Files
nanobot/nanobot/session/manager.py
T

818 lines
32 KiB
Python

"""Session management for conversation history."""
import json
import os
import re
import shutil
from contextlib import suppress
from copy import deepcopy
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path
from typing import Any
from loguru import logger
from nanobot.config.paths import get_legacy_sessions_dir
from nanobot.utils.helpers import (
ensure_dir,
estimate_message_tokens,
find_legal_message_start,
image_placeholder_text,
safe_filename,
strip_think,
)
from nanobot.utils.subagent_channel_display import scrub_subagent_announce_body
FILE_MAX_MESSAGES = 2000
_MESSAGE_TIME_PREFIX_RE = re.compile(r"^\[Message Time: [^\]]+\]\n?")
_LOCAL_IMAGE_BREADCRUMB_RE = re.compile(r"^\[image: (?:/|~)[^\]]+\]\s*$")
_TOOL_CALL_ECHO_RE = re.compile(r'^\s*(?:generate_image|message)\([^)]*\)\s*$')
_SESSION_PREVIEW_MAX_CHARS = 120
_SESSION_LIST_PREVIEW_MAX_RECORDS = 200
_SESSION_LIST_PREVIEW_MAX_CHARS = 1_000_000
_FORK_VOLATILE_METADATA_KEYS = {
"goal_state",
"pending_user_turn",
"runtime_checkpoint",
"thread_goal",
"title",
"title_user_edited",
}
def _sanitize_assistant_replay_text(content: str) -> str:
"""Remove internal replay artifacts that the model may have copied before.
These strings are useful as runtime/session metadata, but when they appear
in assistant examples they become demonstrations for the model to repeat.
"""
content = _MESSAGE_TIME_PREFIX_RE.sub("", content, count=1)
lines = [
line
for line in content.splitlines()
if not _LOCAL_IMAGE_BREADCRUMB_RE.match(line)
and not _TOOL_CALL_ECHO_RE.match(line)
]
return "\n".join(lines).strip()
def _text_preview(content: Any) -> str:
"""Return compact display text for session lists."""
if isinstance(content, str):
text = content
elif isinstance(content, list):
parts: list[str] = []
for block in content:
if isinstance(block, dict) and block.get("type") == "text":
value = block.get("text")
if isinstance(value, str):
parts.append(value)
text = " ".join(parts)
else:
return ""
text = _sanitize_assistant_replay_text(text)
text = re.sub(r"\s+", " ", text).strip()
if len(text) > _SESSION_PREVIEW_MAX_CHARS:
text = text[: _SESSION_PREVIEW_MAX_CHARS - 1].rstrip() + "…"
return text
def _message_preview_text(message: dict[str, Any]) -> str:
"""Session list preview text; subagent inject blobs are shortened for display."""
content: Any = message.get("content")
if message.get("injected_event") == "subagent_result" and isinstance(content, str):
content = scrub_subagent_announce_body(content)
return _text_preview(content)
def _metadata_title(metadata: Any) -> str:
if not isinstance(metadata, dict):
return ""
title = metadata.get("title")
if not isinstance(title, str):
return ""
if metadata.get("title_user_edited") is True:
return title
return strip_think(title)
@dataclass
class Session:
"""A conversation session."""
key: str # channel:chat_id
messages: list[dict[str, Any]] = field(default_factory=list)
created_at: datetime = field(default_factory=datetime.now)
updated_at: datetime = field(default_factory=datetime.now)
metadata: dict[str, Any] = field(default_factory=dict)
last_consolidated: int = 0 # Number of messages already consolidated to files
def __post_init__(self) -> None:
# An out-of-range offset (corrupt metadata) would hide all history; reset it.
if (
isinstance(self.last_consolidated, bool)
or not isinstance(self.last_consolidated, int)
or not 0 <= self.last_consolidated <= len(self.messages)
):
self.last_consolidated = 0
@staticmethod
def _annotate_message_time(message: dict[str, Any], content: Any) -> Any:
"""Expose persisted turn timestamps to the model for relative-date reasoning.
