com.kurento.kmf.repository.internal.repoimpl.filesystem.ItemsMetadata.java Source code

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Here is the source code for com.kurento.kmf.repository.internal.repoimpl.filesystem.ItemsMetadata.java

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/*
 * (C) Copyright 2013 Kurento (http://kurento.org/)
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public License
 * (LGPL) version 2.1 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl-2.1.html
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 */

package com.kurento.kmf.repository.internal.repoimpl.filesystem;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.regex.Pattern;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.mongodb.DBObject;
import com.mongodb.util.JSON;

public class ItemsMetadata {

    private final Logger log = LoggerFactory.getLogger(ItemsMetadata.class);

    // TODO Avoid potential memory leaks using Google's MapMaker
    private ConcurrentMap<String, Map<String, String>> itemsMetadata;

    private final File itemsMetadataFile;

    public ItemsMetadata(File itemsMetadataFile) {
        this.itemsMetadataFile = itemsMetadataFile;
        try {
            loadItemsMetadata();
        } catch (IOException e) {
            log.warn("Exception while loading items metadata", e);
        }
    }

    private void loadItemsMetadata() throws IOException {
        itemsMetadata = new ConcurrentHashMap<>();
        DBObject contents = (DBObject) JSON.parse(loadFileAsString());
        if (contents != null) {
            for (String key : contents.keySet()) {
                try {
                    DBObject metadata = (DBObject) contents.get(key);
                    Map<String, String> map = new HashMap<>();
                    for (String metadataKey : metadata.keySet()) {
                        map.put(metadataKey, metadata.get(metadataKey).toString());
                    }
                    itemsMetadata.put(key, map);
                } catch (ClassCastException e) {
                    log.warn("Attribute '{}' should be an object", key);
                }
            }
        }
    }

    private String loadFileAsString() throws IOException {

        if (!itemsMetadataFile.exists()) {
            return "";
        }

        StringBuilder sb = new StringBuilder();
        try (FileReader metadataFile = new FileReader(itemsMetadataFile)) {
            try (BufferedReader br = new BufferedReader(metadataFile)) {
                String line;
                while ((line = br.readLine()) != null) {
                    sb.append(line).append("\n");
                }
            }
        }
        return sb.toString();
    }

    public synchronized void setMetadataForId(String id, Map<String, String> metadata) {
        itemsMetadata.put(id, metadata);
    }

    public synchronized Map<String, String> loadMetadata(String id) {
        Map<String, String> metadata = itemsMetadata.get(id);
        if (metadata == null) {
            metadata = new HashMap<>();
            itemsMetadata.put(id, metadata);
        }
        return metadata;
    }

    public List<Entry<String, Map<String, String>>> findByAttValue(String attributeName, String value) {

        List<Entry<String, Map<String, String>>> list = new ArrayList<>();

        for (Entry<String, Map<String, String>> item : itemsMetadata.entrySet()) {
            String attValue = item.getValue().get(attributeName);
            if (attValue != null && attValue.equals(value)) {
                list.add(item);
            }
        }

        return list;
    }

    public List<Entry<String, Map<String, String>>> findByAttRegex(String attributeName, String regex) {

        Pattern pattern = Pattern.compile(regex);

        List<Entry<String, Map<String, String>>> list = new ArrayList<>();

        for (Entry<String, Map<String, String>> item : itemsMetadata.entrySet()) {
            String value = item.getValue().get(attributeName);
            if (value != null && pattern.matcher(value).matches()) {
                list.add(item);
            }
        }

        return list;
    }

    public void save() {

        try {
            if (!itemsMetadataFile.exists()) {
                itemsMetadataFile.getParentFile().mkdirs();
                itemsMetadataFile.createNewFile();
            }
            try (PrintWriter writer = new PrintWriter(itemsMetadataFile)) {
                String content = JSON.serialize(itemsMetadata);
                writer.print(content);
            }
        } catch (IOException e) {
            log.error("Exception writing metadata file", e);
        }
    }
}