tp_timestamp/
lib.rs

1// This file is part of Tetcore.
2
3// Copyright (C) 2019-2021 Parity Technologies (UK) Ltd.
4// SPDX-License-Identifier: Apache-2.0
5
6// Licensed under the Apache License, Version 2.0 (the "License");
7// you may not use this file except in compliance with the License.
8// You may obtain a copy of the License at
9//
10// 	http://www.apache.org/licenses/LICENSE-2.0
11//
12// Unless required by applicable law or agreed to in writing, software
13// distributed under the License is distributed on an "AS IS" BASIS,
14// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15// See the License for the specific language governing permissions and
16// limitations under the License.
17
18//! Tetcore core types and inherents for timestamps.
19
20#![cfg_attr(not(feature = "std"), no_std)]
21
22use codec::Encode;
23#[cfg(feature = "std")]
24use codec::Decode;
25#[cfg(feature = "std")]
26use tp_inherents::ProvideInherentData;
27use tp_inherents::{InherentIdentifier, IsFatalError, InherentData};
28
29use tp_runtime::RuntimeString;
30
31/// The identifier for the `timestamp` inherent.
32pub const INHERENT_IDENTIFIER: InherentIdentifier = *b"timstap0";
33/// The type of the inherent.
34pub type InherentType = u64;
35
36/// Errors that can occur while checking the timestamp inherent.
37#[derive(Encode, tp_runtime::RuntimeDebug)]
38#[cfg_attr(feature = "std", derive(Decode))]
39pub enum InherentError {
40	/// The timestamp is valid in the future.
41	/// This is a non-fatal-error and will not stop checking the inherents.
42	ValidAtTimestamp(InherentType),
43	/// Some other error.
44	Other(RuntimeString),
45}
46
47impl IsFatalError for InherentError {
48	fn is_fatal_error(&self) -> bool {
49		match self {
50			InherentError::ValidAtTimestamp(_) => false,
51			InherentError::Other(_) => true,
52		}
53	}
54}
55
56impl InherentError {
57	/// Try to create an instance ouf of the given identifier and data.
58	#[cfg(feature = "std")]
59	pub fn try_from(id: &InherentIdentifier, data: &[u8]) -> Option<Self> {
60		if id == &INHERENT_IDENTIFIER {
61			<InherentError as codec::Decode>::decode(&mut &data[..]).ok()
62		} else {
63			None
64		}
65	}
66}
67
68/// Auxiliary trait to extract timestamp inherent data.
69pub trait TimestampInherentData {
70	/// Get timestamp inherent data.
71	fn timestamp_inherent_data(&self) -> Result<InherentType, tp_inherents::Error>;
72}
73
74impl TimestampInherentData for InherentData {
75	fn timestamp_inherent_data(&self) -> Result<InherentType, tp_inherents::Error> {
76		self.get_data(&INHERENT_IDENTIFIER)
77			.and_then(|r| r.ok_or_else(|| "Timestamp inherent data not found".into()))
78	}
79}
80
81/// Provide duration since unix epoch in millisecond for timestamp inherent.
82#[cfg(feature = "std")]
83pub struct InherentDataProvider;
84
85#[cfg(feature = "std")]
86impl ProvideInherentData for InherentDataProvider {
87	fn inherent_identifier(&self) -> &'static InherentIdentifier {
88		&INHERENT_IDENTIFIER
89	}
90
91	fn provide_inherent_data(
92		&self,
93		inherent_data: &mut InherentData,
94	) -> Result<(), tp_inherents::Error> {
95		use wasm_timer::SystemTime;
96
97		let now = SystemTime::now();
98		now.duration_since(SystemTime::UNIX_EPOCH)
99			.map_err(|_| {
100				"Current time is before unix epoch".into()
101			}).and_then(|d| {
102				let duration: InherentType = d.as_millis() as u64;
103				inherent_data.put_data(INHERENT_IDENTIFIER, &duration)
104			})
105	}
106
107	fn error_to_string(&self, error: &[u8]) -> Option<String> {
108		InherentError::try_from(&INHERENT_IDENTIFIER, error).map(|e| format!("{:?}", e))
109	}
110}
111
112
113/// A trait which is called when the timestamp is set.
114#[impl_trait_for_tuples::impl_for_tuples(30)]
115pub trait OnTimestampSet<Moment> {
116	fn on_timestamp_set(moment: Moment);
117}
tp_timestamp/lib.rs

tp_timestamp/
lib.rs
