Examples with ReplicaAccessor org.apache.hadoop.hdfs.ReplicaAccessor used on opensource projects

Example 1 with ReplicaAccessor

use of org.apache.hadoop.hdfs.ReplicaAccessor in project hadoop by apache.

the class BlockReaderFactory method tryToCreateExternalBlockReader.

private BlockReader tryToCreateExternalBlockReader() {
    List<Class<? extends ReplicaAccessorBuilder>> clses = conf.getReplicaAccessorBuilderClasses();
    for (Class<? extends ReplicaAccessorBuilder> cls : clses) {
        try {
            ByteArrayDataOutput bado = ByteStreams.newDataOutput();
            token.write(bado);
            byte[] tokenBytes = bado.toByteArray();
            Constructor<? extends ReplicaAccessorBuilder> ctor = cls.getConstructor();
            ReplicaAccessorBuilder builder = ctor.newInstance();
            long visibleLength = startOffset + length;
            ReplicaAccessor accessor = builder.setAllowShortCircuitReads(allowShortCircuitLocalReads).setBlock(block.getBlockId(), block.getBlockPoolId()).setGenerationStamp(block.getGenerationStamp()).setBlockAccessToken(tokenBytes).setClientName(clientName).setConfiguration(configuration).setFileName(fileName).setVerifyChecksum(verifyChecksum).setVisibleLength(visibleLength).build();
            if (accessor == null) {
                LOG.trace("{}: No ReplicaAccessor created by {}", this, cls.getName());
            } else {
                return new ExternalBlockReader(accessor, visibleLength, startOffset);
            }
        } catch (Throwable t) {
            LOG.warn("Failed to construct new object of type " + cls.getName(), t);
        }
    }
    return null;
}