yang/yang-model-util/src/main/java/org/opendaylight/yangtools/yang/model/repo/util/FilesystemSchemaSourceCache.java

   1 /*
   2  * Copyright (c) 2014 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 package org.opendaylight.yangtools.yang.model.repo.util;
   9
  10 import com.google.common.base.MoreObjects.ToStringHelper;
  11 import com.google.common.base.Optional;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.base.Strings;
  14 import com.google.common.collect.Lists;
  15 import com.google.common.util.concurrent.CheckedFuture;
  16 import com.google.common.util.concurrent.Futures;
  17 import java.io.File;
  18 import java.io.FilenameFilter;
  19 import java.io.IOException;
  20 import java.io.InputStream;
  21 import java.nio.file.FileVisitResult;
  22 import java.nio.file.Files;
  23 import java.nio.file.Path;
  24 import java.nio.file.SimpleFileVisitor;
  25 import java.nio.file.StandardCopyOption;
  26 import java.nio.file.attribute.BasicFileAttributes;
  27 import java.text.DateFormat;
  28 import java.text.ParseException;
  29 import java.util.Collections;
  30 import java.util.Date;
  31 import java.util.List;
  32 import java.util.Map;
  33 import java.util.TreeMap;
  34 import java.util.regex.Matcher;
  35 import java.util.regex.Pattern;
  36 import org.opendaylight.yangtools.yang.common.SimpleDateFormatUtil;
  37 import org.opendaylight.yangtools.yang.model.repo.api.MissingSchemaSourceException;
  38 import org.opendaylight.yangtools.yang.model.repo.api.RevisionSourceIdentifier;
  39 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceException;
  40 import org.opendaylight.yangtools.yang.model.repo.api.SchemaSourceRepresentation;
  41 import org.opendaylight.yangtools.yang.model.repo.api.SourceIdentifier;
  42 import org.opendaylight.yangtools.yang.model.repo.api.YangTextSchemaSource;
  43 import org.opendaylight.yangtools.yang.model.repo.spi.PotentialSchemaSource.Costs;
  44 import org.opendaylight.yangtools.yang.model.repo.spi.SchemaSourceRegistry;
  45 import org.slf4j.Logger;
  46 import org.slf4j.LoggerFactory;
  47
  48 /**
  49  * Cache implementation that stores schemas in form of files under provided folder.
  50  */
  51 public final class FilesystemSchemaSourceCache<T extends SchemaSourceRepresentation>
  52         extends AbstractSchemaSourceCache<T> {
  53
  54     private static final Logger LOG = LoggerFactory.getLogger(FilesystemSchemaSourceCache.class);
  55
  56     // Init storage adapters
  57     private static final Map<Class<? extends SchemaSourceRepresentation>,
  58             StorageAdapter<? extends SchemaSourceRepresentation>> STORAGE_ADAPTERS = Collections.singletonMap(
  59                     YangTextSchemaSource.class, new YangTextSchemaStorageAdapter());
  60
  61     private static final Pattern CACHED_FILE_PATTERN =
  62             Pattern.compile("(?<moduleName>[^@]+)" + "(@(?<revision>" + SourceIdentifier.REVISION_PATTERN + "))?");
  63
  64     private final Class<T> representation;
  65     private final File storageDirectory;
  66
  67     public FilesystemSchemaSourceCache(
  68             final SchemaSourceRegistry consumer, final Class<T> representation, final File storageDirectory) {
  69         super(consumer, representation, Costs.LOCAL_IO);
  70         this.representation = representation;
  71         this.storageDirectory = Preconditions.checkNotNull(storageDirectory);
  72
  73         checkSupportedRepresentation(representation);
  74
  75         if (!storageDirectory.exists()) {
  76             Preconditions.checkArgument(storageDirectory.mkdirs(), "Unable to create cache directory at %s",
  77                     storageDirectory);
  78         }
  79         Preconditions.checkArgument(storageDirectory.exists());
  80         Preconditions.checkArgument(storageDirectory.isDirectory());
  81         Preconditions.checkArgument(storageDirectory.canWrite());
  82         Preconditions.checkArgument(storageDirectory.canRead());
  83
  84         init();
  85     }
  86
  87     private static void checkSupportedRepresentation(final Class<? extends SchemaSourceRepresentation> representation) {
  88         for (final Class<? extends SchemaSourceRepresentation> supportedRepresentation : STORAGE_ADAPTERS.keySet()) {
  89             if (supportedRepresentation.isAssignableFrom(representation)) {
  90                 return;
  91             }
  92         }
  93
  94         throw new IllegalArgumentException(String.format(
  95                    "This cache does not support representation: %s, supported representations are: %s",
  96                    representation, STORAGE_ADAPTERS.keySet()));
  97     }
  98
  99     /**
 100      * Restore cache state.
