com.google.appengine.repackaged.com.google.common.flogger.parser.MessageParser Maven / Gradle / Ivy
/*
* Copyright (C) 2012 The Flogger Authors.
*
* Licensed 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 com.google.common.flogger.parser;
/**
* Base class from which any specific message parsers are derived (e.g. {@link PrintfMessageParser}
* and {@link BraceStyleMessageParser}).
*/
public abstract class MessageParser {
/**
* The maximum allowed index (this should correspond to the MAX_ALLOWED_WIDTH in
* {@link com.google.common.flogger.backend.FormatOptions FormatOptions} because at times it is
* ambiguous as to which is being parsed).
*/
public static final int MAX_ARG_COUNT = 1000000;
/**
* Abstract parse method implemented by specific subclasses to modify parsing behavior.
*
* Note that when extending parsing behavior, it is expected that specific parsers such as
* {@link DefaultPrintfMessageParser} or {@link DefaultBraceStyleMessageParser} will be
* sub-classed. Extending this class directly is only necessary when an entirely new type of
* format needs to be supported (which should be extremely rare).
*
* Implementations of this method are required to invoke the
* {@link MessageBuilder#addParameterImpl} method of the supplied builder once for each
* parameter place-holder in the message.
*/
protected abstract void parseImpl(MessageBuilder builder) throws ParseException;
/**
* Appends the unescaped literal representation of the given message string (assumed to be escaped
* according to this parser's escaping rules). This method is designed to be invoked from a
* callback method in a {@link MessageBuilder} instance.
*
* @param out the destination into which to append characters
* @param message the escaped log message
* @param start the start index (inclusive) in the log message
* @param end the end index (exclusive) in the log message
*/
public abstract void unescape(StringBuilder out, String message, int start, int end);
}