Files
hermes-agent/tools/memory_tool_store.py
kshitijk4poor 117dc02870 refactor(memory): derive the store label from _path_for, trim the guard comment
Review follow-up on the salvaged #103421 guard: the USER.md/MEMORY.md ternary
was a third copy (also _path_for and memory_tool._memory_target_error); use the
path's name. "profile" → "store" in the error since MEMORY.md is not a profile.
2026-09-06 14:53:13 +05:30

418 lines
23 KiB
Python

"""MemoryStore — bounded, file-backed curated memory (MEMORY.md / USER.md).
Entries are joined by ``ENTRY_DELIMITER``; budgets are in chars (model-independent).
Module state that tests monkeypatch (``get_memory_dir``, ``fcntl``/``msvcrt``) stays
in ``tools.memory_tool`` and is read lazily."""
import logging
import time
from contextlib import contextmanager, suppress
from pathlib import Path
from typing import Any, Dict, List, Optional, Tuple
from utils import atomic_write_text
from tools.threat_patterns import first_threat_message as _first_threat_message
logger = logging.getLogger("tools.memory_tool")
# Block header prefixes rendered by _render_block; agent/conversation_compression.py
# matches them to detect a leftover block for an emptied target — keep in lockstep.
MEMORY_BLOCK_HEADERS = {
"memory": "MEMORY (your personal notes)", "user": "USER PROFILE (who the user is)"}
ENTRY_DELIMITER = "\n§\n"
def _scan_memory_content(content: str) -> Optional[str]:
"""Error string if *content* matches injection/exfil patterns. Strict scope:
memory enters the system prompt, so a poisoned entry persists across sessions."""
return _first_threat_message(content, scope="strict")
def _error(message: str, **extra) -> Dict[str, Any]:
return {"success": False, "error": message, **extra}
def _drift_error(path: Path, bak_path: str) -> Dict[str, Any]:
"""External drift: the file wouldn't round-trip, so flushing would discard content."""
return _error((
f"Refusing to write {path.name}: file on disk has content that wouldn't round-trip "
f"through the memory tool (likely added by the patch tool, a shell append, a manual edit, "
f"or a concurrent session). A snapshot was saved to {bak_path}. Resolve the drift first — "
f"either rewrite the file as a clean §-delimited list of entries, or move the extra "
f"content out — then retry. This guard exists to prevent silent data loss (issue #26045)."
), drift_backup=bak_path, remediation=(
"Open the .bak file, integrate the missing entries into the memory tool one at a time via "
"memory(action=add, content=...), then remove or rewrite the original file to a clean state."))
def _read_failed_error(path: Path) -> Dict[str, Any]:
"""Existing-but-unreadable file: saving from an assumed-empty view would wipe it."""
return _error(
f"Refusing to write {path.name}: the file exists on disk but could not be read right now "
f"(temporarily locked by another program, a permission change, invalid/corrupt text encoding, "
f"or a filesystem error). Treating an unreadable file as empty and saving would wipe existing "
f"memory, so the write is refused. Nothing was changed — retry in a moment.")
def _find_unique_match(entries: List[str], old_text: str) -> Tuple[Optional[int], bool]:
"""``(index, ambiguous)`` for entries containing *old_text*. Exact-duplicate
matches are safe (first wins); distinct matches → ``(None, True)``."""
matches = [i for i, e in enumerate(entries) if old_text in e]
if len({entries[i] for i in matches}) > 1:
return None, True
return (matches[0] if matches else None), False
class MemoryStore:
"""Bounded curated memory with file persistence; one instance per AIAgent.
``_system_prompt_snapshot`` is frozen at load time (prefix-cache stable);
``memory_entries`` / ``user_entries`` are live state persisted to disk."""
