michael@0: /*
michael@0:  * ====================================================================
michael@0:  * Licensed to the Apache Software Foundation (ASF) under one
michael@0:  * or more contributor license agreements.  See the NOTICE file
michael@0:  * distributed with this work for additional information
michael@0:  * regarding copyright ownership.  The ASF licenses this file
michael@0:  * to you under the Apache License, Version 2.0 (the
michael@0:  * "License"); you may not use this file except in compliance
michael@0:  * with the License.  You may obtain a copy of the License at
michael@0:  *
michael@0:  *   http://www.apache.org/licenses/LICENSE-2.0
michael@0:  *
michael@0:  * Unless required by applicable law or agreed to in writing,
michael@0:  * software distributed under the License is distributed on an
michael@0:  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
michael@0:  * KIND, either express or implied.  See the License for the
michael@0:  * specific language governing permissions and limitations
michael@0:  * under the License.
michael@0:  * ====================================================================
michael@0:  *
michael@0:  * This software consists of voluntary contributions made by many
michael@0:  * individuals on behalf of the Apache Software Foundation.  For more
michael@0:  * information on the Apache Software Foundation, please see
michael@0:  * <http://www.apache.org/>.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: package ch.boye.httpclientandroidlib.impl.io;
michael@0: 
michael@0: import java.io.IOException;
michael@0: import java.util.ArrayList;
michael@0: import java.util.List;
michael@0: 
michael@0: import ch.boye.httpclientandroidlib.Header;
michael@0: import ch.boye.httpclientandroidlib.HttpException;
michael@0: import ch.boye.httpclientandroidlib.HttpMessage;
michael@0: import ch.boye.httpclientandroidlib.ParseException;
michael@0: import ch.boye.httpclientandroidlib.ProtocolException;
michael@0: import ch.boye.httpclientandroidlib.io.HttpMessageParser;
michael@0: import ch.boye.httpclientandroidlib.io.SessionInputBuffer;
michael@0: import ch.boye.httpclientandroidlib.message.LineParser;
michael@0: import ch.boye.httpclientandroidlib.message.BasicLineParser;
michael@0: import ch.boye.httpclientandroidlib.params.CoreConnectionPNames;
michael@0: import ch.boye.httpclientandroidlib.params.HttpParams;
michael@0: import ch.boye.httpclientandroidlib.util.CharArrayBuffer;
michael@0: 
michael@0: /**
michael@0:  * Abstract base class for HTTP message parsers that obtain input from
michael@0:  * an instance of {@link SessionInputBuffer}.
michael@0:  * <p>
michael@0:  * The following parameters can be used to customize the behavior of this
michael@0:  * class:
michael@0:  * <ul>
michael@0:  *  <li>{@link ch.boye.httpclientandroidlib.params.CoreConnectionPNames#MAX_HEADER_COUNT}</li>
michael@0:  *  <li>{@link ch.boye.httpclientandroidlib.params.CoreConnectionPNames#MAX_LINE_LENGTH}</li>
michael@0:  * </ul>
michael@0:  *
michael@0:  * @since 4.0
michael@0:  */
michael@0: public abstract class AbstractMessageParser implements HttpMessageParser {
michael@0: 
michael@0:     private static final int HEAD_LINE    = 0;
michael@0:     private static final int HEADERS      = 1;
michael@0: 
michael@0:     private final SessionInputBuffer sessionBuffer;
michael@0:     private final int maxHeaderCount;
michael@0:     private final int maxLineLen;
michael@0:     private final List headerLines;
michael@0:     protected final LineParser lineParser;
michael@0: 
michael@0:     private int state;
michael@0:     private HttpMessage message;
michael@0: 
michael@0:     /**
michael@0:      * Creates an instance of this class.
michael@0:      *
michael@0:      * @param buffer the session input buffer.
michael@0:      * @param parser the line parser.
michael@0:      * @param params HTTP parameters.
