Enum Message 

pub enum Message {
    Version(VersionMessage),
    Verack,
    Ping(Nonce),
    Pong(Nonce),
    Reject {
        message: String,
        ccode: RejectReason,
        reason: String,
        data: Option<[u8; 32]>,
    },
    GetAddr,
    Addr(Vec<MetaAddr>),
    GetBlocks {
        known_blocks: Vec<Hash>,
        stop: Option<Hash>,
    },
    Inv(Vec<InventoryHash>),
    GetHeaders {
        known_blocks: Vec<Hash>,
        stop: Option<Hash>,
    },
    Headers(Vec<CountedHeader>),
    GetData(Vec<InventoryHash>),
    Block(Arc<Block>),
    Tx(UnminedTx),
    NotFound(Vec<InventoryHash>),
    Mempool,
    FilterLoad {
        filter: Filter,
        hash_functions_count: u32,
        tweak: Tweak,
        flags: u8,
    },
    FilterAdd {
        data: Vec<u8>,
    },
    FilterClear,
}

A Bitcoin-like network message for the Zcash protocol.

The Zcash network protocol is mostly inherited from Bitcoin, and a list of Bitcoin network messages can be found on the Bitcoin wiki.

That page describes the wire format of the messages, while this enum stores an internal representation. The internal representation is unlinked from the wire format, and the translation between the two happens only during serialization and deserialization. For instance, Bitcoin identifies messages by a 12-byte ascii command string; we consider this a serialization detail and use the enum discriminant instead. (As a side benefit, this also means that we have a clearly-defined validation boundary for network messages during serialization).

Variants

Version(VersionMessage)

A version message.

Note that although this is called version in Bitcoin, its role is really analogous to a ClientHello message in TLS, used to begin a handshake, and is distinct from a simple version number.

Bitcoin reference

Verack

A verack message.

Bitcoin reference

Ping(Nonce)

A ping message.

Bitcoin reference

Tuple Fields

0: Nonce

A nonce unique to this Self::Ping message.

Pong(Nonce)

A pong message.

Bitcoin reference

Tuple Fields

0: Nonce

The nonce from the Self::Ping message this was in response to.

Reject

A reject message.

Bitcoin reference

Fields

message: String

Type of message rejected.

ccode: RejectReason

RejectReason code relating to rejected message.

reason: String

Human-readable version of rejection reason.

data: Option<[u8; 32]>

Optional extra data provided for some errors.

GetAddr

A getaddr message.

Bitcoin reference

Addr(Vec<MetaAddr>)

A sent or received addr message, or a received addrv2 message.

Currently, Zebra:

• sends and receives addr messages,
• parses received addrv2 messages, ignoring some address types,
• but does not send addrv2 messages.

The list contains 0..=MAX_META_ADDR addresses.

Because some address types are ignored, the deserialized vector can be empty, even if the peer sent addresses. This is not an error.

addr Bitcoin reference addrv2 ZIP 155

GetBlocks

A getblocks message.

known_blocks is a series of known block hashes spaced out along the peer’s best chain. The remote peer uses them to compute the intersection of its best chain and determine the blocks following the intersection point.

The peer responds with an inv packet with the hashes of subsequent blocks. If supplied, the stop parameter specifies the last header to request. Otherwise, an inv packet with the maximum number (500) are sent.

The known blocks list contains zero or more block hashes.

Bitcoin reference

Fields

known_blocks: Vec<Hash>

Hashes of known blocks, ordered from highest height to lowest height.

stop: Option<Hash>

Optionally, the last header to request.

Inv(Vec<InventoryHash>)

An inv message.

Allows a node to advertise its knowledge of one or more objects. It can be received unsolicited, or in reply to getblocks.

The list contains zero or more inventory hashes.

Bitcoin reference ZIP-239

GetHeaders

A getheaders message.

known_blocks is a series of known block hashes spaced out along the peer’s best chain. The remote peer uses them to compute the intersection of its best chain and determine the blocks following the intersection point.

The peer responds with an headers packet with the headers of subsequent blocks. If supplied, the stop parameter specifies the last header to request. Otherwise, the maximum number of block headers (160) are sent.

The known blocks list contains zero or more block hashes.

Bitcoin reference

Fields

known_blocks: Vec<Hash>

Hashes of known blocks, ordered from highest height to lowest height.

stop: Option<Hash>

Optionally, the last header to request.

