/*
* ====================================================================
* 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.nio.codecs;
import java.io.IOException;
import java.nio.channels.ReadableByteChannel;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpException;
import org.apache.http.HttpMessage;
import org.apache.http.MessageConstraintException;
import org.apache.http.ParseException;
import org.apache.http.ProtocolException;
import org.apache.http.annotation.NotThreadSafe;
import org.apache.http.config.MessageConstraints;
import org.apache.http.message.BasicLineParser;
import org.apache.http.message.LineParser;
import org.apache.http.nio.NHttpMessageParser;
import org.apache.http.nio.reactor.SessionInputBuffer;
import org.apache.http.params.HttpParamConfig;
import org.apache.http.params.HttpParams;
import org.apache.http.util.Args;
import org.apache.http.util.CharArrayBuffer;
/**
* Abstract {@link NHttpMessageParser} that serves as a base for all message
* parser implementations.
*
* @since 4.0
*/
@SuppressWarnings("deprecation")
@NotThreadSafe
public abstract class AbstractMessageParser<T extends HttpMessage> implements NHttpMessageParser<T> {
private final SessionInputBuffer sessionBuffer;
private static final int READ_HEAD_LINE = 0;
private static final int READ_HEADERS = 1;
private static final int COMPLETED = 2;
private int state;
private boolean endOfStream;
private T message;
private CharArrayBuffer lineBuf;
private final List<CharArrayBuffer> headerBufs;
protected final LineParser lineParser;
private final MessageConstraints constraints;
/**
* Creates an instance of this class.
*
* @param buffer the session input buffer.
* @param lineParser the line parser.
* @param params HTTP parameters.
*
* @deprecated (4.3) use
* {@link AbstractMessageParser#AbstractMessageParser(SessionInputBuffer, LineParser,
* MessageConstraints)}
*/
@Deprecated
public AbstractMessageParser(
final SessionInputBuffer buffer,
final LineParser lineParser,
final HttpParams params) {
super();
Args.notNull(buffer, "Session input buffer");
Args.notNull(params, "HTTP parameters");
this.sessionBuffer = buffer;
this.state = READ_HEAD_LINE;
this.endOfStream = false;
this.headerBufs = new ArrayList<CharArrayBuffer>();
this.constraints = HttpParamConfig.getMessageConstraints(params);
this.lineParser = (lineParser != null) ? lineParser : BasicLineParser.INSTANCE;
}
/**
* Creates an instance of AbstractMessageParser.
*
* @param buffer the session input buffer.
* @param lineParser the line parser. If {@code null} {@link BasicLineParser#INSTANCE}
* will be used.
* @param constraints Message constraints. If {@code null}
* {@link MessageConstraints#DEFAULT} will be used.
*
* @since 4.3
*/
public AbstractMessageParser(
final SessionInputBuffer buffer,
final LineParser lineParser,
final MessageConstraints constraints) {
super();
this.sessionBuffer = Args.notNull(buffer, "Session input buffer");
this.lineParser = lineParser != null ? lineParser : BasicLineParser.INSTANCE;
this.constraints = constraints != null ? constraints : MessageConstraints.DEFAULT;
this.headerBufs = new ArrayList<CharArrayBuffer>();
this.state = READ_HEAD_LINE;
this.endOfStream = false;
}
@Override
public void reset() {
this.state = READ_HEAD_LINE;
this.endOfStream = false;
this.headerBufs.clear();
this.message = null;
}
@Override
public int fillBuffer(final ReadableByteChannel channel) throws IOException {
final int bytesRead = this.sessionBuffer.fill(channel);
if (bytesRead == -1) {
this.endOfStream = true;
}
return bytesRead;
}
/**
* Creates {@link HttpMessage} instance based on the content of the input
* buffer containing the first line of the incoming HTTP message.
*
* @param buffer the line buffer.
* @return HTTP message.
* @throws HttpException in case of HTTP protocol violation
* @throws ParseException in case of a parse error.
*/
protected abstract T createMessage(CharArrayBuffer buffer)
throws HttpException, ParseException;
private void parseHeadLine() throws HttpException, ParseException {
this.message = createMessage(this.lineBuf);
}
private void parseHeader() throws IOException {
final CharArrayBuffer current = this.lineBuf;
final int count = this.headerBufs.size();
if ((this.lineBuf.charAt(0) == ' ' || this.lineBuf.charAt(0) == '\t') && count > 0) {
// Handle folded header line
final CharArrayBuffer previous = this.headerBufs.get(count - 1);
int i = 0;
while (i < current.length()) {
final char ch = current.charAt(i);
if (ch != ' ' && ch != '\t') {
break;
}
i++;
}
final int maxLineLen = this.constraints.getMaxLineLength();
if (maxLineLen > 0 && previous.length() + 1 + current.length() - i > maxLineLen) {
throw new MessageConstraintException("Maximum line length limit exceeded");
}
previous.append(' ');
previous.append(current, i, current.length() - i);
} else {
this.headerBufs.add(current);
this.lineBuf = null;
}
}
@Override
public T parse() throws IOException, HttpException {
while (this.state != COMPLETED) {
if (this.lineBuf == null) {
this.lineBuf = new CharArrayBuffer(64);
} else {
this.lineBuf.clear();
}
final boolean lineComplete = this.sessionBuffer.readLine(this.lineBuf, this.endOfStream);
final int maxLineLen = this.constraints.getMaxLineLength();
if (maxLineLen > 0 &&
(this.lineBuf.length() > maxLineLen ||
(!lineComplete && this.sessionBuffer.length() > maxLineLen))) {
throw new MessageConstraintException("Maximum line length limit exceeded");
}
if (!lineComplete) {
break;
}
switch (this.state) {
case READ_HEAD_LINE:
try {
parseHeadLine();
} catch (final ParseException px) {
throw new ProtocolException(px.getMessage(), px);
}
this.state = READ_HEADERS;
break;
case READ_HEADERS:
if (this.lineBuf.length() > 0) {
final int maxHeaderCount = this.constraints.getMaxHeaderCount();
if (maxHeaderCount > 0 && headerBufs.size() >= maxHeaderCount) {
throw new MessageConstraintException("Maximum header count exceeded");
}
parseHeader();
} else {
this.state = COMPLETED;
}
break;
}
if (this.endOfStream && !this.sessionBuffer.hasData()) {
this.state = COMPLETED;
}
}
if (this.state == COMPLETED) {
for (final CharArrayBuffer buffer : this.headerBufs) {
try {
this.message.addHeader(lineParser.parseHeader(buffer));
} catch (final ParseException ex) {
throw new ProtocolException(ex.getMessage(), ex);
}
}
return this.message;
} else {
return null;
}
}
}