 101      */
 102     private void init() {
 103
 104         final CachedModulesFileVisitor fileVisitor = new CachedModulesFileVisitor();
 105         try {
 106             Files.walkFileTree(storageDirectory.toPath(), fileVisitor);
 107         } catch (final IOException e) {
 108             LOG.warn("Unable to restore cache from {}. Starting with empty cache", storageDirectory);
 109             return;
 110         }
 111
 112         for (final SourceIdentifier cachedSchema : fileVisitor.getCachedSchemas()) {
 113             register(cachedSchema);
 114         }
 115     }
 116
 117     @Override
 118     public synchronized CheckedFuture<? extends T, SchemaSourceException> getSource(
 119             final SourceIdentifier sourceIdentifier) {
 120         final File file = sourceIdToFile(sourceIdentifier, storageDirectory);
 121         if (file.exists() && file.canRead()) {
 122             LOG.trace("Source {} found in cache as {}", sourceIdentifier, file);
 123             final SchemaSourceRepresentation restored = STORAGE_ADAPTERS.get(representation).restore(sourceIdentifier,
 124                     file);
 125             return Futures.immediateCheckedFuture(representation.cast(restored));
 126         }
 127
 128         LOG.debug("Source {} not found in cache as {}", sourceIdentifier, file);
 129         return Futures.immediateFailedCheckedFuture(new MissingSchemaSourceException("Source not found",
 130                     sourceIdentifier));
 131     }
 132
 133     @Override
 134     protected synchronized void offer(final T source) {
 135         LOG.trace("Source {} offered to cache", source.getIdentifier());
 136         final File file = sourceIdToFile(source);
 137         if (file.exists()) {
 138             LOG.debug("Source {} already in cache as {}", source.getIdentifier(), file);
 139             return;
 140         }
 141
 142         storeSource(file, source);
 143         register(source.getIdentifier());
 144         LOG.trace("Source {} stored in cache as {}", source.getIdentifier(), file);
 145     }
 146
 147     private File sourceIdToFile(final T source) {
 148         return sourceIdToFile(source.getIdentifier(), storageDirectory);
 149     }
 150
 151     static File sourceIdToFile(final SourceIdentifier identifier, final File storageDirectory) {
 152         final String rev = identifier.getRevision();
 153         final File file;
 154         if (Strings.isNullOrEmpty(rev)) {
 155             file = findFileWithNewestRev(identifier, storageDirectory);
 156         } else {
 157             file = new File(storageDirectory, identifier.toYangFilename());
 158         }
 159         return file;
 160     }
 161
 162     private static File findFileWithNewestRev(final SourceIdentifier identifier, final File storageDirectory) {
 163         File[] files = storageDirectory.listFiles(new FilenameFilter() {
 164             final Pattern pat = Pattern.compile(Pattern.quote(identifier.getName())
 165                     + "(\\.yang|@\\d\\d\\d\\d-\\d\\d-\\d\\d.yang)");
 166
 167             @Override
 168             public boolean accept(final File dir, final String name) {
 169                 return pat.matcher(name).matches();
 170             }
 171         });
 172
 173         if (files.length == 0) {
 174             return new File(storageDirectory, identifier.toYangFilename());
 175         }
 176         if (files.length == 1) {
 177             return files[0];
 178         }
 179
 180         File file = null;
 181         TreeMap<Date, File> map = new TreeMap<>();
 182         for (File sorted : files) {
 183             String fileName = sorted.getName();
 184             Matcher match = SourceIdentifier.REVISION_PATTERN.matcher(fileName);
 185             if (match.find()) {
 186                 String revStr = match.group();
 187                 /*
 188                  * FIXME: Consider using string for comparison.
