Support building self-contained Erjang+OTP jar file

Usage: Edit the file erjang_cfg.properties `erjang.otp.root` and make 
it point to an R13-based release before running `ant jar otpjar`.

Remember, Erjang does not work with R14-based releases yet,
because the file driver changed API and we've not updated that.

The current code in ClassPathResource.java is ugly and slow:
implementation of `file:list_dir/1` iterate through the entire classpath.
... and `file:file_info/1` opens the .jar every time it is called.
Should maybe cache some directory-like structure, but those are 
really only called during boot so be careful to cache for too long.

build.xml

@@ -1,6 +1,8 @@
 <?xml version="1.0"?>
 <project name="erjang" default="all">
 	<property name="erjang.version" value="0.1" />
+	<property file="erjang_cfg.properties" />
+
 	<path id="erjang.classpath">
 		<pathelement location="target/classes/" />
 		<pathelement location="lib/js.jar" />
@@ -178,6 +180,27 @@
 		</jar>
 	</target>
 
+	<target name="otpjar">
+	  <jar jarfile="otp-${erjang.otp.version}.jar" basedir="${erjang.otp.root}">
+	     <exclude name="**/*.so" />
+	     <exclude name="**/*.dll" />
+	     <exclude name="**/*.a" />
+	     <exclude name="**/*.erl" />
+	     <exclude name="**/bin/beam" />
+	     <exclude name="**/bin/beam.smp" />
+	     <exclude name="lib/megaco-*/**" />
+	     <exclude name="lib/wx-*/**" />
+	     <exclude name="lib/hipe-*/**" />
+	     <exclude name="lib/jinterface-*/**" />
+
+	     <!-- include all of erjang -->
+	     <zipgroupfileset dir="." includes="erjang-${erjang.version}.jar" />
+
+	     <manifest>
+	       <attribute name="Main-Class" value="erjang.Main" />
+	     </manifest>
+	  </jar>
+	</target>
 
 	<target name="javadoc" description="generate Javadoc documentation">
 		<javadoc destdir="target/doc">

src/main/java/erjang/EModuleLoader.java

@@ -24,6 +24,8 @@
 import erjang.beam.EUtil;
 
 import erjang.beam.loader.ErjangBeamDisLoader;
+import erjang.driver.efile.ClassPathResource;
+import erjang.driver.efile.EFile;
 
 import erjang.util.Progress;
 
@@ -112,6 +114,8 @@ private static File findBeamFile(String module) {
 			File beam = new File(e, n + ".beam");
 			if (beam.exists())
 				return beam;
+			if (ClassPathResource.read_file(beam.getPath()) != null)
+				return beam;
 		}
 
 		return null;

src/main/java/erjang/Main.java

@@ -22,6 +22,8 @@
 import java.io.IOException;
 import java.util.ArrayList;
 
+import erjang.driver.efile.EFile;
+
 public class Main {
 	public static final String SYSTEM_ARCHITECTURE = "java";
 	public static final String OTP_VERSION = ErjangConfig.getString("erjang.otp.version", "R13B04");
@@ -56,6 +58,10 @@ static String setup(String cmd_line_root) {
 
 	private static String guess_erl_root() {
 
+		if (Main.class.getClassLoader().getResource("bin/start.boot") != null) {
+			return EFile.RESOURCE_PREFIX.substring(0, EFile.RESOURCE_PREFIX.length()-1);
+		}
+
 		// this logic works on Unixes ... what about windows?
 		String path = System.getenv("PATH");
 		for (String elem : path.split(File.pathSeparator)) {
@@ -154,7 +160,7 @@ public static void main(String[] args) throws Exception {
 
 		System.setProperty("erjang.path", erl_bootstrap_ebindir);
 
-		if (!(new File(erl_bootstrap_ebindir)).exists()) {
+		if (!(new File(erl_bootstrap_ebindir)).exists() && !erl_bootstrap_ebindir.startsWith(EFile.RESOURCE_PREFIX)) {
 			System.err.println("No bootstrap classes at: "+erl_bootstrap_ebindir);
 			System.exit(1);
 		}

src/main/java/erjang/OTPMain.java

@@ -18,6 +18,7 @@
 
 package erjang;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
@@ -27,6 +28,8 @@
 import java.util.logging.Logger;
 
 import erjang.driver.EDriver;
+import erjang.driver.efile.ClassPathResource;
+import erjang.driver.efile.EFile;
 
 /**
  * This will eventually be the main entrypoint for an OTP node.
@@ -49,9 +52,24 @@ public class OTPMain {
 	};
 
     public static void load_modules_and_drivers() throws ClassNotFoundException, InstantiationException, IllegalAccessException, IOException {
-        for (String m : MODULES) {
-			ERT.load_module(EAtom.intern(m));
-		}
+
+    	if (Main.erl_bootstrap_ebindir.startsWith(EFile.RESOURCE_PREFIX)) {
+
+    		for (String m : MODULES) {
+	    		String beam_path = Main.erl_bootstrap_ebindir + "/" + m + ".beam";
+				EBinary bin = ClassPathResource.read_file(beam_path);
+				if (bin == null) {
+					throw new FileNotFoundException(beam_path);
+				}
+	    		EModuleLoader.load_module(m, bin);
+			}
+
+    	} else {    	
+	    	for (String m : MODULES) {
+				ERT.load_module(EAtom.intern(m));
+			}
+    	}
+
 		for (EDriver d : DRIVERS) {
 			erjang.driver.Drivers.register(d);
 		}

src/main/java/erjang/driver/EDriverInstance.java

@@ -136,7 +136,7 @@ protected void driver_outputv(ByteBuffer hdr, ByteBuffer[] ev) throws Pausable {
 		task.output_from_driver(res);
 	}
 
-	protected void driver_output2(ByteBuffer header, ByteBuffer buf) throws Pausable {
+	public void driver_output2(ByteBuffer header, ByteBuffer buf) throws Pausable {
 
 		int status = task.status;
 

src/main/java/erjang/driver/IO.java

@@ -20,6 +20,7 @@
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.io.OutputStream;
 import java.net.BindException;
 import java.net.ConnectException;
@@ -29,6 +30,7 @@
 import java.nio.charset.Charset;
 import java.util.zip.GZIPOutputStream;
 
+import erjang.EBinary;
 import erjang.ERT;
 import erjang.driver.efile.Posix;
 
@@ -218,4 +220,30 @@ public static String getstr(ByteBuffer buf, boolean term) {
 		}
 	}
 
+	static private class BARR2 extends ByteArrayOutputStream {
+		EBinary asBinary() {
+			return new EBinary(super.buf, 0, super.count);
+		}
+	}
+
+	public static EBinary istream2binary(InputStream in) throws IOException {
+		BARR2 out = new BARR2();
+		byte[] buf = new byte[4 * 1024];
+		int read;
+		while ((read = in.read(buf)) > 0) {
+			out.write(buf, 0, read);
+		}
+		return out.asBinary();
+	}
+
+	public static byte[] istream2bytearray(InputStream in) throws IOException {
+		BARR2 out = new BARR2();
+		byte[] buf = new byte[4 * 1024];
+		int read;
+		while ((read = in.read(buf)) > 0) {
+			out.write(buf, 0, read);
+		}
+		return out.toByteArray();
+	}
+
 }