/*******************************************************************************
* Copyright (c) 2008 LuaJ. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
******************************************************************************/
package org.luaj.vm2.script;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;
import java.util.Iterator;
import javax.script.Bindings;
import javax.script.Compilable;
import javax.script.CompiledScript;
import javax.script.ScriptContext;
import javax.script.ScriptEngine;
import javax.script.ScriptEngineFactory;
import javax.script.ScriptException;
import javax.script.SimpleBindings;
import javax.script.SimpleScriptContext;
import org.luaj.vm2.LoadState;
import org.luaj.vm2.Lua;
import org.luaj.vm2.LuaClosure;
import org.luaj.vm2.LuaError;
import org.luaj.vm2.LuaFunction;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Prototype;
import org.luaj.vm2.Varargs;
import org.luaj.vm2.lib.jse.CoerceJavaToLua;
import org.luaj.vm2.lib.jse.JsePlatform;
/**
*
* @author jim_roseborough
*/
public class LuaScriptEngine implements ScriptEngine, Compilable {
private static final String __ENGINE_VERSION__ = Lua._VERSION;
private static final String __NAME__ = "Luaj";
private static final String __SHORT_NAME__ = "Luaj";
private static final String __LANGUAGE__ = "lua";
private static final String __LANGUAGE_VERSION__ = "5.1";
private static final String __ARGV__ = "arg";
private static final String __FILENAME__ = "?";
private static final ScriptEngineFactory myFactory = new LuaScriptEngineFactory();
private ScriptContext defaultContext;
private final LuaValue _G;
public LuaScriptEngine() {
// create globals
_G = JsePlatform.standardGlobals();
// set up context
ScriptContext ctx = new SimpleScriptContext();
ctx.setBindings(createBindings(), ScriptContext.ENGINE_SCOPE);
setContext(ctx);
// set special values
put(LANGUAGE_VERSION, __LANGUAGE_VERSION__);
put(LANGUAGE, __LANGUAGE__);
put(ENGINE, __NAME__);
put(ENGINE_VERSION, __ENGINE_VERSION__);
put(ARGV, __ARGV__);
put(FILENAME, __FILENAME__);
put(NAME, __SHORT_NAME__);
put("THREADING", null);
}
public Object eval(String script) throws ScriptException {
return eval(new StringReader(script));
}
public Object eval(String script, ScriptContext context) throws ScriptException {
return eval(new StringReader(script), context);
}
public Object eval(String script, Bindings bindings) throws ScriptException {
return eval(new StringReader(script), bindings);
}
public Object eval(Reader reader) throws ScriptException {
return eval(reader, getContext());
}
public Object eval(Reader reader, ScriptContext scriptContext) throws ScriptException {
return compile(reader).eval(scriptContext);
}
public Object eval(Reader reader, Bindings bindings) throws ScriptException {
ScriptContext c = getContext();
Bindings current = c.getBindings(ScriptContext.ENGINE_SCOPE);
c.setBindings(bindings, ScriptContext.ENGINE_SCOPE);
Object result = eval(reader);
c.setBindings(current, ScriptContext.ENGINE_SCOPE);
return result;
}
public void put(String key, Object value) {
Bindings b = getBindings(ScriptContext.ENGINE_SCOPE);
b.put(key, value);
}
public Object get(String key) {
Bindings b = getBindings(ScriptContext.ENGINE_SCOPE);
return b.get(key);
}
public Bindings getBindings(int scope) {
return getContext().getBindings(scope);
}
public void setBindings(Bindings bindings, int scope) {
getContext().setBindings(bindings, scope);
}
public Bindings createBindings() {
return new SimpleBindings();
}
public ScriptContext getContext() {
return defaultContext;
}
