Examples with DefaultMetaDatabase me.retrodaredevil.solarthing.type.closed.meta.DefaultMetaDatabase used on opensource projects

Example 1 with DefaultMetaDatabase

use of me.retrodaredevil.solarthing.type.closed.meta.DefaultMetaDatabase in project solarthing by wildmountainfarms.

the class SimpleQueryHandler method queryMeta.

public MetaDatabase queryMeta() {
    final VersionedPacket<RootMetaPacket> metadata;
    synchronized (this) {
        final VersionedPacket<RootMetaPacket> currentCache = metadataCache;
        final Long lastMetadataCacheNanos = this.lastMetadataCacheNanos;
        if (lastMetadataCacheNanos != null && System.nanoTime() - lastMetadataCacheNanos < METADATA_CACHE_VALID.toNanos()) {
            requireNonNull(currentCache);
            metadata = currentCache;
        } else {
            UpdateToken updateToken = currentCache == null ? null : currentCache.getUpdateToken();
            final VersionedPacket<RootMetaPacket> newMetadata;
            try {
                newMetadata = database.queryMetadata(updateToken);
            } catch (NotFoundSolarThingDatabaseException e) {
                // If we have not defined metadata, then we return an "empty" instance
                return EmptyMetaDatabase.getInstance();
            } catch (SolarThingDatabaseException e) {
                throw new DatabaseException("Could not query meta", e);
            }
            this.lastMetadataCacheNanos = System.nanoTime();
            if (newMetadata == null) {
                requireNonNull(currentCache);
                metadata = currentCache;
            } else {
                metadataCache = newMetadata;
                metadata = newMetadata;
            }
        }
    }
    return new DefaultMetaDatabase(metadata.getPacket());
}