Cache string hashes in TString

1 files changed, 18 insertions, 8 deletions

diff --git a/src/lstring.js b/src/lstring.js
index 3e94171..cc399b8 100644
--- a/src/lstring.js
+++ b/src/lstring.js
@@ -7,6 +7,7 @@ const defs = require('./defs.js');
 class TString {
 
     constructor(L, str) {
+        this.hash = null;
         this.realstring = str;
     }
 
@@ -28,8 +29,16 @@ const luaS_eqlngstr = function(a, b) {
 
 /* converts strings (arrays) to a consistent map key */
 const luaS_hash = function(str) {
-    assert(str instanceof TString);
-    return str.realstring.map(e => `${e}|`).join('');
+    assert(Array.isArray(str));
+    return str.map(e => `${e}|`).join('');
+};
+
+const luaS_hashlongstr = function(ts) {
+    assert(ts instanceof TString);
+    if(ts.hash === null) {
+        ts.hash = luaS_hash(ts.getstr());
+    }
+    return ts.hash;
 };
 
 /* variant that takes ownership of array */
@@ -48,9 +57,10 @@ const luaS_newliteral = function(L, str) {
     return luaS_bless(L, defs.to_luastring(str));
 };
 
-module.exports.luaS_eqlngstr   = luaS_eqlngstr;
-module.exports.luaS_hash       = luaS_hash;
-module.exports.luaS_bless      = luaS_bless;
-module.exports.luaS_new        = luaS_new;
-module.exports.luaS_newliteral = luaS_newliteral;
-module.exports.TString         = TString;
+module.exports.luaS_eqlngstr    = luaS_eqlngstr;
+module.exports.luaS_hash        = luaS_hash;
+module.exports.luaS_hashlongstr = luaS_hashlongstr;
+module.exports.luaS_bless       = luaS_bless;
+module.exports.luaS_new         = luaS_new;
+module.exports.luaS_newliteral  = luaS_newliteral;
+module.exports.TString          = TString;