openethereum/rpc/src/v1/helpers/poll_filter.rs

28 lines
733 B
Rust

//! Helper type with all filter state data.
use std::collections::HashSet;
use ethereum_types::H256;
use v1::types::{Filter, Log};
pub type BlockNumber = u64;
/// Filter state.
#[derive(Clone)]
pub enum PollFilter {
/// Number of last block which client was notified about.
Block(BlockNumber),
/// Hashes of all transactions which client was notified about.
PendingTransaction(Vec<H256>),
/// Number of From block number, pending logs and log filter itself.
Logs(BlockNumber, HashSet<Log>, Filter)
}
/// Returns only last `n` logs
pub fn limit_logs(mut logs: Vec<Log>, limit: Option<usize>) -> Vec<Log> {
let len = logs.len();
match limit {
Some(limit) if len >= limit => logs.split_off(len - limit),
_ => logs,
}
}