Headers(Vec<CountedHeader>)

A headers message.

Returns block headers in response to a getheaders packet.

Each block header is accompanied by a transaction count.

The list contains zero or more headers.

Bitcoin reference

GetData(Vec<InventoryHash>)

A getdata message.

getdata is used in response to inv, to retrieve the content of a specific object, and is usually sent after receiving an inv packet, after filtering known elements.

zcashd returns requested items in a single batch of messages. Missing blocks are silently skipped. Missing transaction hashes are included in a single notfound message following the transactions. Other item or non-item messages can come before or after the batch.

The list contains zero or more inventory hashes.

Bitcoin reference ZIP-239 zcashd code

Block(Arc<Block>)

A block message.

Bitcoin reference

Tx(UnminedTx)

A tx message.

This message can be used to:

• send unmined transactions in response to GetData requests, and
• advertise unmined transactions for the mempool.

Zebra chooses to advertise new transactions using Inv(hash) rather than Tx(transaction).

Bitcoin reference

NotFound(Vec<InventoryHash>)

A notfound message.

Zebra responds with this message when it doesn’t have the requested blocks or transactions.

When a peer requests a list of transaction hashes, zcashd returns:

• a batch of messages containing found transactions, then
• a notfound message containing a list of transaction hashes that aren’t available in its mempool or state.

But when a peer requests blocks or headers, any missing items are silently skipped, without any notfound messages.

The list contains zero or more inventory hashes.

Bitcoin reference ZIP-239 zcashd code

Mempool

A mempool message.

This was defined in BIP35, which is included in Zcash.

Bitcoin reference

FilterLoad

A filterload message.

This was defined in BIP37, which is included in Zcash.

Zebra currently ignores this message.

Bitcoin reference

Fields

filter: Filter

The filter itself is simply a bit field of arbitrary byte-aligned size. The maximum size is 36,000 bytes.

hash_functions_count: u32

The number of hash functions to use in this filter. The maximum value allowed in this field is 50.

tweak: Tweak

A random value to add to the seed value in the hash function used by the bloom filter.

flags: u8

A set of flags that control how matched items are added to the filter.

FilterAdd

A filteradd message.

This was defined in BIP37, which is included in Zcash.

Zebra currently ignores this message.

Bitcoin reference

Fields

data: Vec<u8>

The data element to add to the current filter.

FilterClear

A filterclear message.

This was defined in BIP37, which is included in Zcash.

Zebra currently ignores this message.

Bitcoin reference

Implementations

impl Message

pub fn command(&self) -> &'static str

Returns the Zcash protocol message command as a string.

impl Message

pub fn inv_strategy() -> BoxedStrategy<Self>

Create a strategy that only generates Message::Inv messages.

pub fn get_data_strategy() -> BoxedStrategy<Self>

Create a strategy that only generates Message::GetData messages.

Trait Implementations

impl Arbitrary for Message

type Parameters = (<VersionMessage as Arbitrary>::Parameters, <Nonce as Arbitrary>::Parameters, <Nonce as Arbitrary>::Parameters, (<String as Arbitrary>::Parameters, <RejectReason as Arbitrary>::Parameters, <String as Arbitrary>::Parameters, <Option<[u8; 32]> as Arbitrary>::Parameters), <Vec<MetaAddr> as Arbitrary>::Parameters, (<Vec<Hash> as Arbitrary>::Parameters, <Option<Hash> as Arbitrary>::Parameters), <Vec<InventoryHash> as Arbitrary>::Parameters, (<Vec<Hash> as Arbitrary>::Parameters, <Option<Hash> as Arbitrary>::Parameters), <Vec<CountedHeader> as Arbitrary>::Parameters, (<Vec<InventoryHash> as Arbitrary>::Parameters, <Arc<Block> as Arbitrary>::Parameters, <UnminedTx as Arbitrary>::Parameters, <Vec<InventoryHash> as Arbitrary>::Parameters, (<Filter as Arbitrary>::Parameters, <u32 as Arbitrary>::Parameters, <Tweak as Arbitrary>::Parameters, <u8 as Arbitrary>::Parameters), <Vec<u8> as Arbitrary>::Parameters))

The type of parameters that arbitrary_with accepts for configuration of the generated Strategy. Parameters must implement Default.

