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