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