jsonrpsee_core/

id_providers.rs

// Copyright 2019-2021 Parity Technologies (UK) Ltd.
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//! Subscription ID providers.

use rand::distributions::Alphanumeric;
use rand::Rng;

use crate::traits::IdProvider;
use jsonrpsee_types::SubscriptionId;

/// Generates random integers as subscription ID.
#[derive(Debug, Copy, Clone)]
pub struct RandomIntegerIdProvider;

impl IdProvider for RandomIntegerIdProvider {
	fn next_id(&self) -> SubscriptionId<'static> {
		const JS_NUM_MASK: u64 = !0 >> 11;
		(rand::random::<u64>() & JS_NUM_MASK).into()
	}
}

/// Generates random strings of length `len` as subscription ID.
#[derive(Debug, Copy, Clone)]
pub struct RandomStringIdProvider {
	len: usize,
}

impl RandomStringIdProvider {
	/// Create a new random string provider.
	pub fn new(len: usize) -> Self {
		Self { len }
	}
}

impl IdProvider for RandomStringIdProvider {
	fn next_id(&self) -> SubscriptionId<'static> {
		let mut rng = rand::thread_rng();
		(&mut rng).sample_iter(Alphanumeric).take(self.len).map(char::from).collect::<String>().into()
	}
}

/// No-op implementation to be used for servers that don't support subscriptions.
#[derive(Debug, Copy, Clone)]
pub struct NoopIdProvider;

impl IdProvider for NoopIdProvider {
	fn next_id(&self) -> SubscriptionId<'static> {
		0.into()
	}
}