HTTPCLIENT-1384: Expose CacheInvalidator interface

Contributed by Nicolas Richeton <nicolas.richeton at free.fr>

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1515814 13f79535-47bb-0310-9956-ffa450edef68

RELEASE_NOTES.txt

@@ -2,6 +2,12 @@
 Changes since release 4.3 BETA2
 -------------------
 
+* [HTTPCLIENT-1384] Expose CacheInvalidator interface.
+  Contributed by Nicolas Richeton <nicolas.richeton at free.fr>
+ 
+* [HTTPCLIENT-1385] Fixed path normalization in CacheKeyGenerator
+  Contributed by James Leigh <james at 3roundstones dot com>
+
 * [HTTPCLIENT-1385] Fixed path normalization in CacheKeyGenerator
   Contributed by James Leigh <james at 3roundstones dot com>
 

httpclient-cache/src/main/java/org/apache/http/client/cache/HttpCacheInvalidator.java

@@ -0,0 +1,58 @@
+/*
+ * ====================================================================
+ * 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.client.cache;
+
+import org.apache.http.HttpHost;
+import org.apache.http.HttpRequest;
+import org.apache.http.HttpResponse;
+
+/**
+ * Given a particular HttpRequest, flush any cache entries that this request
+ * would invalidate.
+ *
+ * @since 4.3
+ */
+public interface HttpCacheInvalidator {
+
+    /**
+     * Remove cache entries from the cache that are no longer fresh or have been
+     * invalidated in some way.
+     *
+     * @param host
+     *            The backend host we are talking to
+     * @param req
+     *            The HttpRequest to that host
+     */
+    void flushInvalidatedCacheEntries(HttpHost host, HttpRequest req);
+
+    /**
+     * Flushes entries that were invalidated by the given response received for
+     * the given host/request pair.
+     */
+    void flushInvalidatedCacheEntries(HttpHost host, HttpRequest request, HttpResponse response);
+
+}

httpclient-cache/src/main/java/org/apache/http/impl/client/cache/BasicHttpCache.java

@@ -44,6 +44,7 @@
 import org.apache.http.HttpVersion;
 import org.apache.http.client.cache.HeaderConstants;
 import org.apache.http.client.cache.HttpCacheEntry;
+import org.apache.http.client.cache.HttpCacheInvalidator;
 import org.apache.http.client.cache.HttpCacheStorage;
 import org.apache.http.client.cache.HttpCacheUpdateCallback;
 import org.apache.http.client.cache.HttpCacheUpdateException;
@@ -65,19 +66,40 @@ class BasicHttpCache implements HttpCache {
     private final long maxObjectSizeBytes;
     private final CacheEntryUpdater cacheEntryUpdater;
     private final CachedHttpResponseGenerator responseGenerator;
-    private final CacheInvalidator cacheInvalidator;
+    private final HttpCacheInvalidator cacheInvalidator;
     private final HttpCacheStorage storage;
 
     private final Log log = LogFactory.getLog(getClass());
 
-    public BasicHttpCache(final ResourceFactory resourceFactory, final HttpCacheStorage storage, final CacheConfig config) {
+    public BasicHttpCache(
+            final ResourceFactory resourceFactory,
+            final HttpCacheStorage storage,
+            final CacheConfig config,
+            final CacheKeyGenerator uriExtractor,
+            final HttpCacheInvalidator cacheInvalidator) {
         this.resourceFactory = resourceFactory;
-        this.uriExtractor = new CacheKeyGenerator();
+        this.uriExtractor = uriExtractor;
         this.cacheEntryUpdater = new CacheEntryUpdater(resourceFactory);
         this.maxObjectSizeBytes = config.getMaxObjectSize();
         this.responseGenerator = new CachedHttpResponseGenerator();
         this.storage = storage;
-        this.cacheInvalidator = new CacheInvalidator(this.uriExtractor, this.storage);
+        this.cacheInvalidator = cacheInvalidator;
+    }
+
+    public BasicHttpCache(
+            final ResourceFactory resourceFactory,
+            final HttpCacheStorage storage,
+            final CacheConfig config,
+            final CacheKeyGenerator uriExtractor) {
+        this( resourceFactory, storage, config, uriExtractor,
+                new CacheInvalidator(uriExtractor, storage));
+    }
+
+    public BasicHttpCache(
+            final ResourceFactory resourceFactory,
+            final HttpCacheStorage storage,
+            final CacheConfig config) {
+        this( resourceFactory, storage, config, new CacheKeyGenerator());
     }
 
     public BasicHttpCache(final CacheConfig config) {
@@ -175,7 +197,7 @@ boolean isIncompleteResponse(final HttpResponse resp, final Resource resource) {
         if (hdr == null) {
             return false;
         }
-        int contentLength;
+        final int contentLength;
         try {
             contentLength = Integer.parseInt(hdr.getValue());
         } catch (final NumberFormatException nfe) {

httpclient-cache/src/main/java/org/apache/http/impl/client/cache/CacheInvalidator.java