michael@0:      */
michael@0:     public AbstractMessageParser(
michael@0:             final SessionInputBuffer buffer,
michael@0:             final LineParser parser,
michael@0:             final HttpParams params) {
michael@0:         super();
michael@0:         if (buffer == null) {
michael@0:             throw new IllegalArgumentException("Session input buffer may not be null");
michael@0:         }
michael@0:         if (params == null) {
michael@0:             throw new IllegalArgumentException("HTTP parameters may not be null");
michael@0:         }
michael@0:         this.sessionBuffer = buffer;
michael@0:         this.maxHeaderCount = params.getIntParameter(
michael@0:                 CoreConnectionPNames.MAX_HEADER_COUNT, -1);
michael@0:         this.maxLineLen = params.getIntParameter(
michael@0:                 CoreConnectionPNames.MAX_LINE_LENGTH, -1);
michael@0:         this.lineParser = (parser != null) ? parser : BasicLineParser.DEFAULT;
michael@0:         this.headerLines = new ArrayList();
michael@0:         this.state = HEAD_LINE;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Parses HTTP headers from the data receiver stream according to the generic
michael@0:      * format as given in Section 3.1 of RFC 822, RFC-2616 Section 4 and 19.3.
michael@0:      *
michael@0:      * @param inbuffer Session input buffer
michael@0:      * @param maxHeaderCount maximum number of headers allowed. If the number
michael@0:      *  of headers received from the data stream exceeds maxCount value, an
michael@0:      *  IOException will be thrown. Setting this parameter to a negative value
michael@0:      *  or zero will disable the check.
michael@0:      * @param maxLineLen maximum number of characters for a header line,
michael@0:      *  including the continuation lines. Setting this parameter to a negative
michael@0:      *  value or zero will disable the check.
michael@0:      * @return array of HTTP headers
michael@0:      * @param parser line parser to use. Can be <code>null</code>, in which case
michael@0:      *  the default implementation of this interface will be used.
michael@0:      *
michael@0:      * @throws IOException in case of an I/O error
michael@0:      * @throws HttpException in case of HTTP protocol violation
michael@0:      */
michael@0:     public static Header[] parseHeaders(
michael@0:             final SessionInputBuffer inbuffer,
michael@0:             int maxHeaderCount,
michael@0:             int maxLineLen,
michael@0:             LineParser parser)
michael@0:         throws HttpException, IOException {
michael@0:         if (parser == null) {
michael@0:             parser = BasicLineParser.DEFAULT;
michael@0:         }
michael@0:         List headerLines = new ArrayList();
michael@0:         return parseHeaders(inbuffer, maxHeaderCount, maxLineLen, parser, headerLines);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Parses HTTP headers from the data receiver stream according to the generic
michael@0:      * format as given in Section 3.1 of RFC 822, RFC-2616 Section 4 and 19.3.
michael@0:      *
michael@0:      * @param inbuffer Session input buffer
michael@0:      * @param maxHeaderCount maximum number of headers allowed. If the number
michael@0:      *  of headers received from the data stream exceeds maxCount value, an
michael@0:      *  IOException will be thrown. Setting this parameter to a negative value
michael@0:      *  or zero will disable the check.
michael@0:      * @param maxLineLen maximum number of characters for a header line,
michael@0:      *  including the continuation lines. Setting this parameter to a negative
michael@0:      *  value or zero will disable the check.
michael@0:      * @param parser line parser to use.
michael@0:      * @param headerLines List of header lines. This list will be used to store
michael@0:      *   intermediate results. This makes it possible to resume parsing of
michael@0:      *   headers in case of a {@link java.io.InterruptedIOException}.