Annotating *every* assistant turn trains the model (via in-context
demonstrations) to start its own replies with the same
``[Message Time: ...]`` prefix, which leaks metadata back to the user.
We therefore only annotate user turns. User-side stamps are enough to
pin adjacent assistant replies for relative-time reasoning, including
proactive messages the user replies to later.
"""
timestamp = message.get("timestamp")
if not timestamp or not isinstance(content, str):
return content
role = message.get("role")
if role != "user":
return content
return f"[Message Time: {timestamp}]\n{content}"
def add_message(self, role: str, content: str, **kwargs: Any) -> None:
"""Add a message to the session."""
msg = {
"role": role,
"content": content,
"timestamp": datetime.now().isoformat(),
**kwargs
}
self.messages.append(msg)
self.updated_at = datetime.now()
def get_history(
self,
max_messages: int = 120,
*,
max_tokens: int = 0,
include_timestamps: bool = False,
) -> list[dict[str, Any]]:
"""Return unconsolidated messages for LLM input.
History is sliced by message count first (``max_messages``), then by
token budget from the tail (``max_tokens``) when provided.
"""
unconsolidated = self.messages[self.last_consolidated:]
max_messages = max_messages if max_messages > 0 else 120
sliced = unconsolidated[-max_messages:]
# Avoid starting mid-turn when possible, except for proactive
# assistant deliveries that the user may be replying to.
for i, message in enumerate(sliced):
if message.get("role") == "user":
start = i
if i > 0 and sliced[i - 1].get("_channel_delivery"):
start = i - 1
sliced = sliced[start:]
break
# Drop orphan tool results at the front.
start = find_legal_message_start(sliced)
if start:
sliced = sliced[start:]
out: list[dict[str, Any]] = []
for message in sliced:
if message.get("_command"):
continue
content = message.get("content", "")
role = message.get("role")
if role == "assistant" and isinstance(content, str):
content = _sanitize_assistant_replay_text(content)
# Synthesize an ``[image: path]`` breadcrumb from the persisted
# ``media`` kwarg so LLM replay still sees *something* where the
# image used to be. Without this, an image-only user turn
# replays as an empty user message — the assistant's reply then
# looks like it's responding to nothing.
media = message.get("media")
if role == "user" and isinstance(media, list) and media and isinstance(content, str):
breadcrumbs = "\n".join(
image_placeholder_text(p) for p in media if isinstance(p, str) and p
)
content = f"{content}\n{breadcrumbs}" if content else breadcrumbs
cli_apps = message.get("cli_apps")
if role == "user" and isinstance(cli_apps, list) and cli_apps and isinstance(content, str):
cli_lines: list[str] = []
for item in cli_apps[:8]:
if not isinstance(item, dict):
continue
name = str(item.get("name") or "").strip().lower()
if not name:
continue
entry = str(item.get("entry_point") or "unknown").strip() or "unknown"
cli_lines.append(
f"[CLI App Attachment: @{name}; tool=run_cli_app; entry_point={entry}; "
f"skill=skills/cli-app-{name}/SKILL.md]"
)
if cli_lines:
breadcrumbs = "\n".join(cli_lines)
content = f"{content}\n{breadcrumbs}" if content else breadcrumbs
mcp_presets = message.get("mcp_presets")
if (
role == "user"
and isinstance(mcp_presets, list)
and mcp_presets
and isinstance(content, str)
):
mcp_lines: list[str] = []
for item in mcp_presets[:8]:
if not isinstance(item, dict):
continue
name = str(item.get("name") or "").strip().lower()
if not name:
continue
transport = str(item.get("transport") or "mcp").strip() or "mcp"
mcp_lines.append(
f"[MCP Preset Attachment: @{name}; tool_prefix=mcp_{name}_; "
f"transport={transport}]"
)
if mcp_lines:
breadcrumbs = "\n".join(mcp_lines)
content = f"{content}\n{breadcrumbs}" if content else breadcrumbs
if include_timestamps:
content = self._annotate_message_time(message, content)
if role == "assistant" and isinstance(content, str) and not content.strip():
if not any(key in message for key in ("tool_calls", "reasoning_content", "thinking_blocks")):
continue
entry: dict[str, Any] = {"role": message["role"], "content": content}
for key in ("tool_calls", "tool_call_id", "name", "reasoning_content", "thinking_blocks"):
if key in message:
entry[key] = message[key]
out.append(entry)
if max_tokens > 0 and out:
kept: list[dict[str, Any]] = []
used = 0
for message in reversed(out):
tokens = estimate_message_tokens(message)
if kept and used + tokens > max_tokens:
break
kept.append(message)
used += tokens
kept.reverse()
