diff options
Diffstat (limited to 'src/lua/lstring.c')
| -rw-r--r-- | src/lua/lstring.c | 273 |
1 files changed, 0 insertions, 273 deletions
diff --git a/src/lua/lstring.c b/src/lua/lstring.c deleted file mode 100644 index 13dcaf4..0000000 --- a/src/lua/lstring.c +++ /dev/null | |||
| @@ -1,273 +0,0 @@ | |||
| 1 | /* | ||
| 2 | ** $Id: lstring.c $ | ||
| 3 | ** String table (keeps all strings handled by Lua) | ||
| 4 | ** See Copyright Notice in lua.h | ||
| 5 | */ | ||
| 6 | |||
| 7 | #define lstring_c | ||
| 8 | #define LUA_CORE | ||
| 9 | |||
| 10 | #include "lprefix.h" | ||
| 11 | |||
| 12 | |||
| 13 | #include <string.h> | ||
| 14 | |||
| 15 | #include "lua.h" | ||
| 16 | |||
| 17 | #include "ldebug.h" | ||
| 18 | #include "ldo.h" | ||
| 19 | #include "lmem.h" | ||
| 20 | #include "lobject.h" | ||
| 21 | #include "lstate.h" | ||
| 22 | #include "lstring.h" | ||
| 23 | |||
| 24 | |||
| 25 | /* | ||
| 26 | ** Maximum size for string table. | ||
| 27 | */ | ||
| 28 | #define MAXSTRTB cast_int(luaM_limitN(MAX_INT, TString*)) | ||
| 29 | |||
| 30 | |||
| 31 | /* | ||
| 32 | ** equality for long strings | ||
| 33 | */ | ||
| 34 | int luaS_eqlngstr (TString *a, TString *b) { | ||
| 35 | size_t len = a->u.lnglen; | ||
| 36 | lua_assert(a->tt == LUA_VLNGSTR && b->tt == LUA_VLNGSTR); | ||
| 37 | return (a == b) || /* same instance or... */ | ||
| 38 | ((len == b->u.lnglen) && /* equal length and ... */ | ||
| 39 | (memcmp(getstr(a), getstr(b), len) == 0)); /* equal contents */ | ||
| 40 | } | ||
| 41 | |||
| 42 | |||
| 43 | unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) { | ||
| 44 | unsigned int h = seed ^ cast_uint(l); | ||
| 45 | for (; l > 0; l--) | ||
| 46 | h ^= ((h<<5) + (h>>2) + cast_byte(str[l - 1])); | ||
| 47 | return h; | ||
| 48 | } | ||
| 49 | |||
| 50 | |||
| 51 | unsigned int luaS_hashlongstr (TString *ts) { | ||
| 52 | lua_assert(ts->tt == LUA_VLNGSTR); | ||
| 53 | if (ts->extra == 0) { /* no hash? */ | ||
| 54 | size_t len = ts->u.lnglen; | ||
| 55 | ts->hash = luaS_hash(getstr(ts), len, ts->hash); | ||
| 56 | ts->extra = 1; /* now it has its hash */ | ||
| 57 | } | ||
| 58 | return ts->hash; | ||
| 59 | } | ||
| 60 | |||
| 61 | |||
| 62 | static void tablerehash (TString **vect, int osize, int nsize) { | ||
| 63 | int i; | ||
| 64 | for (i = osize; i < nsize; i++) /* clear new elements */ | ||
| 65 | vect[i] = NULL; | ||
| 66 | for (i = 0; i < osize; i++) { /* rehash old part of the array */ | ||
| 67 | TString *p = vect[i]; | ||
| 68 | vect[i] = NULL; | ||
| 69 | while (p) { /* for each string in the list */ | ||
| 70 | TString *hnext = p->u.hnext; /* save next */ | ||
| 71 | unsigned int h = lmod(p->hash, nsize); /* new position */ | ||
| 72 | p->u.hnext = vect[h]; /* chain it into array */ | ||
| 73 | vect[h] = p; | ||
| 74 | p = hnext; | ||
| 75 | } | ||
| 76 | } | ||
| 77 | } | ||
| 78 | |||
| 79 | |||
| 80 | /* | ||
| 81 | ** Resize the string table. If allocation fails, keep the current size. | ||
| 82 | ** (This can degrade performance, but any non-zero size should work | ||
| 83 | ** correctly.) | ||
| 84 | */ | ||
| 85 | void luaS_resize (lua_State *L, int nsize) { | ||
| 86 | stringtable *tb = &G(L)->strt; | ||
| 87 | int osize = tb->size; | ||
| 88 | TString **newvect; | ||
| 89 | if (nsize < osize) /* shrinking table? */ | ||
| 90 | tablerehash(tb->hash, osize, nsize); /* depopulate shrinking part */ | ||
| 91 | newvect = luaM_reallocvector(L, tb->hash, osize, nsize, TString*); | ||
| 92 | if (l_unlikely(newvect == NULL)) { /* reallocation failed? */ | ||
