[Archive-access-cvs] SF.net SVN: archive-access:[3474] trunk/archive-access/projects/wayback/ wayback-core/src/main/java/org/archive/wayback/util

[<bra...@us...>]

Revision: 3474
          http://archive-access.svn.sourceforge.net/archive-access/?rev=3474&view=rev
Author:   bradtofel
Date:     2011-06-16 17:18:09 +0000 (Thu, 16 Jun 2011)

Log Message:
-----------
INITIAL REV: new classes, as yet unused, for dealing with Iterators

Added Paths:
-----------
    trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/
    trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/AbstractPeekableIterator.java
    trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/IPeekableIterator.java
    trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/PeekableIteratorComparator.java
    trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/SortedCompositeIterator.java

Added: trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/AbstractPeekableIterator.java
===================================================================
--- trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/AbstractPeekableIterator.java	                        (rev 0)
+++ trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/AbstractPeekableIterator.java	2011-06-16 17:18:09 UTC (rev 3474)
@@ -0,0 +1,93 @@
+package org.archive.wayback.util.iterator;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+
+public abstract class AbstractPeekableIterator<E> implements IPeekableIterator<E> {
+	private E cachedNext = null; 
+	private boolean done = false;
+
+	// returns next E, or null if hasNext() would return false;
+	public abstract E getNextInner();
+	
+	public boolean hasNext() {
+		if(cachedNext != null) {
+			return true;
+		}
+		if(done) {
+			return false;
+		}
+		cachedNext = getNextInner();
+		return (cachedNext != null);
+	}
+
+	public E next() {
+		if(cachedNext == null) {
+			if(!hasNext()) {
+				throw new NoSuchElementException("Call hasNext!");
+			}
+		}
+		E tmp = cachedNext;
+		cachedNext = null;
+		return tmp;
+	}
+
+	public void remove() {
+		throw new UnsupportedOperationException("No remove");
+	}
+
+	public E peek() {
+		if(cachedNext == null) {
+			if(!hasNext()) {
+				throw new NoSuchElementException("Call hasNext!");
+			}
+		}
+		return cachedNext;
+	}
+	public static <T> IPeekableIterator<T> wrap(Iterator<T> itr) {
+		return new IteratorWrappedPeekableIterator<T>(itr);
+	}
+	public static IPeekableIterator<String> wrapReader(BufferedReader reader) {
+		return new BufferedReaderPeekableIterator(reader);
+	}
+	
+	private static class IteratorWrappedPeekableIterator<C> extends AbstractPeekableIterator<C> {
+		private Iterator<C> wrapped = null;
+		public IteratorWrappedPeekableIterator(Iterator<C> wrapped) {
+			this.wrapped = wrapped;
+		}
+		@Override
+		public C getNextInner() {
+			C next = null;
+			if(wrapped != null) {
+				if(wrapped.hasNext()) {
+					next = wrapped.next();
+				}
+			}
+			return next;
+		}
+	}
+	private static class BufferedReaderPeekableIterator extends AbstractPeekableIterator<String> {
+		private BufferedReader reader = null;
+		public BufferedReaderPeekableIterator(BufferedReader reader) {
+			this.reader = reader;
+		}
+		@Override
+		public String getNextInner() {
+			String next = null;
+			if(reader != null) {
+				try {
+					next = reader.readLine();
+				} catch (IOException e) {
+					e.printStackTrace();
+				}
+			}
+			return next;
+		}
+	}
+
+}


Property changes on: trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/AbstractPeekableIterator.java
___________________________________________________________________
Added: svn:executable
   + *

Added: trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/IPeekableIterator.java
===================================================================
--- trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/IPeekableIterator.java	                        (rev 0)
+++ trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/IPeekableIterator.java	2011-06-16 17:18:09 UTC (rev 3474)
@@ -0,0 +1,7 @@
+package org.archive.wayback.util.iterator;
+
+import java.util.Iterator;
+
+public interface IPeekableIterator<E> extends Iterator<E> {
+	public E peek();
+}


Property changes on: trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/IPeekableIterator.java
___________________________________________________________________
Added: svn:executable
   + *

Added: trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/PeekableIteratorComparator.java
===================================================================
--- trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/PeekableIteratorComparator.java	                        (rev 0)
+++ trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/PeekableIteratorComparator.java	2011-06-16 17:18:09 UTC (rev 3474)
@@ -0,0 +1,44 @@
+/*
+ *  This file is part of the Wayback archival access software
+ *   (http://archive-access.sourceforge.net/projects/wayback/).
+ *
+ *  Licensed to the Internet Archive (IA) by one or more individual 
+ *  contributors. 
+ *
+ *  The IA 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.archive.wayback.util.iterator;
+
+import java.util.Comparator;
+
+/**
+ * @author brad
+ *
+ * @param <J> type found in Iterators
+ */
+public class PeekableIteratorComparator<J> implements Comparator<IPeekableIterator<J>> {
+	private Comparator<J> comparator = null;
+	/**
+	 * @param comparator to compare the iterators
+	 */
+	public PeekableIteratorComparator(Comparator<J> comparator) {
+		this.comparator = comparator;
+	}
+
+	public int compare(IPeekableIterator<J> o1, IPeekableIterator<J> o2) {
+		return comparator.compare(o1.peek(), o2.peek());
+	}
+	public static <K> Comparator<IPeekableIterator<K>> getComparator(Comparator<K> comparator) {
+		return new PeekableIteratorComparator<K>(comparator);
+	}
+}

Added: trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/SortedCompositeIterator.java
===================================================================
--- trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/SortedCompositeIterator.java	                        (rev 0)
+++ trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/SortedCompositeIterator.java	2011-06-16 17:18:09 UTC (rev 3474)
@@ -0,0 +1,56 @@
+package org.archive.wayback.util.iterator;
+
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+import java.util.PriorityQueue;
+
+
+public class SortedCompositeIterator<E> implements Iterator<E> {
+	private static final int DEFAULT_CAPACITY = 10;
+	PriorityQueue<IPeekableIterator<E>> q = null;
+
+	public SortedCompositeIterator(Comparator<E> comparator) {
+		this(DEFAULT_CAPACITY,comparator);
+	}
+	public SortedCompositeIterator(int capacity, Comparator<E> comparator) {
+		q = new PriorityQueue<IPeekableIterator<E>>(capacity, 
+				new PeekableIteratorComparator<E>(comparator));
+	}
+	public void addAll(Collection<Iterator<E>> toAdd) {
+		for(Iterator<E> e : toAdd) {
+			addIterator(e);
+		}
+	}
+	public void addIterator(Iterator<E> itr) {
+		IPeekableIterator<E> i = null;
+		if(itr instanceof IPeekableIterator) {
+			i = (IPeekableIterator<E>) itr;
+		} else {
+			i = AbstractPeekableIterator.wrap(itr);
+		}
+		if(i.hasNext()) {
+			q.add(i);
+		}
+	}
+
+	public boolean hasNext() {
+		return (q.peek() != null);
+	}
+
+	public E next() {
+		IPeekableIterator<E> i = q.poll();
+		if(i == null) {
+			throw new NoSuchElementException("Call hasNext!");
+		}
+		E tmp = i.next();
+		if(i.hasNext()) {
+			q.add(i);
+		}
+		return tmp;
+	}
+	public void remove() {
+		throw new UnsupportedOperationException("No remove");
+	}
+}


Property changes on: trunk/archive-access/projects/wayback/wayback-core/src/main/java/org/archive/wayback/util/iterator/SortedCompositeIterator.java
___________________________________________________________________
Added: svn:executable
   + *


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