# Keep history aligned to the first visible user turn.
first_user = next((i for i, m in enumerate(kept) if m.get("role") == "user"), None)
if first_user is not None:
kept = kept[first_user:]
else:
# Tight token budgets can otherwise leave assistant-only tails.
# If a user turn exists in the unsliced output, recover the
# nearest one even if it slightly exceeds the token budget.
recovered_user = next(
(i for i in range(len(out) - 1, -1, -1) if out[i].get("role") == "user"),
None,
)
if recovered_user is not None:
kept = out[recovered_user:]
# And keep a legal tool-call boundary at the front.
start = find_legal_message_start(kept)
if start:
kept = kept[start:]
out = kept
return out
def clear(self) -> None:
"""Clear all messages and reset session to initial state."""
self.messages = []
self.last_consolidated = 0
self.updated_at = datetime.now()
self.metadata.pop("_last_summary", None)
def retain_recent_legal_suffix(self, max_messages: int) -> tuple[list[dict], int]:
"""Keep a legal recent suffix constrained by a hard message cap.
Returns ``(dropped, already_consolidated_count)`` where *dropped* is
the list of removed messages (in original order) and
*already_consolidated_count* is how many of those were inside the
pre-existing ``last_consolidated`` prefix and therefore do not need
raw archiving.
"""
if max_messages <= 0:
dropped = list(self.messages)
lc = self.last_consolidated
self.clear()
return dropped, min(lc, len(dropped))
if len(self.messages) <= max_messages:
return [], 0
original = list(self.messages)
before_lc = self.last_consolidated
retained = list(self.messages[-max_messages:])
# Prefer starting at a user turn when one exists within the tail.
first_user = next((i for i, m in enumerate(retained) if m.get("role") == "user"), None)
if first_user is not None:
retained = retained[first_user:]
else:
# If the tail is assistant/tool-only, anchor to the latest user in
# the full session and take a capped forward window from there.
latest_user = next(
(i for i in range(len(self.messages) - 1, -1, -1)
if self.messages[i].get("role") == "user"),
None,
)
if latest_user is not None:
retained = list(self.messages[latest_user: latest_user + max_messages])
# Mirror get_history(): avoid persisting orphan tool results at the front.
start = find_legal_message_start(retained)
if start:
retained = retained[start:]
# Hard-cap guarantee: never keep more than max_messages.
if len(retained) > max_messages:
retained = retained[-max_messages:]
start = find_legal_message_start(retained)
if start:
retained = retained[start:]
# Compute actually-dropped messages using identity comparison so that
# even when retained is a non-contiguous slice of original (the else
# branch above), we never duplicate or lose messages.
retained_ids = set(id(m) for m in retained)
dropped = [m for m in original if id(m) not in retained_ids]
# Count how many dropped messages were in the already-consolidated
# prefix of the original list. This cannot be a simple min() because
# dropped may include messages from *after* the consolidated prefix
# (e.g. in the else branch).
already_consolidated = sum(
1 for i, m in enumerate(original)
if i < before_lc and id(m) not in retained_ids
)
# New last_consolidated = count of retained messages that were inside
# the old consolidated prefix.
new_lc = sum(
1 for i, m in enumerate(original)
if i < before_lc and id(m) in retained_ids
)
self.messages = retained
self.last_consolidated = new_lc
self.updated_at = datetime.now()
return dropped, already_consolidated
def enforce_file_cap(
self,
on_archive: Any = None,
limit: int = FILE_MAX_MESSAGES,
) -> None:
"""Bound session message growth by archiving and trimming old prefixes."""
