1 files changed, 75 insertions, 0 deletions
diff --git a/build/annotationProcessors/classloader/IterableJarLoadingURLClassLoader.java b/build/annotationProcessors/classloader/IterableJarLoadingURLClassLoader.java
new file mode 100644
index 000000000..7e74399ca
--- /dev/null
+++ b/build/annotationProcessors/classloader/IterableJarLoadingURLClassLoader.java
@@ -0,0 +1,75 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.annotationProcessors.classloader;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.net.URLClassLoader;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.Iterator;
+import java.util.LinkedList;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+/**
+ * A classloader which can be initialised with a list of jar files and which can provide an iterator
+ * over the top level classes in the jar files it was initialised with.
+ * classNames is kept sorted to ensure iteration order is consistent across program invocations.
+ * Otherwise, we'd forever be reporting the outdatedness of the generated code as we permute its
+ * contents.
+ */
+public class IterableJarLoadingURLClassLoader extends URLClassLoader {
+    LinkedList<String> classNames = new LinkedList<String>();
+
+    /**
+     * Create an instance and return its iterator. Provides an iterator over the classes in the jar
+     * files provided as arguments.
+     * Inner classes are not supported.
+     *
+     * @param args A list of jar file names an iterator over the classes of which is desired.
+     * @return An iterator over the top level classes in the jar files provided, in arbitrary order.
+     */
+    public static Iterator<ClassWithOptions> getIteratorOverJars(String[] args) {
+        URL[] urlArray = new URL[args.length];
+        LinkedList<String> aClassNames = new LinkedList<String>();
+
+        for (int i = 0; i < args.length; i++) {
+            try {
+                urlArray[i] = (new File(args[i])).toURI().toURL();
+
+                Enumeration<JarEntry> entries = new JarFile(args[i]).entries();
+                while (entries.hasMoreElements()) {
+                    JarEntry e = entries.nextElement();
+                    String fName = e.getName();
+                    if (!fName.endsWith(".class")) {
+                        continue;
+                    }
+                    final String className = fName.substring(0, fName.length() - 6).replace('/', '.');
+
+                    aClassNames.add(className);
+                }
+            } catch (IOException e) {
+                System.err.println("Error loading jar file \"" + args[i] + '"');
+                e.printStackTrace(System.err);
+            }
+        }
+        Collections.sort(aClassNames);
+        return new JarClassIterator(new IterableJarLoadingURLClassLoader(urlArray, aClassNames));
+    }
+
+    /**
+     * Constructs a classloader capable of loading all classes given as URLs in urls. Used by static
+     * method above.
+     *
+     * @param urls        URLs for all classes the new instance shall be capable of loading.
+     * @param aClassNames A list of names of the classes this instance shall be capable of loading.
+     */
+    protected IterableJarLoadingURLClassLoader(URL[] urls, LinkedList<String> aClassNames) {// Array to populate with URLs for each class in the given jars.
+        super(urls);
+        classNames = aClassNames;
+    }
+}