common_primitives/
rpc.rs

1#[cfg(feature = "std")]
2use crate::utils::as_hex;
3#[cfg(feature = "std")]
4use serde::{Deserialize, Serialize};
5
6use frame_system::{EventRecord, Phase};
7use parity_scale_codec::{Codec, Decode, DecodeWithMemTracking, Encode, EncodeLike};
8use scale_info::TypeInfo;
9extern crate alloc;
10use alloc::vec::Vec;
11use core::fmt::Debug;
12
13/// The Struct for the getEvents RPC
14/// This handles the Scale encoding of ONLY the event
15/// Making a standardized and easy way to get events only caring about
16/// the SCALE types of the events you care about
17#[cfg_attr(feature = "std", derive(Serialize, Deserialize))]
18#[derive(Debug, TypeInfo, Clone, Encode, Decode, PartialEq, Eq)]
19pub struct RpcEvent {
20	/// Which extrinsic call/Aka block index
21	/// A None here means that it was in the Initialization or Finalization Phase
22	pub phase: Option<u32>,
23	/// Pallet index from the runtime
24	pub pallet: u8,
25	/// Index of the Event from the Pallet
26	pub event: u8,
27	/// The data of just the event SCALE Encoded
28	#[cfg_attr(feature = "std", serde(with = "as_hex",))]
29	pub data: Vec<u8>,
30}
31
32impl<RuntimeEvent, Hash> From<EventRecord<RuntimeEvent, Hash>> for RpcEvent
33where
34	RuntimeEvent: DecodeWithMemTracking
35		+ Codec
36		+ Sync
37		+ Send
38		+ TypeInfo
39		+ Debug
40		+ Eq
41		+ Clone
42		+ EncodeLike
43		+ 'static,
44{
45	fn from(event: EventRecord<RuntimeEvent, Hash>) -> Self {
46		let phase = match event.phase {
47			Phase::ApplyExtrinsic(i) => Some(i),
48			_ => None,
49		};
50
51		// This requires that SCALE encoding does NOT change how it encodes u8s and indexes on enums
52		let full_encoding = Encode::encode(&event.event);
53		let pallet = full_encoding[0];
54		let event = full_encoding[1];
55		let data = &full_encoding[2..];
56
57		RpcEvent { phase, pallet, event, data: data.to_vec() }
58	}
59}
60
61#[cfg(test)]
62mod tests {
63	use super::*;
64
65	#[derive(Debug, TypeInfo, Clone, Encode, Decode, DecodeWithMemTracking, Eq, PartialEq)]
66	enum FakeRuntime {
67		#[codec(index = 60)]
68		FakePallet(FakePalletEvents),
69	}
70
71	#[derive(Debug, TypeInfo, Clone, Encode, Decode, DecodeWithMemTracking, Eq, PartialEq)]
72	enum FakePalletEvents {
73		#[codec(index = 7)]
74		FakeEvent { msa_id: u64 },
75	}
76
77	#[test]
78	fn rpc_event_from_event_record() {
79		let event: EventRecord<FakeRuntime, ()> = EventRecord {
80			phase: Phase::ApplyExtrinsic(5),
81			event: FakeRuntime::FakePallet(FakePalletEvents::FakeEvent { msa_id: 42 }),
82			topics: vec![],
83		};
84		let rpc_event: RpcEvent = event.into();
85		assert_eq!(
86			rpc_event,
87			RpcEvent { phase: Some(5), pallet: 60, event: 7, data: vec![42, 0, 0, 0, 0, 0, 0, 0] }
88		);
89	}
90
91	#[test]
92	fn rpc_event_from_event_record_with_different_phase() {
93		let event: EventRecord<FakeRuntime, ()> = EventRecord {
94			phase: Phase::Finalization,
95			event: FakeRuntime::FakePallet(FakePalletEvents::FakeEvent { msa_id: 42 }),
96			topics: vec![],
97		};
98		let rpc_event: RpcEvent = event.into();
99		assert_eq!(
100			rpc_event,
101			RpcEvent { phase: None, pallet: 60, event: 7, data: vec![42, 0, 0, 0, 0, 0, 0, 0] }
102		);
103	}
104}
common_primitives/rpc.rs

common_primitives/
rpc.rs
