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/*
* 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.
*/
package org.apache.tomcat.util.http;
public class Method {
/*
* This class was originally created to hold the bytes to String conversion method. It turns out that these
* constants are just as much of a benefit to performance - if used consistently.
*
* If the String constants for the methods are used throughout the code-base, that allows String.equals() to use the
* 'same object shortcut' when checking if a request is (or is not) using a particular method. That is faster than a
* character by character comparison. That results in a further performance improvement that is as big - or possibly
* slightly bigger - than the improvement obtained by using the optimised conversion.
*/
// Standard HTTP methods supported by HttpServlet
public static final String GET = "GET";
public static final String POST = "POST";
public static final String PUT = "PUT";
public static final String PATCH = "PATCH";
public static final String HEAD = "HEAD";
public static final String OPTIONS = "OPTIONS";
public static final String DELETE = "DELETE";
public static final String TRACE = "TRACE";
// Additional WebDAV methods
public static final String PROPFIND = "PROPFIND";
public static final String PROPPATCH = "PROPPATCH";
public static final String MKCOL = "MKCOL";
public static final String COPY = "COPY";
public static final String MOVE = "MOVE";
public static final String LOCK = "LOCK";
public static final String UNLOCK = "UNLOCK";
// Other methods recognised by Tomcat
public static final String CONNECT = "CONNECT";
/**
* Provides optimised conversion from bytes to Strings for known HTTP methods. The bytes are assumed to be an
* ISO-8859-1 encoded representation of an HTTP method. The method is not validated as being a token, but only valid
* HTTP method names will be returned.
* <p>
* Doing it this way is ~10x faster than using MessageBytes.toStringType() saving ~40ns per request which is ~1% of
* the processing time for a minimal "Hello World" type servlet. For non-standard methods there is an additional
* overhead of ~2.5ns per request.
* <p>
* Pretty much every request ends up converting the method to a String so it is more efficient to do this straight
* away and always use Strings.
*
* @param buf The byte buffer containing the HTTP method to convert
* @param start The first byte of the HTTP method
* @param len The number of bytes to convert
*
* @return The HTTP method as a String or {@code null} if the method is not recognised.
*/
public static String bytesToString(byte[] buf, int start, int len) {
switch (buf[start]) {
case 'G': {
if (len == 3 && buf[start + 1] == 'E' && buf[start + 2] == 'T') {
return GET;
}
break;
}
case 'P': {
if (len == 4 && buf[start + 1] == 'O' && buf[start + 2] == 'S' && buf[start + 3] == 'T') {
return POST;
} else if (len == 3 && buf[start + 1] == 'U' && buf[start + 2] == 'T') {
return PUT;
} else if (len == 5 && buf[start + 1] == 'A' && buf[start + 2] == 'T' && buf[start + 3] == 'C' &&
buf[start + 4] == 'H') {
return PATCH;
} else if (len == 8 && buf[start + 1] == 'R' && buf[start + 2] == 'O' && buf[start + 3] == 'P' &&
buf[start + 4] == 'F' && buf[start + 5] == 'I' && buf[start + 6] == 'N' &&
buf[start + 7] == 'D') {
return PROPFIND;
} else if (len == 9 && buf[start + 1] == 'R' && buf[start + 2] == 'O' && buf[start + 3] == 'P' &&
buf[start + 4] == 'P' && buf[start + 5] == 'A' && buf[start + 6] == 'T' &&
buf[start + 7] == 'C' && buf[start + 8] == 'H') {
return PROPPATCH;
}
break;
}
case 'H': {
if (len == 4 && buf[start + 1] == 'E' && buf[start + 2] == 'A' && buf[start + 3] == 'D') {
return HEAD;
}
break;
}
case 'O': {
if (len == 7 && buf[start + 1] == 'P' && buf[start + 2] == 'T' && buf[start + 3] == 'I' &&
buf[start + 4] == 'O' && buf[start + 5] == 'N' && buf[start + 6] == 'S') {
return OPTIONS;
}
break;
}
case 'D': {
if (len == 6 && buf[start + 1] == 'E' && buf[start + 2] == 'L' && buf[start + 3] == 'E' &&
buf[start + 4] == 'T' && buf[start + 5] == 'E') {
return DELETE;
}
break;
}
case 'T': {
if (len == 5 && buf[start + 1] == 'R' && buf[start + 2] == 'A' && buf[start + 3] == 'C' &&
buf[start + 4] == 'E') {
return TRACE;
}
break;
}
case 'M': {
if (len == 5 && buf[start + 1] == 'K' && buf[start + 2] == 'C' && buf[start + 3] == 'O' &&
buf[start + 4] == 'L') {
return MKCOL;
} else if (len == 4 && buf[start + 1] == 'O' && buf[start + 2] == 'V' && buf[start + 3] == 'E') {
return MOVE;
}
break;
}
case 'C': {
if (len == 4 && buf[start + 1] == 'O' && buf[start + 2] == 'P' && buf[start + 3] == 'Y') {
return COPY;
} else if (len == 7 && buf[start + 1] == 'O' && buf[start + 2] == 'N' && buf[start + 3] == 'N' &&
buf[start + 4] == 'E' && buf[start + 5] == 'C' && buf[start + 6] == 'T') {
return CONNECT;
}
break;
}
case 'L': {
if (len == 4 && buf[start + 1] == 'O' && buf[start + 2] == 'C' && buf[start + 3] == 'K') {
return LOCK;
}
break;
}
case 'U': {
if (len == 6 && buf[start + 1] == 'N' && buf[start + 2] == 'L' && buf[start + 3] == 'O' &&
buf[start + 4] == 'C' && buf[start + 5] == 'K') {
return UNLOCK;
}
break;
}
}
return null;
}
private Method() {
// Utility class - hide default constructor
}
}
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