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/*******************************************************************************
* Copyright (c) 2010-2011 Luaj.org. 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
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* 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
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package org.luaj.vm2.lib;
import java.io.InputStream;
import java.io.PrintStream;
import org.luaj.vm2.LuaFunction;
import org.luaj.vm2.LuaString;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaThread;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
/**
* Subclass of {@link LibFunction} which implements the lua standard package and module
* library functions.
*
*
* Typically, this library is included as part of a call to either
* {@link JsePlatform#standardGlobals()} or {@link JmePlatform#standardGlobals()}
*
* To instantiate and use it directly,
* link it into your globals table via {@link LuaValue#load(LuaValue)} using code such as:
*
{@code
* LuaTable _G = new LuaTable();
* LuaThread.setGlobals(_G);
* _G.load(new BaseLib());
* _G.load(new PackageLib());
* System.out.println( _G.get("require").call(LuaValue.valueOf("hyperbolic")) );
* }
* In practice, the first 4 lines of the above are minimal requirements to get
* and initialize a globals table capable of basic reqire, print, and other functions,
* so it is much more convenient to use the {@link JsePlatform} and {@link JmePlatform}
* utility classes instead.
*
* This has been implemented to match as closely as possible the behavior in the corresponding library in C.
* However, the default filesystem search semantics are different and delegated to the bas library
* as outlined in the {@link BaseLib} and {@link JseBaseLib} documetnation.
* @see LibFunction
* @see BaseLib
* @see JseBaseLib
* @see JsePlatform
* @see JmePlatform
* @see http://www.lua.org/manual/5.1/manual.html#5.3
*/
public class PackageLib extends OneArgFunction {
public static String DEFAULT_LUA_PATH = "?.lua";
public InputStream STDIN = null;
public PrintStream STDOUT = System.out;
public LuaTable LOADED;
public LuaTable PACKAGE;
/** Most recent instance of PackageLib */
public static PackageLib instance;
/** Loader that loads from preload table if found there */
public LuaValue preload_loader;
/** Loader that loads as a lua script using the LUA_PATH */
public LuaValue lua_loader;
/** Loader that loads as a Java class. Class must have public constructor and be a LuaValue */
public LuaValue java_loader;
private static final LuaString _M = valueOf("_M");
private static final LuaString _NAME = valueOf("_NAME");
private static final LuaString _PACKAGE = valueOf("_PACKAGE");
private static final LuaString _DOT = valueOf(".");
private static final LuaString _LOADERS = valueOf("loaders");
private static final LuaString _LOADED = valueOf("loaded");
private static final LuaString _LOADLIB = valueOf("loadlib");
private static final LuaString _PRELOAD = valueOf("preload");
private static final LuaString _PATH = valueOf("path");
private static final LuaString _SEEALL = valueOf("seeall");
private static final LuaString _SENTINEL = valueOf("\u0001");
private static final int OP_MODULE = 0;
private static final int OP_REQUIRE = 1;
private static final int OP_LOADLIB = 2;
private static final int OP_SEEALL = 3;
private static final int OP_PRELOAD_LOADER = 4;
private static final int OP_LUA_LOADER = 5;
private static final int OP_JAVA_LOADER = 6;
public PackageLib() {
instance = this;
}
public LuaValue call(LuaValue arg) {
env.set("require", new PkgLib1(env,"require",OP_REQUIRE,this));
env.set("module", new PkgLibV(env,"module",OP_MODULE,this));
env.set( "package", PACKAGE=tableOf( new LuaValue[] {
_LOADED, LOADED=tableOf(),
_PRELOAD, tableOf(),
_PATH, valueOf(DEFAULT_LUA_PATH),
_LOADLIB, new PkgLibV(env,"loadlib",OP_LOADLIB,this),
_SEEALL, new PkgLib1(env,"seeall",OP_SEEALL,this),
_LOADERS, listOf(new LuaValue[] {
preload_loader = new PkgLibV(env,"preload_loader", OP_PRELOAD_LOADER,this),
lua_loader = new PkgLibV(env,"lua_loader", OP_LUA_LOADER,this),
java_loader = new PkgLibV(env,"java_loader", OP_JAVA_LOADER,this),
}) }) );
LOADED.set("package", PACKAGE);
return env;
}
static final class PkgLib1 extends OneArgFunction {
PackageLib lib;
public PkgLib1(LuaValue env,String name, int opcode, PackageLib lib) {
this.env = env;
this.name = name;
this.opcode = opcode;
this.lib = lib;
}
public LuaValue call(LuaValue arg) {
