WIN-JHFT4D3SIVT\caoxiaozhu
11160ec4d2
- M.2: ForgettingCurve, MemoryDecay, MemoryReinforcement (selective forgetting) - M.3: DailyDigestGenerator, ReminderScheduler, ProactiveInformer (proactive reminders) - M.4: MemoryExtractor with LLM-based memory extraction from conversations - M.5: MemoryRecallInjector with token budget control for prompt injection - All phases include comprehensive unit tests (109 tests passing) - Updated checklist.md to mark all tasks complete
71 lines
2.3 KiB
Python
71 lines
2.3 KiB
Python
"""
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ForgettingCurve
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Calculates memory decay based on Ebbinghaus forgetting curve.
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decay_score = exp(-days_since_access / half_life)
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Importance level affects half-life:
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- high: half_life = 30 * 3 = 90 days (slowest decay)
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- medium: half_life = 30 * 1 = 30 days
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- low: half_life = 30 * 0.5 = 15 days (fastest decay)
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"""
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import math
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from datetime import UTC, datetime
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from typing import TYPE_CHECKING
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if TYPE_CHECKING:
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from app.models.memory import UserMemory
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class ForgettingCurve:
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"""Calculate memory decay based on time and importance."""
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BASE_HALF_LIFE_DAYS = 30
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# Half-life multipliers by importance level
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HALF_LIFE_MULTIPLIERS = {
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"high": 3.0,
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"medium": 1.0,
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"low": 0.5,
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}
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def calculate_decay(self, memory: "UserMemory") -> float:
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"""Calculate decay score (0.0-1.0). Higher = more remembered.
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Uses exponential decay: exp(-days_since_access / half_life)
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"""
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last_accessed = getattr(memory, "last_accessed_at", None) or getattr(
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memory, "last_recalled_at", None
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)
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if last_accessed is None:
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return 1.0 # Never accessed = full retention
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now = datetime.now(UTC)
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if isinstance(last_accessed, datetime):
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if last_accessed.tzinfo is None:
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last_accessed = last_accessed.replace(tzinfo=UTC)
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days_since = (now - last_accessed).total_seconds() / 86400
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else:
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days_since = 0
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half_life = self.get_half_life(memory)
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decay = math.exp(-days_since / half_life)
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return min(1.0, max(0.0, decay))
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def get_half_life(self, memory: "UserMemory") -> float:
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"""Get half-life in days based on importance level."""
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importance_level = getattr(memory, "importance_level", "medium") or "medium"
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multiplier = self.HALF_LIFE_MULTIPLIERS.get(importance_level, 1.0)
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return self.BASE_HALF_LIFE_DAYS * multiplier
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def should_archive(self, memory: "UserMemory") -> bool:
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"""decay < 0.2 → memory should be archived (cold storage)."""
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decay = self.calculate_decay(memory)
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return decay < 0.2
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def should_deprioritize(self, memory: "UserMemory") -> bool:
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"""decay < 0.5 → memory should be deprioritized (not in active reminders)."""
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decay = self.calculate_decay(memory)
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return decay < 0.5
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