# Failed consolidation attempts (overflow / zero-match) allowed per turn before
# a TERMINAL "save skipped" result, so a fragile replace/add can't loop the turn
# to budget exhaustion and suppress the user's reply.
# See #42405.
_MAX_CONSOLIDATION_FAILURES_PER_TURN = 3
def __init__(self, memory_char_limit: int = 2200, user_char_limit: int = 1375, *,
memory_enabled: bool = True, user_profile_enabled: bool = True):
self.memory_entries: List[str] = []
self.user_entries: List[str] = []
self.memory_char_limit, self.user_char_limit = memory_char_limit, user_char_limit
self.memory_enabled, self.user_profile_enabled = memory_enabled, user_profile_enabled
self._system_prompt_snapshot: Dict[str, str] = {"memory": "", "user": ""}
self._consolidation_failures = 0 # per turn; reset by reset_consolidation_failures()
# Per-turn counter of failed at-capacity consolidation attempts; reset at each turn boundary by
# reset_consolidation_failures() (#42405).
def target_enabled(self, target: str) -> bool:
return self.user_profile_enabled if target == "user" else self.memory_enabled
def reset_consolidation_failures(self) -> None:
"""Call at turn start."""
self._consolidation_failures = 0
def _consolidation_failure(self, response: Dict[str, Any]) -> Dict[str, Any]:
"""Count a consolidation failure: under the per-turn cap return ``response``
(it says how to retry); past it a TERMINAL result so the model stops looping.
Once the cap is exceeded, drop the retry instruction and return a TERMINAL result so the model stops
looping memory calls and proceeds to answer the user — a failed memory side effect must never block
the turn's reply (#42405).
"""
self._consolidation_failures += 1
if self._consolidation_failures <= self._MAX_CONSOLIDATION_FAILURES_PER_TURN:
return response
return {"success": False, "done": True, "error": (
f"Memory consolidation failed {self._consolidation_failures} times this turn. Stop retrying "
"memory calls — leave memory unchanged for now and continue with your reply to the user. "
"The fact can be saved in a later turn.")}
def load_from_disk(self):
"""Load MEMORY.md / USER.md and capture the frozen system-prompt snapshot.
Threat hits are replaced by a ``[BLOCKED: …]`` placeholder in the SNAPSHOT only;
live lists keep the raw text so the user can see and remove poisoned entries
(dropping them silently would hide the attack)."""
from tools.threat_patterns import scan_for_threats
def _sanitize(entry, filename):
# Strict scope, same as writes; empty / already-blocked entries pass through.
findings = scan_for_threats(entry, scope="strict") if entry and not entry.startswith("[BLOCKED:") else None
if not findings:
return entry
logger.warning("Memory entry from %s blocked at load time: %s", filename, ", ".join(findings))
return (f"[BLOCKED: {filename} entry contained threat pattern(s): {', '.join(findings)}. "
f"Removed from system prompt; use memory(action=remove) to delete the original.]")
for target in ("memory", "user"):
path = self._path_for(target)
path.parent.mkdir(parents=True, exist_ok=True)
# Deduplicate (order-preserving, first occurrence wins).
entries = list(dict.fromkeys(self._read_file(path)))
self._set_entries(target, entries)
self._system_prompt_snapshot[target] = self._render_block(target, [_sanitize(e, path.name) for e in entries])
@staticmethod
@contextmanager
def _file_lock(path: Path):
"""Exclusive lock on a separate .lock file so the memory file itself can
still be atomically replaced."""
from tools import memory_tool as _mt # fcntl/msvcrt live (and are patched) there
fcntl, msvcrt = _mt.fcntl, _mt.msvcrt
lock_path = path.with_suffix(path.suffix + ".lock")
lock_path.parent.mkdir(parents=True, exist_ok=True)
if fcntl is None and msvcrt is None:
yield
return
with open(lock_path, "a+", encoding="utf-8") as fd:
def _flock(unlock: bool):
if fcntl:
fcntl.flock(fd, fcntl.LOCK_UN if unlock else fcntl.LOCK_EX)
else:
fd.seek(0)
msvcrt.locking(fd.fileno(), msvcrt.LK_UNLCK if unlock else msvcrt.LK_LOCK, 1)
_flock(False)
try:
yield
finally:
with suppress(OSError):
_flock(True)
@staticmethod
def _path_for(target: str) -> Path:
from tools import memory_tool # get_memory_dir is monkeypatched there
return memory_tool.get_memory_dir() / ("USER.md" if target == "user" else "MEMORY.md")
def _entries_for(self, target: str) -> List[str]:
return self.user_entries if target == "user" else self.memory_entries
def _set_entries(self, target: str, entries: List[str]):
setattr(self, "user_entries" if target == "user" else "memory_entries", entries)
def _char_count(self, target: str) -> int:
return len(ENTRY_DELIMITER.join(self._entries_for(target)))
def _char_limit(self, target: str) -> int:
return self.user_char_limit if target == "user" else self.memory_char_limit
def _usage(self, target: str) -> str:
return f"{self._char_count(target):,}/{self._char_limit(target):,}"
def _usage_pct(self, target: str, current: int) -> str:
limit = self._char_limit(target)
return f"{min(100, int((current / limit) * 100)) if limit > 0 else 0}% — {current:,}/{limit:,} chars"
def _failure_with_entries(self, target: str, message: str) -> Dict[str, Any]:
"""Consolidation failure carrying the live entries so the model can consolidate."""
