alloy-pubsub 2.0.0

Ethereum JSON-RPC publish-subscribe tower service and type definitions
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102

use crate::{managers::ActiveSubscription, RawSubscription};
use alloy_json_rpc::{EthNotification, SerializedRequest, SubId};
use alloy_primitives::B256;
use bimap::BiBTreeMap;

#[derive(Debug, Default)]
pub(crate) struct SubscriptionManager {
    /// The subscriptions.
    local_to_sub: BiBTreeMap<B256, ActiveSubscription>,
    /// Tracks the CURRENT server id for a subscription.
    local_to_server: BiBTreeMap<B256, SubId>,
}

impl SubscriptionManager {
    /// Get an iterator over the subscriptions.
    pub(crate) fn iter(&self) -> impl Iterator<Item = (&B256, &ActiveSubscription)> {
        self.local_to_sub.iter()
    }

    /// Get the number of subscriptions.
    pub(crate) fn len(&self) -> usize {
        self.local_to_sub.len()
    }

    /// Insert a subscription.
    fn insert(
        &mut self,
        request: SerializedRequest,
        server_id: SubId,
        channel_size: usize,
    ) -> RawSubscription {
        let active = ActiveSubscription::new(request, channel_size);
        let sub = active.subscribe();

        let local_id = active.local_id;
        self.local_to_server.insert(local_id, server_id);
        self.local_to_sub.insert(local_id, active);

        sub
    }

    /// Insert or update the server_id for a subscription.
    pub(crate) fn upsert(
        &mut self,
        request: SerializedRequest,
        server_id: SubId,
        channel_size: usize,
    ) -> RawSubscription {
        let local_id = request.params_hash();

        // If we already know a subscription with the exact params,
        // we can just update the server_id and get a new listener.
        if self.local_to_sub.contains_left(&local_id) {
            self.change_server_id(local_id, server_id);
            self.get_subscription(local_id).expect("checked existence")
        } else {
            self.insert(request, server_id, channel_size)
        }
    }

    /// De-alias an alias, getting the original ID.
    pub(crate) fn local_id_for(&self, server_id: &SubId) -> Option<B256> {
        self.local_to_server.get_by_right(server_id).copied()
    }

    /// De-alias an alias, getting the original ID.
    pub(crate) fn server_id_for(&self, local_id: &B256) -> Option<&SubId> {
        self.local_to_server.get_by_left(local_id)
    }

    /// Drop all server_ids.
    pub(crate) fn drop_server_ids(&mut self) {
        self.local_to_server.clear();
    }

    /// Change the server_id of a subscription.
    fn change_server_id(&mut self, local_id: B256, server_id: SubId) {
        self.local_to_server.insert(local_id, server_id);
    }

    /// Remove a subscription by its local_id.
    pub(crate) fn remove_sub(&mut self, local_id: B256) {
        let _ = self.local_to_sub.remove_by_left(&local_id);
        let _ = self.local_to_server.remove_by_left(&local_id);
    }

    /// Notify the subscription channel of a new value, if the sub is known,
    /// and if any receiver exists. If the sub id is unknown, or no receiver
    /// exists, the notification is dropped.
    pub(crate) fn notify(&mut self, notification: EthNotification) {
        if let Some(local_id) = self.local_id_for(&notification.subscription) {
            if let Some(sub) = self.local_to_sub.get_by_left(&local_id) {
                sub.notify(notification.result);
            }
        }
    }

    /// Get a receiver for a subscription.
    pub(crate) fn get_subscription(&self, local_id: B256) -> Option<RawSubscription> {
        self.local_to_sub.get_by_left(&local_id).map(ActiveSubscription::subscribe)
    }
}