switch ( opcode ) {
case OP_REQUIRE:
return lib.require(arg);
case OP_SEEALL: {
LuaTable t = arg.checktable();
LuaValue m = t.getmetatable();
if ( m == null )
t.setmetatable(m=tableOf());
m.set( INDEX, LuaThread.getGlobals() );
return NONE;
}
}
return NIL;
}
}
static final class PkgLibV extends VarArgFunction {
PackageLib lib;
public PkgLibV(LuaValue env,String name, int opcode, PackageLib lib) {
this.env = env;
this.name = name;
this.opcode = opcode;
this.lib = lib;
}
public Varargs invoke(Varargs args) {
switch ( opcode ) {
case OP_MODULE:
return lib.module(args);
case OP_LOADLIB:
return loadlib(args);
case OP_PRELOAD_LOADER: {
return lib.loader_preload(args);
}
case OP_LUA_LOADER: {
return lib.loader_Lua(args);
}
case OP_JAVA_LOADER: {
return lib.loader_Java(args);
}
}
return NONE;
}
}
/** Allow packages to mark themselves as loaded */
public void setIsLoaded(String name, LuaTable value) {
LOADED.set(name, value);
}
public void setLuaPath( String newLuaPath ) {
PACKAGE.set( _PATH, valueOf(newLuaPath) );
}
public String tojstring() {
return "package";
}
// ======================== Module, Package loading =============================
/**
* module (name [, ...])
*
* Creates a module. If there is a table in package.loaded[name], this table
* is the module. Otherwise, if there is a global table t with the given
* name, this table is the module. Otherwise creates a new table t and sets
* it as the value of the global name and the value of package.loaded[name].
* This function also initializes t._NAME with the given name, t._M with the
* module (t itself), and t._PACKAGE with the package name (the full module
* name minus last component; see below). Finally, module sets t as the new
* environment of the current function and the new value of
* package.loaded[name], so that require returns t.
*
* If name is a compound name (that is, one with components separated by
* dots), module creates (or reuses, if they already exist) tables for each
* component. For instance, if name is a.b.c, then module stores the module
* table in field c of field b of global a.
*
* This function may receive optional options after the module name, where
* each option is a function to be applied over the module.
*/
public Varargs module(Varargs args) {
LuaString modname = args.checkstring(1);
int n = args.narg();
LuaValue value = LOADED.get(modname);
LuaValue module;
if ( ! value.istable() ) { /* not found? */
/* try global variable (and create one if it does not exist) */
LuaValue globals = LuaThread.getGlobals();
module = findtable( globals, modname );
if ( module == null )
error( "name conflict for module '"+modname+"'" );
LOADED.set(modname, module);
} else {
module = (LuaTable) value;
}
/* check whether table already has a _NAME field */
LuaValue name = module.get(_NAME);
if ( name.isnil() ) {
modinit( module, modname );
}
// set the environment of the current function
LuaFunction f = LuaThread.getCallstackFunction(1);
if ( f == null )
error("no calling function");
if ( ! f.isclosure() )
error("'module' not called from a Lua function");
f.setfenv(module);
// apply the functions
for ( int i=2; i<=n; i++ )
args.arg(i).call( module );
// returns no results
return NONE;
}
/**
*
* @param table the table at which to start the search
* @param fname the name to look up or create, such as "abc.def.ghi"
* @return the table for that name, possible a new one, or null if a non-table has that name already.
*/
private static final LuaValue findtable(LuaValue table, LuaString fname) {
int b, e=(-1);
do {
e = fname.indexOf(_DOT, b=e+1 );
if ( e < 0 )
e = fname.m_length;
LuaString key = fname.substring(b, e);
LuaValue val = table.rawget(key);
if ( val.isnil() ) { /* no such field? */
LuaTable field = new LuaTable(); /* new table for field */
table.set(key, field);
table = field;
} else if ( ! val.istable() ) { /* field has a non-table value? */
return null;
} else {
table = val;
}
} while ( e < fname.m_length );
return table;
}
private static final void modinit(LuaValue module, LuaString modname) {
/* module._M = module */
module.set(_M, module);
int e = modname.lastIndexOf(_DOT);
module.set(_NAME, modname );
module.set(_PACKAGE, (e<0? EMPTYSTRING: modname.substring(0,e+1)) );
}
/**
* require (modname)
*
* Loads the given module. The function starts by looking into the package.loaded table to
* determine whether modname is already loaded. If it is, then require returns the value
* stored at package.loaded[modname]. Otherwise, it tries to find a loader for the module.
