config-loader/config-loader-impl/src/main/java/org/opendaylight/bgpcep/config/loader/impl/ConfigLoaderImpl.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.bgpcep.config.loader.impl;
  10
  11 import static java.util.Objects.requireNonNull;
  12
  13 import java.io.File;
  14 import java.io.FileInputStream;
  15 import java.io.IOException;
  16 import java.io.InputStream;
  17 import java.net.URISyntaxException;
  18 import java.nio.file.ClosedWatchServiceException;
  19 import java.nio.file.WatchEvent;
  20 import java.nio.file.WatchKey;
  21 import java.nio.file.WatchService;
  22 import java.util.HashMap;
  23 import java.util.Map;
  24 import java.util.regex.Pattern;
  25 import javax.annotation.concurrent.GuardedBy;
  26 import javax.xml.parsers.ParserConfigurationException;
  27 import javax.xml.stream.XMLInputFactory;
  28 import javax.xml.stream.XMLStreamException;
  29 import javax.xml.stream.XMLStreamReader;
  30 import org.opendaylight.bgpcep.config.loader.spi.ConfigFileProcessor;
  31 import org.opendaylight.bgpcep.config.loader.spi.ConfigLoader;
  32 import org.opendaylight.mdsal.binding.dom.codec.api.BindingNormalizedNodeSerializer;
  33 import org.opendaylight.yangtools.concepts.AbstractRegistration;
  34 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  35 import org.opendaylight.yangtools.yang.data.api.schema.stream.NormalizedNodeStreamWriter;
  36 import org.opendaylight.yangtools.yang.data.codec.xml.XmlParserStream;
  37 import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNormalizedNodeStreamWriter;
  38 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeResult;
  39 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
  40 import org.opendaylight.yangtools.yang.model.api.SchemaNode;
  41 import org.opendaylight.yangtools.yang.model.util.SchemaContextUtil;
  42 import org.slf4j.Logger;
  43 import org.slf4j.LoggerFactory;
  44 import org.xml.sax.SAXException;
  45
  46 public final class ConfigLoaderImpl implements ConfigLoader, AutoCloseable {
  47     private static final Logger LOG = LoggerFactory.getLogger(ConfigLoaderImpl.class);
  48     private static final String INTERRUPTED = "InterruptedException";
  49     private static final String EXTENSION = "-.*\\.xml";
  50     private static final String INITIAL = "^";
  51     @GuardedBy("this")
  52     private final Map<String, ConfigFileProcessor> configServices = new HashMap<>();
  53     private final SchemaContext schemaContext;
  54     private final BindingNormalizedNodeSerializer bindingSerializer;
  55     private final String path;
  56     private final Thread watcherThread;
  57     @GuardedBy("this")
  58     private boolean closed = false;
  59
  60     public ConfigLoaderImpl(final SchemaContext schemaContext, final BindingNormalizedNodeSerializer bindingSerializer,
  61             final FileWatcher fileWatcher) {
  62         this.schemaContext = requireNonNull(schemaContext);
  63         this.bindingSerializer = requireNonNull(bindingSerializer);
  64         this.path = requireNonNull(fileWatcher.getPathFile());
  65         this.watcherThread = new Thread(new ConfigLoaderImplRunnable(requireNonNull(fileWatcher.getWatchService())));
  66     }
  67
  68     public void init() {
  69         this.watcherThread.start();
  70         LOG.info("Config Loader service initiated");
  71     }
  72
  73     private void handleConfigFile(final ConfigFileProcessor config, final String filename) {
  74         final NormalizedNode<?, ?> dto;
  75         try {
  76             dto = parseDefaultConfigFile(config, filename);
  77         } catch (final IOException | XMLStreamException | ParserConfigurationException | SAXException
  78                 | URISyntaxException e) {
  79             LOG.warn("Failed to parse config file {}", filename, e);
  80             return;
  81         }
  82         LOG.info("Loading initial config {}", filename);
  83         config.loadConfiguration(dto);
  84     }
  85
  86     private NormalizedNode<?, ?> parseDefaultConfigFile(final ConfigFileProcessor config, final String filename)
  87             throws IOException, XMLStreamException, ParserConfigurationException, SAXException, URISyntaxException {
  88         final NormalizedNodeResult result = new NormalizedNodeResult();