 189                  * String is comparable, pattern check tested format
 190                  * so comparing as ASCII string should be sufficient
 191                  */
 192                 DateFormat df = SimpleDateFormatUtil.getRevisionFormat();
 193                 try {
 194                     Date date = df.parse(revStr);
 195                     map.put(date, sorted);
 196                 } catch (final ParseException e) {
 197                     LOG.info("Unable to parse date from yang file name {}", fileName);
 198                     map.put(new Date(0L), sorted);
 199                 }
 200
 201             } else {
 202                 map.put(new Date(0L), sorted);
 203             }
 204         }
 205         file = map.lastEntry().getValue();
 206
 207         return file;
 208     }
 209
 210     private void storeSource(final File file, final T schemaRepresentation) {
 211         STORAGE_ADAPTERS.get(representation).store(file, schemaRepresentation);
 212     }
 213
 214     private abstract static class StorageAdapter<T extends SchemaSourceRepresentation> {
 215
 216         private final Class<T> supportedType;
 217
 218         protected StorageAdapter(final Class<T> supportedType) {
 219             this.supportedType = supportedType;
 220         }
 221
 222         void store(final File file, final SchemaSourceRepresentation schemaSourceRepresentation) {
 223             Preconditions.checkArgument(supportedType.isAssignableFrom(schemaSourceRepresentation.getClass()),
 224                     "Cannot store schema source %s, this adapter only supports %s", schemaSourceRepresentation,
 225                     supportedType);
 226
 227             storeAsType(file, supportedType.cast(schemaSourceRepresentation));
 228         }
 229
 230         protected abstract void storeAsType(final File file, final T cast);
 231
 232         public T restore(final SourceIdentifier sourceIdentifier, final File cachedSource) {
 233             Preconditions.checkArgument(cachedSource.isFile());
 234             Preconditions.checkArgument(cachedSource.exists());
 235             Preconditions.checkArgument(cachedSource.canRead());
 236             return restoreAsType(sourceIdentifier, cachedSource);
 237         }
 238
 239         protected abstract T restoreAsType(final SourceIdentifier sourceIdentifier, final File cachedSource);
 240     }
 241
 242     private static final class YangTextSchemaStorageAdapter extends StorageAdapter<YangTextSchemaSource> {
 243
 244         protected YangTextSchemaStorageAdapter() {
 245             super(YangTextSchemaSource.class);
 246         }
 247
 248         @Override
 249         protected void storeAsType(final File file, final YangTextSchemaSource cast) {
 250             try (final InputStream castStream = cast.openStream()) {
 251                 Files.copy(castStream, file.toPath(), StandardCopyOption.REPLACE_EXISTING);
 252             } catch (final IOException e) {
 253                 throw new IllegalStateException("Cannot store schema source " + cast.getIdentifier() + " to " + file,
 254                         e);
 255             }
 256         }
 257
 258         @Override
 259         public YangTextSchemaSource restoreAsType(final SourceIdentifier sourceIdentifier, final File cachedSource) {
 260             return new YangTextSchemaSource(sourceIdentifier) {
 261
 262                 @Override
 263                 protected ToStringHelper addToStringAttributes(final ToStringHelper toStringHelper) {
 264                     return toStringHelper;
 265                 }
 266
 267                 @Override
 268                 public InputStream openStream() throws IOException {
 269                     return Files.newInputStream(cachedSource.toPath());
 270                 }
 271             };
 272         }
 273     }
 274
 275     private static final class CachedModulesFileVisitor extends SimpleFileVisitor<Path> {
 276         private final List<SourceIdentifier> cachedSchemas = Lists.newArrayList();
 277
 278         @Override
 279         public FileVisitResult visitFile(final Path file, final BasicFileAttributes attrs) throws IOException {
 280             final FileVisitResult fileVisitResult = super.visitFile(file, attrs);
 281             String fileName = file.toFile().getName();
 282             fileName = com.google.common.io.Files.getNameWithoutExtension(fileName);
 283
 284             final Optional<SourceIdentifier> si = getSourceIdentifier(fileName);
 285             if (si.isPresent()) {
 286                 LOG.trace("Restoring cached file {} as {}", file, si.get());
 287                 cachedSchemas.add(si.get());
 288             } else {
 289                 LOG.debug("Skipping cached file {}, cannot restore source identifier from filename: {},"
 290                         + " does not match {}", file, fileName, CACHED_FILE_PATTERN);
 291             }
 292             return fileVisitResult;
 293         }
 294
 295         private static Optional<SourceIdentifier> getSourceIdentifier(final String fileName) {
 296             final Matcher matcher = CACHED_FILE_PATTERN.matcher(fileName);
 297             if (matcher.matches()) {
 298                 final String moduleName = matcher.group("moduleName");
 299                 final String revision = matcher.group("revision");
 300                 return Optional.of(RevisionSourceIdentifier.create(moduleName, Optional.fromNullable(revision)));
 301             }
 302             return Optional.absent();
 303         }
 304
 305         @Override
 306         public FileVisitResult visitFileFailed(final Path file, final IOException exc) throws IOException {
 307             LOG.warn("Unable to restore cached file {}. Ignoring", file, exc);
 308             return FileVisitResult.CONTINUE;
 309         }
 310
 311         public List<SourceIdentifier> getCachedSchemas() {
 312             return cachedSchemas;
 313         }
 314     }
 315 }