Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 5205 | clevermous | 1 | /* |
| 2 | ** $Id: lstring.c,v 2.19 2011/05/03 16:01:57 roberto Exp $ |
||
| 3 | ** String table (keeps all strings handled by Lua) |
||
| 4 | ** See Copyright Notice in lua.h |
||
| 5 | */ |
||
| 6 | |||
| 7 | |||
| 8 | #include |
||
| 9 | |||
| 10 | #define lstring_c |
||
| 11 | #define LUA_CORE |
||
| 12 | |||
| 13 | #include "lua.h" |
||
| 14 | |||
| 15 | #include "lmem.h" |
||
| 16 | #include "lobject.h" |
||
| 17 | #include "lstate.h" |
||
| 18 | #include "lstring.h" |
||
| 19 | |||
| 20 | |||
| 21 | |||
| 22 | void luaS_resize (lua_State *L, int newsize) { |
||
| 23 | int i; |
||
| 24 | stringtable *tb = &G(L)->strt; |
||
| 25 | /* cannot resize while GC is traversing strings */ |
||
| 26 | luaC_runtilstate(L, ~bitmask(GCSsweepstring)); |
||
| 27 | if (newsize > tb->size) { |
||
| 28 | luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *); |
||
| 29 | for (i = tb->size; i < newsize; i++) tb->hash[i] = NULL; |
||
| 30 | } |
||
| 31 | /* rehash */ |
||
| 32 | for (i=0; i |
||
| 33 | GCObject *p = tb->hash[i]; |
||
| 34 | tb->hash[i] = NULL; |
||
| 35 | while (p) { /* for each node in the list */ |
||
| 36 | GCObject *next = gch(p)->next; /* save next */ |
||
| 37 | unsigned int h = lmod(gco2ts(p)->hash, newsize); /* new position */ |
||
| 38 | gch(p)->next = tb->hash[h]; /* chain it */ |
||
| 39 | tb->hash[h] = p; |
||
| 40 | resetoldbit(p); /* see MOVE OLD rule */ |
||
| 41 | p = next; |
||
| 42 | } |
||
| 43 | } |
||
| 44 | if (newsize < tb->size) { |
||
| 45 | /* shrinking slice must be empty */ |
||
| 46 | lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL); |
||
| 47 | luaM_reallocvector(L, tb->hash, tb->size, newsize, GCObject *); |
||
| 48 | } |
||
| 49 | tb->size = newsize; |
||
| 50 | } |
||
| 51 | |||
| 52 | |||
| 53 | static TString *newlstr (lua_State *L, const char *str, size_t l, |
||
| 54 | unsigned int h) { |
||
| 55 | size_t totalsize; /* total size of TString object */ |
||
| 56 | GCObject **list; /* (pointer to) list where it will be inserted */ |
||
| 57 | TString *ts; |
||
| 58 | stringtable *tb = &G(L)->strt; |
||
| 59 | if (l+1 > (MAX_SIZET - sizeof(TString))/sizeof(char)) |
||
| 60 | luaM_toobig(L); |
||
| 61 | if (tb->nuse >= cast(lu_int32, tb->size) && tb->size <= MAX_INT/2) |
||
| 62 | luaS_resize(L, tb->size*2); /* too crowded */ |
||
| 63 | totalsize = sizeof(TString) + ((l + 1) * sizeof(char)); |
||
| 64 | list = &tb->hash[lmod(h, tb->size)]; |
||
| 65 | ts = &luaC_newobj(L, LUA_TSTRING, totalsize, list, 0)->ts; |
||
| 66 | ts->tsv.len = l; |
||
| 67 | ts->tsv.hash = h; |
||
| 68 | ts->tsv.reserved = 0; |
||
| 69 | memcpy(ts+1, str, l*sizeof(char)); |
||
| 70 | ((char *)(ts+1))[l] = '\0'; /* ending 0 */ |
||
| 71 | tb->nuse++; |
||
| 72 | return ts; |
||
| 73 | } |
||
| 74 | |||
| 75 | |||
| 76 | TString *luaS_newlstr (lua_State *L, const char *str, size_t l) { |
||
| 77 | GCObject *o; |
||
| 78 | unsigned int h = cast(unsigned int, l); /* seed */ |
||
| 79 | size_t step = (l>>5)+1; /* if string is too long, don't hash all its chars */ |
||
| 80 | size_t l1; |
||
| 81 | for (l1=l; l1>=step; l1-=step) /* compute hash */ |
||
| 82 | h = h ^ ((h<<5)+(h>>2)+cast(unsigned char, str[l1-1])); |
||
| 83 | for (o = G(L)->strt.hash[lmod(h, G(L)->strt.size)]; |
||
| 84 | o != NULL; |
||
| 85 | o = gch(o)->next) { |
||
| 86 | TString *ts = rawgco2ts(o); |
||
| 87 | if (h == ts->tsv.hash && |
||
| 88 | ts->tsv.len == l && |
||
| 89 | (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) { |
||
| 90 | if (isdead(G(L), o)) /* string is dead (but was not collected yet)? */ |
||
| 91 | changewhite(o); /* resurrect it */ |
||
| 92 | return ts; |
||
| 93 | } |
||
| 94 | } |
||
| 95 | return newlstr(L, str, l, h); /* not found; create a new string */ |
||
| 96 | } |
||
| 97 | |||
| 98 | |||
| 99 | TString *luaS_new (lua_State *L, const char *str) { |
||
| 100 | return luaS_newlstr(L, str, strlen(str)); |
||
| 101 | } |
||
| 102 | |||
| 103 | |||
| 104 | Udata *luaS_newudata (lua_State *L, size_t s, Table *e) { |
||
| 105 | Udata *u; |
||
| 106 | if (s > MAX_SIZET - sizeof(Udata)) |
||
| 107 | luaM_toobig(L); |
||
| 108 | u = &luaC_newobj(L, LUA_TUSERDATA, sizeof(Udata) + s, NULL, 0)->u; |
||
| 109 | u->uv.len = s; |
||
| 110 | u->uv.metatable = NULL; |
||
| 111 | u->uv.env = e; |
||
| 112 | return u; |
||
| 113 | } |
||
| 114 |