refactor: Implement modular candle-binding architecture


- Restructure codebase into modular layers (core/, ffi/, model_architectures/, classifiers/)
- Add unified error handling and configuration loading systems
- Implement dual-path architecture for traditional and LoRA models
- Add comprehensive FFI layer with memory safety

Maintains backward compatibility while enabling future model integrations.

Signed-off-by: OneZero-Y <[email protected]>

Author: OneZero-Y

candle-binding/src/bert_official.rs

@@ -0,0 +1,138 @@
+//! Intent classification with LoRA adapters
+//!
+//! High-performance intent classification using real model inference
+
+use crate::core::{processing_errors, ModelErrorType, UnifiedError};
+use crate::model_architectures::lora::bert_lora::HighPerformanceBertClassifier;
+use crate::model_error;
+use candle_core::Result;
+use std::time::Instant;
+
+/// Intent classifier with real model inference (merged LoRA models)
+pub struct IntentLoRAClassifier {
+    /// High-performance BERT classifier for intent classification
+    bert_classifier: HighPerformanceBertClassifier,
+    /// Confidence threshold for predictions
+    confidence_threshold: f32,
+    /// Intent labels mapping
+    intent_labels: Vec<String>,
+    /// Model path for reference
+    model_path: String,
+}
+
+/// Intent classification result
+#[derive(Debug, Clone)]
+pub struct IntentResult {
+    pub intent: String,
+    pub confidence: f32,
+    pub processing_time_ms: u64,
+}
+
+impl IntentLoRAClassifier {
+    /// Create new intent classifier using real model inference
+    pub fn new(model_path: &str, use_cpu: bool) -> Result<Self> {
+        // Load labels from model config
+        let intent_labels = Self::load_labels_from_config(model_path)?;
+        let num_classes = intent_labels.len();
+
+        // Load the high-performance BERT classifier for merged LoRA models
+        let classifier = HighPerformanceBertClassifier::new(model_path, num_classes, use_cpu)
+            .map_err(|e| {
+                let unified_err = model_error!(
+                    ModelErrorType::LoRA,
+                    "intent classifier creation",
+                    format!("Failed to create BERT classifier: {}", e),
+                    model_path
+                );
+                candle_core::Error::from(unified_err)
+            })?;
+
+        Ok(Self {
+            bert_classifier: classifier,
+            confidence_threshold: 0.7,
+            intent_labels,
+            model_path: model_path.to_string(),
+        })
+    }
+
+    /// Load intent labels from model config.json using unified config loader
+    fn load_labels_from_config(model_path: &str) -> Result<Vec<String>> {
+        use crate::core::config_loader;
+
+        match config_loader::load_intent_labels(model_path) {
+            Ok(result) => Ok(result),
+            Err(unified_err) => Err(candle_core::Error::from(unified_err)),
+        }
+    }
+
+    /// Classify intent using real model inference
+    pub fn classify_intent(&self, text: &str) -> Result<IntentResult> {
+        let start_time = Instant::now();
+
+        // Use real BERT model for classification
+        let (predicted_class, confidence) =
+            self.bert_classifier.classify_text(text).map_err(|e| {
+                let unified_err = model_error!(
+                    ModelErrorType::LoRA,
+                    "intent classification",
+                    format!("Classification failed: {}", e),
+                    text
+                );
+                candle_core::Error::from(unified_err)
+            })?;
+
+        // Map class index to intent label
+        let intent = if predicted_class < self.intent_labels.len() {
+            self.intent_labels[predicted_class].clone()
+        } else {
+            format!("UNKNOWN_{}", predicted_class)
+        };
+
+        let processing_time = start_time.elapsed().as_millis() as u64;
+
+        Ok(IntentResult {
+            intent,
+            confidence,
+            processing_time_ms: processing_time,
+        })
+    }
+
+    /// Parallel classification for multiple texts
+    pub fn parallel_classify(&self, texts: &[&str]) -> Result<Vec<IntentResult>> {
+        // Process each text using real model inference
+        texts
+            .iter()
+            .map(|text| self.classify_intent(text))
+            .collect()
+    }
+
+    /// Batch classification for multiple texts (optimized)
+    pub fn batch_classify(&self, texts: &[&str]) -> Result<Vec<IntentResult>> {
+        let start_time = Instant::now();
+
+        // Use BERT's batch processing capability
+        let batch_results = self.bert_classifier.classify_batch(texts).map_err(|e| {
+            let unified_err = processing_errors::batch_processing(texts.len(), &e.to_string());
+            candle_core::Error::from(unified_err)
+        })?;
+
+        let processing_time = start_time.elapsed().as_millis() as u64;
+
+        let mut results = Vec::new();
+        for (predicted_class, confidence) in batch_results {
+            let intent = if predicted_class < self.intent_labels.len() {
+                self.intent_labels[predicted_class].clone()
+            } else {
+                format!("UNKNOWN_{}", predicted_class)
+            };
+
+            results.push(IntentResult {
+                intent,
+                confidence,
+                processing_time_ms: processing_time,
+            });
+        }
+
+        Ok(results)
+    }
+}

