io.gravitee.gateway.handlers.api.path.impl.AbstractPathResolver Maven / Gradle / Ivy

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/*
 * Copyright © 2015 The Gravitee team (http://gravitee.io)
 *
 * 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 io.gravitee.gateway.handlers.api.path.impl;

import io.gravitee.definition.model.Rule;
import io.gravitee.gateway.api.Request;
import io.gravitee.gateway.handlers.api.path.Path;
import io.gravitee.gateway.handlers.api.path.PathParam;
import io.gravitee.gateway.handlers.api.path.PathResolver;
import io.netty.handler.codec.http.QueryStringDecoder;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.regex.Pattern;

/**
 * A simple path resolver based on context paths definition.
 *
 * @author David BRASSELY (david.brassely at graviteesource.com)
 * @author GraviteeSource Team
 */
public abstract class AbstractPathResolver implements PathResolver {

    private static final String URL_PATH_SEPARATOR = "/";
    private static final String PATH_PARAM_PREFIX = ":";
    private static final String PATH_PARAM_REGEX = "[a-zA-Z0-9\\-._~%!$&'()* +,;=:@/|]+";

    private final List registeredPaths = new ArrayList<>();

    private static final Path UNKNOWN_PATH = new Path() {
        @Override
        public String getPath() {
            return null;
        }

        @Override
        public List getRules() {
            return Collections.emptyList();
        }
    };

    @Override
    public Path resolve(final Request request) {
        if (registeredPaths.size() == 1) {
            return registeredPaths.get(0);
        }

        String path = request.pathInfo();

        try {
            path = QueryStringDecoder.decodeComponent(path, Charset.defaultCharset());
        } catch (IllegalArgumentException iae) {}

        int pieces = -1;
        Path bestPath = null;

        // TODO PERF: We must navigate from the longest path to the shortest to avoid counting pieces.
        for (Path registerPath : registeredPaths) {
            if (registerPath.getPattern().matcher(path).lookingAt()) {
                int split = registerPath.getPath().split(URL_PATH_SEPARATOR).length;
                if (split > pieces) {
                    pieces = split;
                    bestPath = registerPath;
                }
            }
        }

        return (bestPath != null) ? bestPath : UNKNOWN_PATH;
    }

    protected void register(Path path) {
        String[] branches = path.getPath().split(URL_PATH_SEPARATOR);
        StringBuilder buffer = new StringBuilder(URL_PATH_SEPARATOR);
        List parameters = new ArrayList<>();

        for (int i = 0; i < branches.length; i++) {
            final String branch = branches[i];
            if (!branch.isEmpty()) {
                if (branch.startsWith(PATH_PARAM_PREFIX)) {
                    buffer.append(PATH_PARAM_REGEX);
                    parameters.add(new PathParam(branch.substring(PATH_PARAM_PREFIX.length()), i));
                } else {
                    buffer.append(branch);
                }

                buffer.append(URL_PATH_SEPARATOR);
            }
        }

        // Last path separator is not required to match
        buffer.append('?');

        path.setPattern(Pattern.compile(buffer.toString()));
        path.setParameters(parameters);

        registeredPaths.add(path);
    }
}