Crate capnp

Cap'n Proto Runtime Library

Cap'n Proto is an extremely efficient protocol for sharing data and capabilities.

The Rust implementation is split into three separate crates.

Code generation is handled by capnpc-rust.

The present crate is the runtime library required by that generated code. It is hosted on Github here.

capnp-rpc-rust is an implementation of a distributed object-capability layer.

Modules

any_pointer	Dynamically typed value.
capability	Hooks for for the RPC system.
data	Sequence of bytes.
data_list	List of sequences of bytes.
enum_list	List of enums.
list_list	List of lists.
message	Untyped root container for a Cap'n Proto value.
primitive_list	List of primitives.
private	Implementation details that should never be directly used by clients.
serialize	Reading and writing of messages using the standard stream framing.
serialize_packed	Reading and writing of messages using the packed stream encoding.
struct_list	List of structs.
text	UTF-8 encoded text.
text_list	List of strings containing UTF-8 encoded text.
traits

Macros

capnp_word

Constructs a Word from its constituent bytes. This macro can be used to construct constants. In the future, when Rust supports constant functions, this macro will be replaced by such a function.

Structs

Error	Describes an arbitrary error that prevented an operation from completing.
MessageSize	Size of a message. Every generated struct has a method .total_size() that returns this.
NotInSchema	An enum value or union discriminant that was not found among those defined in a schema.
Word	Eight bytes of memory with opaque interior. Use capnp_word!() to construct one of these.

Enums

ErrorKind
OutputSegments	Helper struct that allows MessageBuilder::get_segments_for_output() to avoid heap allocations in the single-segment case.

Type Definitions

Result

Because messages are lazily validated, the return type of any method that reads a pointer field must be wrapped in a Result.