io.rsocket.metadata

Class CompositeMetadata

java.lang.Object

io.rsocket.metadata.CompositeMetadata

All Implemented Interfaces:

Iterable<CompositeMetadata.Entry>

public final class CompositeMetadata
extends Object
implements Iterable<CompositeMetadata.Entry>

An Iterable wrapper around a ByteBuf that exposes metadata entry information at each decoding step. This is only possible on frame types used to initiate interactions, if the SETUP metadata mime type was WellKnownMimeType.MESSAGE_RSOCKET_COMPOSITE_METADATA.

This allows efficient incremental decoding of the entries (without moving the source's ByteBuf.readerIndex()). The buffer is assumed to contain just enough bytes to represent one or more entries (mime type compressed or not). The decoding stops when the buffer reaches 0 readable bytes, and fails if it contains bytes but not enough to correctly decode an entry.

A note on future-proofness: it is possible to come across a compressed mime type that this implementation doesn't recognize. This is likely to be due to the use of a byte id that is merely reserved in this implementation, but maps to a WellKnownMimeType in the implementation that encoded the metadata. This can be detected by detecting that an entry is a CompositeMetadata.ReservedMimeTypeEntry. In this case CompositeMetadata.Entry.getMimeType() will return null. The encoded id can be retrieved using CompositeMetadata.ReservedMimeTypeEntry.getType(). The byte and content buffer should be kept around and re-encoded using CompositeMetadataCodec.encodeAndAddMetadata(CompositeByteBuf, ByteBufAllocator, byte, ByteBuf) in case passing that entry through is required.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	CompositeMetadata.Entry An entry in the CompositeMetadata.
static class	CompositeMetadata.ExplicitMimeTimeEntry An CompositeMetadata.Entry backed by an explicitly declared MIME type.
static class	CompositeMetadata.ReservedMimeTypeEntry An CompositeMetadata.Entry backed by a WellKnownMimeType entry, but one that is not understood by this implementation.
static class	CompositeMetadata.WellKnownMimeTypeEntry An CompositeMetadata.Entry backed by a WellKnownMimeType.

Constructor Summary

Constructors

Constructor and Description
CompositeMetadata(ByteBuf source, boolean retainSlices)

Method Summary

Modifier and Type	Method and Description
Iterator<CompositeMetadata.Entry>	iterator() An Iterator that lazily decodes CompositeMetadata.Entry in this composite metadata.
Stream<CompositeMetadata.Entry>	stream() Turn this CompositeMetadata into a sequential Stream.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

CompositeMetadata

public CompositeMetadata(ByteBuf source,
                         boolean retainSlices)

Method Detail

stream

public Stream<CompositeMetadata.Entry> stream()

Turn this CompositeMetadata into a sequential Stream.

Returns:

the composite metadata sequential Stream

iterator

public Iterator<CompositeMetadata.Entry> iterator()

An Iterator that lazily decodes CompositeMetadata.Entry in this composite metadata.

Specified by:

iterator in interface Iterable<CompositeMetadata.Entry>

Returns:

the composite metadata Iterator