return self._consolidation_failure(
_error(message, current_entries=self._entries_for(target), usage=self._usage(target)))
def _mutate(self, target: str, mutate, *, skip_drift: bool = False) -> Dict[str, Any]:
"""Lock, re-read from disk, run ``mutate(entries, limit)`` -> ``(new_entries, message)``
or an error dict, then persist and return the success response. The reload aborts
on an existing-but-unreadable file (even append-only ``add`` rewrites the whole
file) and, unless *skip_drift*, on external drift (flushing would discard
un-roundtrippable content). Drift check and parse use the SAME raw snapshot —
a failed second read used to count as "no drift"."""
path = self._path_for(target)
with self._file_lock(path):
raw, read_ok = self._read_raw_checked(path)
if not read_ok:
return _read_failed_error(path)
bak = None if skip_drift else self._detect_external_drift(target, raw)
self._set_entries(target, list(dict.fromkeys(self._parse_entries(raw))))
if bak:
return _drift_error(path, bak)
result = mutate(self._entries_for(target), self._char_limit(target))
if isinstance(result, dict):
return result
self._set_entries(target, result[0])
path.parent.mkdir(parents=True, exist_ok=True)
self._write_file(path, result[0])
return self._success_response(target, result[1])
def add(self, target: str, content: str) -> Dict[str, Any]:
"""Append a new entry. Returns error if it would exceed the char limit."""
content = content.strip()
if not content:
return _error("Content cannot be empty.")
if scan_error := _scan_memory_content(content):
return _error(scan_error)
def _add(entries, limit):
if content in entries:
return self._success_response(target, "Entry already exists (no duplicate added).")
if len(ENTRY_DELIMITER.join(entries + [content])) > limit:
return self._failure_with_entries(target, (
f"Memory at {self._char_count(target):,}/{limit:,} chars. Adding this entry "
f"({len(content)} chars) would exceed the limit. Consolidate now: use 'replace' to merge "
f"overlapping entries into shorter ones or 'remove' stale or less important entries (see "
f"current_entries below), then retry this add — all in this turn."))
return entries + [content], "Entry added."
# Append-only: skip the drift guard (appending never clobbers foreign
# content) but still refuse a failed read — add rewrites the WHOLE file.
return self._mutate(target, _add, skip_drift=True)
def replace(self, target: str, old_text: str, new_content: str) -> Dict[str, Any]:
"""Find entry containing old_text substring, replace it with new_content."""
new_content = new_content.strip()
if not old_text.strip():
return _error("old_text cannot be empty.")
if not new_content:
return _error("new_content cannot be empty. Use 'remove' to delete entries.")
if scan_error := _scan_memory_content(new_content):
return _error(scan_error)
return self._edit(target, old_text.strip(), new_content)
def remove(self, target: str, old_text: str) -> Dict[str, Any]:
"""Remove the entry containing old_text substring."""
if not old_text.strip():
return _error("old_text cannot be empty.")
return self._edit(target, old_text.strip(), None)
def _edit(self, target: str, old_text: str, new_content: Optional[str]) -> Dict[str, Any]:
"""Locked replace (``new_content`` set) or remove (None) of the entry matching *old_text*."""
