */ + return ts; } -/* -** 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 *luaS_newlstr (lua_State *L, const char *str, size_t l) { GCObject *o; - global_State *g = G(L); - unsigned int h = luaS_hash(str, l, g->seed); - for (o = g->strt.hash[lmod(h, g->strt.size)]; + unsigned int h = cast(unsigned int, 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)+cast(unsigned char, str[l1-1])); + for (o = G(L)->strt.hash[lmod(h, G(L)->strt.size)]; o != NULL; - o = gch(o)->next) { + o = o->gch.next) { TString *ts = rawgco2ts(o); - if (h == ts->tsv.hash && - l == ts->tsv.len && - (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) { - if (isdead(G(L), o)) /* string is dead (but was not collected yet)? */ - changewhite(o); /* resurrect it */ + if (ts->tsv.len == l && (memcmp(str, getstr(ts), l) == 0)) { + /* string may be dead */ + if (isdead(G(L), o)) changewhite(o); return ts; } } - return newshrstr(L, str, l, h); /* not found; create a new string */ -} - - -/* -** 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 { - if (l + 1 > (MAX_SIZET - sizeof(TString))/sizeof(char)) - luaM_toobig(L); - return createstrobj(L, str, l, LUA_TLNGSTR, G(L)->seed, NULL); - } -} - - -/* -** new zero-terminated string -*/ -TString *luaS_new (lua_State *L, const char *str) { - return luaS_newlstr(L, str, strlen(str)); + return newlstr(L, str, l, h); /* not found */ } @@ -176,10 +97,15 @@ Udata *luaS_newudata (lua_State *L, size_t s, Table *e) { Udata *u; if (s > MAX_SIZET - sizeof(Udata)) luaM_toobig(L); - u = &luaC_newobj(L, LUA_TUSERDATA, sizeof(Udata) + s, NULL, 0)->u; + u = cast(Udata *, luaM_malloc(L, s + sizeof(Udata))); + u->uv.marked = luaC_white(G(L)); /* is not finalized */ + u->uv.tt = LUA_TUSERDATA; u->uv.len = s; u->uv.metatable = NULL; u->uv.env = e; + /* chain it on udata list (after main thread) */ + u->uv.next = G(L)->mainthread->next; + G(L)->mainthread->next = obj2gco(u); return u; } |