LocatableResolver { @Nonnull public CompletableFuture<String> reverseLookup(@Nullable FDBStoreTimer timer, @Nonnull Long value) { Cache<ScopedValue<Long>, String> inMemoryReverseCache = database.getReverseDirectoryInMemoryCache(); String cachedValue = inMemoryReverseCache.getIfPresent(wrap(value)); if (cachedValue != null) { return CompletableFuture.completedFuture(cachedValue); } return readReverse(timer, value) .thenApply(maybeRead -> maybeRead.map(read -> { inMemoryReverseCache.put(wrap(value), read); return read; }).orElseThrow(() -> new NoSuchElementException("reverse lookup of " + wrap(value)))); } protected  LocatableResolver(@Nonnull FDBDatabase database,
                                @Nullable KeySpacePath path,
                                @Nullable CompletableFuture<ResolvedKeySpacePath> resolvedPath); ScopedValue<T> wrap(T value); @Nonnull FDBDatabase getDatabase(); @Nonnull CompletableFuture<Long> resolve(@Nonnull String name); @Nonnull CompletableFuture<Long> resolve(@Nullable FDBStoreTimer timer, @Nonnull String name); @API(API.Status.UNSTABLE) @Nonnull CompletableFuture<Long> resolve(@Nonnull FDBRecordContext context, @Nonnull String name); @Nonnull CompletableFuture<Long> resolve(@Nonnull String name,
                                           @Nonnull ResolverCreateHooks hooks); @Nonnull CompletableFuture<Long> resolve(@Nullable FDBStoreTimer timer,
                                           @Nonnull String name,
                                           @Nonnull ResolverCreateHooks hooks); @API(API.Status.UNSTABLE) @Nonnull CompletableFuture<Long> resolve(@Nonnull FDBRecordContext context,
                                           @Nonnull String name,
                                           @Nonnull ResolverCreateHooks hooks); @Nonnull CompletableFuture<ResolverResult> resolveWithMetadata(@Nonnull String name,
                                                                 @Nonnull ResolverCreateHooks hooks); @Nonnull CompletableFuture<ResolverResult> resolveWithMetadata(@Nullable FDBStoreTimer timer,
                                                                 @Nonnull String name,
                                                                 @Nonnull ResolverCreateHooks hooks); @API(API.Status.UNSTABLE) @Nonnull CompletableFuture<ResolverResult> resolveWithMetadata(@Nonnull FDBRecordContext context, @Nonnull String name, @Nonnull ResolverCreateHooks hooks); @Nonnull CompletableFuture<ResolverResult> mustResolveWithMetadata(@Nonnull FDBRecordContext context, @Nonnull String name); CompletableFuture<Long> mustResolve(@Nonnull FDBRecordContext context, @Nonnull String name); @Nonnull CompletableFuture<String> reverseLookup(@Nullable FDBStoreTimer timer, @Nonnull Long value); @Nonnull CompletableFuture<Void> exclusiveLock(); @Nonnull CompletableFuture<Void> enableWriteLock(); @Nonnull CompletableFuture<Void> disableWriteLock(); @Nonnull CompletableFuture<Void> retireLayer(); @Nonnull CompletableFuture<Void> incrementVersion(); @Nonnull CompletableFuture<Integer> getVersion(@Nullable FDBStoreTimer timer); @Nonnull CompletableFuture<Boolean> retired(@Nullable FDBStoreTimer timer); @Nonnull CompletableFuture<Boolean> retiredSkipCache(@Nonnull FDBRecordContext context); @Nonnull CompletableFuture<Void> updateMetadataAndVersion(@Nonnull final String key,
                                                            @Nullable final byte[] metadata); @VisibleForTesting final CompletableFuture<Void> setMapping(FDBRecordContext context, String key, Long value); @VisibleForTesting abstract CompletableFuture<Void> setWindow(long count); @Nonnull @API(API.Status.DEPRECATED) @Deprecated Subspace getMappingSubspace(); @Nonnull abstract CompletableFuture<Subspace> getMappingSubspaceAsync(); @Nonnull @API(API.Status.DEPRECATED) @Deprecated Subspace getBaseSubspace(); @Nonnull abstract CompletableFuture<Subspace> getBaseSubspaceAsync(); @Nonnull abstract ResolverResult deserializeValue(byte[] value); @Override String toString(); @Override boolean equals(Object obj); @Override int hashCode();  }
@Test public void testReverseLookup() { Long value; try (FDBRecordContext context = database.openContext()) { value = globalScope.resolve(context.getTimer(), "something").join(); context.commit(); } String lookupString = globalScope.reverseLookup(null, value).join(); assertThat("reverse lookup works in a new context", lookupString, is("something")); }
@Test public void testReverseLookupNotFound() { try { globalScope.reverseLookup(null, -1L).join(); fail("should throw CompletionException"); } catch (CompletionException ex) { assertThat(ex.getCause(), is(instanceOf(NoSuchElementException.class))); } }