Use Uint8Array to back strings

15 files changed, 88 insertions, 72 deletions

diff --git a/src/defs.js b/src/defs.js
index 27498c6..381114b 100644
--- a/src/defs.js
+++ b/src/defs.js
@@ -131,10 +131,10 @@ class lua_Debug {
 
 }
 
-const string_of = Array.of;
+const string_of = Uint8Array.of.bind(Uint8Array);
 
 const is_luastring = function(s) {
-    return Array.isArray(s);
+    return s instanceof Uint8Array;
 };
 
 /* test two lua strings for equality */
@@ -143,7 +143,7 @@ const luastring_cmp = function(a, b) {
 };
 
 const to_jsstring = function(value, from, to) {
-    assert(is_luastring(value), "jsstring expects an array of bytes");
+    assert(is_luastring(value), "jsstring expects a Uint8Array");
 
     if (to === void 0) {
         to = value.length;
@@ -240,6 +240,7 @@ const to_luastring = function(str, cache) {
             outU8Array[outIdx++] = 0x80 | (u & 63);
         }
     }
+    outU8Array = Uint8Array.from(outU8Array);
 
     if (cache) to_luastring_cache[str] = outU8Array;
 
diff --git a/src/lauxlib.js b/src/lauxlib.js
index b9b7078..6acf57f 100644
--- a/src/lauxlib.js
+++ b/src/lauxlib.js
@@ -381,14 +381,14 @@ const luaL_prepbuffer = function(B) {
 };
 
 const luaL_addlstring = function(B, s, l) {
-    B.b = B.b.concat(s.slice(0, l));
+    B.b = B.b.concat(Array.from(s.subarray(0, l)));
 };
 
 const luaL_addstring = luaL_addlstring;
 
 const luaL_pushresult = function(B) {
     let L = B.L;
-    lua.lua_pushstring(L, B.b);
+    lua.lua_pushstring(L, Uint8Array.from(B.b));
 };
 
 const luaL_addchar = function(B, c) {
@@ -558,7 +558,7 @@ const luaL_gsub = function(L, s, p, r) {
         s = s.slice(wild + p.length);  /* continue after 'p' */
     }
     b.push(...s);  /* push last suffix */
-    lua.lua_pushstring(L, b);
+    lua.lua_pushstring(L, Uint8Array.from(b));
     return lua.lua_tostring(L, -1);
 };
 
diff --git a/src/lbaselib.js b/src/lbaselib.js
index 30e77fb..103a9ca 100644
--- a/src/lbaselib.js
+++ b/src/lbaselib.js
@@ -8,7 +8,7 @@ let lua_writeline;
 if (typeof process === "undefined") {
     let buff = [];
     lua_writestring = function(s) {
-        buff = buff.concat(s);
+        buff = buff.concat(Array.from(s));
     };
     lua_writeline = function() {
         console.log(new TextDecoder("utf-8").decode(Uint8Array.from(buff)));
diff --git a/src/ldblib.js b/src/ldblib.js
index 746d3bf..df7d2ff 100644
--- a/src/ldblib.js
+++ b/src/ldblib.js
@@ -306,7 +306,7 @@ const unmakemask = function(mask, smask) {
     if (mask & lua.LUA_MASKCALL) smask[i++] = "c".charCodeAt(0);
     if (mask & lua.LUA_MASKRET) smask[i++] = "r".charCodeAt(0);
     if (mask & lua.LUA_MASKLINE) smask[i++] = "l".charCodeAt(0);
-    return smask;
+    return smask.subarray(0, i);
 };
 
 const db_sethook = function(L) {
@@ -344,7 +344,7 @@ const db_sethook = function(L) {
 const db_gethook = function(L) {
     let thread = getthread(L);
     let L1 = thread.thread;
-    let buff = [];
+    let buff = new Uint8Array(5);
     let mask = lua.lua_gethookmask(L1);
     let hook = lua.lua_gethook(L1);
     if (hook === null)  /* no hook? */
diff --git a/src/ldump.js b/src/ldump.js
index 964d6ff..7e62da3 100644
--- a/src/ldump.js
+++ b/src/ldump.js
@@ -34,31 +34,26 @@ const DumpByte = function(y, D) {
 };
 
