1 files changed, 301 insertions, 0 deletions
diff --git a/src/org/apache/http/impl/conn/tsccm/RouteSpecificPool.java b/src/org/apache/http/impl/conn/tsccm/RouteSpecificPool.java
new file mode 100644
index 0000000..5c63933
--- /dev/null
+++ b/src/org/apache/http/impl/conn/tsccm/RouteSpecificPool.java
@@ -0,0 +1,301 @@
+/*
+ * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk/module-client/src/main/java/org/apache/http/impl/conn/tsccm/RouteSpecificPool.java $
+ * $Revision: 677240 $
+ * $Date: 2008-07-16 04:25:47 -0700 (Wed, 16 Jul 2008) $
+ *
+ * ====================================================================
+ *
+ *  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.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ *
+ */
+
+package org.apache.http.impl.conn.tsccm;
+
+import java.io.IOException;
+import java.util.ListIterator;
+import java.util.Queue;
+import java.util.LinkedList;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.http.conn.OperatedClientConnection;
+import org.apache.http.conn.routing.HttpRoute;
+import org.apache.http.util.LangUtils;
+
+
+/**
+ * A connection sub-pool for a specific route, used by {@link ConnPoolByRoute}.
+ * The methods in this class are unsynchronized. It is expected that the
+ * containing pool takes care of synchronization.
+ */
+public class RouteSpecificPool {
+
+    private final Log log = LogFactory.getLog(getClass());
+    
+    /** The route this pool is for. */
+    protected final HttpRoute route;
+
+    /** the maximum number of entries allowed for this pool */
+    protected final int maxEntries;
+    
+    /**
+     * The list of free entries.
+     * This list is managed LIFO, to increase idle times and
+     * allow for closing connections that are not really needed.
+     */
+    protected final LinkedList<BasicPoolEntry> freeEntries;
+
+    /** The list of threads waiting for this pool. */
+    protected final Queue<WaitingThread> waitingThreads;
+
+    /** The number of created entries. */
+    protected int numEntries;
+
+
+    /**
+     * Creates a new route-specific pool.
+     *
+     * @param route the route for which to pool
+     * @param maxEntries the maximum number of entries allowed for this pool
+     */
+    public RouteSpecificPool(HttpRoute route, int maxEntries) {
+        this.route = route;
+        this.maxEntries = maxEntries;
+        this.freeEntries = new LinkedList<BasicPoolEntry>();
+        this.waitingThreads = new LinkedList<WaitingThread>();
+        this.numEntries = 0;
+    }
+
+
+    /**
+     * Obtains the route for which this pool is specific.
+     *
+     * @return  the route
+     */
+    public final HttpRoute getRoute() {
+        return route;
+    }
+
+    
+    /**
+     * Obtains the maximum number of entries allowed for this pool.
+     *
+     * @return  the max entry number
+     */
+    public final int getMaxEntries() {
+        return maxEntries;
+    }
+    
+    
+    /**
+     * Indicates whether this pool is unused.
+     * A pool is unused if there is neither an entry nor a waiting thread.
+     * All entries count, not only the free but also the allocated ones.
+     *
+     * @return  <code>true</code> if this pool is unused,
+     *          <code>false</code> otherwise
+     */
+    public boolean isUnused() {
+        return (numEntries < 1) && waitingThreads.isEmpty();
+    }
+
+
+    /**
+     * Return remaining capacity of this pool
+     * 
+     * @return capacity
+     */
+    public int getCapacity() {
+        return maxEntries - numEntries;
+    }
+    
+    
+    /**
+     * Obtains the number of entries.
+     * This includes not only the free entries, but also those that
+     * have been created and are currently issued to an application.
+     *
+     * @return  the number of entries for the route of this pool
+     */
+    public final int getEntryCount() {
+        return numEntries;
+    }
+
+
+    /**
+     * Obtains a free entry from this pool, if one is available.