| 93 | if (nsize < osize) /* was it shrinking table? */ | ||
| 94 | tablerehash(tb->hash, nsize, osize); /* restore to original size */ | ||
| 95 | /* leave table as it was */ | ||
| 96 | } | ||
| 97 | else { /* allocation succeeded */ | ||
| 98 | tb->hash = newvect; | ||
| 99 | tb->size = nsize; | ||
| 100 | if (nsize > osize) | ||
| 101 | tablerehash(newvect, osize, nsize); /* rehash for new size */ | ||
| 102 | } | ||
| 103 | } | ||
| 104 | |||
| 105 | |||
| 106 | /* | ||
| 107 | ** Clear API string cache. (Entries cannot be empty, so fill them with | ||
| 108 | ** a non-collectable string.) | ||
| 109 | */ | ||
| 110 | void luaS_clearcache (global_State *g) { | ||
| 111 | int i, j; | ||
| 112 | for (i = 0; i < STRCACHE_N; i++) | ||
| 113 | for (j = 0; j < STRCACHE_M; j++) { | ||
| 114 | if (iswhite(g->strcache[i][j])) /* will entry be collected? */ | ||
| 115 | g->strcache[i][j] = g->memerrmsg; /* replace it with something fixed */ | ||
| 116 | } | ||
| 117 | } | ||
| 118 | |||
| 119 | |||
| 120 | /* | ||
| 121 | ** Initialize the string table and the string cache | ||
| 122 | */ | ||
| 123 | void luaS_init (lua_State *L) { | ||
| 124 | global_State *g = G(L); | ||
| 125 | int i, j; | ||
| 126 | stringtable *tb = &G(L)->strt; | ||
| 127 | tb->hash = luaM_newvector(L, MINSTRTABSIZE, TString*); | ||
| 128 | tablerehash(tb->hash, 0, MINSTRTABSIZE); /* clear array */ | ||
| 129 | tb->size = MINSTRTABSIZE; | ||
| 130 | /* pre-create memory-error message */ | ||
| 131 | g->memerrmsg = luaS_newliteral(L, MEMERRMSG); | ||
| 132 | luaC_fix(L, obj2gco(g->memerrmsg)); /* it should never be collected */ | ||
| 133 | for (i = 0; i < STRCACHE_N; i++) /* fill cache with valid strings */ | ||
| 134 | for (j = 0; j < STRCACHE_M; j++) | ||
| 135 | g->strcache[i][j] = g->memerrmsg; | ||
| 136 | } | ||
| 137 | |||
| 138 | |||
| 139 | |||
| 140 | /* | ||
| 141 | ** creates a new string object | ||
| 142 | */ | ||
| 143 | static TString *createstrobj (lua_State *L, size_t l, int tag, unsigned int h) { | ||
| 144 | TString *ts; | ||
| 145 | GCObject *o; | ||
| 146 | size_t totalsize; /* total size of TString object */ | ||
| 147 | totalsize = sizelstring(l); | ||
| 148 | o = luaC_newobj(L, tag, totalsize); | ||
| 149 | ts = gco2ts(o); | ||
| 150 | ts->hash = h; | ||
| 151 | ts->extra = 0; | ||
| 152 | getstr(ts)[l] = '\0'; /* ending 0 */ | ||
| 153 | return ts; | ||
| 154 | } | ||
| 155 | |||
| 156 | |||
| 157 | TString *luaS_createlngstrobj (lua_State *L, size_t l) { | ||
| 158 | TString *ts = createstrobj(L, l, LUA_VLNGSTR, G(L)->seed); | ||
| 159 | ts->u.lnglen = l; | ||
| 160 | return ts; | ||
| 161 | } | ||
| 162 | |||
| 163 | |||
| 164 | void luaS_remove (lua_State *L, TString *ts) { | ||
| 165 | stringtable *tb = &G(L)->strt; | ||
| 166 | TString **p = &tb->hash[lmod(ts->hash, tb->size)]; | ||
| 167 | while (*p != ts) /* find previous element */ | ||
| 168 | p = &(*p)->u.hnext; | ||
| 169 | *p = (*p)->u.hnext; /* remove element from its list */ | ||
| 170 | tb->nuse--; | ||
| 171 | } | ||
| 172 | |||
| 173 | |||
| 174 | static void growstrtab (lua_State *L, stringtable *tb) { | ||
| 175 | if (l_unlikely(tb->nuse == MAX_INT)) { /* too many strings? */ | ||
| 176 | luaC_fullgc(L, 1); /* try to free some... */ | ||
| 177 | if (tb->nuse == MAX_INT) /* still too many? */ | ||
| 178 | luaM_error(L); /* cannot even create a message... */ | ||
| 179 | } | ||
| 180 | if (tb->size <= MAXSTRTB / 2) /* can grow string table? */ | ||
| 181 | luaS_resize(L, tb->size * 2); | ||
| 182 | } | ||
| 183 | |||
| 184 | |||
