| /******************************************************************************* |
| * Copyright (c) 2012 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 |
| * 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; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.PrintStream; |
| import java.io.Reader; |
| |
| import org.luaj.vm2.lib.BaseLib; |
| import org.luaj.vm2.lib.DebugLib; |
| import org.luaj.vm2.lib.PackageLib; |
| import org.luaj.vm2.lib.ResourceFinder; |
| |
| /** |
| * Global environment used by luaj. Contains global variables referenced by executing lua. |
| * <p> |
| * |
| * <h3>Constructing and Initializing Instances</h3> |
| * Typically, this is constructed indirectly by a call to |
| * {@link JsePlatform.standardGlobasl()} or {@link JmePlatform.standardGlobals()}, |
| * and then used to load lua scripts for execution as in the following example. |
| * <pre> {@code |
| * Globals globals = JsePlatform.standardGlobals(); |
| * globals.load( new StringReader("print 'hello'"), "main.lua" ).call(); |
| * } </pre> |
| * The creates a complete global environment with the standard libraries loaded. |
| * <p> |
| * For specialized circumstances, the Globals may be constructed directly and loaded |
| * with only those libraries that are needed, for example. |
| * <pre> {@code |
| * Globals globals = new Globals(); |
| * globals.load( new BaseLib() ); |
| * } </pre> |
| * |
| * <h3>Loading and Executing Lua Code</h3> |
| * Globals contains convenience functions to load and execute lua source code given a Reader. |
| * A simple example is: |
| * <pre> {@code |
| * globals.load( new StringReader("print 'hello'"), "main.lua" ).call(); |
| * } </pre> |
| * |
| * <h3>Fine-Grained Control of Compiling and Loading Lua</h3> |
| * Executable LuaFunctions are created from lua code in several steps |
| * <ul> |
| * <li>find the resource using the platform's {@link ResourceFinder} |
| * <li>compile lua to lua bytecode using {@link Compiler} |
| * <li>load lua bytecode to a {@link LuaPrototpye} using {@link Undumper} |
| * <li>construct {@link LuaClosure} from {@link Prototype} with {@link Globals} using {@link Loader} |
| * </ul> |
| * <p> |
| * There are alternate flows when the direct lua-to-Java bytecode compiling {@link LuaJC} is used. |
| * <ul> |
| * <li>compile lua to lua bytecode using {@link Compiler} or load precompiled code using {@link Undumper} |
| * <li>convert lua bytecode to equivalent Java bytecode using {@link LuaJC} that implements {@link Loader} directly |
| * </ul> |
| * |
| * <h3>Java Field</h3> |
| * Certain public fields are provided that contain the current values of important global state: |
| * <ul> |
| * <li>{@link STDIN} Current value for standard input in the laaded IoLib, if any. |
| * <li>{@link STDOUT} Current value for standard output in the loaded IoLib, if any. |
| * <li>{@link STDERR} Current value for standard error in the loaded IoLib, if any. |
| * <li>{@link FINDER} Current loaded {@link ResourceFinder}, if any. |
| * <li>{@link compiler} Current loaded {@link Compiler}, if any. |
| * <li>{@link undumper} Current loaded {@link Undumper}, if any. |
| * <li>{@link loader} Current loaded {@link Loader}, if any. |
| * </ul> |
| * |
| * <h3>Lua Environment Variables</h3> |
| * When using {@link JsePlatform} or {@link JmePlatform}, |
| * these environment variables are created within the Globals. |
| * <ul> |
| * <li>"_G" Pointer to this Globals. |
| * <li>"_VERSION" String containing the version of luaj. |
| * </ul> |
| * |
| * <h3>Use in Multithreaded Environments</h3> |
| * In a multi-threaded server environment, each server thread should create one Globals instance, |
| * which will be logically distinct and not interfere with each other, but share certain |
| * static immutable resources such as class data and string data. |
| * <p> |
| * |
| * @see org.luaj.vm2.lib.jse.JsePlatform |
| * @see org.luaj.vm2.lib.jme.JmePlatform |
| * @see LuaValue |
| * @see Compiler |
| * @see Loader |
| * @see Undumper |
| * @see ResourceFinder |
| * @see LuaC |
| * @see LuaJC |
| */ |
| public class Globals extends LuaTable { |
| |
| /** The current default input stream. */ |
