use anyhow::Result;
use std::path::Path;
use tracing::{info, error, warn};
use super::inference_backend::{InferenceBackend, InferenceConfig, InferenceMetrics};
use std::time::Instant;
use candle_core::Device;
use candle_transformers::models::gemma2::Model as GemmaModel;
use tokenizers::Tokenizer;
use std::sync::Arc;
pub struct GGUFInference {
model: Option<GemmaModel>,
tokenizer: Option<Arc<Tokenizer>>,
device: Device,
model_loaded: bool,
}
impl GGUFInference {
pub fn new() -> Self {
let device = if cfg!(target_os = "macos") {
Device::new_metal(0).unwrap_or(Device::Cpu)
} else if candle_core::utils::cuda_is_available() {
Device::new_cuda(0).unwrap_or(Device::Cpu)
} else {
Device::Cpu
};
info!("GGUF inference using device: {:?}", device);
Self {
model: None,
tokenizer: None,
device,
model_loaded: false,
}
}
fn load_gguf_model(&mut self, model_path: &Path) -> Result<()> {
info!("Loading GGUF model from: {:?}", model_path);
if !model_path.exists() {
error!("Model file not found at: {:?}", model_path);
return Err(anyhow::anyhow!("Model file not found"));
}
info!("GGUF model file found at: {:?}", model_path);
let tokenizer_path = model_path.parent()
.unwrap_or(Path::new("."))
.join("tokenizer.json");
if tokenizer_path.exists() {
info!("Loading tokenizer from: {:?}", tokenizer_path);
match Tokenizer::from_file(&tokenizer_path) {
Ok(tokenizer) => {
self.tokenizer = Some(Arc::new(tokenizer));
info!("Tokenizer loaded successfully");
}
Err(e) => {
warn!("Failed to load tokenizer: {}", e);
}
}
} else {
info!("Tokenizer not found locally, downloading tokenizer...");
let tokenizer_url = "https://huggingface.co/unsloth/gemma-2-2b-it-bnb-4bit/resolve/main/tokenizer.json";
let tokenizer_path_clone = tokenizer_path.clone();
let download_result = std::thread::spawn(move || {
let client = reqwest::blocking::Client::builder()
.build()
.map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, format!("Failed to create client: {}", e)))?;
match client.get(tokenizer_url).send() {
Ok(response) => {
if response.status().is_success() {
match response.bytes() {
Ok(bytes) => {
std::fs::write(&tokenizer_path_clone, bytes)
}
Err(e) => {
Err(std::io::Error::new(std::io::ErrorKind::Other, format!("Failed to read response: {}", e)))
}
}
} else {
Err(std::io::Error::new(std::io::ErrorKind::Other, format!("HTTP error: {}", response.status())))
}
}
Err(e) => {
Err(std::io::Error::new(std::io::ErrorKind::Other, format!("Request failed: {}", e)))
}
}
}).join().unwrap();
match download_result {
Ok(_) => {
info!("Tokenizer downloaded successfully");
match Tokenizer::from_file(&tokenizer_path) {
Ok(tokenizer) => {
self.tokenizer = Some(Arc::new(tokenizer));
info!("Tokenizer loaded successfully");
}
Err(e) => {
error!("Failed to load downloaded tokenizer: {}", e);
}
}
}
Err(e) => {
error!("Failed to download/save tokenizer: {}", e);
}
}
}
warn!("GGUF model loading with Candle is not fully implemented yet");
warn!("To use actual inference, we need to:");
warn!("1. Implement GGUF format parsing");
warn!("2. Load quantized weights into Candle tensors");
warn!("3. Set up the Gemma model architecture");
self.model_loaded = true;
Ok(())
}
}
impl InferenceBackend for GGUFInference {
fn load_model(&mut self, model_path: &Path) -> Result<()> {
self.load_gguf_model(model_path)
}
fn is_loaded(&self) -> bool {
self.model_loaded
}
fn generate(&self, prompt: &str, config: &InferenceConfig) -> Result<String> {
if !self.model_loaded {
return Err(anyhow::anyhow!("Model not loaded"));
}
info!("GGUF Backend - Generating response for prompt: {}", prompt);
info!("Config: max_tokens={}, temp={}, top_p={}",
config.max_tokens, config.temperature, config.top_p);
if let Some(tokenizer) = &self.tokenizer {
info!("Tokenizer available, attempting to tokenize prompt");
match tokenizer.encode(prompt, true) {
Ok(encoding) => {
let tokens = encoding.get_ids();
info!("Prompt tokenized to {} tokens", tokens.len());
error!("GGUF inference with Candle is not yet implemented");
return Err(anyhow::anyhow!("GGUF inference with Candle is not yet implemented. Please use a different backend or wait for implementation."));
}
Err(e) => {
error!("Failed to tokenize prompt: {}", e);
return Err(anyhow::anyhow!("Tokenization failed: {}", e));
}
}
} else {
error!("No tokenizer available for GGUF model");
return Err(anyhow::anyhow!("No tokenizer available. GGUF models require a tokenizer.json file."));
}
}
fn generate_with_metrics(&self, prompt: &str, config: &InferenceConfig) -> Result<(String, InferenceMetrics)> {
let start = Instant::now();
let initial_memory = self.get_memory_usage_mb();
let result = self.generate(prompt, config)?;
let total_time = start.elapsed();
let tokens = result.split_whitespace().count();
let metrics = InferenceMetrics {
tokens_generated: tokens,
time_to_first_token_ms: 50.0, tokens_per_second: tokens as f64 / total_time.as_secs_f64(),
total_time_ms: total_time.as_millis() as f64,
peak_memory_mb: self.get_memory_usage_mb() - initial_memory,
};
Ok((result, metrics))
}
fn name(&self) -> &str {
"GGUF (Candle)"
}
fn is_available() -> bool {
true
}
fn get_memory_usage_mb(&self) -> f64 {
0.0
}
}