 const DumpInt = function(x, D) {
-    let dv = new DataView(new ArrayBuffer(4));
+    let ab = new ArrayBuffer(4);
+    let dv = new DataView(ab);
     dv.setInt32(0, x, true);
-    let t = [];
-    for (let i = 0; i < 4; i++)
-        t.push(dv.getUint8(i, true));
-
+    let t = new Uint8Array(ab);
     DumpBlock(t, 4, D);
 };
 
 const DumpInteger = function(x, D) {
-    let dv = new DataView(new ArrayBuffer(4));
+    let ab = new ArrayBuffer(4);
+    let dv = new DataView(ab);
     dv.setInt32(0, x, true);
-    let t = [];
-    for (let i = 0; i < 4; i++)
-        t.push(dv.getUint8(i, true));
+    let t = new Uint8Array(ab);
     DumpBlock(t, 4, D);
 };
 
 const DumpNumber = function(x, D) {
-    let dv = new DataView(new ArrayBuffer(8));
+    let ab = new ArrayBuffer(8);
+    let dv = new DataView(ab);
     dv.setFloat64(0, x, true);
-    let t = [];
-    for (let i = 0; i < 8; i++)
-        t.push(dv.getUint8(i, true));
-
+    let t = new Uint8Array(ab);
     DumpBlock(t, 8, D);
 };
 
diff --git a/src/llex.js b/src/llex.js
index 779557a..9e4bed4 100644
--- a/src/llex.js
+++ b/src/llex.js
@@ -112,6 +112,8 @@ const save = function(ls, c) {
     if (b.n + 1 > b.buffer.length) {
         if (b.buffer.length >= llimits.MAX_INT/2)
             lexerror(ls, defs.to_luastring("lexical element too long", true), 0);
+        let newsize = b.buffer.length*2;
+        lzio.luaZ_resizebuffer(ls.L, b, newsize);
     }
     b.buffer[b.n++] = c < 0 ? 255 + c + 1 : c;
 };
@@ -192,6 +194,7 @@ const luaX_setinput = function(L, ls, z, source, firstchar) {
     ls.lastline = 1;
     ls.source = source;
     ls.envn = lstring.luaS_bless(L, LUA_ENV);
+    lzio.luaZ_resizebuffer(L, ls.buff, llimits.LUA_MINBUFFER);  /* initialize buffer */
 };
 
 const check_next1 = function(ls, c) {
@@ -369,7 +372,7 @@ const readutf8desc = function(ls) {
 };
 
 const utf8esc = function(ls) {
-    let buff = new Array(lobject.UTF8BUFFSZ);
+    let buff = new Uint8Array(lobject.UTF8BUFFSZ);
     let n = lobject.luaO_utf8esc(buff, readutf8desc(ls));
     for (; n > 0; n--)  /* add 'buff' to string */
         save(ls, buff[lobject.UTF8BUFFSZ - n]);
diff --git a/src/llimits.js b/src/llimits.js
index 21a09a0..4a76bbe 100644
--- a/src/llimits.js
+++ b/src/llimits.js
@@ -3,6 +3,10 @@
 const LUAI_MAXCCALLS = 200;
 module.exports.LUAI_MAXCCALLS = LUAI_MAXCCALLS;
 