@@ -37,9 +37,10 @@
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
 import org.apache.http.HttpResponse;
-import org.apache.http.annotation.ThreadSafe;
+import org.apache.http.annotation.Immutable;
 import org.apache.http.client.cache.HeaderConstants;
 import org.apache.http.client.cache.HttpCacheEntry;
+import org.apache.http.client.cache.HttpCacheInvalidator;
 import org.apache.http.client.cache.HttpCacheStorage;
 import org.apache.http.client.utils.DateUtils;
 import org.apache.http.protocol.HTTP;
@@ -50,8 +51,8 @@
  *
  * @since 4.1
  */
-@ThreadSafe // so long as the cache implementation is thread-safe
-class CacheInvalidator {
+@Immutable
+class CacheInvalidator implements HttpCacheInvalidator {
 
     private final HttpCacheStorage storage;
     private final CacheKeyGenerator cacheKeyGenerator;

httpclient-cache/src/main/java/org/apache/http/impl/client/cache/CachingHttpClientBuilder.java

@@ -28,6 +28,7 @@
 
 import java.io.File;
 
+import org.apache.http.client.cache.HttpCacheInvalidator;
 import org.apache.http.client.cache.HttpCacheStorage;
 import org.apache.http.client.cache.ResourceFactory;
 import org.apache.http.impl.client.HttpClientBuilder;
@@ -46,6 +47,7 @@ public class CachingHttpClientBuilder extends HttpClientBuilder {
     private File cacheDir;
     private CacheConfig cacheConfig;
     private SchedulingStrategy schedulingStrategy;
+    private HttpCacheInvalidator httpCacheInvalidator;
 
     public static CachingHttpClientBuilder create() {
         return new CachingHttpClientBuilder();
@@ -85,6 +87,12 @@ public final CachingHttpClientBuilder setSchedulingStrategy(
         return this;
     }
 
+    public final CachingHttpClientBuilder setHttpCacheInvalidator(
+            final HttpCacheInvalidator cacheInvalidator) {
+        this.httpCacheInvalidator = cacheInvalidator;
+        return this;
+    }
+
     @Override
     protected ClientExecChain decorateMainExec(final ClientExecChain mainExec) {
         final CacheConfig config = this.cacheConfig != null ? this.cacheConfig : CacheConfig.DEFAULT;
@@ -105,17 +113,28 @@ protected ClientExecChain decorateMainExec(final ClientExecChain mainExec) {
                 addCloseable(managedStorage);
                 storage = managedStorage;
             }
-            storage = new BasicHttpCacheStorage(cacheConfig);
         }
         final AsynchronousValidator revalidator = createAsynchronousRevalidator(config);
+        final CacheKeyGenerator uriExtractor = new CacheKeyGenerator();
+
+        HttpCacheInvalidator cacheInvalidator = this.httpCacheInvalidator;
+        if (cacheInvalidator == null) {
+            cacheInvalidator = new CacheInvalidator(uriExtractor, storage);
+        }
+
         return new CachingExec(mainExec,
-                new BasicHttpCache(resourceFactory, storage, config), config, revalidator);
+                new BasicHttpCache(
+                        resourceFactory,
+                        storage, config,
+                        uriExtractor,
+                        cacheInvalidator), config, revalidator);
     }
 
     private AsynchronousValidator createAsynchronousRevalidator(final CacheConfig config) {
         if (config.getAsynchronousWorkersMax() > 0) {
             final SchedulingStrategy configuredSchedulingStrategy = createSchedulingStrategy(config);
-            final AsynchronousValidator revalidator = new AsynchronousValidator(configuredSchedulingStrategy);
+            final AsynchronousValidator revalidator = new AsynchronousValidator(
+                    configuredSchedulingStrategy);
             addCloseable(revalidator);
             return revalidator;
         }