| 185 | /* | ||
| 186 | ** Checks whether short string exists and reuses it or creates a new one. | ||
| 187 | */ | ||
| 188 | static TString *internshrstr (lua_State *L, const char *str, size_t l) { | ||
| 189 | TString *ts; | ||
| 190 | global_State *g = G(L); | ||
| 191 | stringtable *tb = &g->strt; | ||
| 192 | unsigned int h = luaS_hash(str, l, g->seed); | ||
| 193 | TString **list = &tb->hash[lmod(h, tb->size)]; | ||
| 194 | lua_assert(str != NULL); /* otherwise 'memcmp'/'memcpy' are undefined */ | ||
| 195 | for (ts = *list; ts != NULL; ts = ts->u.hnext) { | ||
| 196 | if (l == ts->shrlen && (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) { | ||
| 197 | /* found! */ | ||
| 198 | if (isdead(g, ts)) /* dead (but not collected yet)? */ | ||
| 199 | changewhite(ts); /* resurrect it */ | ||
| 200 | return ts; | ||
| 201 | } | ||
| 202 | } | ||
| 203 | /* else must create a new string */ | ||
| 204 | if (tb->nuse >= tb->size) { /* need to grow string table? */ | ||
| 205 | growstrtab(L, tb); | ||
| 206 | list = &tb->hash[lmod(h, tb->size)]; /* rehash with new size */ | ||
| 207 | } | ||
| 208 | ts = createstrobj(L, l, LUA_VSHRSTR, h); | ||
| 209 | memcpy(getstr(ts), str, l * sizeof(char)); | ||
| 210 | ts->shrlen = cast_byte(l); | ||
| 211 | ts->u.hnext = *list; | ||
| 212 | *list = ts; | ||
| 213 | tb->nuse++; | ||
| 214 | return ts; | ||
| 215 | } | ||
| 216 | |||
| 217 | |||
| 218 | /* | ||
| 219 | ** new string (with explicit length) | ||
| 220 | */ | ||
| 221 | TString *luaS_newlstr (lua_State *L, const char *str, size_t l) { | ||
| 222 | if (l <= LUAI_MAXSHORTLEN) /* short string? */ | ||
| 223 | return internshrstr(L, str, l); | ||
| 224 | else { | ||
| 225 | TString *ts; | ||
| 226 | if (l_unlikely(l >= (MAX_SIZE - sizeof(TString))/sizeof(char))) | ||
| 227 | luaM_toobig(L); | ||
| 228 | ts = luaS_createlngstrobj(L, l); | ||
| 229 | memcpy(getstr(ts), str, l * sizeof(char)); | ||
| 230 | return ts; | ||
| 231 | } | ||
| 232 | } | ||
| 233 | |||
| 234 | |||
| 235 | /* | ||
| 236 | ** Create or reuse a zero-terminated string, first checking in the | ||
| 237 | ** cache (using the string address as a key). The cache can contain | ||
| 238 | ** only zero-terminated strings, so it is safe to use 'strcmp' to | ||
| 239 | ** check hits. | ||
| 240 | */ | ||
| 241 | TString *luaS_new (lua_State *L, const char *str) { | ||
| 242 | unsigned int i = point2uint(str) % STRCACHE_N; /* hash */ | ||
| 243 | int j; | ||
| 244 | TString **p = G(L)->strcache[i]; | ||
| 245 | for (j = 0; j < STRCACHE_M; j++) { | ||
| 246 | if (strcmp(str, getstr(p[j])) == 0) /* hit? */ | ||
| 247 | return p[j]; /* that is it */ | ||
| 248 | } | ||
| 249 | /* normal route */ | ||
| 250 | for (j = STRCACHE_M - 1; j > 0; j--) | ||
| 251 | p[j] = p[j - 1]; /* move out last element */ | ||
| 252 | /* new element is first in the list */ | ||
| 253 | p[0] = luaS_newlstr(L, str, strlen(str)); | ||
| 254 | return p[0]; | ||
| 255 | } | ||
| 256 | |||
| 257 | |||
| 258 | Udata *luaS_newudata (lua_State *L, size_t s, int nuvalue) { | ||
| 259 | Udata *u; | ||
| 260 | int i; | ||
| 261 | GCObject *o; | ||
| 262 | if (l_unlikely(s > MAX_SIZE - udatamemoffset(nuvalue))) | ||
| 263 | luaM_toobig(L); | ||
| 264 | o = luaC_newobj(L, LUA_VUSERDATA, sizeudata(nuvalue, s)); | ||
| 265 | u = gco2u(o); | ||
| 266 | u->len = s; | ||
| 267 | u->nuvalue = nuvalue; | ||
| 268 | u->metatable = NULL; | ||
| 269 | for (i = 0; i < nuvalue; i++) | ||
| 270 | setnilvalue(&u->uv[i].uv); | ||
| 271 | return u; | ||
| 272 | } | ||
| 273 | |||