| public InputStream STDIN = null; |
| |
| /** The current default output stream. */ |
| public PrintStream STDOUT = System.out; |
| |
| /** The current default error stream. */ |
| public PrintStream STDERR = System.err; |
| |
| /** The installed ResourceFinder for looking files by name. */ |
| public ResourceFinder FINDER; |
| |
| /** The currently running thread. Should not be changed by non-library code. */ |
| public LuaThread running = new LuaThread(this); |
| |
| /** The BaseLib instance loaded into this Globals */ |
| public BaseLib baselib; |
| |
| /** The PackageLib instance loaded into this Globals */ |
| public PackageLib package_; |
| |
| /** The DebugLib instance loaded into this Globals, or null if debugging is not enabled */ |
| public DebugLib debuglib; |
| |
| /** Interface for module that converts a Prototype into a LuaFunction with an environment. */ |
| public interface Loader { |
| /** Convert the prototype into a LuaFunction with the supplied environment. */ |
| LuaFunction load(Prototype prototype, String chunkname, LuaValue env) throws IOException; |
| } |
| |
| /** Interface for module that converts lua source text into a prototype. */ |
| public interface Compiler { |
| /** Compile lua source into a Prototype. The InputStream is assumed to be in UTF-8. */ |
| Prototype compile(InputStream stream, String chunkname) throws IOException; |
| } |
| |
| /** Interface for module that loads lua binary chunk into a prototype. */ |
| public interface Undumper { |
| /** Load the supplied input stream into a prototype. */ |
| Prototype undump(InputStream stream, String chunkname) throws IOException; |
| } |
| |
| /** Check that this object is a Globals object, and return it, otherwise throw an error. */ |
| public Globals checkglobals() { |
| return this; |
| } |
| |
| /** The installed loader. |
| * @see Loader */ |
| public Loader loader; |
| |
| /** The installed compiler. |
| * @see Compiler */ |
| public Compiler compiler; |
| |
| /** The installed undumper. |
| * @see Undumper */ |
| public Undumper undumper; |
| |
| /** Convenience function for loading a file that is either binary lua or lua source. |
| * @param filename Name of the file to load. |
| * @return LuaValue that can be call()'ed or invoke()'ed. |
| * @throws LuaError if the file could not be loaded. |
| */ |
| public LuaValue loadfile(String filename) { |
| try { |
| return load(FINDER.findResource(filename), "@"+filename, "bt", this); |
| } catch (Exception e) { |
| return error("load "+filename+": "+e); |
| } |
| } |
| |
| /** Convenience function to load a string value as a script. Must be lua source. |
| * @param script Contents of a lua script, such as "print 'hello, world.'" |
| * @param chunkname Name that will be used within the chunk as the source. |
| * @return LuaValue that may be executed via .call(), .invoke(), or .method() calls. |
| * @throws LuaError if the script could not be compiled. |
| */ |
| public LuaValue load(String script, String chunkname) { |
| return load(new StrReader(script), chunkname); |
| } |
| |
| /** Convenience function to load a string value as a script. Must be lua source. |
| * @param script Contents of a lua script, such as "print 'hello, world.'" |
| * @return LuaValue that may be executed via .call(), .invoke(), or .method() calls. |
| * @throws LuaError if the script could not be compiled. |
| */ |
| public LuaValue load(String script) { |
| return load(new StrReader(script), script); |
| } |
| |
| /** Load the content form a reader as a text file. Must be lua source. |
| * The source is converted to UTF-8, so any characters appearing in quoted literals |
| * above the range 128 will be converted into multiple bytes. */ |
| public LuaValue load(Reader reader, String chunkname) { |
| return load(new UTF8Stream(reader), chunkname, "t", this); |
| } |
| |
| /** Load the content form an input stream as a binary chunk or text file. */ |
| public LuaValue load(InputStream is, String chunkname, String mode, LuaValue env) { |
| try { |
| Prototype p = loadPrototype(is, chunkname, mode); |
| return loader.load(p, chunkname, env); |
| } catch (LuaError l) { |
| throw l; |
