types.h File Reference

A11's core wire value types: chunks, node fragments and messages. More...

#include <optional>
#include <string>
#include <string_view>
#include <variant>
#include <vector>
#include <absl/base/nullability.h>
#include <absl/container/flat_hash_map.h>
#include <absl/status/status.h>
#include <absl/status/statusor.h>
#include <absl/time/time.h>

Go to the source code of this file.

Classes
struct	a11::data::ChunkMetadata
	Descriptive metadata attached to a a11::data::Chunk. More...
class	a11::data::ChunkObject
	An in-process value a chunk may carry instead of its encoded bytes. More...
struct	a11::data::Chunk
	A unit of data: bytes plus optional descriptive metadata. More...
struct	a11::data::NodeRef
	A reference to a (slice of a) logical node, in lieu of inline data. More...
struct	a11::data::NodeFragment
	One piece of a node's stream: an inline chunk or a node reference. More...
struct	a11::data::Port
	Binds an action's port name to the concrete node id serving it. More...
struct	a11::data::ActionMessage
	The wire description of an action invocation. More...
struct	a11::data::WireMessage
	The top-level frame exchanged between two A11 endpoints. More...

Namespaces
namespace	a11
namespace	a11::data

Typedefs
using	a11::data::Bytes = std::string
	Raw byte payload; an alias of std::string.
using	a11::data::ByteMap = absl::flat_hash_map< std::string, Bytes >
	String-keyed map of byte values (headers, attributes, etc.).

Functions
absl::Status	a11::data::ValidateName (std::string_view name)
	Validates an A11 identifier (node/port/action name).
absl::StatusOr< Chunk >	a11::data::MakeStatusChunk (const absl::Status &status, bool closing=false)
	Encodes status as a chunk of mimetype kStatusMimetype.
bool	a11::data::IsStatusChunk (const Chunk &chunk)
	Whether chunk carries a packed status.
bool	a11::data::IsCloseStatusChunk (const Chunk &chunk)
	Whether chunk is a status chunk marking write-half closure.
absl::StatusOr< absl::Status >	a11::data::StatusFromStatusChunk (const Chunk &chunk)
	Decodes a status previously encoded by MakeStatusChunk.
bool	a11::data::IsHalfCloseMessage (const WireMessage &message)
	Whether message is a transport half-close signal.
WireMessage	a11::data::MakeHalfCloseMessage (ByteMap trailers={})
	Builds a half-close WireMessage carrying optional trailers.
size_t	a11::data::EmptyWireMessageSize ()
	The encoded size of an empty WireMessage.

Variables
constexpr std::string_view	a11::data::kStatusMimetype = "application/x-a11-status"
	Mimetype marking a chunk whose payload is a packed status.
constexpr std::string_view	a11::data::kCloseAttribute = "a11-close"
	Metadata attribute marking a status chunk as a closure marker.

Detailed Description

A11's core wire value types: chunks, node fragments and messages.

These are the plain data records that A11 moves between endpoints. A a11::data::Chunk is a blob of bytes plus a a11::data::ChunkMetadata (mimetype and attributes); chunks flow through named nodes as a11::data::NodeFragment values (either an inline chunk or a a11::data::NodeRef pointing at a slice of another node). Actions are described on the wire by a11::data::ActionMessage (a named invocation with input/output a11::data::Port lists and headers), and one or more of these, together with node fragments, are batched into a a11::data::WireMessage – the unit exchanged across a stream.

Every record validates itself, reports an approximate encoded size, prints a debug string, and round-trips through MessagePack via ToMsgpack / FromMsgpack.