HTTPCLIENT-1032: added a method to HttpCache to allow updating a specific

variant cache entry if its cache key is known. Committed patch with the
additional acceptance test, which now passes. We are still caching extra
copies of the re-used variant, though, so the issue is not yet closed.

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1049048 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -194,6 +194,19 @@ class BasicHttpCache implements HttpCache {
         return updatedEntry;
     }
 
+    public HttpCacheEntry updateVariantCacheEntry(HttpHost target, HttpRequest request,
+            HttpCacheEntry stale, HttpResponse originResponse,
+            Date requestSent, Date responseReceived, String cacheKey) throws IOException {
+        HttpCacheEntry updatedEntry = cacheEntryUpdater.updateCacheEntry(
+                request.getRequestLine().getUri(),
+                stale,
+                requestSent,
+                responseReceived,
+                originResponse);
+        storage.putEntry(cacheKey, updatedEntry);
+        return updatedEntry;
+    }
+    
     public HttpResponse cacheAndReturnResponse(HttpHost host, HttpRequest request,
             HttpResponse originResponse, Date requestSent, Date responseReceived)
             throws IOException {

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

@@ -635,7 +635,8 @@ public class CachingHttpClient implements HttpClient {
         // SHOULD update cache entry according to rfc
         HttpCacheEntry responseEntry = matchedEntry;
         try {
-            responseEntry = responseCache.updateCacheEntry(target, conditionalRequest, matchedEntry, backendResponse, requestDate, responseDate);
+            responseEntry = responseCache.updateVariantCacheEntry(target, conditionalRequest,
+                    matchedEntry, backendResponse, requestDate, responseDate, matchingVariant.getCacheKey());
         } catch (IOException ioe) {
             log.warn("Could not update cache entry", ioe);
         }

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

@@ -109,4 +109,22 @@ interface HttpCache {
             Date requestSent, Date responseReceived)
         throws IOException;
 
+    /**
+     * Update a specific {@link HttpCacheEntry} representing a cached variant
+     * using a 304 {@link HttpResponse}.
+     * @param target host for client request
+     * @param request actual request from upstream client 
+     * @param stale current variant cache entry
+     * @param originResponse 304 response received from origin
+     * @param requestSent when the validating request was sent
+     * @param responseReceived when the validating response was received
+     * @param cacheKey where in the cache this entry is currently stored
+     * @return
+     * @throws IOException
+     */
+    HttpCacheEntry updateVariantCacheEntry(HttpHost target, HttpRequest request,
+            HttpCacheEntry stale, HttpResponse originResponse, Date requestSent,
+            Date responseReceived, String cacheKey)
+        throws IOException;
+
 }

httpclient-cache/src/test/java/org/apache/http/impl/client/cache/TestCachingHttpClient.java

@@ -1615,7 +1615,7 @@ public class TestCachingHttpClient {
 
         backendCall(variantConditionalRequest, originResponse);
 
-        EasyMock.expect(mockCache.updateCacheEntry(EasyMock.same(host), EasyMock.same(variantConditionalRequest), EasyMock.same(variant2), EasyMock.same(originResponse), EasyMock.isA(Date.class), EasyMock.isA(Date.class))).andReturn(updatedMatchedEntry);
+        EasyMock.expect(mockCache.updateVariantCacheEntry(EasyMock.same(host), EasyMock.same(variantConditionalRequest), EasyMock.same(variant2), EasyMock.same(originResponse), EasyMock.isA(Date.class), EasyMock.isA(Date.class), EasyMock.eq("D"))).andReturn(updatedMatchedEntry);
 
         EasyMock.expect(mockResponseGenerator.generateResponse(updatedMatchedEntry)).andReturn(matchedResponse);
 

httpclient-cache/src/test/java/org/apache/http/impl/client/cache/TestProtocolRecommendations.java

@@ -865,4 +865,66 @@ public class TestProtocolRecommendations extends AbstractProtocolTest {
         }
         assertTrue(foundEtag1 && foundEtag2);
     }
+    
+    /* "If the entity-tag of the new response matches that of an existing
+     * entry, the new response SHOULD be used to update the header fields
+     * of the existing entry, and the result MUST be returned to the
+     * client."
+     *
+     * http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html#sec13.6
+     */
+    @Test
+    public void testResponseToExistingVariantsUpdatesEntry()
+        throws Exception {
+
+        Date now = new Date();
+        Date tenSecondsAgo = new Date(now.getTime() - 10 * 1000L);
+
+        HttpRequest req1 = new BasicHttpRequest("GET", "/", HttpVersion.HTTP_1_1);
+        req1.setHeader("User-Agent", "agent1");
+
+        HttpResponse resp1 = HttpTestUtils.make200Response();
+        resp1.setHeader("Date", DateUtils.formatDate(tenSecondsAgo));
+        resp1.setHeader("Vary", "User-Agent");
+        resp1.setHeader("Cache-Control", "max-age=3600");
+        resp1.setHeader("ETag", "\"etag1\"");
+
+
+        backendExpectsAnyRequest().andReturn(resp1);
+
+        HttpRequest req2 = new BasicHttpRequest("GET", "/", HttpVersion.HTTP_1_1);
+        req2.setHeader("User-Agent", "agent2");
+
+        HttpResponse resp2 = HttpTestUtils.make200Response();
+        resp2.setHeader("Date", DateUtils.formatDate(tenSecondsAgo));
+        resp2.setHeader("Vary", "User-Agent");
+        resp2.setHeader("Cache-Control", "max-age=3600");
+        resp2.setHeader("ETag", "\"etag2\"");
+
+        backendExpectsAnyRequest().andReturn(resp2);
+
+        HttpRequest req3 = new BasicHttpRequest("GET", "/", HttpVersion.HTTP_1_1);
+        req3.setHeader("User-Agent", "agent3");
+
+        HttpResponse resp3 = new BasicHttpResponse(HttpVersion.HTTP_1_1, HttpStatus.SC_NOT_MODIFIED, "Not Modified");
+        resp3.setHeader("Date", DateUtils.formatDate(now));
+        resp3.setHeader("ETag", "\"etag1\"");
+
+        backendExpectsAnyRequest().andReturn(resp3);
+
+        HttpRequest req4 = new BasicHttpRequest("GET", "/", HttpVersion.HTTP_1_1);
+        req4.setHeader("User-Agent", "agent1");
+
+        replayMocks();
+        impl.execute(host, req1);
+        impl.execute(host, req2);
+        HttpResponse result1 = impl.execute(host, req3);
+        HttpResponse result2 = impl.execute(host, req4);
+        verifyMocks();
+
+        assertEquals(HttpStatus.SC_OK, result1.getStatusLine().getStatusCode());
+        assertEquals("\"etag1\"", result1.getFirstHeader("ETag").getValue());
+        assertEquals(DateUtils.formatDate(now), result1.getFirstHeader("Date").getValue());
+        assertEquals(DateUtils.formatDate(now), result2.getFirstHeader("Date").getValue());
+    }
 }