/*******************************************************************************
* Copyright (c) 2010-2011 Luaj.org. All rights reserved.
* <p/>
* 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:
* <p/>
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* <p/>
* 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.lib;
//TODO 与3.0不一样
import com.taobao.luaview.util.LogUtil;
import org.luaj.vm2.Globals;
import org.luaj.vm2.LuaFunction;
import org.luaj.vm2.LuaString;
import org.luaj.vm2.LuaTable;
import org.luaj.vm2.LuaValue;
import org.luaj.vm2.Varargs;
import java.io.InputStream;
/**
* Subclass of {@link LibFunction} which implements the lua standard package and module
* library functions.
* <p/>
* <h3>Lua Environment Variables</h3>
* The following variables are available to lua scrips when this library has been loaded:
* <ul>
* <li><code>"package.loaded"</code> Lua table of loaded modules.
* <li><code>"package.path"</code> Search path for lua scripts.
* <li><code>"package.preload"</code> Lua table of uninitialized preload functions.
* <li><code>"package.searchers"</code> Lua table of functions that search for object to load.
* </ul>
* <p/>
* <h3>Java Environment Variables</h3>
* These Java environment variables affect the library behavior:
* <ul>
* <li><code>"luaj.package.path"</code> Initial value for <code>"package.path"</code>. Default value is <code>"?.lua"</code>
* </ul>
* <p/>
* <h3>Loading</h3>
* Typically, this library is included as part of a call to either
* {@link JsePlatform#standardGlobals()} or {@link JmePlatform#standardGlobals()}
* <pre> {@code
* Globals globals = JsePlatform.standardGlobals();
* System.out.println( globals.get("require").call"foo") );
* } </pre>
* <p/>
* To instantiate and use it directly,
* link it into your globals table via {@link LuaValue#load(LuaValue)} using code such as:
* <pre> {@code
* Globals globals = new Globals();
* globals.load(new JseBaseLib());
* globals.load(new PackageLib());
* System.out.println( globals.get("require").call("foo") );
* } </pre>
* <h3>Limitations</h3>
* This library 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} documentation.
* <p/>
*
* @see LibFunction
* @see BaseLib
* @see JseBaseLib
* @see JsePlatform
* @see JmePlatform
* @see <a href="http://www.lua.org/manual/5.2/manual.html#6.3">Lua 5.2 Package Lib Reference</a>
*/
public class PackageLib extends TwoArgFunction {
/**
* The default value to use for package.path. This can be set with the system property
* <code>"luaj.package.path"</code>, and is <code>"?.lua"</code> by default.
*/
public static String DEFAULT_LUA_PATH;
static {
try {
DEFAULT_LUA_PATH = System.getProperty("luaj.package.path");
} catch (Exception e) {
LogUtil.i(e.toString());
// System.out.println(e.toString());
}
if (DEFAULT_LUA_PATH == null)
DEFAULT_LUA_PATH = "?.lua";
}
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 _SEARCHPATH = valueOf("searchpath");
private static final LuaString _SEARCHERS = valueOf("searchers");
/**
* The globals that were used to load this library.
*/
Globals globals;
/**
* The table for this package.
*/
LuaTable package_;
/**
* Loader that loads from {@link preload} table if found there
*/
public preload_searcher preload_searcher;
/**
* Loader that loads as a lua script using the lua path currently in {@link path}
*/
public lua_searcher lua_searcher;
/**
* Loader that loads as a Java class. Class must have public constructor and be a LuaValue.
*/
public java_searcher java_searcher;
private static final LuaString _SENTINEL = valueOf("\u0001");
private static final String FILE_SEP = System.getProperty("file.separator");
public PackageLib() {
}
public LuaValue call(LuaValue modname, LuaValue env) {
globals = env.checkglobals();
globals.set("require", new require());
package_ = new LuaTable();
package_.set(_LOADED, new LuaTable());
package_.set(_PRELOAD, new LuaTable());
package_.set(_PATH, LuaValue.valueOf(DEFAULT_LUA_PATH));
package_.set(_LOADLIB, new loadlib());
package_.set(_SEARCHPATH, new searchpath());
LuaTable searchers = new LuaTable();
searchers.set(1, preload_searcher = new preload_searcher());
searchers.set(2, lua_searcher = new lua_searcher());
searchers.set(3, java_searcher = new java_searcher());
package_.set(_SEARCHERS, searchers);
package_.get(_LOADED).set("package", package_);
env.set("package", package_);
globals.package_ = this;
return env;
}
/**
* Allow packages to mark themselves as loaded
*/
public void setIsLoaded(String name, LuaTable value) {
package_.get(_LOADED).set(name, value);
}
/**
* Set the lua path used by this library instance to a new value.
* Merely sets the value of {@link path} to be used in subsequent searches.
*/
public void setLuaPath(String newLuaPath) {
package_.set(_PATH, LuaValue.valueOf(newLuaPath));
}
public String tojstring() {
return "package";
}
// ======================== Package loading =============================
/**
* require (modname)
* <p/>
* 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.
* <p/>
* To find a loader, require is guided by the package.searchers sequence.