candle-binding/src/classifiers/lora/intent_lora.rs

@@ -0,0 +1,16 @@
+//! LoRA Classifiers - High-Performance Parallel Processing
+
+#![allow(dead_code)]
+
+// LoRA classifier modules
+pub mod intent_lora;
+pub mod parallel_engine;
+pub mod pii_lora;
+pub mod security_lora;
+pub mod token_lora;
+
+// Re-export LoRA classifier types
+pub use intent_lora::*;
+pub use parallel_engine::*;
+pub use pii_lora::*;
+pub use security_lora::*;

candle-binding/src/classifiers/lora/mod.rs

@@ -0,0 +1,181 @@
+//! Parallel LoRA processing engine
+//!
+//! Enables parallel execution of Intent||PII||Security classification tasks
+//! Using thread-based parallelism instead of async/await
+
+use crate::classifiers::lora::{
+    intent_lora::{IntentLoRAClassifier, IntentResult},
+    pii_lora::{PIILoRAClassifier, PIIResult},
+    security_lora::{SecurityLoRAClassifier, SecurityResult},
+};
+use crate::core::{concurrency_error, ModelErrorType, UnifiedError};
+use crate::model_error;
+use candle_core::{Device, Result};
+use std::sync::{Arc, Mutex};
+use std::thread;
+
+/// Parallel LoRA processing engine
+pub struct ParallelLoRAEngine {
+    intent_classifier: Arc<IntentLoRAClassifier>,
+    pii_classifier: Arc<PIILoRAClassifier>,
+    security_classifier: Arc<SecurityLoRAClassifier>,
+    device: Device,
+}
+
+impl ParallelLoRAEngine {
+    pub fn new(
+        device: Device,
+        intent_model_path: &str,
+        pii_model_path: &str,
+        security_model_path: &str,
+        use_cpu: bool,
+    ) -> Result<Self> {
+        // Create intent classifier
+        let intent_classifier = Arc::new(
+            IntentLoRAClassifier::new(intent_model_path, use_cpu).map_err(|e| {
+                let unified_err = model_error!(
+                    ModelErrorType::LoRA,
+                    "intent classifier creation",
+                    format!("Failed to create intent classifier: {}", e),
+                    intent_model_path
+                );
+                candle_core::Error::from(unified_err)
+            })?,
+        );
+
+        // Create PII classifier
+        let pii_classifier = Arc::new(PIILoRAClassifier::new(pii_model_path, use_cpu).map_err(
+            |e| {
+                let unified_err = model_error!(
+                    ModelErrorType::LoRA,
+                    "PII classifier creation",
+                    format!("Failed to create PII classifier: {}", e),
+                    pii_model_path
+                );
+                candle_core::Error::from(unified_err)
+            },
+        )?);
+
+        // Create security classifier
+        let security_classifier = Arc::new(
+            SecurityLoRAClassifier::new(security_model_path, use_cpu).map_err(|e| {
+                let unified_err = model_error!(
+                    ModelErrorType::LoRA,
+                    "security classifier creation",
+                    format!("Failed to create security classifier: {}", e),
+                    security_model_path
+                );
+                candle_core::Error::from(unified_err)
+            })?,
+        );
+
+        Ok(Self {
+            intent_classifier,
+            pii_classifier,
+            security_classifier,
+            device,
+        })
+    }
+
+    /// Parallel classification across all three tasks
+    pub fn parallel_classify(&self, texts: &[&str]) -> Result<ParallelResult> {
+        let texts_owned: Vec<String> = texts.iter().map(|s| s.to_string()).collect();
+
+        // Create shared results