if limit <= 0 or len(self.messages) <= limit:
return
dropped, already_consolidated = self.retain_recent_legal_suffix(limit)
if not dropped:
return
archive_chunk = dropped[already_consolidated:]
if archive_chunk and on_archive:
on_archive(archive_chunk)
logger.info(
"Session file cap hit for {}: dropped {}, raw-archived {}, kept {}",
self.key,
len(dropped),
len(archive_chunk),
len(self.messages),
)
class SessionManager:
"""
Manages conversation sessions.
Sessions are stored as JSONL files in the sessions directory.
"""
def __init__(self, workspace: Path):
self.workspace = workspace
self.sessions_dir = ensure_dir(self.workspace / "sessions")
self.legacy_sessions_dir = get_legacy_sessions_dir()
self._cache: dict[str, Session] = {}
@staticmethod
def safe_key(key: str) -> str:
"""Public helper used by HTTP handlers to map an arbitrary key to a stable filename stem."""
return safe_filename(key.replace(":", "_"))
def _get_session_path(self, key: str) -> Path:
"""Get the file path for a session."""
return self.sessions_dir / f"{self.safe_key(key)}.jsonl"
def _get_legacy_session_path(self, key: str) -> Path:
"""Legacy global session path (~/.nanobot/sessions/)."""
return self.legacy_sessions_dir / f"{self.safe_key(key)}.jsonl"
def get_or_create(self, key: str) -> Session:
"""
Get an existing session or create a new one.
Args:
key: Session key (usually channel:chat_id).
Returns:
The session.
"""
if key in self._cache:
return self._cache[key]
session = self._load(key)
if session is None:
session = Session(key=key)
self._cache[key] = session
return session
def _load(self, key: str) -> Session | None:
"""Load a session from disk."""
path = self._get_session_path(key)
if not path.exists():
legacy_path = self._get_legacy_session_path(key)
if legacy_path.exists():
try:
shutil.move(str(legacy_path), str(path))
logger.info("Migrated session {} from legacy path", key)
except Exception:
logger.exception("Failed to migrate session {}", key)
if not path.exists():
return None
try:
messages = []
metadata = {}
created_at = None
updated_at = None
last_consolidated = 0
with open(path, encoding="utf-8") as f:
for line in f:
line = line.strip()
if not line:
continue
data = json.loads(line)
if data.get("_type") == "metadata":
metadata = data.get("metadata", {})
created_at = datetime.fromisoformat(data["created_at"]) if data.get("created_at") else None
updated_at = datetime.fromisoformat(data["updated_at"]) if data.get("updated_at") else None
last_consolidated = data.get("last_consolidated", 0)
else:
messages.append(data)
return Session(
key=key,
messages=messages,
created_at=created_at or datetime.now(),
updated_at=updated_at or datetime.now(),
metadata=metadata,
last_consolidated=last_consolidated
)
except Exception as e:
logger.warning("Failed to load session {}: {}", key, e)
repaired = self._repair(key)
if repaired is not None:
logger.info("Recovered session {} from corrupt file ({} messages)", key, len(repaired.messages))
return repaired
def _repair(self, key: str) -> Session | None:
"""Attempt to recover a session from a corrupt JSONL file."""
