Two-level wire framing: outer length-prefixed blocks, inner messages. More...

#include "core/bytes.h"
#include <cstdint>

Include dependency graph for frame.h:

This graph shows which files directly or indirectly include this file:

Classes
struct	librats::FrameHeader
	Fixed header of an inner message. More...

struct	librats::Frame
	A decoded inner message. `payload` is a non-owning view into the source bytes. More...

struct	librats::framer::Block

struct	librats::framer::Message

Namespaces
namespace	librats

namespace	librats::framer

Enumerations
enum class	librats::MessageType : uint8_t { librats::App = 1 , librats::Control = 2 , librats::Gossip = 3 , librats::FileChunk = 4 , librats::Ping = 5 , librats::Storage = 6 , librats::Typed = 7 , librats::Pex = 8 }
	Inner-message kind. Application traffic uses App, addressed by `channel`. More...

Functions
void	librats::framer::encode_block (Bytes &out, ByteView body)
	Append `[u32 len][body]` to `out`.

Block	librats::framer::try_take_block (const uint8_t *data, size_t size)
	Try to take one block from the front of `[data, data+size)` without copying.

void	librats::framer::encode_message (Bytes &out, FrameHeader header, ByteView payload)
	Append `[type][flags][channel][payload]` to `out` (no length prefix).

Message	librats::framer::parse_message (ByteView inner)
	Parse an inner message from `inner` (header + payload). `ok` false if short.

Variables
constexpr size_t	librats::framer::kLengthPrefixSize = 4

constexpr size_t	librats::framer::kHeaderSize = 4
	type+flags+channel

constexpr uint32_t	librats::framer::kMaxBlockSize = 64u * 1024 * 1024
	body cap

Detailed Description

Two-level wire framing: outer length-prefixed blocks, inner messages.

The wire is a stream of length-prefixed blocks:

┌──────────────┬───────────────────────────┐ │ length (u32) │ body │ │ 4 bytes │ length bytes │ └──────────────┴───────────────────────────┘

A block's body is opaque at this layer. The Connection uses it for two things:

during the handshake, the body is a raw handshake message (Noise / id);
once established, the body is the Session-encrypted bytes of an inner message, which has its own fixed 4-byte header:

┌──────┬───────┬─────────┬───────────────┐ │ type │ flags │ channel │ payload … │ │ u8 │ u8 │ u16 │ │ └──────┴───────┴─────────┴───────────────┘

Splitting "outer block" from "inner message" keeps encryption clean: the cipher wraps the whole inner message (type included), and the block layer never needs to understand it. Decoding is zero-copy — views point into the caller's buffer and are valid only until it is consumed.

Definition in file frame.h.

Classes

Namespaces

Enumerations

Functions

Variables

Detailed Description