RegexPathMapping.java

/*
 * Copyright 2015 LINE Corporation
 *
 * LINE Corporation 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 com.linecorp.armeria.server;

import static java.util.Objects.requireNonNull;

import java.util.regex.Pattern;

final class RegexPathMapping extends AbstractPathMapping {

    private final Pattern regex;
    private final String loggerName;
    private final String strVal;

    RegexPathMapping(Pattern regex) {
        this.regex = requireNonNull(regex, "regex");
        loggerName = toLoggerName(regex);
        strVal = "regex: " + regex.pattern();
    }

    @Override
    protected String doApply(String path) {
        return regex.matcher(path).find() ? path : null;
    }

    @Override
    public String loggerName() {
        return loggerName;
    }

    private static String toLoggerName(Pattern regex) {
        final String regexStr = regex.pattern();
        final String prefix = "regex.";
        final StringBuilder buf = new StringBuilder(prefix.length() + regexStr.length());
        buf.append(prefix);
        for (int i = 0; i < regexStr.length(); i++) {
            final char ch = regexStr.charAt(i);
            if (Character.isJavaIdentifierPart(ch)) {
                buf.append(ch);
            } else {
                buf.append('_');
            }
        }
        return buf.toString();
    }

    @Override
    public String metricName() {
        return strVal;
    }

    @Override
    public int hashCode() {
        return strVal.hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        return obj instanceof RegexPathMapping &&
               (this == obj || regex.pattern().equals(((RegexPathMapping) obj).regex.pattern()));
    }

    @Override
    public String toString() {
        return strVal;
    }
}