def _apply(entries, limit):
idx, ambiguous = _find_unique_match(entries, old_text)
if ambiguous:
return _error(f"Multiple entries matched '{old_text}'. Be more specific.",
matches=[e[:80] + ("..." if len(e) > 80 else "") for e in entries if old_text in e])
if idx is None:
return self._consolidation_failure(_error(
f"No entry matched '{old_text}'. Check current_entries below and retry with the exact text "
f"of the entry you want to {'replace' if new_content else 'remove'}.", current_entries=entries))
replaced = entries[:idx] + ([] if new_content is None else [new_content]) + entries[idx + 1:]
if new_content is None:
return replaced, "Entry removed."
new_total = len(ENTRY_DELIMITER.join(replaced))
if new_total > limit:
return self._failure_with_entries(target, (
f"Replacement would put memory at {new_total:,}/{limit:,} chars. Shorten the new content, "
f"or 'remove' other stale or less important entries to make room (see current_entries "
f"below), then retry — all in this turn."))
return replaced, "Entry replaced."
return self._mutate(target, _apply)
@staticmethod
def _apply_batch_op(working: List[str], act: str, content: str, old_text: str, pos: str) -> Optional[str]:
"""Apply one batch op to *working* in place; return an error message or None."""
if act == "add":
if not content:
return f"{pos}: content is required."
if content not in working: # idempotent -- skip duplicate, don't fail the batch
working.append(content)
return None
if act not in ("replace", "remove"):
return f"{pos}: unknown action. Use add, replace, or remove."
if not old_text:
return f"{pos}: old_text is required."
if act == "replace" and not content:
return f"{pos}: content is required (use action='remove' to delete)."
idx, ambiguous = _find_unique_match(working, old_text)
if ambiguous:
return f"{pos}: '{old_text}' matched multiple distinct entries -- be more specific."
if idx is None:
return f"{pos}: no entry matched '{old_text}'."
working[idx:idx + 1] = [content] if act == "replace" else []
return None
def apply_batch(self, target: str, operations: List[Dict[str, Any]]) -> Dict[str, Any]:
"""Apply add/replace/remove ops atomically against the FINAL budget, so one call
can free space and add entries. All-or-nothing: any malformed / unmatched op or
an over-limit result writes NOTHING and returns the first failure plus live state."""
if not operations:
return _error("operations list is empty.")
ops = [op or {} for op in operations]
# Scan every add/replace content BEFORE touching disk -- one poisoned op rejects the batch.
for i, op in enumerate(ops):
scan_error = op.get("action") in {"add", "replace"} and op.get("content") and _scan_memory_content(op["content"])
if scan_error:
return _error(f"Operation {i + 1}: {scan_error}")
def _apply(entries, limit):
working = list(entries) # only committed if the whole batch validates
for i, op in enumerate(ops):
act = op.get("action")
msg = self._apply_batch_op(working, act, (op.get("content") or op.get("new_text") or "").strip(),
(op.get("old_text") or "").strip(), f"Operation {i + 1} ({act or 'unknown'})")
if msg:
return self._failure_with_entries(target, msg + " No operations were applied (batch is all-or-nothing).")
if entries and not working:
# #103419: a consolidation batch that removes the last entry would
# commit an empty file as a normal successful write. Refuse; single
# remove() is the deliberate-wipe path.
label = self._path_for(target).name
return self._failure_with_entries(target, (
f"Refusing to empty {label}: this batch would remove every entry from a "
f"previously non-empty store. Nothing was applied (batch is all-or-nothing). "
f"Keep at least one entry — merge overlapping entries into a shorter one instead "
f"of removing the last one (see current_entries below). To delete the final entry "
f"deliberately, use single remove() calls."))
new_total = len(ENTRY_DELIMITER.join(working)) # budget check against the FINAL state only
if new_total > limit:
return self._failure_with_entries(target, (
f"After applying all {len(operations)} operations, memory would be at "
f"{new_total:,}/{limit:,} chars -- over the limit. Remove or shorten more "
f"entries in the same batch (see current_entries below), then retry."))
return working, f"Applied {len(operations)} operation(s)."
return self._mutate(target, _apply)
def format_for_system_prompt(self, target: str) -> Optional[str]:
"""Frozen load-time snapshot (NOT live state — mid-session writes don't touch
it, preserving the prefix cache); None if empty."""
return self._system_prompt_snapshot.get(target, "") or None
def _success_response(self, target: str, message: str = None) -> Dict[str, Any]:
"""TERMINAL and WITHOUT the entries list: echoing entries invites the model to
"find more to fix" and re-issue the same ops. A successful write resets the
per-turn failure budget."""
