Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(976)

Unified Diff: third_party/lua/src/lstring.c

Issue 14907017: add SkLuaCanvas (Closed) Base URL: https://skia.googlecode.com/svn/trunk
Patch Set: Created 7 years, 7 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« no previous file with comments | « third_party/lua/src/lstring.h ('k') | third_party/lua/src/lstrlib.c » ('j') | no next file with comments »
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: third_party/lua/src/lstring.c
diff --git a/third_party/lua/src/lstring.c b/third_party/lua/src/lstring.c
new file mode 100644
index 0000000000000000000000000000000000000000..8b5af0b2e77cc23757d2187a76e8c01dcda0e7a9
--- /dev/null
+++ b/third_party/lua/src/lstring.c
@@ -0,0 +1,185 @@
+/*
+** $Id: lstring.c,v 2.26 2013/01/08 13:50:10 roberto Exp $
+** String table (keeps all strings handled by Lua)
+** See Copyright Notice in lua.h
+*/
+
+
+#include <string.h>
+
+#define lstring_c
+#define LUA_CORE
+
+#include "lua.h"
+
+#include "lmem.h"
+#include "lobject.h"
+#include "lstate.h"
+#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) {
+ 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;
+ }
+ /* 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 */
+ 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 *);
+ }
+ tb->size = newsize;
+}
+
+
+/*
+** creates a new string object
+*/
+static TString *createstrobj (lua_State *L, const char *str, size_t l,
+ int tag, unsigned int h, GCObject **list) {
+ 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;
+ ts->tsv.len = l;
+ ts->tsv.hash = h;
+ ts->tsv.extra = 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->nuse++;
+ return s;
+}
+
+
+/*
+** 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) {
+ 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)];
+ o != NULL;
+ o = gch(o)->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 */
+ 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));
+}
+
+
+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->uv.len = s;
+ u->uv.metatable = NULL;
+ u->uv.env = e;
+ return u;
+}
+
« no previous file with comments | « third_party/lua/src/lstring.h ('k') | third_party/lua/src/lstrlib.c » ('j') | no next file with comments »

Powered by Google App Engine
This is Rietveld 408576698