path = self._get_session_path(key)
if not path.exists():
return None
try:
messages: list[dict[str, Any]] = []
metadata: dict[str, Any] = {}
created_at: datetime | None = None
updated_at: datetime | None = None
last_consolidated = 0
skipped = 0
with open(path, encoding="utf-8") as f:
for line in f:
line = line.strip()
if not line:
continue
try:
data = json.loads(line)
except json.JSONDecodeError:
skipped += 1
continue
if data.get("_type") == "metadata":
metadata = data.get("metadata", {})
if data.get("created_at"):
with suppress(ValueError, TypeError):
created_at = datetime.fromisoformat(data["created_at"])
if data.get("updated_at"):
with suppress(ValueError, TypeError):
updated_at = datetime.fromisoformat(data["updated_at"])
last_consolidated = data.get("last_consolidated", 0)
else:
messages.append(data)
if skipped:
logger.warning("Skipped {} corrupt lines in session {}", skipped, key)
if not messages and not metadata:
return None
return Session(
key=key,
messages=messages,
created_at=created_at or datetime.now(),
updated_at=updated_at or datetime.now(),
metadata=metadata,
last_consolidated=last_consolidated
)
except Exception as e:
logger.warning("Repair failed for session {}: {}", key, e)
return None
@staticmethod
def _session_payload(session: Session) -> dict[str, Any]:
return {
"key": session.key,
"created_at": session.created_at.isoformat(),
"updated_at": session.updated_at.isoformat(),
"metadata": session.metadata,
"messages": session.messages,
}
def save(self, session: Session, *, fsync: bool = False) -> None:
"""Save a session to disk atomically.
When *fsync* is ``True`` the final file and its parent directory are
explicitly flushed to durable storage. This is intentionally off by
default (the OS page-cache is sufficient for normal operation) but
should be enabled during graceful shutdown so that filesystems with
write-back caching (e.g. rclone VFS, NFS, FUSE mounts) do not lose
the most recent writes.
"""
path = self._get_session_path(session.key)
tmp_path = path.with_suffix(".jsonl.tmp")
try:
with open(tmp_path, "w", encoding="utf-8") as f:
metadata_line = {
"_type": "metadata",
"key": session.key,
"created_at": session.created_at.isoformat(),
"updated_at": session.updated_at.isoformat(),
"metadata": session.metadata,
"last_consolidated": session.last_consolidated
}
f.write(json.dumps(metadata_line, ensure_ascii=False) + "\n")
for msg in session.messages:
f.write(json.dumps(msg, ensure_ascii=False) + "\n")
if fsync:
f.flush()
os.fsync(f.fileno())
os.replace(tmp_path, path)
if fsync:
# fsync the directory so the rename is durable.
# On Windows, opening a directory with O_RDONLY raises
# PermissionError — skip the dir sync there (NTFS
# journals metadata synchronously).
with suppress(PermissionError):
fd = os.open(str(path.parent), os.O_RDONLY)
try:
os.fsync(fd)
finally:
os.close(fd)
except BaseException:
tmp_path.unlink(missing_ok=True)
raise
self._cache[session.key] = session
def flush_all(self) -> int:
"""Re-save every cached session with fsync for durable shutdown.
Returns the number of sessions flushed. Errors on individual
sessions are logged but do not prevent other sessions from being
flushed.
"""
flushed = 0
for key, session in list(self._cache.items()):
try:
self.save(session, fsync=True)
flushed += 1
except Exception:
logger.warning("Failed to flush session {}", key, exc_info=True)
return flushed
def invalidate(self, key: str) -> None:
"""Remove a session from the in-memory cache."""
self._cache.pop(key, None)
def delete_session(self, key: str) -> bool:
"""Remove a session from disk and the in-memory cache.
Returns True if a JSONL file was found and unlinked.
"""
path = self._get_session_path(key)
self.invalidate(key)
if not path.exists():
return False
try:
path.unlink()
return True
except OSError as e:
logger.warning("Failed to delete session file {}: {}", path, e)
return False
def fork_session_before_user_index(
self,
source_key: str,
target_key: str,
before_user_index: int,
) -> Session | None:
"""Create *target_key* from *source_key* before a global user-message index.
``before_user_index`` is zero-based over user messages in the full session:
``0`` means "before the first user message", ``1`` means "before the
second user message", and so on. A value equal to the total user-message
count copies the full session prefix. WebUI assistant-reply forks pass
the next user index so the selected completed assistant turn is included.