*
* To find a loader, require is guided by the package.loaders array. By changing this array,
* we can change how require looks for a module. The following explanation is based on the
* default configuration for package.loaders.
*
* First require queries package.preload[modname]. If it has a value, this value
* (which should be a function) is the loader. Otherwise require searches for a Lua loader
* using the path stored in package.path. If that also fails, it searches for a C loader
* using the path stored in package.cpath. If that also fails, it tries an all-in-one loader
* (see package.loaders).
*
* Once a loader is found, require calls the loader with a single argument, modname.
* If the loader returns any value, require assigns the returned value to package.loaded[modname].
* If the loader returns no value and has not assigned any value to package.loaded[modname],
* then require assigns true to this entry. In any case, require returns the final value of
* package.loaded[modname].
*
* If there is any error loading or running the module, or if it cannot find any loader for
* the module, then require signals an error.
*/
public LuaValue require( LuaValue arg ) {
LuaString name = arg.checkstring();
LuaValue loaded = LOADED.get(name);
if ( loaded.toboolean() ) {
if ( loaded == _SENTINEL )
error("loop or previous error loading module '"+name+"'");
return loaded;
}
/* else must load it; iterate over available loaders */
LuaTable tbl = PACKAGE.get(_LOADERS).checktable();
StringBuffer sb = new StringBuffer();
LuaValue chunk = null;
for ( int i=1; true; i++ ) {
LuaValue loader = tbl.get(i);
if ( loader.isnil() ) {
error( "module '"+name+"' not found: "+name+sb );
}
/* call loader with module name as argument */
chunk = loader.call(name);
if ( chunk.isfunction() )
break;
if ( chunk.isstring() )
sb.append( chunk.tojstring() );
}
// load the module using the loader
LOADED.set(name, _SENTINEL);
LuaValue result = chunk.call(name);
if ( ! result.isnil() )
LOADED.set( name, result );
else if ( (result = LOADED.get(name)) == _SENTINEL )
LOADED.set( name, result = LuaValue.TRUE );
return result;
}
public static Varargs loadlib( Varargs args ) {
args.checkstring(1);
return varargsOf(NIL, valueOf("dynamic libraries not enabled"), valueOf("absent"));
}
LuaValue loader_preload( Varargs args ) {
LuaString name = args.checkstring(1);
LuaValue preload = PACKAGE.get(_PRELOAD).checktable();
LuaValue val = preload.get(name);
return val.isnil()?
valueOf("\n\tno field package.preload['"+name+"']"):
val;
}
LuaValue loader_Lua( Varargs args ) {
String name = args.checkjstring(1);
InputStream is = null;
// get package path
LuaValue pp = PACKAGE.get(_PATH);
if ( ! pp.isstring() )
return valueOf("package.path is not a string");
String path = pp.tojstring();
// check the path elements
int e = -1;
int n = path.length();
StringBuffer sb = null;
name = name.replace('.','/');
while ( e < n ) {
// find next template
int b = e+1;
e = path.indexOf(';',b);
if ( e < 0 )
e = path.length();
String template = path.substring(b,e);
// create filename
int q = template.indexOf('?');
String filename = template;
if ( q >= 0 ) {
filename = template.substring(0,q) + name + template.substring(q+1);
}
// try loading the file
Varargs v = BaseLib.loadFile(filename);
if ( v.arg1().isfunction() )
return v.arg1();
// report error
if ( sb == null )
sb = new StringBuffer();
sb.append( "\n\t'"+filename+"': "+v.arg(2) );
}
return valueOf(sb.toString());
}
LuaValue loader_Java( Varargs args ) {
String name = args.checkjstring(1);
String classname = toClassname( name );
Class c = null;
LuaValue v = null;
try {
c = Class.forName(classname);
v = (LuaValue) c.newInstance();
v.setfenv(env);
return v;
} catch ( ClassNotFoundException cnfe ) {
return valueOf("\n\tno class '"+classname+"'" );
} catch ( Exception e ) {
return valueOf("\n\tjava load failed on '"+classname+"', "+e );
}
}
/** Convert lua filename to valid class name */
public static final String toClassname( String filename ) {
int n=filename.length();
int j=n;
if ( filename.endsWith(".lua") )
j -= 4;
for ( int k=0; k='a'&&c<='z') || (c>='A'&&c<='Z') || (c>='0'&&c<='9') )
return true;
switch ( c ) {
case '.':
case '$':
case '_':
return true;
default:
return false;
}
}
}