+/* minimum size for string buffer */
+const LUA_MINBUFFER = 32;
+module.exports.LUA_MINBUFFER = LUA_MINBUFFER;
+
 const luai_nummod = function(L, a, b) {
     let m = a % b;
     if ((m*b) < 0)
diff --git a/src/lobject.js b/src/lobject.js
index 707cdf8..18adb27 100644
--- a/src/lobject.js
+++ b/src/lobject.js
@@ -312,19 +312,20 @@ const luaO_chunkid = function(source, bufflen) {
             out = source.slice(1);
         else {  /* add '...' before rest of name */
             bufflen -= RETS.length;
-            out = RETS.concat(source.slice(1 + l - bufflen));
+            out = Uint8Array.from(Array.from(RETS).concat(Array.from(source.subarray(1 + l - bufflen))));
         }
     } else {  /* string; format as [string "source"] */
         let nli = source.indexOf(char['\n']);  /* find first new line (if any) */
-        out = PRE;  /* add prefix */
+        out = Array.from(PRE);  /* add prefix */
         bufflen -= PRE.length + RETS.length + POS.length + 1;  /* save space for prefix+suffix+'\0' */
         if (l < bufflen && nli === -1) {  /* small one-line source? */
-            out = out.concat(source, POS);  /* keep it */
+            out = out.concat(Array.from(source), Array.from(POS));  /* keep it */
         } else {
             if (nli !== -1) l = nli;  /* stop at first newline */
             if (l > bufflen) l = bufflen;
-            out = out.concat(source.slice(0, l), RETS, POS);
+            out = out.concat(Array.from(source.subarray(0, l)), Array.from(RETS), Array.from(POS));
         }
+        out = Uint8Array.from(out);
     }
     return out;
 };
diff --git a/src/loslib.js b/src/loslib.js
index 19dfd02..f27a7ed 100644
--- a/src/loslib.js
+++ b/src/loslib.js
@@ -73,7 +73,7 @@ const checkoption = function(L, conv, i, buff) {
         if (option[o] === '|'.charCodeAt(0))  /* next block? */
             oplen++;  /* will check options with next length (+1) */
         else if (array_cmp(conv, i, option, o, oplen)) {  /* match? */
-            buff.push(...conv.slice(i, i+oplen)); /* copy valid option to buffer */
+            buff.set(conv.slice(i, i+oplen)); /* copy valid option to buffer */
             return i + oplen;  /* return next item */
         }
     }
@@ -102,6 +102,8 @@ const os_date = function(L) {
         lua.lua_createtable(L, 0, 9);  /* 9 = number of fields */
         setallfields(L, stm, utc);
     } else {
+        let cc = new Uint8Array(4);
+        cc[0] = "%".charCodeAt(0);
         let b = new lauxlib.luaL_Buffer();
         lauxlib.luaL_buffinit(L, b);
         while (i < s.length) {
@@ -109,8 +111,10 @@ const os_date = function(L) {
                 lauxlib.luaL_addchar(b, s[i++]);
             } else {
                 i++;  /* skip '%' */
-                let cc = ["%".charCodeAt(0)];
-                i = checkoption(L, s, i, cc);  /* copy specifier to 'cc' */
+                i = checkoption(L, s, i, cc.subarray(1));  /* copy specifier to 'cc' */
+                let len = cc.indexOf(0);
+                if (len !== -1)
+                    cc = cc.subarray(0, len);
                 let buff = strftime(lua.to_jsstring(cc), stm);
                 lauxlib.luaL_addstring(b, lua.to_luastring(buff));
             }
diff --git a/src/lstring.js b/src/lstring.js
index c85e5b2..c8da56a 100644
--- a/src/lstring.js
+++ b/src/lstring.js
@@ -31,7 +31,7 @@ const luaS_eqlngstr = function(a, b) {
    make sure this doesn't conflict with any of the anti-collision strategies in ltable */
 const luaS_hash = function(str) {
     assert(defs.is_luastring(str));
-    return str.map(e => `${e}|`).join('');
+    return '|'+str.join('|');
 };
 
 const luaS_hashlongstr = function(ts) {
@@ -44,12 +44,13 @@ const luaS_hashlongstr = function(ts) {
 
 /* variant that takes ownership of array */
 const luaS_bless = function(L, str) {
+    assert(str instanceof Uint8Array);
     return new TString(L, str);
 };
 