public void setContext(ScriptContext context) {
defaultContext = context;
}
public ScriptEngineFactory getFactory() {
return myFactory;
}
public CompiledScript compile(String script) throws ScriptException {
return compile(new StringReader(script));
}
public CompiledScript compile(Reader reader) throws ScriptException {
try {
InputStream ris = new Utf8Encoder(reader);
try {
final LuaFunction f = LoadState.load(ris, "script", null);
if ( f.isclosure() ) {
// most compiled functions are closures with prototypes
final Prototype p = f.checkclosure().p;
return new CompiledScriptImpl() {
protected LuaFunction newFunctionInstance() {
return new LuaClosure( p, null );
}
};
} else {
// when luajc is used, functions are java class instances
final Class c = f.getClass();
return new CompiledScriptImpl() {
protected LuaFunction newFunctionInstance() throws ScriptException {
try {
return (LuaFunction) c.newInstance();
} catch (Exception e) {
throw new ScriptException("instantiation failed: "+e.toString());
}
}
};
}
} catch ( LuaError lee ) {
throw new ScriptException(lee.getMessage() );
} finally {
ris.close();
}
} catch ( Throwable t ) {
throw new ScriptException("eval threw "+t.toString());
}
}
abstract protected class CompiledScriptImpl extends CompiledScript {
abstract protected LuaFunction newFunctionInstance() throws ScriptException;
public ScriptEngine getEngine() {
return LuaScriptEngine.this;
}
public Object eval(ScriptContext context) throws ScriptException {
Bindings b = context.getBindings(ScriptContext.ENGINE_SCOPE);
LuaFunction f = newFunctionInstance();
ClientBindings cb = new ClientBindings(b);
f.setfenv(cb.env);
Varargs result = f.invoke(LuaValue.NONE);
cb.copyGlobalsToBindings();
return result;
}
}
public class ClientBindings {
public final Bindings b;
public final LuaTable env;
public ClientBindings( Bindings b ) {
this.b = b;
this.env = new LuaTable();
env.setmetatable(LuaTable.tableOf(new LuaValue[] { LuaValue.INDEX, _G }));
this.copyBindingsToGlobals();
}
public void copyBindingsToGlobals() {
for ( Iterator i = b.keySet().iterator(); i.hasNext(); ) {
String key = (String) i.next();
Object val = b.get(key);
LuaValue luakey = toLua(key);
LuaValue luaval = toLua(val);
env.set(luakey, luaval);
i.remove();
}
}
private LuaValue toLua(Object javaValue) {
return javaValue == null? LuaValue.NIL:
javaValue instanceof LuaValue? (LuaValue) javaValue:
CoerceJavaToLua.coerce(javaValue);
}
public void copyGlobalsToBindings() {
LuaValue[] keys = env.keys();
for ( int i=0; i<keys.length; i++ ) {
LuaValue luakey = keys[i];
LuaValue luaval = env.get(luakey);
String key = luakey.tojstring();
Object val = toJava( luaval );
b.put(key,val);
}
}
private Object toJava(LuaValue v) {
switch ( v.type() ) {
case LuaValue.TNIL: return null;
case LuaValue.TSTRING: return v.tojstring();
case LuaValue.TUSERDATA: return v.checkuserdata(Object.class);
case LuaValue.TNUMBER: return v.isinttype()? (Object) new Integer(v.toint()): (Object) new Double(v.todouble());
default: return v;
}
}
}
// ------ convert char stream to byte stream for lua compiler -----
private final class Utf8Encoder extends InputStream {
private final Reader r;
private final int[] buf = new int[2];
private int n;
private Utf8Encoder(Reader r) {
this.r = r;
}
public int read() throws IOException {
if ( n > 0 )
return buf[--n];
int c = r.read();
if ( c < 0x80 )
return c;
n = 0;
if ( c < 0x800 ) {
buf[n++] = (0x80 | ( c & 0x3f));
return (0xC0 | ((c>>6) & 0x1f));
} else {
buf[n++] = (0x80 | ( c & 0x3f));
buf[n++] = (0x80 | ((c>>6) & 0x3f));
return (0xE0 | ((c>>12) & 0x0f));
}
}
}
}