michael@0:      *
michael@0:      * @return array of HTTP headers
michael@0:      *
michael@0:      * @throws IOException in case of an I/O error
michael@0:      * @throws HttpException in case of HTTP protocol violation
michael@0:      *
michael@0:      * @since 4.1
michael@0:      */
michael@0:     public static Header[] parseHeaders(
michael@0:             final SessionInputBuffer inbuffer,
michael@0:             int maxHeaderCount,
michael@0:             int maxLineLen,
michael@0:             final LineParser parser,
michael@0:             final List headerLines)
michael@0:         throws HttpException, IOException {
michael@0: 
michael@0:         if (inbuffer == null) {
michael@0:             throw new IllegalArgumentException("Session input buffer may not be null");
michael@0:         }
michael@0:         if (parser == null) {
michael@0:             throw new IllegalArgumentException("Line parser may not be null");
michael@0:         }
michael@0:         if (headerLines == null) {
michael@0:             throw new IllegalArgumentException("Header line list may not be null");
michael@0:         }
michael@0: 
michael@0:         CharArrayBuffer current = null;
michael@0:         CharArrayBuffer previous = null;
michael@0:         for (;;) {
michael@0:             if (current == null) {
michael@0:                 current = new CharArrayBuffer(64);
michael@0:             } else {
michael@0:                 current.clear();
michael@0:             }
michael@0:             int l = inbuffer.readLine(current);
michael@0:             if (l == -1 || current.length() < 1) {
michael@0:                 break;
michael@0:             }
michael@0:             // Parse the header name and value
michael@0:             // Check for folded headers first
michael@0:             // Detect LWS-char see HTTP/1.0 or HTTP/1.1 Section 2.2
michael@0:             // discussion on folded headers
michael@0:             if ((current.charAt(0) == ' ' || current.charAt(0) == '\t') && previous != null) {
michael@0:                 // we have continuation folded header
michael@0:                 // so append value
michael@0:                 int i = 0;
michael@0:                 while (i < current.length()) {
michael@0:                     char ch = current.charAt(i);
michael@0:                     if (ch != ' ' && ch != '\t') {
michael@0:                         break;
michael@0:                     }
michael@0:                     i++;
michael@0:                 }
michael@0:                 if (maxLineLen > 0
michael@0:                         && previous.length() + 1 + current.length() - i > maxLineLen) {
michael@0:                     throw new IOException("Maximum line length limit exceeded");
michael@0:                 }
michael@0:                 previous.append(' ');
michael@0:                 previous.append(current, i, current.length() - i);
michael@0:             } else {
michael@0:                 headerLines.add(current);
michael@0:                 previous = current;
michael@0:                 current = null;
michael@0:             }
michael@0:             if (maxHeaderCount > 0 && headerLines.size() >= maxHeaderCount) {
michael@0:                 throw new IOException("Maximum header count exceeded");
michael@0:             }
michael@0:         }
michael@0:         Header[] headers = new Header[headerLines.size()];
michael@0:         for (int i = 0; i < headerLines.size(); i++) {
michael@0:             CharArrayBuffer buffer = (CharArrayBuffer) headerLines.get(i);
michael@0:             try {
michael@0:                 headers[i] = parser.parseHeader(buffer);
michael@0:             } catch (ParseException ex) {
michael@0:                 throw new ProtocolException(ex.getMessage());
michael@0:             }
michael@0:         }
michael@0:         return headers;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Subclasses must override this method to generate an instance of
michael@0:      * {@link HttpMessage} based on the initial input from the session buffer.
michael@0:      * <p>
michael@0:      * Usually this method is expected to read just the very first line or
michael@0:      * the very first valid from the data stream and based on the input generate
michael@0:      * an appropriate instance of {@link HttpMessage}.
michael@0:      *
michael@0:      * @param sessionBuffer the session input buffer.
michael@0:      * @return HTTP message based on the input from the session buffer.
michael@0:      * @throws IOException in case of an I/O error.
michael@0:      * @throws HttpException in case of HTTP protocol violation.
michael@0:      * @throws ParseException in case of a parse error.
michael@0:      */
michael@0:     protected abstract HttpMessage parseHead(SessionInputBuffer sessionBuffer)
michael@0:         throws IOException, HttpException, ParseException;
michael@0: 
michael@0:     public HttpMessage parse() throws IOException, HttpException {
michael@0:         int st = this.state;
michael@0:         switch (st) {
michael@0:         case HEAD_LINE:
michael@0:             try {
michael@0:                 this.message = parseHead(this.sessionBuffer);
michael@0:             } catch (ParseException px) {
michael@0:                 throw new ProtocolException(px.getMessage(), px);
michael@0:             }
michael@0:             this.state = HEADERS;
michael@0:             //$FALL-THROUGH$
michael@0:         case HEADERS:
michael@0:             Header[] headers = AbstractMessageParser.parseHeaders(
michael@0:                     this.sessionBuffer,
michael@0:                     this.maxHeaderCount,
michael@0:                     this.maxLineLen,
michael@0:                     this.lineParser,
michael@0:                     this.headerLines);
michael@0:             this.message.setHeaders(headers);
michael@0:             HttpMessage result = this.message;
michael@0:             this.message = null;
michael@0:             this.headerLines.clear();
michael@0:             this.state = HEAD_LINE;
michael@0:             return result;
michael@0:         default:
michael@0:             throw new IllegalStateException("Inconsistent parser state");
michael@0:         }
michael@0:     }
michael@0: 
michael@0: }