* By changing this sequence, we can change how require looks for a module.
* The following explanation is based on the default configuration for package.searchers.
* <p/>
* 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 Java loader using
* the classpath, using the public default constructor, and casting the instance to LuaFunction.
* <p/>
* Once a loader is found, require calls the loader with two arguments: modname and an extra value
* dependent on how it got the loader. If the loader came from a file, this extra value is the file name.
* If the loader is a Java instance of LuaFunction, this extra value is the environment.
* If the loader returns any non-nil value, require assigns the returned value to package.loaded[modname].
* If the loader does not return a non-nil 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].
* <p/>
* If there is any error loading or running the module, or if it cannot find any loader for the module,
* then require raises an error.
*/
public class require extends OneArgFunction {
public LuaValue call(LuaValue arg) {
LuaString name = arg.checkstring();
LuaValue loaded = package_.get(_LOADED);
LuaValue result = loaded.get(name);
if (result.toboolean()) {
if (result == _SENTINEL)
error("loop or previous error loading module '" + name + "'");
return result;
}/* else if (globals != null && (result = globals.lazyLoad(name.checkjstring())) != null){//TODO add by song, 如果是加载自定义的内容则使用globals加载
loaded.set(name, _SENTINEL);
return result;
}*/
/* else must load it; iterate over available loaders */
LuaTable tbl = package_.get(_SEARCHERS).checktable();
StringBuffer sb = new StringBuffer();
Varargs loader = null;
for (int i = 1; true; i++) {
LuaValue searcher = tbl.get(i);
if (searcher.isnil()) {
error("module '" + name + "' not found: " + name + sb);
}
/* call loader with module name as argument */
loader = searcher.invoke(name);
if (loader.isfunction(1))
break;
if (loader.isstring(1))
sb.append(loader.tojstring(1));
}
// load the module using the loader
loaded.set(name, _SENTINEL);
try {
result = loader.arg1().call(name, loader.arg(2));
if (!result.isnil())
loaded.set(name, result);
else if ((result = loaded.get(name)) == _SENTINEL)
loaded.set(name, result = LuaValue.TRUE);
return result;
} catch (Exception e){
LogUtil.e("[PackageLib]", name, "load failed!", e);
return NIL;
}
}
}
public static class loadlib extends VarArgFunction {
public Varargs loadlib(Varargs args) {
args.checkstring(1);
return varargsOf(NIL, valueOf("dynamic libraries not enabled"), valueOf("absent"));
}
}
public class preload_searcher extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaString name = args.checkstring(1);
LuaValue val = package_.get(_PRELOAD).get(name);
return val.isnil() ?
valueOf("\n\tno field package.preload['" + name + "']") :
val;
}
}
public class lua_searcher extends VarArgFunction {
public Varargs invoke(Varargs args) {
LuaString name = args.checkstring(1);
InputStream is = null;
// get package path
LuaValue path = package_.get(_PATH);
if (!path.isstring())
return valueOf("package.path is not a string");
// get the searchpath function.
Varargs v = package_.get(_SEARCHPATH).invoke(varargsOf(name, path));
// Did we get a result?
if (!v.isstring(1))
return v.arg(2).tostring();
LuaString filename = v.arg1().strvalue();
// Try to load the file.
v = globals.loadfile(filename.tojstring());
if (v.arg1().isfunction())
return LuaValue.varargsOf(v.arg1(), filename);
// report error
return varargsOf(NIL, valueOf("'" + filename + "': " + v.arg(2).tojstring()));
}
}
public class searchpath extends VarArgFunction {
public Varargs invoke(Varargs args) {
String name = args.checkjstring(1);
String path = args.checkjstring(2);
String sep = args.optjstring(3, ".");
String rep = args.optjstring(4, FILE_SEP);
// check the path elements
int e = -1;
int n = path.length();
StringBuffer sb = null;
name = name.replace(sep.charAt(0), rep.charAt(0));
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 opening the file
InputStream is = globals.getLuaResourceFinder().findResource(filename);//modify by song
if (is != null) {
try {
is.close();
} catch (java.io.IOException ioe) {
}
return valueOf(filename);
}
// report error
if (sb == null)
sb = new StringBuffer();
sb.append("\n\t" + filename);
}
return varargsOf(NIL, valueOf(sb.toString()));
}
}
public class java_searcher extends VarArgFunction {
public Varargs invoke(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();
if (v.isfunction())
((LuaFunction) v).initupvalue1(globals);
return varargsOf(v, globals);
} 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 < j; k++) {
char c = filename.charAt(k);
if ((!isClassnamePart(c)) || (c == '/') || (c == '\\')) {
StringBuffer sb = new StringBuffer(j);
for (int i = 0; i < j; i++) {
c = filename.charAt(i);
sb.append(
(isClassnamePart(c)) ? c :
((c == '/') || (c == '\\')) ? '.' : '_');
}
return sb.toString();
}
}
return n == j ? filename : filename.substring(0, j);
}
private static final boolean isClassnamePart(char c) {
if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9'))
return true;
switch (c) {
case '.':
case '$':
case '_':
return true;
default:
return false;
}
}
}