org.jruby.runtime.load.ClassExtensionLibrary Maven / Gradle / Ivy
/***** BEGIN LICENSE BLOCK *****
* Version: EPL 1.0/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Eclipse Public
* License Version 1.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.eclipse.org/legal/epl-v10.html
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Copyright (C) 2006 Ola Bini
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the EPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the EPL, the GPL or the LGPL.
***** END LICENSE BLOCK *****/
package org.jruby.runtime.load;
import org.jruby.Ruby;
import java.net.URL;
/**
* The ClassExtensionLibrary wraps a class which implements BasicLibraryService,
* and when asked to load the service, does a basicLoad of the BasicLibraryService.
*
* When the time comes to add other loading mechanisms for loading a class, this
* is the place where they will be added. The load method will check interface
* you can load a class with, and do the right thing.
*/
public class ClassExtensionLibrary implements Library {
private final Class theClass;
private final String name;
/**
* Try to locate an extension service in the current classloader resources. This happens
* after the jar has been added to JRuby's URLClassLoader (JRubyClassLoader) and is how
* extensions can magically load.
*
* The basic logic is to use the require name (@param searchName) to build the name of
* a class ending in "Service", and then invoke that class to boot the extension.
*
* The looping logic here was in response to a RubyGems change that started absolutizing
* the path to the extension jar under some circumstances, leading to an incorrect
* package/class name for the service contained therein. The new logic will try
* successively more trailing elements until one of them is not a valid package
* name or all elements have been exhausted.
*
* @param runtime the current JRuby runtime
* @param searchName the name passed to `require`
* @return a ClassExtensionLibrary that will boot the ext, or null if none was found
*/
static ClassExtensionLibrary tryFind(Ruby runtime, String searchName) {
// Create package name, by splitting on / and joining all but the last elements with a ".", and downcasing them.
String[] all = searchName.split("/");
// search backward for any non-identifier strings and don't try to use them
int leftmostIdentifier = findLeftmostIdentifier(all);
if (leftmostIdentifier == all.length) return null;
// make service name out of last element
String serviceName = buildServiceName(all[all.length - 1]);
// allocate once with plenty of space, to reduce object churn
StringBuilder classNameBuilder = new StringBuilder(searchName.length() * 2);
StringBuilder classFileBuilder = new StringBuilder(searchName.length() * 2);
for (int i = all.length - 1; i >= leftmostIdentifier; i--) {
buildClassName(classNameBuilder, classFileBuilder, all, i, serviceName);
String classFileName = classFileBuilder.toString();
// bail out once if see a dash in the name
if (classFileName.contains("-")) return null;
// look for the filename in classloader resources
URL resource = runtime.getJRubyClassLoader().getResource(classFileBuilder.toString());
if (resource == null) continue;
String className = classNameBuilder.toString();
try {
Class theClass = runtime.getJavaSupport().loadJavaClass(className);
return new ClassExtensionLibrary(className + ".java", theClass);
} catch (ClassNotFoundException cnfe) {
// file was found but class couldn't load; continue to next package segment
continue;
} catch (UnsupportedClassVersionError ucve) {
if (runtime.isDebug()) ucve.printStackTrace();
throw runtime.newLoadError("JRuby ext built for wrong Java version in `" + className + "': " + ucve, className.toString());
}
}
// not found
return null;
}
public static int findLeftmostIdentifier(String[] all) {
int firstElement = all.length - 1;
for (; firstElement >= 0; firstElement--) {
if (!isJavaIdentifier(all[firstElement])) {
break;
}
}
return firstElement + 1; // go forward one to the last good element
}
private static boolean isJavaIdentifier(String str) {
if (str.isEmpty()) return false;
if (!Character.isJavaIdentifierStart(str.charAt(0))) return false;
for (int i = 1; i < str.length(); i++) {
if (!Character.isJavaIdentifierPart(str.charAt(i))) return false;
}
return true;
}
private static void buildClassName(StringBuilder nameBuilder, StringBuilder fileBuilder, String[] all, int i, String serviceName) {
nameBuilder.setLength(0);
fileBuilder.setLength(0);
for (int j = i; j < all.length - 1; j++) {
nameBuilder.append(all[j]).append(".");
fileBuilder.append(all[j]).append("/");
}
nameBuilder.append(serviceName);
fileBuilder.append(serviceName).append(".class");
}
private static String buildServiceName(String jarName) {
String[] last = jarName.split("_");
StringBuilder serviceName = new StringBuilder();
for (int i = 0, j = last.length; i < j; i++) {
if ("".equals(last[i])) break;
serviceName.append(Character.toUpperCase(last[i].charAt(0))).append(last[i].substring(1));
}
serviceName.append("Service");
return serviceName.toString();
}
public ClassExtensionLibrary(String name, Class extension) {
theClass = extension;
this.name = name;
}
public String getName() {
return name;
}
public void load(Ruby runtime, boolean wrap) {
if(BasicLibraryService.class.isAssignableFrom(theClass)) {
try {
runtime.loadExtension(name, (BasicLibraryService)theClass.newInstance(), wrap);
} catch(final Exception ee) {
throw new RuntimeException(ee.getMessage(),ee);
}
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy