quantrs2_tytan/sampler/hardware/
fujitsu.rs

1//! Fujitsu Digital Annealer integration
2//!
3//! This module provides integration with Fujitsu's Digital Annealer,
4//! a quantum-inspired optimization processor.
5
6use crate::sampler::{SampleResult, Sampler, SamplerError, SamplerResult};
7use scirs2_core::ndarray::Array2;
8use std::collections::HashMap;
9use std::time::Duration;
10
11/// Fujitsu Digital Annealer configuration
12#[derive(Debug, Clone)]
13pub struct FujitsuConfig {
14    /// API endpoint
15    pub endpoint: String,
16    /// API key
17    pub api_key: String,
18    /// Annealing time in milliseconds
19    pub annealing_time: u32,
20    /// Number of replicas
21    pub num_replicas: u32,
22    /// Offset increment
23    pub offset_increment: f64,
24    /// Temperature start
25    pub temperature_start: f64,
26    /// Temperature end
27    pub temperature_end: f64,
28    /// Temperature mode
29    pub temperature_mode: TemperatureMode,
30}
31
32#[derive(Debug, Clone)]
33pub enum TemperatureMode {
34    /// Linear temperature schedule
35    Linear,
36    /// Exponential temperature schedule
37    Exponential,
38    /// Adaptive temperature schedule
39    Adaptive,
40}
41
42impl Default for FujitsuConfig {
43    fn default() -> Self {
44        Self {
45            endpoint: "https://api.da.fujitsu.com/v2".to_string(),
46            api_key: String::new(),
47            annealing_time: 1000,
48            num_replicas: 16,
49            offset_increment: 100.0,
50            temperature_start: 1000.0,
51            temperature_end: 0.1,
52            temperature_mode: TemperatureMode::Exponential,
53        }
54    }
55}
56
57/// Fujitsu Digital Annealer sampler
58pub struct FujitsuDigitalAnnealerSampler {
59    config: FujitsuConfig,
60    /// Maximum problem size
61    max_variables: usize,
62    /// Connectivity constraints
63    connectivity: ConnectivityType,
64}
65
66#[derive(Debug, Clone)]
67pub enum ConnectivityType {
68    /// Fully connected
69    FullyConnected,
70    /// King's graph connectivity
71    KingsGraph,
72    /// Chimera graph connectivity
73    Chimera { unit_size: usize },
74}
75
76impl FujitsuDigitalAnnealerSampler {
77    /// Create new Fujitsu Digital Annealer sampler
78    pub const fn new(config: FujitsuConfig) -> Self {
79        Self {
80            config,
81            max_variables: 8192, // Current DA3 limit
82            connectivity: ConnectivityType::FullyConnected,
83        }
84    }
85
86    /// Set connectivity type
87    pub const fn with_connectivity(mut self, connectivity: ConnectivityType) -> Self {
88        self.connectivity = connectivity;
89        self
90    }
91
92    /// Submit problem to Digital Annealer
93    fn submit_problem(&self, _qubo: &Array2<f64>) -> Result<String, SamplerError> {
94        // In a real implementation, this would:
95        // 1. Format QUBO for DA API
96        // 2. Submit via HTTP POST
97        // 3. Return job ID
98
99        // Placeholder implementation
100        Ok("job_12345".to_string())
101    }
102
103    /// Poll for results
104    fn get_results(
105        &self,
106        _job_id: &str,
107        _timeout: Duration,
108    ) -> Result<Vec<DASolution>, SamplerError> {
109        // In a real implementation, this would:
110        // 1. Poll the API for job completion
111        // 2. Parse results
112        // 3. Return solutions
113
114        // Placeholder implementation
115        Ok(vec![DASolution {
116            configuration: vec![0; self.max_variables],
117            energy: -100.0,
118            frequency: 10,
119        }])
120    }
121
122    /// Convert DA solution to sample result
123    fn to_sample_result(
124        &self,
125        solution: &DASolution,
126        var_map: &HashMap<String, usize>,
127    ) -> SampleResult {
128        let mut assignments = HashMap::new();
129
130        for (var_name, &index) in var_map {
131            if index < solution.configuration.len() {
132                assignments.insert(var_name.clone(), solution.configuration[index] == 1);
133            }
134        }
135
136        SampleResult {
137            assignments,
138            energy: solution.energy,
139            occurrences: solution.frequency as usize,
140        }
141    }
142}
143
144/// Digital Annealer solution format
145#[derive(Debug, Clone)]
146struct DASolution {
147    /// Binary configuration
148    configuration: Vec<u8>,
149    /// Solution energy
150    energy: f64,
151    /// Occurrence frequency
152    frequency: u32,
153}
154
155impl Sampler for FujitsuDigitalAnnealerSampler {
156    fn run_qubo(
157        &self,
158        model: &(Array2<f64>, HashMap<String, usize>),
159        shots: usize,
160    ) -> SamplerResult<Vec<SampleResult>> {
161        let (qubo, var_map) = model;
162
163        // Check problem size
164        if qubo.shape()[0] > self.max_variables {
165            return Err(SamplerError::InvalidModel(format!(
166                "Problem size {} exceeds Digital Annealer limit of {}",
167                qubo.shape()[0],
168                self.max_variables
169            )));
170        }
171
172        // Submit problem
173        let job_id = self.submit_problem(qubo)?;
174
175        // Get results
176        let timeout = Duration::from_millis(self.config.annealing_time as u64 + 5000);
177        let da_solutions = self.get_results(&job_id, timeout)?;
178
179        // Convert to sample results
180        let mut results: Vec<SampleResult> = da_solutions
181            .iter()
182            .map(|sol| self.to_sample_result(sol, var_map))
183            .collect();
184
185        // Sort by energy
186        results.sort_by(|a, b| {
187            a.energy
188                .partial_cmp(&b.energy)
189                .unwrap_or(std::cmp::Ordering::Equal)
190        });
191
192        // Limit to requested shots
193        results.truncate(shots);
194
195        Ok(results)
196    }
197
198    fn run_hobo(
199        &self,
200        _hobo: &(scirs2_core::ndarray::ArrayD<f64>, HashMap<String, usize>),
201        _shots: usize,
202    ) -> SamplerResult<Vec<SampleResult>> {
203        Err(SamplerError::NotImplemented(
204            "HOBO not supported by Fujitsu hardware".to_string(),
205        ))
206    }
207}
208
209#[cfg(test)]
210mod tests {
211    use super::*;
212
213    #[test]
214    fn test_fujitsu_config() {
215        let mut config = FujitsuConfig::default();
216        assert_eq!(config.annealing_time, 1000);
217        assert_eq!(config.num_replicas, 16);
218    }
219
220    #[test]
221    fn test_connectivity_types() {
222        let sampler = FujitsuDigitalAnnealerSampler::new(FujitsuConfig::default())
223            .with_connectivity(ConnectivityType::KingsGraph);
224
225        match sampler.connectivity {
226            ConnectivityType::KingsGraph => (),
227            _ => panic!("Wrong connectivity type"),
228        }
229    }
230}
quantrs2_tytan/sampler/hardware/fujitsu.rs

quantrs2_tytan/sampler/hardware/
fujitsu.rs