  89         final NormalizedNodeStreamWriter streamWriter = ImmutableNormalizedNodeStreamWriter.from(result);
  90
  91         try (InputStream resourceAsStream = new FileInputStream(new File(this.path, filename))) {
  92             final XMLInputFactory factory = XMLInputFactory.newInstance();
  93             final XMLStreamReader reader = factory.createXMLStreamReader(resourceAsStream);
  94
  95             final SchemaNode schemaNode = SchemaContextUtil
  96                     .findDataSchemaNode(this.schemaContext, config.getSchemaPath());
  97             final XmlParserStream xmlParser = XmlParserStream.create(streamWriter, this.schemaContext, schemaNode);
  98             xmlParser.parse(reader);
  99             resourceAsStream.close();
 100             reader.close();
 101             xmlParser.close();
 102         }
 103
 104         return result.getResult();
 105     }
 106
 107     @Override
 108     public synchronized AbstractRegistration registerConfigFile(final ConfigFileProcessor config) {
 109         final String pattern = INITIAL + config.getSchemaPath().getLastComponent().getLocalName() + EXTENSION;
 110         this.configServices.put(pattern, config);
 111
 112         final File[] fList = new File(this.path).listFiles();
 113         if (fList != null) {
 114             for (final File file : fList) {
 115                 if (file.isFile()) {
 116                     final String filename = file.getName();
 117                     if (Pattern.matches(pattern, filename)) {
 118                         handleConfigFile(config, filename);
 119                     }
 120                 }
 121             }
 122         }
 123
 124         return new AbstractRegistration() {
 125             @Override
 126             protected void removeRegistration() {
 127                 synchronized (ConfigLoaderImpl.this) {
 128                     ConfigLoaderImpl.this.configServices.remove(pattern);
 129                 }
 130             }
 131         };
 132     }
 133
 134     @Override
 135     public BindingNormalizedNodeSerializer getBindingNormalizedNodeSerializer() {
 136         return this.bindingSerializer;
 137     }
 138
 139
 140     @Override
 141     public synchronized void close() throws Exception {
 142         LOG.info("Config Loader service closed");
 143         this.closed = true;
 144         this.watcherThread.interrupt();
 145     }
 146
 147     private class ConfigLoaderImplRunnable implements Runnable {
 148         private final WatchService watchService;
 149
 150         ConfigLoaderImplRunnable(final WatchService watchService) {
 151             this.watchService = watchService;
 152         }
 153
 154         @Override
 155         public void run() {
 156             while (!Thread.currentThread().isInterrupted()) {
 157                 handleChanges(this.watchService);
 158             }
 159         }
 160
 161         private synchronized void handleChanges(final WatchService watchService) {
 162             final WatchKey key;
 163             try {
 164                 key = watchService.take();
 165             } catch (final InterruptedException | ClosedWatchServiceException e) {
 166                 if (!ConfigLoaderImpl.this.closed) {
 167                     LOG.warn(INTERRUPTED, e);
 168                     Thread.currentThread().interrupt();
 169                 }
 170                 return;
 171             }
 172
 173             if (key != null) {
 174                 for (final WatchEvent<?> event : key.pollEvents()) {
 175                     handleEvent(event.context().toString());
 176                 }
 177                 final boolean reset = key.reset();
 178                 if (!reset) {
 179                     LOG.warn("Could not reset the watch key.");
 180                 }
 181             }
 182         }
 183
 184         private synchronized void handleEvent(final String filename) {
 185             ConfigLoaderImpl.this.configServices.entrySet().stream()
 186                     .filter(entry -> Pattern.matches(entry.getKey(), filename))
 187                     .forEach(entry -> handleConfigFile(entry.getValue(), filename));
 188         }
 189     }
 190 }