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.util.concurrent.FluentFuture;
  16 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  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.time.format.DateTimeParseException;
  28 import java.util.ArrayList;
  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         checkArgument(storageDirectory.mkdirs() || storageDirectory.isDirectory(),
  75                 "Unable to create cache directory at %s", storageDirectory);
  76         checkArgument(storageDirectory.canWrite());
  77         checkArgument(storageDirectory.canRead());
  78
  79         init();
  80     }
  81
  82     private static void checkSupportedRepresentation(final Class<? extends SchemaSourceRepresentation> representation) {
  83         for (final Class<? extends SchemaSourceRepresentation> supportedRepresentation : STORAGE_ADAPTERS.keySet()) {
  84             if (supportedRepresentation.isAssignableFrom(representation)) {
  85                 return;
  86             }
  87         }
  88
  89         throw new IllegalArgumentException(String.format(
  90                    "This cache does not support representation: %s, supported representations are: %s",
  91                    representation, STORAGE_ADAPTERS.keySet()));
  92     }
  93
  94     /**
  95      * Restore cache state.
  96      */
  97     private void init() {
  98
  99         final CachedModulesFileVisitor fileVisitor = new CachedModulesFileVisitor();
 100         try {
 101             Files.walkFileTree(storageDirectory.toPath(), fileVisitor);
 102         } catch (final IOException e) {
 103             LOG.warn("Unable to restore cache from {}. Starting with an empty cache", storageDirectory, e);
 104             return;
 105         }
 106
 107         fileVisitor.getCachedSchemas().stream().forEach(this::register);
 108     }
 109
 110     @Override
 111     public synchronized FluentFuture<? extends T> getSource(final SourceIdentifier sourceIdentifier) {
 112         final File file = sourceIdToFile(sourceIdentifier, storageDirectory);
 113         if (file.exists() && file.canRead()) {
 114             LOG.trace("Source {} found in cache as {}", sourceIdentifier, file);
 115             final SchemaSourceRepresentation restored = STORAGE_ADAPTERS.get(representation).restore(sourceIdentifier,
 116                     file);
 117             return immediateFluentFuture(representation.cast(restored));
 118         }
 119
 120         LOG.debug("Source {} not found in cache as {}", sourceIdentifier, file);
 121         return immediateFailedFluentFuture(new MissingSchemaSourceException("Source not found", sourceIdentifier));
 122     }
 123
 124     @Override
 125     protected synchronized void offer(final T source) {
 126         LOG.trace("Source {} offered to cache", source.getIdentifier());
 127         final File file = sourceIdToFile(source);
 128         if (file.exists()) {
 129             LOG.debug("Source {} already in cache as {}", source.getIdentifier(), file);
 130             return;
 131         }
 132
 133         storeSource(file, source);
 134         register(source.getIdentifier());
 135         LOG.trace("Source {} stored in cache as {}", source.getIdentifier(), file);
 136     }
 137
 138     private File sourceIdToFile(final T source) {
 139         return sourceIdToFile(source.getIdentifier(), storageDirectory);
 140     }
 141
 142     static File sourceIdToFile(final SourceIdentifier identifier, final File storageDirectory) {
 143         final Optional<Revision> rev = identifier.getRevision();
 144         final File file;
 145         if (rev.isEmpty()) {
 146             // FIXME: this does not look right
 147             file = findFileWithNewestRev(identifier, storageDirectory);
 148         } else {
 149             file = new File(storageDirectory, identifier.toYangFilename());
 150         }
 151         return file;
 152     }
 153
 154     @SuppressFBWarnings(value = "NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE",
 155             justification = "listFiles is analyzed to return null")
 156     private static File findFileWithNewestRev(final SourceIdentifier identifier, final File storageDirectory) {
 157         File[] files = storageDirectory.listFiles(new FilenameFilter() {
 158             final Pattern pat = Pattern.compile(Pattern.quote(identifier.getName())
 159                     + "(\\.yang|@\\d\\d\\d\\d-\\d\\d-\\d\\d.yang)");
 160
 161             @Override
 162             public boolean accept(final File dir, final String name) {
 163                 return pat.matcher(name).matches();
 164             }
 165         });
 166
 167         if (files.length == 0) {
 168             return new File(storageDirectory, identifier.toYangFilename());
 169         }
 170         if (files.length == 1) {
 171             return files[0];
 172         }
 173
 174         File file = null;
 175         TreeMap<Optional<Revision>, File> map = new TreeMap<>(Revision::compare);
 176         for (File sorted : files) {
 177             String fileName = sorted.getName();
 178             Matcher match = Revision.STRING_FORMAT_PATTERN.matcher(fileName);
 179             if (match.find()) {
 180                 String revStr = match.group();
 181                 Revision rev;
 182                 try {
 183                     rev = Revision.of(revStr);
