Files
LEANN/packages/leann-core/src/leann/chat.py
2025-07-15 22:40:40 -07:00

563 lines
21 KiB
Python

#!/usr/bin/env python3
"""
This file contains the chat generation logic for the LEANN project,
supporting different backends like Ollama, Hugging Face Transformers, and a simulation mode.
"""
from abc import ABC, abstractmethod
from typing import Dict, Any, Optional, List
import logging
import os
import difflib
# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)
def check_ollama_models() -> List[str]:
"""Check available Ollama models and return a list"""
try:
import requests
response = requests.get("http://localhost:11434/api/tags", timeout=5)
if response.status_code == 200:
data = response.json()
return [model["name"] for model in data.get("models", [])]
return []
except Exception:
return []
def search_ollama_models_fuzzy(query: str, available_models: List[str]) -> List[str]:
"""Use intelligent fuzzy search for Ollama models"""
if not available_models:
return []
query_lower = query.lower()
suggestions = []
# 1. Exact matches first
exact_matches = [m for m in available_models if query_lower == m.lower()]
suggestions.extend(exact_matches)
# 2. Starts with query
starts_with = [m for m in available_models if m.lower().startswith(query_lower) and m not in suggestions]
suggestions.extend(starts_with)
# 3. Contains query
contains = [m for m in available_models if query_lower in m.lower() and m not in suggestions]
suggestions.extend(contains)
# 4. Base model name matching (remove version numbers)
def get_base_name(model_name: str) -> str:
"""Extract base name without version (e.g., 'llama3:8b' -> 'llama3')"""
return model_name.split(':')[0].split('-')[0]
query_base = get_base_name(query_lower)
base_matches = [
m for m in available_models
if get_base_name(m.lower()) == query_base and m not in suggestions
]
suggestions.extend(base_matches)
# 5. Family/variant matching
model_families = {
'llama': ['llama2', 'llama3', 'alpaca', 'vicuna', 'codellama'],
'qwen': ['qwen', 'qwen2', 'qwen3'],
'gemma': ['gemma', 'gemma2'],
'phi': ['phi', 'phi2', 'phi3'],
'mistral': ['mistral', 'mixtral', 'openhermes'],
'dolphin': ['dolphin', 'openchat'],
'deepseek': ['deepseek', 'deepseek-coder']
}
query_family = None
for family, variants in model_families.items():
if any(variant in query_lower for variant in variants):
query_family = family
break
if query_family:
family_variants = model_families[query_family]
family_matches = [
m for m in available_models
if any(variant in m.lower() for variant in family_variants) and m not in suggestions
]
suggestions.extend(family_matches)
# 6. Use difflib for remaining fuzzy matches
remaining_models = [m for m in available_models if m not in suggestions]
difflib_matches = difflib.get_close_matches(query_lower, remaining_models, n=3, cutoff=0.4)
suggestions.extend(difflib_matches)
return suggestions[:8] # Return top 8 suggestions
# Remove this function entirely - we don't need external API calls for Ollama
# Remove this too - no need for fallback
def suggest_similar_models(invalid_model: str, available_models: List[str]) -> List[str]:
"""Use difflib to find similar model names"""
if not available_models:
return []
# Get close matches using fuzzy matching
suggestions = difflib.get_close_matches(
invalid_model, available_models, n=3, cutoff=0.3
)
return suggestions
def check_hf_model_exists(model_name: str) -> bool:
"""Quick check if HuggingFace model exists without downloading"""
try:
from huggingface_hub import model_info
model_info(model_name)
return True
except Exception:
return False
def get_popular_hf_models() -> List[str]:
"""Return a list of popular HuggingFace models for suggestions"""
try:
from huggingface_hub import list_models
# Get popular text-generation models, sorted by downloads
models = list_models(
filter="text-generation",
sort="downloads",
direction=-1,
limit=20 # Get top 20 most downloaded
)
# Extract model names and filter for chat/conversation models
model_names = []
chat_keywords = ['chat', 'instruct', 'dialog', 'conversation', 'assistant']
for model in models:
model_name = model.id if hasattr(model, 'id') else str(model)
# Prioritize models with chat-related keywords
if any(keyword in model_name.lower() for keyword in chat_keywords):
model_names.append(model_name)
elif len(model_names) < 10: # Fill up with other popular models
model_names.append(model_name)
return model_names[:10] if model_names else _get_fallback_hf_models()