+     *
+     * @return an available pool entry, or <code>null</code> if there is none
+     */
+    public BasicPoolEntry allocEntry(final Object state) {
+        if (!freeEntries.isEmpty()) {
+            ListIterator<BasicPoolEntry> it = freeEntries.listIterator(freeEntries.size());
+            while (it.hasPrevious()) {
+                BasicPoolEntry entry = it.previous();
+                if (LangUtils.equals(state, entry.getState())) {
+                    it.remove();
+                    return entry;
+                }
+            }
+        }
+        if (!freeEntries.isEmpty()) {
+            BasicPoolEntry entry = freeEntries.remove();   
+            entry.setState(null);
+            OperatedClientConnection conn = entry.getConnection();
+            try {
+                conn.close();
+            } catch (IOException ex) {
+                log.debug("I/O error closing connection", ex);
+            }
+            return entry;
+        }
+        return null;
+    }
+
+
+    /**
+     * Returns an allocated entry to this pool.
+     *
+     * @param entry     the entry obtained from {@link #allocEntry allocEntry}
+     *                  or presented to {@link #createdEntry createdEntry}
+     */
+    public void freeEntry(BasicPoolEntry entry) {
+
+        if (numEntries < 1) {
+            throw new IllegalStateException
+                ("No entry created for this pool. " + route);
+        }
+        if (numEntries <= freeEntries.size()) {
+            throw new IllegalStateException
+                ("No entry allocated from this pool. " + route);
+        }
+        freeEntries.add(entry);
+    }
+
+
+    /**
+     * Indicates creation of an entry for this pool.
+     * The entry will <i>not</i> be added to the list of free entries,
+     * it is only recognized as belonging to this pool now. It can then
+     * be passed to {@link #freeEntry freeEntry}.
+     *
+     * @param entry     the entry that was created for this pool
+     */
+    public void createdEntry(BasicPoolEntry entry) {
+
+        if (!route.equals(entry.getPlannedRoute())) {
+            throw new IllegalArgumentException
+                ("Entry not planned for this pool." +
+                 "\npool: " + route +
+                 "\nplan: " + entry.getPlannedRoute());
+        }
+
+        numEntries++;
+    }
+
+
+    /**
+     * Deletes an entry from this pool.
+     * Only entries that are currently free in this pool can be deleted.
+     * Allocated entries can not be deleted.
+     *
+     * @param entry     the entry to delete from this pool
+     *
+     * @return  <code>true</code> if the entry was found and deleted, or
+     *          <code>false</code> if the entry was not found
+     */
+    public boolean deleteEntry(BasicPoolEntry entry) {
+
+        final boolean found = freeEntries.remove(entry);
+        if (found)
+            numEntries--;
+        return found;
+    }
+
+
+    /**
+     * Forgets about an entry from this pool.
+     * This method is used to indicate that an entry
+     * {@link #allocEntry allocated}
+     * from this pool has been lost and will not be returned.
+     */
+    public void dropEntry() {
+        if (numEntries < 1) {
+            throw new IllegalStateException
+                ("There is no entry that could be dropped.");
+        }
+        numEntries--;
+    }
+
+
+    /**
+     * Adds a waiting thread.
+     * This pool makes no attempt to match waiting threads with pool entries.
+     * It is the caller's responsibility to check that there is no entry
+     * before adding a waiting thread.
+     *
+     * @param wt        the waiting thread
+     */
+    public void queueThread(WaitingThread wt) {
+        if (wt == null) {
+            throw new IllegalArgumentException
+                ("Waiting thread must not be null.");
+        }
+        this.waitingThreads.add(wt);
+    }
+
+
+    /**
+     * Checks whether there is a waiting thread in this pool.
+     *
+     * @return  <code>true</code> if there is a waiting thread,
+     *          <code>false</code> otherwise
+     */
+    public boolean hasThread() {
+        return !this.waitingThreads.isEmpty();
+    }
+
+
+    /**
+     * Returns the next thread in the queue.
+     *
+     * @return  a waiting thread, or <code>null</code> if there is none
+     */
+    public WaitingThread nextThread() {
+        return this.waitingThreads.peek();
+    }
+
+
+    /**
+     * Removes a waiting thread, if it is queued.
+     *
+     * @param wt        the waiting thread
+     */
+    public void removeThread(WaitingThread wt) {
+        if (wt == null)
+            return;
+
+        this.waitingThreads.remove(wt);
+    }
+
+
+} // class RouteSpecificPool