com.twosigma.beaker.core.rest.RecentMenuRest.java Source code

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Here is the source code for com.twosigma.beaker.core.rest.RecentMenuRest.java

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/*
 *  Copyright 2014 TWO SIGMA OPEN SOURCE, LLC
 *
 *  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.twosigma.beaker.core.rest;

import com.google.inject.Inject;
import com.google.inject.Singleton;
import com.twosigma.beaker.core.module.config.BeakerConfig;
import com.twosigma.beaker.shared.module.util.GeneralUtils;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.nio.file.attribute.PosixFilePermission;
import java.util.ArrayList;
import java.util.Deque;
import java.util.Iterator;
import java.util.List;
import java.util.concurrent.LinkedBlockingDeque;
import javax.ws.rs.FormParam;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Implementation of recent file manager that offers a RESTful API
 */
@Path("recent-menu")
@Produces(MediaType.APPLICATION_JSON)
@Singleton
@SuppressWarnings("unchecked")
public class RecentMenuRest {

    private final static Logger logger = LoggerFactory.getLogger(RecentMenuRest.class.getName());

    private final java.nio.file.Path recentDocumentsFile;
    private final Deque<String> recentDocuments;
    private final GeneralUtils utils;

    @Inject
    public RecentMenuRest(BeakerConfig bkConfig, GeneralUtils utils) {
        this.utils = utils;
        this.recentDocumentsFile = Paths.get(bkConfig.getRecentNotebooksFileUrl());
        this.recentDocuments = new LinkedBlockingDeque<>();

        // read from file -> recentDocuments
        List<String> lines = new ArrayList<>();
        if (Files.exists(recentDocumentsFile)) {
            try {
                lines = Files.readAllLines(recentDocumentsFile, StandardCharsets.UTF_8);
            } catch (IOException ex) {
                logger.warn("Failed to get recent documents", ex);
            }
        }
        for (String line : lines) {
            addRecentDocument(line.trim());
        }
    }

    private List<String> getRecentDocuments() {
        return new ArrayList<>(this.recentDocuments);
    }

    private void removeRecentDocument(String json) {
        if (this.recentDocuments.contains(json)) {
            this.recentDocuments.remove(json);
        }
    }

    private void addRecentDocument(String json) {
        removeRecentDocument(json);
        this.recentDocuments.addFirst(json);
    }

    private void recordToFile() throws IOException {
        this.utils.saveFile(this.recentDocumentsFile, StringUtils.join(reverseView(this.recentDocuments), "\n"));
        try {
            utils.setPermissions(this.recentDocumentsFile, PosixFilePermission.OWNER_READ,
                    PosixFilePermission.OWNER_WRITE);
        } catch (IOException e) {
            logger.warn("Unable to set permissions to recent document", e);
        }
    }

    private static List<String> reverseView(Deque<String> input) {
        List<String> ret = new ArrayList<>(input.size());
        Iterator<String> it = input.descendingIterator();
        while (it.hasNext()) {
            ret.add(it.next());
        }
        return ret;
    }

    @GET
    @Path("getItems")
    public List<String> getItems() {
        return getRecentDocuments();
    }

    @POST
    @Path("addItem")
    public void addItem(@FormParam("item") String item) throws IOException {
        addRecentDocument(item);
        recordToFile();
    }

    @POST
    @Path("removeItem")
    public void removeItem(@FormParam("item") String json) throws IOException {
        removeRecentDocument(json);
        recordToFile();
    }

    @POST
    @Path("clear")
    public void clear() throws IOException {
        this.recentDocuments.clear();
        recordToFile();
    }
}