type Strategy = TupleUnion<((u32, Arc<Map<<VersionMessage as Arbitrary>::Strategy, fn(VersionMessage) -> Message>>), (u32, Arc<fn() -> Message>), (u32, Arc<Map<<Nonce as Arbitrary>::Strategy, fn(Nonce) -> Message>>), (u32, Arc<Map<<Nonce as Arbitrary>::Strategy, fn(Nonce) -> Message>>), (u32, Arc<Map<(<String as Arbitrary>::Strategy, <RejectReason as Arbitrary>::Strategy, <String as Arbitrary>::Strategy, <Option<[u8; 32]> as Arbitrary>::Strategy), fn((String, RejectReason, String, Option<[u8; 32]>)) -> Message>>), (u32, Arc<fn() -> Message>), (u32, Arc<Map<<Vec<MetaAddr> as Arbitrary>::Strategy, fn(Vec<MetaAddr>) -> Message>>), (u32, Arc<Map<(<Vec<Hash> as Arbitrary>::Strategy, <Option<Hash> as Arbitrary>::Strategy), fn((Vec<Hash>, Option<Hash>)) -> Message>>), (u32, Arc<Map<<Vec<InventoryHash> as Arbitrary>::Strategy, fn(Vec<InventoryHash>) -> Message>>), (u32, Arc<TupleUnion<((u32, Arc<Map<(<Vec<Hash> as Arbitrary>::Strategy, <Option<Hash> as Arbitrary>::Strategy), fn((Vec<Hash>, Option<Hash>)) -> Message>>), (u32, Arc<Map<<Vec<CountedHeader> as Arbitrary>::Strategy, fn(Vec<CountedHeader>) -> Message>>), (u32, Arc<Map<<Vec<InventoryHash> as Arbitrary>::Strategy, fn(Vec<InventoryHash>) -> Message>>), (u32, Arc<Map<<Arc<Block> as Arbitrary>::Strategy, fn(Arc<Block>) -> Message>>), (u32, Arc<Map<<UnminedTx as Arbitrary>::Strategy, fn(UnminedTx) -> Message>>), (u32, Arc<Map<<Vec<InventoryHash> as Arbitrary>::Strategy, fn(Vec<InventoryHash>) -> Message>>), (u32, Arc<fn() -> Message>), (u32, Arc<Map<(<Filter as Arbitrary>::Strategy, <u32 as Arbitrary>::Strategy, <Tweak as Arbitrary>::Strategy, <u8 as Arbitrary>::Strategy), fn((Filter, u32, Tweak, u8)) -> Message>>), (u32, Arc<Map<<Vec<u8> as Arbitrary>::Strategy, fn(Vec<u8>) -> Message>>), (u32, Arc<fn() -> Message>))>>))>

The type of Strategy used to generate values of type Self.

fn arbitrary_with(_top: Self::Parameters) -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self). The strategy is passed the arguments given in args.

fn arbitrary() -> Self::Strategy

Generates a Strategy for producing arbitrary values of type the implementing type (Self).

impl Clone for Message

fn clone(&self) -> Message

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Message

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Message

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Encoder<Message> for Codec

type Error = SerializationError

The type of encoding errors.

fn encode( &mut self, item: Message, dst: &mut BytesMut, ) -> Result<(), Self::Error>

Encodes a frame into the buffer provided.

impl<E> From<E> for Message

where E: Error,

fn from(e: E) -> Self

Converts to this type from the input type.

impl From<VersionMessage> for Message

fn from(version_message: VersionMessage) -> Self

Converts to this type from the input type.

impl PartialEq for Message

fn eq(&self, other: &Message) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl TryFrom<Message> for VersionMessage

type Error = Box<dyn Error + Sync + Send>

The type returned in the event of a conversion error.

fn try_from(message: Message) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for Message

impl StructuralPartialEq for Message

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 144 bytes

Size for each variant:

• Version: 144 bytes
• Verack: 0 bytes
• Ping: 16 bytes
• Pong: 16 bytes
• Reject: 96 bytes
• GetAddr: 0 bytes
• Addr: 32 bytes
• GetBlocks: 72 bytes
• Inv: 32 bytes
• GetHeaders: 72 bytes
• Headers: 32 bytes
• GetData: 32 bytes
• Block: 16 bytes
• Tx: 104 bytes
• NotFound: 32 bytes
• Mempool: 0 bytes
• FilterLoad: 48 bytes
• FilterAdd: 32 bytes
• FilterClear: 0 bytes