scirs2-linalg 0.4.2

//! Pattern recognition and hashing for memory access patterns.

use super::types::*;
use scirs2_core::ndarray::Array2;
use std::collections::HashMap;

/// Pattern database for memory access patterns
#[derive(Debug)]
#[allow(dead_code)]
pub struct PatternDatabase<T> {
    /// Stored patterns
    patterns: HashMap<PatternId, MemoryAccessPattern<T>>,
    /// Pattern similarity index
    similarity_index: PatternSimilarityIndex,
    /// Pattern occurrence frequency
    frequency_counter: HashMap<PatternId, usize>,
    /// Pattern performance mapping
    performance_mapping: HashMap<PatternId, f64>,
}

/// Pattern similarity index for fast lookup
#[derive(Debug)]
#[allow(dead_code)]
pub struct PatternSimilarityIndex {
    /// Locality sensitive hashing
    lsh_index: LocalitySensitiveHashing,
    /// Similarity threshold
    similarity_threshold: f64,
    /// Index build parameters
    index_params: IndexParameters,
}

/// Locality sensitive hashing for pattern similarity
#[derive(Debug)]
#[allow(dead_code)]
pub struct LocalitySensitiveHashing {
    /// Hash functions
    hash_functions: Vec<HashFunction>,
    /// Hash tables
    hash_tables: Vec<HashMap<u64, Vec<PatternId>>>,
    /// Dimensionality
    dimension: usize,
}

/// Hash function for LSH
#[derive(Debug)]
pub struct HashFunction {
    /// Random projection matrix
    pub projection: Array2<f64>,
    /// Bias term
    pub bias: f64,
    /// Hash bucket width
    pub bucket_width: f64,
}

/// Index parameters for similarity search
#[derive(Debug, Clone)]
pub struct IndexParameters {
    /// Number of hash functions
    pub num_hash_functions: usize,
    /// Number of hash tables
    pub num_hash_tables: usize,
    /// Bucket width
    pub bucket_width: f64,
    /// Dimensionality reduction
    pub dimension_reduction: Option<usize>,
}

/// Memory access pattern representation
#[derive(Debug, Clone)]
pub struct MemoryAccessPattern<T> {
    /// Pattern ID
    pub id: PatternId,
    /// Access sequence
    pub access_sequence: Vec<MemoryAccess>,
    /// Pattern features
    pub features: PatternFeatures,
    /// Context information
    pub context: AccessContext<T>,
    /// Performance characteristics
    pub performance: PatternPerformance,
}

/// Individual memory access
#[derive(Debug, Clone)]
pub struct MemoryAccess {
    /// Memory address
    pub address: usize,
    /// Access size
    pub size: usize,
    /// Access type
    pub access_type: MemoryAccessType,
    /// Timestamp
    pub timestamp: u64,
    /// Thread ID
    pub thread_id: usize,
}

/// Pattern features for classification and similarity
#[derive(Debug, Clone)]
pub struct PatternFeatures {
    /// Spatial locality score
    pub spatial_locality: f64,
    /// Temporal locality score
    pub temporal_locality: f64,
    /// Stride pattern
    pub stride_pattern: Vec<isize>,
    /// Access density
    pub access_density: f64,
    /// Repetition factor
    pub repetition_factor: f64,
    /// Working set size
    pub working_setsize: usize,
    /// Cache utilization
    pub cache_utilization: f64,
}

/// Performance characteristics of a pattern
#[derive(Debug, Clone)]
pub struct PatternPerformance {
    /// Average latency
    pub average_latency: f64,
    /// Bandwidth utilization
    pub bandwidth_utilization: f64,
    /// Cache hit rate
    pub cache_hit_rate: f64,
    /// Energy efficiency
    pub energy_efficiency: f64,
    /// Scalability factor
    pub scalability_factor: f64,
}

// Implementations
impl<T> Default for PatternDatabase<T> {
    fn default() -> Self {
        Self::new()
    }
}

impl<T> PatternDatabase<T> {
    pub fn new() -> Self {
        Self {
            patterns: HashMap::new(),
            similarity_index: PatternSimilarityIndex::new(),
            frequency_counter: HashMap::new(),
            performance_mapping: HashMap::new(),
        }
    }
}

impl Default for PatternSimilarityIndex {
    fn default() -> Self {
        Self::new()
    }
}

impl PatternSimilarityIndex {
    pub fn new() -> Self {
        Self {
            lsh_index: LocalitySensitiveHashing::new(),
            similarity_threshold: 0.8,
            index_params: IndexParameters::default(),
        }
    }
}

impl Default for LocalitySensitiveHashing {
    fn default() -> Self {
        Self::new()
    }
}

impl LocalitySensitiveHashing {
    pub fn new() -> Self {
        Self {
            hash_functions: Vec::new(),
            hash_tables: Vec::new(),
            dimension: 128,
        }
    }
}

impl Default for IndexParameters {
    fn default() -> Self {
        Self {
            num_hash_functions: 10,
            num_hash_tables: 5,
            bucket_width: 1.0,
            dimension_reduction: Some(64),
        }
    }
}