Struct EventScanner 

pub struct EventScanner<Mode = Unspecified, N: Network = Ethereum> { /* private fields */ }

An event scanner configured in mode Mode and bound to network N.

Create an instance via EventScannerBuilder, register subscriptions with EventScanner::subscribe, then start the scanner with the mode-specific start() method.

Starting the scanner

All scanner modes follow the same general startup pattern:

• Register subscriptions first: call EventScanner::subscribe before starting the scanner with start(). The scanner sends events only to subscriptions that have already been registered.
• Non-blocking start: start() returns immediately after spawning background tasks. Subscription streams yield events asynchronously.
• Errors after startup: most runtime failures are delivered through subscription streams as ScannerError items, rather than being returned from start().

Implementations

impl<N: Network> EventScanner<Historic, N>

pub async fn start(self) -> Result<StartProof, ScannerError>

Starts the scanner in Historic mode.

See EventScanner for general startup notes.

Errors

• ScannerError::Timeout - if an RPC call required for startup times out.
• ScannerError::RpcError - if an RPC call required for startup fails.
• ScannerError::BlockNotFound - if from_block or to_block cannot be resolved.

impl<N: Network> EventScanner<LatestEvents, N>

pub async fn start(self) -> Result<StartProof, ScannerError>

Starts the scanner in LatestEvents mode.

See EventScanner for general startup notes.

Errors

• ScannerError::Timeout - if an RPC call required for startup times out.
• ScannerError::RpcError - if an RPC call required for startup fails.
• ScannerError::BlockNotFound - if from_block or to_block cannot be resolved.

impl<N: Network> EventScanner<Live, N>

pub async fn start(self) -> Result<StartProof, ScannerError>

Starts the scanner in Live mode.

See EventScanner for general startup notes.

Errors

• ScannerError::Timeout - if an RPC call required for startup times out.
• ScannerError::RpcError - if an RPC call required for startup fails.

impl<N: Network> EventScanner<SyncFromBlock, N>

pub async fn start(self) -> Result<StartProof, ScannerError>

Starts the scanner in SyncFromBlock mode.

See EventScanner for general startup notes.

Errors

• ScannerError::Timeout - if an RPC call required for startup times out.
• ScannerError::RpcError - if an RPC call required for startup fails.
• ScannerError::BlockNotFound - if from_block cannot be resolved.

impl<N: Network> EventScanner<SyncFromLatestEvents, N>

pub async fn start(self) -> Result<StartProof, ScannerError>

Starts the scanner in SyncFromLatestEvents mode.

See EventScanner for general startup notes.

Errors

• ScannerError::Timeout - if an RPC call required for startup times out.
• ScannerError::RpcError - if an RPC call required for startup fails.

impl<Mode, N: Network> EventScanner<Mode, N>

pub fn new(config: Mode, block_range_scanner: BlockRangeScanner<N>) -> Self

impl<Mode, N: Network> EventScanner<Mode, N>

pub fn buffer_capacity(&self) -> usize

Returns the configured stream buffer capacity.

pub fn subscribe(&mut self, filter: EventFilter) -> EventSubscription

Registers an event subscription.

Each call creates a separate subscription with its own buffer.

Ordering

Ordering is guaranteed only within a single returned subscription. There is no ordering guarantee across subscriptions created by multiple calls to this method.

Trait Implementations

impl<Mode: Debug, N: Debug + Network> Debug for EventScanner<Mode, N>

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

Formats the value using the given formatter.