except Exception:
# Fallback to static list if API call fails
return _get_fallback_hf_models()
def _get_fallback_hf_models() -> List[str]:
"""Fallback list of popular HuggingFace models"""
return [
"microsoft/DialoGPT-medium",
"microsoft/DialoGPT-large",
"facebook/blenderbot-400M-distill",
"microsoft/phi-2",
"deepseek-ai/deepseek-llm-7b-chat",
"microsoft/DialoGPT-small",
"facebook/blenderbot_small-90M",
"microsoft/phi-1_5",
"facebook/opt-350m",
"EleutherAI/gpt-neo-1.3B"
]
def search_hf_models_fuzzy(query: str, limit: int = 10) -> List[str]:
"""Use HuggingFace Hub's native fuzzy search for model suggestions"""
try:
from huggingface_hub import list_models
# HF Hub's search is already fuzzy! It handles typos and partial matches
models = list_models(
search=query,
filter="text-generation",
sort="downloads",
direction=-1,
limit=limit
)
model_names = [model.id if hasattr(model, 'id') else str(model) for model in models]
# If direct search doesn't return enough results, try some variations
if len(model_names) < 3:
# Try searching for partial matches or common variations
variations = []
# Extract base name (e.g., "gpt3" from "gpt-3.5")
base_query = query.lower().replace('-', '').replace('.', '').replace('_', '')
if base_query != query.lower():
variations.append(base_query)
# Try common model name patterns
if 'gpt' in query.lower():
variations.extend(['gpt2', 'gpt-neo', 'gpt-j', 'dialoGPT'])
elif 'llama' in query.lower():
variations.extend(['llama2', 'alpaca', 'vicuna'])
elif 'bert' in query.lower():
variations.extend(['roberta', 'distilbert', 'albert'])
# Search with variations
for var in variations[:2]: # Limit to 2 variations to avoid too many API calls
try:
var_models = list_models(
search=var,
filter="text-generation",
sort="downloads",
direction=-1,
limit=3
)
var_names = [model.id if hasattr(model, 'id') else str(model) for model in var_models]
model_names.extend(var_names)
except:
continue
# Remove duplicates while preserving order
seen = set()
unique_models = []
for model in model_names:
if model not in seen:
seen.add(model)
unique_models.append(model)
return unique_models[:limit]
except Exception:
# If search fails, return empty list
return []
def search_hf_models(query: str, limit: int = 10) -> List[str]:
"""Simple search for HuggingFace models based on query (kept for backward compatibility)"""
return search_hf_models_fuzzy(query, limit)
def validate_model_and_suggest(model_name: str, llm_type: str) -> Optional[str]:
"""Validate model name and provide suggestions if invalid"""
if llm_type == "ollama":
available_models = check_ollama_models()
if available_models and model_name not in available_models:
# Use intelligent fuzzy search based on locally installed models
suggestions = search_ollama_models_fuzzy(model_name, available_models)
error_msg = f"Model '{model_name}' not found in your local Ollama installation."
if suggestions:
error_msg += "\n\nDid you mean one of these installed models?\n"
for i, suggestion in enumerate(suggestions, 1):
error_msg += f" {i}. {suggestion}\n"
else:
error_msg += "\n\nYour installed models:\n"
for i, model in enumerate(available_models[:8], 1):
error_msg += f" {i}. {model}\n"
if len(available_models) > 8:
error_msg += f" ... and {len(available_models) - 8} more\n"
error_msg += "\nTo list all models: ollama list"
error_msg += "\nTo download a new model: ollama pull <model_name>"
error_msg += "\nBrowse models: https://ollama.com/library"
return error_msg
elif llm_type == "hf":
# For HF models, we can do a quick existence check
if not check_hf_model_exists(model_name):
# Use HF Hub's native fuzzy search directly
search_suggestions = search_hf_models_fuzzy(model_name, limit=8)
error_msg = f"Model '{model_name}' not found on HuggingFace Hub."
if search_suggestions:
error_msg += "\n\nDid you mean one of these?\n"
for i, suggestion in enumerate(search_suggestions, 1):
error_msg += f" {i}. {suggestion}\n"
else:
# Fallback to popular models if search returns nothing
popular_models = get_popular_hf_models()
error_msg += "\n\nPopular chat models:\n"
for i, model in enumerate(popular_models[:5], 1):
error_msg += f" {i}. {model}\n"
error_msg += f"\nSearch more: https://huggingface.co/models?search={model_name}&pipeline_tag=text-generation"
return error_msg
return None # Model is valid or we can't check
class LLMInterface(ABC):
"""Abstract base class for a generic Language Model (LLM) interface."""