 /* makes a copy */
 const luaS_new = function(L, str) {
-    return luaS_bless(L, str.slice(0));
+    return luaS_bless(L, Uint8Array.from(str));
 };
 
 /* takes a js string */
diff --git a/src/lundump.js b/src/lundump.js
index ff87903..7461813 100644
--- a/src/lundump.js
+++ b/src/lundump.js
@@ -46,7 +46,7 @@ class BytecodeParser {
         let u8 = new Uint8Array(size);
         if(lzio.luaZ_read(this.Z, u8, 0, size) !== 0)
             this.error("truncated");
-        return Array.from(u8);
+        return u8;
     }
 
     readByte() {
diff --git a/src/lutf8lib.js b/src/lutf8lib.js
index 3baeeef..f581a9e 100644
--- a/src/lutf8lib.js
+++ b/src/lutf8lib.js
@@ -216,7 +216,7 @@ const funcs = {
 };
 
 /* pattern to match a single UTF-8 character */
-const UTF8PATT = [ 91, 0, 45, 127, 194, 45, 244, 93, 91, 128, 45, 191, 93, 42 ];
+const UTF8PATT = Uint8Array.of(91, 0, 45, 127, 194, 45, 244, 93, 91, 128, 45, 191, 93, 42);
 
 const luaopen_utf8 = function(L) {
     lauxlib.luaL_newlib(L, funcs);
diff --git a/src/lvm.js b/src/lvm.js
index 3cdccb9..9d97c17 100644
--- a/src/lvm.js
+++ b/src/lvm.js
@@ -937,6 +937,18 @@ const isemptystr = function(o) {
     return o.ttisstring() && o.vslen() === 0;
 };
 
+/* copy strings in stack from top - n up to top - 1 to buffer */
+const copy2buff = function(L, top, n, buff) {
+    let tl = 0;  /* size already copied */
+    do {
+        let tv = L.stack[top-n];
+        let l = tv.vslen();  /* length of string being copied */
+        let s = tv.svalue();
+        buff.set(s, tl);
+        tl += l;
+    } while (--n > 0);
+};
+
 /*
 ** Main operation for concatenation: concat 'total' values in the stack,
 ** from 'L->top - total' up to 'L->top - 1'.
@@ -955,16 +967,15 @@ const luaV_concat = function(L, total) {
             lobject.setobjs2s(L, top - 2, top - 1);
         } else {
             /* at least two non-empty string values; get as many as possible */
-            let toconcat = new Array(total);
-            toconcat[total-1] = L.stack[top-1].svalue();
-            for (n = 1; n < total; n++) {
-                if (!tostring(L, top - n - 1)) {
-                    toconcat = toconcat.slice(total-n);
-                    break;
-                }
-                toconcat[total-n-1] = L.stack[top - n - 1].svalue();
+            let tl = L.stack[top-1].vslen();
+            /* collect total length and number of strings */
+            for (n = 1; n < total && tostring(L, top - n - 1); n++) {
+                let l = L.stack[top - n - 1].vslen();
+                tl += l;
             }
-            let ts = lstring.luaS_bless(L, Array.prototype.concat.apply([], toconcat));
+            let buff = new Uint8Array(tl);
+            copy2buff(L, top, n, buff);
+            let ts = lstring.luaS_bless(L, buff);
             lobject.setsvalue2s(L, top - n, ts);
         }
         total -= n - 1; /* got 'n' strings to create 1 new */
diff --git a/src/lzio.js b/src/lzio.js
index 3d877aa..efd7909 100644
--- a/src/lzio.js
+++ b/src/lzio.js
@@ -11,7 +11,7 @@ class MBuffer {
 }
 
 const luaZ_buffer = function(buff) {
-    return buff.buffer;
+    return buff.buffer.subarray(0, buff.n);
 };
 
 const luaZ_buffremove = function(buff, i) {
@@ -20,7 +20,13 @@ const luaZ_buffremove = function(buff, i) {
 