+        let intent_results = Arc::new(Mutex::new(Vec::new()));
+        let pii_results = Arc::new(Mutex::new(Vec::new()));
+        let security_results = Arc::new(Mutex::new(Vec::new()));
+
+        let handles = vec![
+            self.spawn_intent_task(texts_owned.clone(), Arc::clone(&intent_results)),
+            self.spawn_pii_task(texts_owned.clone(), Arc::clone(&pii_results)),
+            self.spawn_security_task(texts_owned, Arc::clone(&security_results)),
+        ];
+
+        // Wait for all threads to complete
+        for handle in handles {
+            handle.join().map_err(|_| {
+                let unified_err = concurrency_error(
+                    "thread join",
+                    "Failed to join parallel classification thread",
+                );
+                candle_core::Error::from(unified_err)
+            })?;
+        }
+
+        Ok(ParallelResult {
+            intent_results: Arc::try_unwrap(intent_results)
+                .unwrap()
+                .into_inner()
+                .unwrap(),
+            pii_results: Arc::try_unwrap(pii_results).unwrap().into_inner().unwrap(),
+            security_results: Arc::try_unwrap(security_results)
+                .unwrap()
+                .into_inner()
+                .unwrap(),
+        })
+    }
+
+    fn spawn_intent_task(
+        &self,
+        texts: Vec<String>,
+        results: Arc<Mutex<Vec<IntentResult>>>,
+    ) -> thread::JoinHandle<()> {
+        let classifier = Arc::clone(&self.intent_classifier);
+        thread::spawn(move || {
+            let text_refs: Vec<&str> = texts.iter().map(|s| s.as_str()).collect();
+            match classifier.batch_classify(&text_refs) {
+                Ok(task_results) => {
+                    let mut guard = results.lock().unwrap();
+                    *guard = task_results;
+                }
+                Err(e) => {
+                    eprintln!("Intent classification failed: {}", e);
+                }
+            }
+        })
+    }
+
+    fn spawn_pii_task(
+        &self,
+        texts: Vec<String>,
+        results: Arc<Mutex<Vec<PIIResult>>>,
+    ) -> thread::JoinHandle<()> {
+        let classifier = Arc::clone(&self.pii_classifier);
+        thread::spawn(move || {
+            let text_refs: Vec<&str> = texts.iter().map(|s| s.as_str()).collect();
+            if let Ok(task_results) = classifier.batch_detect(&text_refs) {
+                let mut guard = results.lock().unwrap();
+                *guard = task_results;
+            }
+        })
+    }
+
+    fn spawn_security_task(
+        &self,
+        texts: Vec<String>,
+        results: Arc<Mutex<Vec<SecurityResult>>>,
+    ) -> thread::JoinHandle<()> {
+        let classifier = Arc::clone(&self.security_classifier);
+        thread::spawn(move || {
+            let text_refs: Vec<&str> = texts.iter().map(|s| s.as_str()).collect();
+            match classifier.batch_detect(&text_refs) {
+                Ok(task_results) => {
+                    let mut guard = results.lock().unwrap();
+                    *guard = task_results;
+                }
+                Err(e) => {
+                    eprintln!("Security classification failed: {}", e);
+                }
+            }
+        })
+    }
+}
+
+/// Results from parallel classification
+#[derive(Debug, Clone)]
+pub struct ParallelResult {
+    pub intent_results: Vec<IntentResult>,
+    pub pii_results: Vec<PIIResult>,
+    pub security_results: Vec<SecurityResult>,
+}