@abstractmethod
def ask(self, prompt: str, **kwargs) -> str:
"""
Additional keyword arguments (kwargs) for advanced search customization. Example usage:
chat.ask(
"What is ANN?",
top_k=10,
complexity=64,
beam_width=8,
USE_DEFERRED_FETCH=True,
skip_search_reorder=True,
recompute_beighbor_embeddings=True,
dedup_node_dis=True,
prune_ratio=0.1,
batch_recompute=True,
global_pruning=True
)
Supported kwargs:
- complexity (int): Search complexity parameter (default: 32)
- beam_width (int): Beam width for search (default: 4)
- USE_DEFERRED_FETCH (bool): Enable deferred fetch mode (default: False)
- skip_search_reorder (bool): Skip search reorder step (default: False)
- recompute_beighbor_embeddings (bool): Enable ZMQ embedding server for neighbor recomputation (default: False)
- dedup_node_dis (bool): Deduplicate nodes by distance (default: False)
- prune_ratio (float): Pruning ratio for search (default: 0.0)
- batch_recompute (bool): Enable batch recomputation (default: False)
- global_pruning (bool): Enable global pruning (default: False)
"""
# """
# Sends a prompt to the LLM and returns the generated text.
# Args:
# prompt: The input prompt for the LLM.
# **kwargs: Additional keyword arguments for the LLM backend.
# Returns:
# The response string from the LLM.
# """
pass
class OllamaChat(LLMInterface):
"""LLM interface for Ollama models."""
def __init__(self, model: str = "llama3:8b", host: str = "http://localhost:11434"):
self.model = model
self.host = host
logger.info(f"Initializing OllamaChat with model='{model}' and host='{host}'")
try:
import requests
# Check if the Ollama server is responsive
if host:
requests.get(host)
# Pre-check model availability with helpful suggestions
model_error = validate_model_and_suggest(model, "ollama")
if model_error:
raise ValueError(model_error)
except ImportError:
raise ImportError(
"The 'requests' library is required for Ollama. Please install it with 'pip install requests'."
)
except requests.exceptions.ConnectionError:
logger.error(
f"Could not connect to Ollama at {host}. Please ensure Ollama is running."
)
raise ConnectionError(
f"Could not connect to Ollama at {host}. Please ensure Ollama is running."
)
def ask(self, prompt: str, **kwargs) -> str:
import requests
import json
full_url = f"{self.host}/api/generate"
payload = {
"model": self.model,
"prompt": prompt,
"stream": False, # Keep it simple for now
"options": kwargs,
}
logger.info(f"Sending request to Ollama: {payload}")
try:
response = requests.post(full_url, data=json.dumps(payload))
response.raise_for_status()
# The response from Ollama can be a stream of JSON objects, handle this
response_parts = response.text.strip().split("\n")
full_response = ""
for part in response_parts:
if part:
json_part = json.loads(part)
full_response += json_part.get("response", "")
if json_part.get("done"):
break
return full_response
except requests.exceptions.RequestException as e:
logger.error(f"Error communicating with Ollama: {e}")
return f"Error: Could not get a response from Ollama. Details: {e}"
class HFChat(LLMInterface):
"""LLM interface for local Hugging Face Transformers models."""
def __init__(self, model_name: str = "deepseek-ai/deepseek-llm-7b-chat"):
logger.info(f"Initializing HFChat with model='{model_name}'")
# Pre-check model availability with helpful suggestions
model_error = validate_model_and_suggest(model_name, "hf")
if model_error:
raise ValueError(model_error)
try:
from transformers.pipelines import pipeline
import torch
except ImportError:
raise ImportError(
"The 'transformers' and 'torch' libraries are required for Hugging Face models. Please install them with 'pip install transformers torch'."
