How justification_period affect the proof and optimization

[hackfisher]

/// Configuration for the GRANDPA service
#[derive(Clone)]
pub struct Config {
	/// The expected duration for a message to be gossiped across the network.
	pub gossip_duration: Duration,
	/// Justification generation period (in blocks). GRANDPA will try to generate justifications
	/// at least every justification_period blocks. There are some other events which might cause
	/// justification generation.
	pub justification_period: u32,
	/// Whether the GRANDPA observer protocol is live on the network and thereby
	/// a full-node not running as a validator is running the GRANDPA observer
	/// protocol (we will only issue catch-up requests to authorities when the
	/// observer protocol is enabled).
	pub observer_enabled: bool,
	/// The role of the local node (i.e. authority, full-node or light).
	pub local_role: sc_network::config::Role,
	/// Some local identifier of the voter.
	pub name: Option<String>,
	/// The keystore that manages the keys of this node.
	pub keystore: Option<SyncCryptoStorePtr>,
	/// TelemetryHandle instance.
	pub telemetry: Option<TelemetryHandle>,
}