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
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137

// This file is part of Substrate.

// Copyright (C) Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: GPL-3.0-or-later WITH Classpath-exception-2.0

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.

// file-level lint whitelist to avoid problem with bitflags macro below
// TODO: can be dropped after an update to bitflags 2.4
#![allow(clippy::bad_bit_mask)]

use codec::{self, Encode, EncodeLike, Input, Output};

/// Role that the peer sent to us during the handshake, with the addition of what our local node
/// knows about that peer.
///
/// > **Note**: This enum is different from the `Role` enum. The `Role` enum indicates what a
/// >			node says about itself, while `ObservedRole` is a `Role` merged with the
/// >			information known locally about that node.
#[derive(Debug, Copy, Clone, PartialEq, Eq)]
pub enum ObservedRole {
	/// Full node.
	Full,
	/// Light node.
	Light,
	/// Third-party authority.
	Authority,
}

impl ObservedRole {
	/// Returns `true` for `ObservedRole::Light`.
	pub fn is_light(&self) -> bool {
		matches!(self, Self::Light)
	}
}

impl From<Roles> for ObservedRole {
	fn from(roles: Roles) -> Self {
		if roles.is_authority() {
			ObservedRole::Authority
		} else if roles.is_full() {
			ObservedRole::Full
		} else {
			ObservedRole::Light
		}
	}
}

/// Role of the local node.
#[derive(Debug, Clone, Copy)]
pub enum Role {
	/// Regular full node.
	Full,
	/// Actual authority.
	Authority,
}

impl Role {
	/// True for [`Role::Authority`].
	pub fn is_authority(&self) -> bool {
		matches!(self, Self::Authority)
	}
}

impl std::fmt::Display for Role {
	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
		match self {
			Self::Full => write!(f, "FULL"),
			Self::Authority => write!(f, "AUTHORITY"),
		}
	}
}

bitflags::bitflags! {
	/// Bitmask of the roles that a node fulfills.
	pub struct Roles: u8 {
		/// No network.
		const NONE = 0b00000000;
		/// Full node, does not participate in consensus.
		const FULL = 0b00000001;
		/// Light client node.
		const LIGHT = 0b00000010;
		/// Act as an authority
		const AUTHORITY = 0b00000100;
	}
}

impl Roles {
	/// Does this role represents a client that holds full chain data locally?
	pub fn is_full(&self) -> bool {
		self.intersects(Self::FULL | Self::AUTHORITY)
	}

	/// Does this role represents a client that does not participates in the consensus?
	pub fn is_authority(&self) -> bool {
		*self == Self::AUTHORITY
	}

	/// Does this role represents a client that does not hold full chain data locally?
	pub fn is_light(&self) -> bool {
		!self.is_full()
	}
}

impl<'a> From<&'a Role> for Roles {
	fn from(roles: &'a Role) -> Self {
		match roles {
			Role::Full => Self::FULL,
			Role::Authority => Self::AUTHORITY,
		}
	}
}

impl Encode for Roles {
	fn encode_to<T: Output + ?Sized>(&self, dest: &mut T) {
		dest.push_byte(self.bits())
	}
}

impl EncodeLike for Roles {}

impl codec::Decode for Roles {
	fn decode<I: Input>(input: &mut I) -> Result<Self, codec::Error> {
		Self::from_bits(input.read_byte()?).ok_or_else(|| codec::Error::from("Invalid bytes"))
	}
}