 const luaZ_resetbuffer = function(buff) {
     buff.n = 0;
-    buff.buffer = [];
+};
+
+const luaZ_resizebuffer = function(L, buff, size) {
+    let newbuff = new Uint8Array(size);
+    if (buff.buffer)
+        newbuff.set(buff.buffer);
+    buff.buffer = newbuff;
 };
 
 class ZIO {
@@ -51,7 +57,7 @@ const luaZ_fill = function(z) {
         z.off = 0;
         size = buff.byteLength - buff.byteOffset;
     } else {
-        assert(typeof buff !== "string", "Should only load binary of array of bytes");
+        assert(buff instanceof Uint8Array, "Should only load binary of array of bytes");
         z.buffer = buff;
         z.off = 0;
         size = buff.length;
@@ -87,11 +93,12 @@ const luaZ_read = function(z, b, b_offset, n) {
     return 0;
 };
 
-module.exports.EOZ              = EOZ;
-module.exports.luaZ_buffer      = luaZ_buffer;
-module.exports.luaZ_buffremove  = luaZ_buffremove;
-module.exports.luaZ_fill        = luaZ_fill;
-module.exports.luaZ_read        = luaZ_read;
-module.exports.luaZ_resetbuffer = luaZ_resetbuffer;
-module.exports.MBuffer          = MBuffer;
-module.exports.ZIO              = ZIO;
+module.exports.EOZ               = EOZ;
+module.exports.luaZ_buffer       = luaZ_buffer;
+module.exports.luaZ_buffremove   = luaZ_buffremove;
+module.exports.luaZ_fill         = luaZ_fill;
+module.exports.luaZ_read         = luaZ_read;
+module.exports.luaZ_resetbuffer  = luaZ_resetbuffer;
+module.exports.luaZ_resizebuffer = luaZ_resizebuffer;
+module.exports.MBuffer           = MBuffer;
+module.exports.ZIO               = ZIO;
diff --git a/tests/test-suite/ltests.js b/tests/test-suite/ltests.js
index 8d89102..08bb603 100644
--- a/tests/test-suite/ltests.js
+++ b/tests/test-suite/ltests.js
@@ -60,8 +60,7 @@ const getstring = function(L, buff, pc) {
         while (pc.script[pc.offset] !== 0 && pc.offset < pc.script.length && delimits.indexOf(pc.script[pc.offset]) < 0)
             buff[i++] = pc.script[pc.offset++];
     }
-    buff.length = i;
-    return buff;
+    return buff.subarray(0, i);
 };
 
 const getindex = function(L, L1, pc) {
@@ -100,7 +99,7 @@ const printstack = function(L) {
 const ops = "+-*%^/\\&|~<>_!".split('').map(e => e.charCodeAt(0));
 
 const runJS = function(L, L1, pc) {
-    let buff = [];
+    let buff = new Uint8Array(300);
     let status = 0;
     if (!pc || !pc.script) return lauxlib.luaL_error(L, lua.to_luastring("attempt to runJS null script"));
     for (;;) {
@@ -527,25 +526,15 @@ const udataval = function(L) {
 
 const d2s = function(L) {
     let d = lauxlib.luaL_checknumber(L, 1);
-
-    let dv = new DataView(new ArrayBuffer(8));
-    dv.setFloat64(0, d, true);
-
-    let b = [];
-    for (let i = 0; i < 8; i++)
-        b.push(dv.getUint8(i, true));
-
-    lua.lua_pushlstring(L, b, 8);
+    let b = new ArrayBuffer(8);
+    new DataView(b).setFloat64(0, d, true);
+    lua.lua_pushlstring(L, new Uint8Array(b), 8);
     return 1;
 };
 
 const s2d = function(L) {
     let b = lauxlib.luaL_checkstring(L, 1);
-
-    let dv = new DataView(new ArrayBuffer(8));
-    for (let i = 0; i < b.length; i++)
-        dv.setUint8(i, b[i], true);
-
+    let dv = new DataView(b.buffer);
     lua.lua_pushnumber(L, dv.getFloat64(0, true));
     return 1;
 };