1 files changed, 176 insertions, 0 deletions
diff --git a/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/LazyResourceCollectionWrapper.java b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/LazyResourceCollectionWrapper.java
new file mode 100644
index 00000000..4f9acd32
--- /dev/null
+++ b/framework/src/ant/apache-ant-1.9.6/src/main/org/apache/tools/ant/types/resources/LazyResourceCollectionWrapper.java
@@ -0,0 +1,176 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (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.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ */
+package org.apache.tools.ant.types.resources;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+import org.apache.tools.ant.types.Resource;
+
+/**
+ * Resource collection which load underlying resource collection only on demand
+ * with support for caching
+ */
+public class LazyResourceCollectionWrapper extends
+        AbstractResourceCollectionWrapper {
+
+    /** List of cached resources */
+    private final List<Resource> cachedResources = new ArrayList<Resource>();
+
+    private FilteringIterator filteringIterator;
+
+    @Override
+    protected Iterator<Resource> createIterator() {
+        Iterator<Resource> iterator;
+        if (isCache()) {
+            if (filteringIterator == null) {
+                // no worry of thread safety here, see function's contract
+                filteringIterator = new FilteringIterator(
+                        getResourceCollection().iterator());
+            }
+            iterator = new CachedIterator(filteringIterator);
+        } else {
+            iterator = new FilteringIterator(getResourceCollection().iterator());
+        }
+        return iterator;
+    }
+
+    @Override
+    protected int getSize() {
+        // to compute the size, just iterate: the iterator will take care of
+        // caching
+        final Iterator<Resource> it = createIterator();
+        int size = 0;
+        while (it.hasNext()) {
+            it.next();
+            size++;
+        }
+        return size;
+    }
+
+    /**
+     * Specify if the resource should be filtered or not. This function should
+     * be overrided in order to define the filtering algorithm
+     *
+     * @param r resource considered for filtration
+     * @return whether the resource should be filtered or not
+     */
+    protected boolean filterResource(final Resource r) {
+        return false;
+    }
+
+    private class FilteringIterator implements Iterator<Resource> {
+
+        Resource next = null;
+
+        boolean ended = false;
+
+        protected final Iterator<Resource> it;
+
+        public FilteringIterator(final Iterator<Resource> it) {
+            this.it = it;
+        }
+
+        public boolean hasNext() {
+            if (ended) {
+                return false;
+            }
+            while (next == null) {
+                if (!it.hasNext()) {
+                    ended = true;
+                    return false;
+                }
+                next = it.next();
+                if (filterResource(next)) {
+                    next = null;
+                }
+            }
+            return true;
+        }
+
+        public Resource next() {
+            if (!hasNext()) {
+                throw new UnsupportedOperationException();
+            }
+            final Resource r = next;
+            next = null;
+            return r;
+        }
+
+        public void remove() {
+            throw new UnsupportedOperationException();
+        }
+    }
+
+    /**
+     * Iterator that will put in the shared cache array list the selected
+     * resources
+     */
+    private class CachedIterator implements Iterator<Resource> {
+
+        int cusrsor = 0;
+
+        private final Iterator<Resource> it;
+
+        /**
+         * Default constructor
+         *
+         * @param it
+         *            the iterator which will provide the resources to put in
+         *            cache
+         */
+        public CachedIterator(final Iterator<Resource> it) {
+            this.it = it;
+        }
+
+        public boolean hasNext() {
+            synchronized (cachedResources) {
+                // have we already cached the next entry ?
+                if (cachedResources.size() > cusrsor) {
+                    return true;
+                }
+                // does the wrapped iterator any more resource ?
+                if (!it.hasNext()) {
+                    return false;
+                }
+                // put in cache the next resource
+                final Resource r = it.next();
+                cachedResources.add(r);
+            }
+            return true;
+        }
+
+        public Resource next() {
+            // first check that we have some to deliver
+            if (!hasNext()) {
+                throw new NoSuchElementException();
+            }
+            synchronized (cachedResources) {
+                // return the cached entry as hasNext should have put one for
+                // this iterator
+                return cachedResources.get(cusrsor++);
+            }
+        }
+
+        public void remove() {
+            throw new UnsupportedOperationException();
+        }
+    }
+}