)
# Auto-detect device
if torch.cuda.is_available():
device = "cuda"
logger.info("CUDA is available. Using GPU.")
elif hasattr(torch.backends, "mps") and torch.backends.mps.is_available():
device = "mps"
logger.info("MPS is available. Using Apple Silicon GPU.")
else:
device = "cpu"
logger.info("No GPU detected. Using CPU.")
self.pipeline = pipeline("text-generation", model=model_name, device=device)
def ask(self, prompt: str, **kwargs) -> str:
# Map OpenAI-style arguments to Hugging Face equivalents
if "max_tokens" in kwargs:
# Prefer user-provided max_new_tokens if both are present
kwargs.setdefault("max_new_tokens", kwargs["max_tokens"])
# Remove the unsupported key to avoid errors in Transformers
kwargs.pop("max_tokens")
# Handle temperature=0 edge-case for greedy decoding
if "temperature" in kwargs and kwargs["temperature"] == 0.0:
# Remove unsupported zero temperature and use deterministic generation
kwargs.pop("temperature")
kwargs.setdefault("do_sample", False)
# Sensible defaults for text generation
params = {"max_length": 500, "num_return_sequences": 1, **kwargs}
logger.info(f"Generating text with Hugging Face model with params: {params}")
results = self.pipeline(prompt, **params)
# Handle different response formats from transformers
if isinstance(results, list) and len(results) > 0:
generated_text = (
results[0].get("generated_text", "")
if isinstance(results[0], dict)
else str(results[0])
)
else:
generated_text = str(results)
# Extract only the newly generated portion by removing the original prompt
if isinstance(generated_text, str) and generated_text.startswith(prompt):
response = generated_text[len(prompt) :].strip()
else:
# Fallback: return the full response if prompt removal fails
response = str(generated_text)
return response
class OpenAIChat(LLMInterface):
"""LLM interface for OpenAI models."""
def __init__(self, model: str = "gpt-4o", api_key: Optional[str] = None):
self.model = model
self.api_key = api_key or os.getenv("OPENAI_API_KEY")
if not self.api_key:
raise ValueError(
"OpenAI API key is required. Set OPENAI_API_KEY environment variable or pass api_key parameter."
)
logger.info(f"Initializing OpenAI Chat with model='{model}'")
try:
import openai
self.client = openai.OpenAI(api_key=self.api_key)
except ImportError:
raise ImportError(
"The 'openai' library is required for OpenAI models. Please install it with 'pip install openai'."
)
def ask(self, prompt: str, **kwargs) -> str:
# Default parameters for OpenAI
params = {
"model": self.model,
"messages": [{"role": "user", "content": prompt}],
"max_tokens": kwargs.get("max_tokens", 1000),
"temperature": kwargs.get("temperature", 0.7),
**{
k: v
for k, v in kwargs.items()
if k not in ["max_tokens", "temperature"]
},
}
logger.info(f"Sending request to OpenAI with model {self.model}")
try:
response = self.client.chat.completions.create(**params)
return response.choices[0].message.content.strip()
except Exception as e:
logger.error(f"Error communicating with OpenAI: {e}")
return f"Error: Could not get a response from OpenAI. Details: {e}"
class SimulatedChat(LLMInterface):
"""A simple simulated chat for testing and development."""
def ask(self, prompt: str, **kwargs) -> str:
logger.info("Simulating LLM call...")
print("Prompt sent to LLM (simulation):", prompt[:500] + "...")
return "This is a simulated answer from the LLM based on the retrieved context."
def get_llm(llm_config: Optional[Dict[str, Any]] = None) -> LLMInterface:
"""
Factory function to get an LLM interface based on configuration.
Args:
llm_config: A dictionary specifying the LLM type and its parameters.
Example: {"type": "ollama", "model": "llama3"}
{"type": "hf", "model": "distilgpt2"}
None (for simulation mode)
Returns:
An instance of an LLMInterface subclass.
"""
if llm_config is None:
llm_config = {
"type": "openai",
"model": "gpt-4o",
"api_key": os.getenv("OPENAI_API_KEY"),
}
llm_type = llm_config.get("type", "openai")
model = llm_config.get("model")
logger.info(f"Attempting to create LLM of type='{llm_type}' with model='{model}'")
if llm_type == "ollama":
return OllamaChat(
model=model or "llama3:8b",
host=llm_config.get("host", "http://localhost:11434"),
)
elif llm_type == "hf":
return HFChat(model_name=model or "deepseek-ai/deepseek-llm-7b-chat")
elif llm_type == "openai":
return OpenAIChat(model=model or "gpt-4o", api_key=llm_config.get("api_key"))
elif llm_type == "simulated":
return SimulatedChat()
else:
raise ValueError(f"Unknown LLM type: '{llm_type}'")