Crate framing_sv2

The SV2 protocol is binary, with fixed message framing. Each message begins with the extension type, message type, and message length (six bytes in total), followed by a variable length message.

This crate provides primitives for framing of SV2 binary messages.

The message framing is outlined below (according to SV2 specs):

Protocol Type	Byte Length	Description
extension_type	U16	Unique identifier of the extension describing this protocol message. Most significant bit (i.e.bit 15, 0-indexed, aka channel_msg) indicates a message which is specific to a channel, whereas if the most significant bit is unset, the message is to be interpreted by the immediate receiving device. Note that the channel_msg bit is ignored in the extension lookup, i.e.an extension_type of 0x8ABC is for the same “extension” as 0x0ABC. If the channel_msg bit is set, the first four bytes of the payload field is a U32 representing the channel_id this message is destined for (these bytes are repeated in the message framing descriptions below). Note that for the Job Declaration and Template Distribution Protocols the channel_msg bit is always unset.
msg_type	U8	Unique identifier of the extension describing this protocol message.
msg_length	U24	Length of the protocol message, not including this header.
payload	BYTES	Message-specific payload of length msg_length. If the MSB in extension_type (the channel_msg bit) is set the first four bytes are defined as a U32 "channel_id", though this definition is repeated in the message definitions below and these 4 bytes are included in msg_length.

Features

This crate can be built with the following features:

• with_serde: builds binary_sv2 and buffer_sv2 crates with serde-based encoding and decoding.
• with_buffer_pool: uses buffer_sv2 to provide a more efficient allocation method for non_std environments. Please refer to buffer_sv2 crate docs for more context.

The with_serde feature flag is only used for the Message Generator, and deprecated for any other kind of usage. It will likely be fully deprecated in the future.

Re-exports

• pub use error::Error;

Modules

• error
  SV2 framing errors
• framing2
  SV2 framing types
• header
  SV2 framing header