HTTPCORE-106: Moved garbage tolerant HTTP response parser to HttpClient

git-svn-id: https://svn.apache.org/repos/asf/jakarta/httpcomponents/httpclient/trunk@562715 13f79535-47bb-0310-9956-ffa450edef68

module-client/src/main/java/org/apache/http/conn/params/HttpConnectionManagerParams.java

@@ -82,6 +82,25 @@ public final class HttpConnectionManagerParams {
      */
     public static final String MAX_TOTAL_CONNECTIONS = "http.connection-manager.max-total";
 
+    /**
+     * Defines the maximum number of ignorable lines before we expect
+     * a HTTP response's status code.
+     * <p>
+     * With HTTP/1.1 persistent connections, the problem arises that
+     * broken scripts could return a wrong Content-Length
+     * (there are more bytes sent than specified).<br />
+     * Unfortunately, in some cases, this is not possible after the bad response,
+     * but only before the next one. <br />
+     * So, HttpClient must be able to skip those surplus lines this way.
+     * </p>
+     * <p>
+     * Set this to 0 to disallow any garbage/empty lines before the status line.<br />
+     * To specify no limit, use {@link java.lang.Integer#MAX_VALUE} (default in lenient mode).
+     * </p>
+     *  
+     * This parameter expects a value of type {@link Integer}.
+     */
+    public static final String MAX_STATUS_LINE_GARBAGE = "http.connection.max-status-line-garbage";
 
     /**
      * Sets the default maximum number of connections allowed for routes.

module-client/src/main/java/org/apache/http/impl/conn/DefaultClientConnection.java

@@ -42,8 +42,10 @@ import org.apache.http.HttpException;
 import org.apache.http.HttpHost;
 import org.apache.http.HttpRequest;
 import org.apache.http.HttpResponse;
+import org.apache.http.HttpResponseFactory;
 import org.apache.http.params.HttpParams;
 import org.apache.http.impl.SocketHttpClientConnection;
+import org.apache.http.io.HttpMessageParser;
 import org.apache.http.io.SessionInputBuffer;
 import org.apache.http.io.SessionOutputBuffer;
 
@@ -166,6 +168,14 @@ public class DefaultClientConnection extends SocketHttpClientConnection
     }
 
     
+    protected HttpMessageParser createResponseParser(
+            final SessionInputBuffer buffer,
+            final HttpResponseFactory responseFactory, 
+            final HttpParams params) {
+        return new DefaultResponseParser(buffer, responseFactory, params);
+    }
+
+
     // non-javadoc, see interface OperatedClientConnection
     public void open(Socket sock, HttpHost target,
                      boolean secure, HttpParams params)

module-client/src/main/java/org/apache/http/impl/conn/DefaultResponseParser.java

@@ -0,0 +1,118 @@
+/*
+ * $HeadURL$
+ * $Revision$
+ * $Date$
+ *
+ * ====================================================================
+ * 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;
+
+import java.io.IOException;
+
+import org.apache.http.HttpException;
+import org.apache.http.HttpMessage;
+import org.apache.http.HttpResponseFactory;
+import org.apache.http.NoHttpResponseException;
+import org.apache.http.ProtocolException;
+import org.apache.http.StatusLine;
+import org.apache.http.conn.params.HttpConnectionManagerParams;
+import org.apache.http.impl.io.AbstractMessageParser;
+import org.apache.http.io.SessionInputBuffer;
+import org.apache.http.message.BasicStatusLine;
+import org.apache.http.params.HttpParams;
+import org.apache.http.protocol.HTTP;
+import org.apache.http.util.CharArrayBuffer;
+
+public class DefaultResponseParser extends AbstractMessageParser {
+    
+    private final HttpResponseFactory responseFactory;
+    private final CharArrayBuffer lineBuf;
+    private final int maxGarbageLines;
+    
+    public DefaultResponseParser(
+            final SessionInputBuffer buffer,
+            final HttpResponseFactory responseFactory,
+            final HttpParams params) {
+        super(buffer, params);
+        if (responseFactory == null) {
+            throw new IllegalArgumentException("Response factory may not be null");
+        }
+        this.responseFactory = responseFactory;
+        this.lineBuf = new CharArrayBuffer(128);
+        this.maxGarbageLines = params.getIntParameter(
+                HttpConnectionManagerParams.MAX_STATUS_LINE_GARBAGE, Integer.MAX_VALUE);
+    }
+
+    /**
+     * Tests if the string starts with 'HTTP' signature.
+     * @param buffer buffer to test
+     * @return <tt>true</tt> if the line starts with 'HTTP' 
+     *   signature, <tt>false</tt> otherwise.
+     */
+    protected static boolean startsWithHTTP(final CharArrayBuffer buffer) {
+        try {
+            int i = 0;
+            while (HTTP.isWhitespace(buffer.charAt(i))) {
+                ++i;
+            }
+            return buffer.charAt(i) == 'H' 
+                && buffer.charAt(i + 1) == 'T'
+                && buffer.charAt(i + 2) == 'T'
+                && buffer.charAt(i + 3) == 'P';
+        } catch (IndexOutOfBoundsException e) {
+            return false;
+        }
+    }
+    
+    protected HttpMessage parseHead(
+            final SessionInputBuffer sessionBuffer) throws IOException, HttpException {
+        // clear the buffer
+        this.lineBuf.clear();
+        //read out the HTTP status string
+        int count = 0;
+        do {
+            int i = sessionBuffer.readLine(this.lineBuf);
+            if (i == -1 && count == 0) {
+                // The server just dropped connection on us
+                throw new NoHttpResponseException("The target server failed to respond");
+            }
+            if (startsWithHTTP(this.lineBuf)) {
+                // Got one
+                break;
+            } else if (i == -1 || count >= this.maxGarbageLines) {
+                // Giving up
+                throw new ProtocolException("The server failed to respond with a " +
+                        "valid HTTP response");
+            }
+            count++;
+        } while(true);
+        //create the status line from the status string
+        StatusLine statusline = BasicStatusLine.parse(this.lineBuf, 0, this.lineBuf.length());
+        return this.responseFactory.newHttpResponse(statusline, null);
+    }
+
+}