Struct Config 

pub struct Config<B, P, ES, T>
where
    B: Block,
    P: Provider<Scope = Epoch>,
    ES: Epocher,
    T: Strategy,
{

    pub provider: P,
    pub epocher: ES,
    pub partition_prefix: String,
    pub mailbox_size: usize,
    pub view_retention_timeout: ViewDelta,
    pub prunable_items_per_section: NonZeroU64,
    pub page_cache: CacheRef,
    pub replay_buffer: NonZeroUsize,
    pub key_write_buffer: NonZeroUsize,
    pub value_write_buffer: NonZeroUsize,
    pub block_codec_config: B::Cfg,
    pub max_repair: NonZeroUsize,
    pub max_pending_acks: NonZeroUsize,
    pub strategy: T,
}

Marshal configuration.

Epocher and Provider Coverage

Any height marshal is asked to sync must be covered by both the epocher and the provider. If either returns None for a requested height, resolved requests will be acknowledged and then dropped. If no longer needed (say a duplicate request for a height we’ve long since processed), this drop is harmless. However, failing to provide either the epocher or the provider for a height we still require to process the canonical chain will lead marshal to stall (acknowledged requests may not be retried).

Safe Pruning

Applications may prune epocher/provider entries once the last processed height passes a prune target. The last processed height can be derived from an Update::Block at height H as H - max_pending_acks (the maximum backlog of blocks the application can buffer).

Fields

provider: P

Provider for epoch-specific signing schemes.

Must cover every epoch that contains heights the marshal will sync.

epocher: ES

Configuration for epoch lengths across block height ranges.

Must cover every height the marshal will sync.

partition_prefix: String

The prefix to use for all partitions.

mailbox_size: usize

Size of backfill request/response mailbox.

view_retention_timeout: ViewDelta

Minimum number of views to retain temporary data after the application processes a block.

Useful for keeping around information that peers may desire to have.

prunable_items_per_section: NonZeroU64

Prunable archive partition prefix.

page_cache: CacheRef

The page cache to use for the freezer journal.

replay_buffer: NonZeroUsize

The size of the replay buffer for storage archives.

key_write_buffer: NonZeroUsize

The size of the write buffer for the key journal of storage archives.

value_write_buffer: NonZeroUsize

The size of the write buffer for the value journal of storage archives.

block_codec_config: B::Cfg

Codec configuration for block type.

max_repair: NonZeroUsize

Maximum number of blocks to repair at once.

max_pending_acks: NonZeroUsize

Maximum number of blocks dispatched to the application that have not yet been acknowledged. Increasing this value allows the application to buffer work while marshal continues dispatching, hiding ack latency.

strategy: T

Strategy for parallel operations.