# A successful write means the consolidation loop made progress, so the per-turn failure budget
# resets (the cap counts consecutive failures, not lifetime ones within a turn) (#42405).
self._consolidation_failures = 0
return {"success": True, "done": True, "target": target,
"usage": self._usage_pct(target, self._char_count(target)),
"entry_count": len(self._entries_for(target)), **({"message": message} if message else {}),
"note": "Write saved. This update is complete — do not repeat it."}
def _render_block(self, target: str, entries: List[str]) -> str:
"""System prompt block: header + usage indicator + entries ("" when empty)."""
if not entries:
return ""
content, sep = ENTRY_DELIMITER.join(entries), "═" * 46
title = MEMORY_BLOCK_HEADERS["user" if target == "user" else "memory"]
return f"{sep}\n{title} [{self._usage_pct(target, len(content))}]\n{sep}\n{content}"
@staticmethod
def _read_raw_checked(path: Path) -> Tuple[str, bool]:
"""``(raw, read_ok)``; ``read_ok`` is False ONLY when the file EXISTS but can't be
read. Decoding stays STRICT (``errors="replace"`` would hand callers a lossy view
a save then persists); ``utf-8-sig`` strips a Notepad BOM off the first entry."""
if not path.exists():
return "", True
try:
# utf-8-sig strips a leading UTF-8 BOM (Notepad-edited memory files on Windows) and is
# byte-identical to utf-8 otherwise. Plain utf-8 kept U+FEFF glued to the first entry,
# corrupting matching/dedup for that entry forever (#10878 / PR #10888). Decode errors stay
# STRICT on purpose: errors="replace" would hand read-modify-write callers a lossy view that a
# subsequent save persists over the real bytes — the wipe class documented above. Undecodable
# bytes must surface as read_ok=False.
return path.read_text(encoding="utf-8-sig"), True
except (OSError, UnicodeDecodeError):
return "", False
@staticmethod
def _parse_entries(raw: str) -> List[str]:
"""Stripped, non-empty entries; splits on the FULL delimiter so a bare "§" survives."""
return [e for e in (x.strip() for x in raw.split(ENTRY_DELIMITER)) if e]
@staticmethod
def _read_file(path: Path) -> List[str]:
"""Entries of a memory file ([] on any error). Read-only callers only; mutation
paths use ``_read_raw_checked`` so they can refuse to overwrite an unreadable file."""
return MemoryStore._parse_entries(MemoryStore._read_raw_checked(path)[0])
@staticmethod
def _write_file(path: Path, entries: List[str]):
"""Atomic temp-file + rename: readers never see a truncated file. Also used by
agent/learning_mutations.py."""
try:
atomic_write_text(path, ENTRY_DELIMITER.join(entries), tmp_prefix=".mem_")
except OSError as e:
raise RuntimeError(f"Failed to write memory file {path}: {e}")
def _detect_external_drift(self, target: str, raw: str) -> Optional[str]:
"""``.bak.<ts>`` snapshot path if *raw* shows external drift, else None. Signals:
round-trip mismatch, or one entry over the whole-file limit (no tool-written
entry can be — an external writer appended free-form text)."""
parsed = self._parse_entries(raw)
if not raw.strip() or (raw.strip() == ENTRY_DELIMITER.join(parsed)
and max(map(len, parsed), default=0) <= self._char_limit(target)):
return None
path = self._path_for(target)
bak_path = path.with_suffix(path.suffix + f".bak.{int(time.time())}")
try:
bak_path.write_text(raw, encoding="utf-8")
except OSError:
return str(bak_path) + " (BACKUP FAILED — file unchanged on disk)"
return str(bak_path)