"""
if before_user_index < 0:
return None
source = self._cache.get(source_key) or self._load(source_key)
if source is None:
return None
copied: list[dict[str, Any]] = []
user_index = 0
found_target = False
for message in source.messages:
if message.get("role") == "user":
if user_index == before_user_index:
found_target = True
break
user_index += 1
copied.append(deepcopy(message))
if user_index == before_user_index:
found_target = True
if not found_target:
return None
metadata = deepcopy(source.metadata)
for key in _FORK_VOLATILE_METADATA_KEYS:
metadata.pop(key, None)
last_consolidated = min(source.last_consolidated, len(copied))
if source.last_consolidated > len(copied):
metadata.pop("_last_summary", None)
last_consolidated = 0
now = datetime.now()
target = Session(
key=target_key,
messages=copied,
created_at=now,
updated_at=now,
metadata=metadata,
last_consolidated=last_consolidated,
)
self.save(target, fsync=True)
return target
def read_session_file(self, key: str) -> dict[str, Any] | None:
"""Load a session from disk without caching; intended for read-only HTTP endpoints.
Returns ``{"key", "created_at", "updated_at", "metadata", "messages"}`` or
``None`` when the session file does not exist or fails to parse.
"""
path = self._get_session_path(key)
if not path.exists():
return None
try:
messages: list[dict[str, Any]] = []
metadata: dict[str, Any] = {}
created_at: str | None = None
updated_at: str | None = None
stored_key: str | None = None
with open(path, encoding="utf-8") as f:
for line in f:
line = line.strip()
if not line:
continue
data = json.loads(line)
if data.get("_type") == "metadata":
metadata = data.get("metadata", {})
created_at = data.get("created_at")
updated_at = data.get("updated_at")
stored_key = data.get("key")
else:
messages.append(data)
return {
"key": stored_key or key,
"created_at": created_at,
"updated_at": updated_at,
"metadata": metadata,
"messages": messages,
}
except Exception as e:
logger.warning("Failed to read session {}: {}", key, e)
repaired = self._repair(key)
if repaired is not None:
logger.info("Recovered read-only session view {} from corrupt file", key)
return self._session_payload(repaired)
return None
def list_sessions(self) -> list[dict[str, Any]]:
"""
List all sessions.
Returns:
List of session info dicts.
"""
sessions = []
for path in self.sessions_dir.glob("*.jsonl"):
fallback_key = path.stem.replace("_", ":", 1)
try:
# Read the metadata line and a small preview for session lists.
with open(path, encoding="utf-8") as f:
first_line = f.readline().strip()
if first_line:
data = json.loads(first_line)
if data.get("_type") == "metadata":
key = data.get("key") or path.stem.replace("_", ":", 1)
metadata = data.get("metadata", {})
title = _metadata_title(metadata)
preview = ""
fallback_preview = ""
scanned_records = 0
scanned_chars = 0
for line in f:
if not line.strip():
continue
scanned_records += 1
scanned_chars += len(line)
if (
scanned_records > _SESSION_LIST_PREVIEW_MAX_RECORDS
or scanned_chars > _SESSION_LIST_PREVIEW_MAX_CHARS
):
break
item = json.loads(line)
if item.get("_type") == "metadata":
continue
text = _message_preview_text(item)
if not text:
continue
if item.get("role") == "user":
preview = text
break
if not fallback_preview and item.get("role") == "assistant":
fallback_preview = text
preview = preview or fallback_preview
sessions.append(
{
"key": key,
"created_at": data.get("created_at"),
"updated_at": data.get("updated_at"),
"title": title,
"preview": preview,
"path": str(path),
}
)
except Exception:
repaired = self._repair(fallback_key)
if repaired is not None:
sessions.append(
{
"key": repaired.key,
"created_at": repaired.created_at.isoformat(),
"updated_at": repaired.updated_at.isoformat(),
"title": _metadata_title(repaired.metadata),
"preview": next(
(
text
for msg in repaired.messages
if (text := _message_preview_text(msg))
),
"",
),
"path": str(path),
}
)
continue
return sorted(sessions, key=lambda x: x.get("updated_at", ""), reverse=True)