| } catch (Exception e) { |
| return error("load "+chunkname+": "+e); |
| } |
| } |
| |
| /** Load lua source or lua binary from an input stream into a Prototype. |
| * The InputStream is either a binary lua chunk starting with the lua binary chunk signature, |
| * or a text input file. If it is a text input file, it is interpreted as a UTF-8 byte sequence. |
| */ |
| public Prototype loadPrototype(InputStream is, String chunkname, String mode) throws IOException { |
| if (mode.indexOf('b') >= 0) { |
| if (undumper == null) |
| error("No undumper."); |
| if (!is.markSupported()) |
| is = new MarkStream(is); |
| is.mark(4); |
| final Prototype p = undumper.undump(is, chunkname); |
| if (p != null) |
| return p; |
| is.reset(); |
| } |
| if (mode.indexOf('t') >= 0) { |
| return compilePrototype(is, chunkname); |
| } |
| error("Failed to load prototype "+chunkname+" using mode '"+mode+"'"); |
| return null; |
| } |
| |
| /** Compile lua source from a Reader into a Prototype. The characters in the reader |
| * are converted to bytes using the UTF-8 encoding, so a string literal containing |
| * characters with codepoints 128 or above will be converted into multiple bytes. |
| */ |
| public Prototype compilePrototype(Reader reader, String chunkname) throws IOException { |
| return compilePrototype(new UTF8Stream(reader), chunkname); |
| } |
| |
| /** Compile lua source from an InputStream into a Prototype. |
| * The input is assumed to be UTf-8, but since bytes in the range 128-255 are passed along as |
| * literal bytes, any ASCII-compatible encoding such as ISO 8859-1 may also be used. |
| */ |
| public Prototype compilePrototype(InputStream stream, String chunkname) throws IOException { |
| if (compiler == null) |
| error("No compiler."); |
| return compiler.compile(stream, chunkname); |
| } |
| |
| /** Function which yields the current thread. |
| * @param args Arguments to supply as return values in the resume function of the resuming thread. |
| * @return Values supplied as arguments to the resume() call that reactivates this thread. |
| */ |
| public Varargs yield(Varargs args) { |
| if (running == null || running.isMainThread()) |
| throw new LuaError("cannot yield main thread"); |
| final LuaThread.State s = running.state; |
| return s.lua_yield(args); |
| } |
| |
| /** Reader implementation to read chars from a String in JME or JSE. */ |
| static class StrReader extends Reader { |
| final String s; |
| int i = 0, n; |
| StrReader(String s) { |
| this.s = s; |
| n = s.length(); |
| } |
| public void close() throws IOException { |
| i = n; |
| } |
| public int read(char[] cbuf, int off, int len) throws IOException { |
| int j = 0; |
| for (; j < len && i < n; ++j, ++i) |
| cbuf[off+j] = s.charAt(i); |
| return j > 0 || len == 0 ? j : -1; |
| } |
| } |
| |
| /** Simple converter from Reader to InputStream using UTF8 encoding that will work |
| * on both JME and JSE. |
| */ |
| static class UTF8Stream extends InputStream { |
| final char[] c = new char[32]; |
| final byte[] b = new byte[96]; |
| int i = 0, j = 0; |
| final Reader r; |
| UTF8Stream(Reader r) { |
| this.r = r; |
| } |
| public int read() throws IOException { |
| if (i < j) |
| return c[i++]; |
| int n = r.read(c); |
| if (n < 0) |
| return -1; |
| j = LuaString.encodeToUtf8(c, n, b, i = 0); |
| return b[i++]; |
| } |
| } |
| |
| /** Simple InputStream that supports mark. |
| * Used to examine an InputStream for a 4-byte binary lua signature, |
| * and fall back to text input when the signature is not found. |
| */ |
| static class MarkStream extends InputStream { |
| private int[] b; |
| private int i = 0, j = 0; |
| private final InputStream s; |
| MarkStream(InputStream s) { |
| this.s = s; |
| } |
| public int read() throws IOException { |
| if (i < j) |
| return b[i++]; |
| final int c = s.read(); |
| if (c < 0) |
| return -1; |
| if (j < b.length) { |
| b[j++] = c; |
| i = j; |
| } |
| return c; |
| } |
| public synchronized void mark(int n) { |
| b = new int[n]; |
| i = j = 0; |
| } |
| public boolean markSupported() { |
| return true; |
| } |
| public synchronized void reset() throws IOException { |
| i = 0; |
| } |
| } |
| |
| } |