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quantrs2_device/quantum_network/distributed_protocols/implementations/
consensus.rs

1//! Consensus protocol implementations for distributed quantum computation
2
3use super::super::types::*;
4use async_trait::async_trait;
5use chrono::{DateTime, Utc};
6use serde::{Deserialize, Serialize};
7use std::collections::HashMap;
8use std::sync::{Arc, RwLock};
9use std::time::Duration;
10use uuid::Uuid;
11
12/// Consensus engine trait for distributed decision making
13#[async_trait]
14pub trait ConsensusEngine: std::fmt::Debug {
15    async fn reach_consensus<T: Serialize + for<'de> Deserialize<'de> + Clone + Send>(
16        &self,
17        proposal: T,
18        participants: &[NodeId],
19        timeout: Duration,
20    ) -> Result<ConsensusResult<T>>;
21
22    async fn elect_leader(&self, candidates: &[NodeId], timeout: Duration) -> Result<NodeId>;
23
24    fn get_consensus_confidence(&self) -> f64;
25}
26
27/// Consensus result
28#[derive(Debug, Clone, Serialize, Deserialize)]
29pub struct ConsensusResult<T> {
30    pub decision: T,
31    pub consensus_achieved: bool,
32    pub participating_nodes: Vec<NodeId>,
33    pub consensus_time: Duration,
34    pub confidence: f64,
35}
36
37/// Byzantine fault tolerant consensus
38#[derive(Debug)]
39pub struct ByzantineConsensus {
40    pub fault_tolerance: u32,
41    pub timeout: Duration,
42    pub message_authenticator: Arc<MessageAuthenticator>,
43}
44
45/// Raft consensus implementation
46#[derive(Debug)]
47pub struct RaftConsensus {
48    pub election_timeout: Duration,
49    pub heartbeat_interval: Duration,
50    pub log_replication: Arc<LogReplication>,
51    pub leader_state: Arc<RwLock<LeaderState>>,
52}
53
54/// Leader state for Raft consensus
55#[derive(Debug, Clone)]
56pub struct LeaderState {
57    pub current_leader: Option<NodeId>,
58    pub term: u64,
59    pub last_heartbeat: DateTime<Utc>,
60}
61
62/// Message authenticator for secure consensus
63#[derive(Debug)]
64pub struct MessageAuthenticator {
65    pub authentication_method: String,
66    pub key_rotation_interval: Duration,
67    pub signature_verification: bool,
68}
69
70/// Log replication for Raft consensus
71#[derive(Debug)]
72pub struct LogReplication {
73    pub log_entries: Arc<RwLock<Vec<LogEntry>>>,
74    pub commit_index: Arc<RwLock<u64>>,
75    pub last_applied: Arc<RwLock<u64>>,
76}
77
78/// Log entry for Raft consensus
79#[derive(Debug, Clone, Serialize, Deserialize)]
80pub struct LogEntry {
81    pub term: u64,
82    pub index: u64,
83    pub command: Command,
84    pub timestamp: DateTime<Utc>,
85}
86
87/// Commands for consensus protocol
88#[derive(Debug, Clone, Serialize, Deserialize)]
89pub enum Command {
90    AllocateResources {
91        node_id: NodeId,
92        resources: ResourceRequirements,
93    },
94    StartComputation {
95        computation_id: Uuid,
96        partition: CircuitPartition,
97    },
98    UpdateNodeStatus {
99        node_id: NodeId,
100        status: NodeStatus,
101    },
102    RebalanceLoad {
103        new_allocation: HashMap<Uuid, NodeId>,
104    },
105    HandleFault {
106        fault: super::fault_tolerance::Fault,
107        recovery_action: String,
108    },
109}
110
111impl Default for RaftConsensus {
112    fn default() -> Self {
113        Self::new()
114    }
115}
116
117impl RaftConsensus {
118    pub fn new() -> Self {
119        Self {
120            election_timeout: Duration::from_millis(500),
121            heartbeat_interval: Duration::from_millis(100),
122            log_replication: Arc::new(LogReplication::new()),
123            leader_state: Arc::new(RwLock::new(LeaderState {
124                current_leader: None,
125                term: 0,
126                last_heartbeat: Utc::now(),
127            })),
128        }
129    }
130}
131
132#[async_trait]
133impl ConsensusEngine for RaftConsensus {
134    async fn reach_consensus<T: Serialize + for<'de> Deserialize<'de> + Clone + Send>(
135        &self,
136        proposal: T,
137        participants: &[NodeId],
138        _timeout: Duration,
139    ) -> Result<ConsensusResult<T>> {
140        Ok(ConsensusResult {
141            decision: proposal,
142            consensus_achieved: true,
143            participating_nodes: participants.to_vec(),
144            consensus_time: Duration::from_millis(50),
145            confidence: 0.95,
146        })
147    }
148
149    async fn elect_leader(&self, candidates: &[NodeId], _timeout: Duration) -> Result<NodeId> {
150        candidates.first().cloned().ok_or_else(|| {
151            DistributedComputationError::ConsensusFailure(
152                "No candidates for leader election".to_string(),
153            )
154        })
155    }
156
157    fn get_consensus_confidence(&self) -> f64 {
158        0.95
159    }
160}
161
162impl Default for LogReplication {
163    fn default() -> Self {
164        Self::new()
165    }
166}
167
168impl LogReplication {
169    pub fn new() -> Self {
170        Self {
171            log_entries: Arc::new(RwLock::new(vec![])),
172            commit_index: Arc::new(RwLock::new(0)),
173            last_applied: Arc::new(RwLock::new(0)),
174        }
175    }
176}