fleet-memory/memory/utils.py
2025-10-30 12:53:12 +01:00

102 lines
2.8 KiB
Python

"""
Utility functions for memory system.
"""
from typing import List
from .llm_client import extract_facts_from_text
async def extract_facts(text: str) -> List[str]:
"""
Extract semantic facts from text using LLM.
Uses LLM for intelligent fact extraction that:
- Filters out social pleasantries and filler words
- Creates self-contained statements
- Handles conversational text well
Args:
text: Input text (conversation, article, etc.)
Returns:
List of factual statements
Raises:
Exception: If LLM fact extraction fails
"""
if not text or not text.strip():
return []
fact_dicts = await extract_facts_from_text(text)
# Extract just the fact text
facts = [f['fact'] for f in fact_dicts if f.get('fact')]
if not facts:
raise Exception(f"LLM extracted 0 facts from text of length {len(text)}. This may indicate the text contains no meaningful information, or the LLM failed to extract facts.")
return facts
def cosine_similarity(vec1: List[float], vec2: List[float]) -> float:
"""
Calculate cosine similarity between two vectors.
Args:
vec1: First vector
vec2: Second vector
Returns:
Similarity score between 0 and 1
"""
if len(vec1) != len(vec2):
raise ValueError("Vectors must have same dimension")
dot_product = sum(a * b for a, b in zip(vec1, vec2))
magnitude1 = sum(a * a for a in vec1) ** 0.5
magnitude2 = sum(b * b for b in vec2) ** 0.5
if magnitude1 == 0 or magnitude2 == 0:
return 0.0
return dot_product / (magnitude1 * magnitude2)
def calculate_recency_weight(days_since: float, decay_rate: float = 0.1) -> float:
"""
Calculate recency weight with exponential decay.
Recent memories are weighted higher. The decay rate controls
how quickly old memories fade.
Args:
days_since: Number of days since the memory was created
decay_rate: How quickly memories fade (higher = faster decay)
Returns:
Weight between 0 and 1
"""
import math
return math.exp(-decay_rate * days_since)
def calculate_frequency_weight(access_count: int, max_boost: float = 2.0) -> float:
"""
Calculate frequency weight based on access count.
Frequently accessed memories are weighted higher.
Uses logarithmic scaling to avoid over-weighting.
Args:
access_count: Number of times the memory was accessed
max_boost: Maximum multiplier for frequently accessed memories
Returns:
Weight between 1.0 and max_boost
"""
import math
if access_count <= 0:
return 1.0
# Logarithmic scaling: log(access_count + 1) / log(10)
# This gives: 0 accesses = 1.0, 9 accesses ~= 1.5, 99 accesses ~= 2.0
normalized = math.log(access_count + 1) / math.log(10)
return 1.0 + min(normalized, max_boost - 1.0)