 184                 } catch (final DateTimeParseException e) {
 185                     LOG.info("Unable to parse date from yang file name {}, falling back to not-present", fileName, e);
 186                     rev = null;
 187                 }
 188
 189                 map.put(Optional.ofNullable(rev), sorted);
 190
 191             } else {
 192                 map.put(Optional.empty(), sorted);
 193             }
 194         }
 195         file = map.lastEntry().getValue();
 196
 197         return file;
 198     }
 199
 200     private void storeSource(final File file, final T schemaRepresentation) {
 201         STORAGE_ADAPTERS.get(representation).store(file, schemaRepresentation);
 202     }
 203
 204     private abstract static class StorageAdapter<T extends SchemaSourceRepresentation> {
 205
 206         private final Class<T> supportedType;
 207
 208         protected StorageAdapter(final Class<T> supportedType) {
 209             this.supportedType = supportedType;
 210         }
 211
 212         void store(final File file, final SchemaSourceRepresentation schemaSourceRepresentation) {
 213             checkArgument(supportedType.isAssignableFrom(schemaSourceRepresentation.getClass()),
 214                     "Cannot store schema source %s, this adapter only supports %s", schemaSourceRepresentation,
 215                     supportedType);
 216
 217             storeAsType(file, supportedType.cast(schemaSourceRepresentation));
 218         }
 219
 220         protected abstract void storeAsType(File file, T cast);
 221
 222         public T restore(final SourceIdentifier sourceIdentifier, final File cachedSource) {
 223             checkArgument(cachedSource.isFile());
 224             checkArgument(cachedSource.exists());
 225             checkArgument(cachedSource.canRead());
 226             return restoreAsType(sourceIdentifier, cachedSource);
 227         }
 228
 229         protected abstract T restoreAsType(SourceIdentifier sourceIdentifier, File cachedSource);
 230     }
 231
 232     private static final class YangTextSchemaStorageAdapter extends StorageAdapter<YangTextSchemaSource> {
 233
 234         protected YangTextSchemaStorageAdapter() {
 235             super(YangTextSchemaSource.class);
 236         }
 237
 238         @Override
 239         @SuppressFBWarnings(value = "RCN_REDUNDANT_NULLCHECK_WOULD_HAVE_BEEN_A_NPE",
 240             justification = "https://github.com/spotbugs/spotbugs/issues/600")
 241         protected void storeAsType(final File file, final YangTextSchemaSource cast) {
 242             try (InputStream castStream = cast.openStream()) {
 243                 Files.copy(castStream, file.toPath(), StandardCopyOption.REPLACE_EXISTING);
 244             } catch (final IOException e) {
 245                 throw new IllegalStateException("Cannot store schema source " + cast.getIdentifier() + " to " + file,
 246                         e);
 247             }
 248         }
 249
 250         @Override
 251         public YangTextSchemaSource restoreAsType(final SourceIdentifier sourceIdentifier, final File cachedSource) {
 252             return YangTextSchemaSource.forFile(cachedSource, sourceIdentifier);
 253         }
 254     }
 255
 256     private static final class CachedModulesFileVisitor extends SimpleFileVisitor<Path> {
 257         private final List<SourceIdentifier> cachedSchemas = new ArrayList<>();
 258
 259         @Override
 260         public FileVisitResult visitFile(final Path file, final BasicFileAttributes attrs) throws IOException {
 261             final FileVisitResult fileVisitResult = super.visitFile(file, attrs);
 262             String fileName = file.toFile().getName();
 263             fileName = com.google.common.io.Files.getNameWithoutExtension(fileName);
 264
 265             final Optional<SourceIdentifier> si = getSourceIdentifier(fileName);
 266             if (si.isPresent()) {
 267                 LOG.trace("Restoring cached file {} as {}", file, si.get());
 268                 cachedSchemas.add(si.get());
 269             } else {
 270                 LOG.debug("Skipping cached file {}, cannot restore source identifier from filename: {},"
 271                         + " does not match {}", file, fileName, CACHED_FILE_PATTERN);
 272             }
 273             return fileVisitResult;
 274         }
 275
 276         private static Optional<SourceIdentifier> getSourceIdentifier(final String fileName) {
 277             final Matcher matcher = CACHED_FILE_PATTERN.matcher(fileName);
 278             if (matcher.matches()) {
 279                 final String moduleName = matcher.group("moduleName");
 280                 final String revision = matcher.group("revision");
 281                 return Optional.of(RevisionSourceIdentifier.create(moduleName, Revision.ofNullable(revision)));
 282             }
 283             return Optional.empty();
 284         }
 285
 286         @Override
 287         public FileVisitResult visitFileFailed(final Path file, final IOException exc) throws IOException {
 288             LOG.warn("Unable to restore cached file {}. Ignoring", file, exc);
 289             return FileVisitResult.CONTINUE;
 290         }
 291
 292         public List<SourceIdentifier> getCachedSchemas() {
 293             return cachedSchemas;
 294         }
 295     }
 296 }