ResourceMatcher.java

/*
 * 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.ranger.plugin.resourcematcher;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.ranger.plugin.util.StringTokenReplacer;

import java.util.Map;

abstract class ResourceMatcher implements Comparable<ResourceMatcher> {
    private static final Log LOG = LogFactory.getLog(ResourceMatcher.class);

    protected final String value;
    protected StringTokenReplacer tokenReplacer;

    static final int DYNAMIC_EVALUATION_PENALTY = 8;

    ResourceMatcher(String value) { this.value = value; }

    abstract boolean isMatch(String resourceValue, Map<String, Object> evalContext);
    abstract int getPriority();

    boolean isMatchAny() { return value != null && value.length() == 0; }

    boolean getNeedsDynamicEval() {
        return tokenReplacer != null;
    }

    @Override
    public int compareTo(ResourceMatcher other) { return Integer.compare(getPriority(), other.getPriority()); }

    @Override
    public String toString() {
        return this.getClass().getName() + "(" + this.value + ")";
    }

    void setDelimiters(char startDelimiterChar, char endDelimiterChar, char escapeChar, String tokenPrefix) {
        if(LOG.isDebugEnabled()) {
            LOG.debug("==> setDelimiters(value= " + value + ", startDelimiter=" + startDelimiterChar +
                    ", endDelimiter=" + endDelimiterChar + ", escapeChar=" + escapeChar + ", prefix=" + tokenPrefix);
        }

        if(value != null && (value.indexOf(escapeChar) != -1 || (value.indexOf(startDelimiterChar) != -1 && value.indexOf(endDelimiterChar) != -1))) {
            tokenReplacer = new StringTokenReplacer(startDelimiterChar, endDelimiterChar, escapeChar, tokenPrefix);
        }

        if(LOG.isDebugEnabled()) {
            LOG.debug("<== setDelimiters(value= " + value + ", startDelimiter=" + startDelimiterChar +
                    ", endDelimiter=" + endDelimiterChar + ", escapeChar=" + escapeChar + ", prefix=" + tokenPrefix);
        }
    }

    String getExpandedValue(Map<String, Object> evalContext) {
        final String ret;

        if(tokenReplacer != null) {
            ret = tokenReplacer.replaceTokens(value, evalContext);
        } else {
            ret = value;
        }

        return ret;
    }
}