Files
nanobot/nanobot/session/manager.py
T

1815 lines
72 KiB
Python

"""Session management for conversation history."""
import base64
import errno
import hashlib
import json
import os
import re
import secrets
import shutil
import stat
from collections import OrderedDict
from contextlib import contextmanager, suppress
from copy import deepcopy
from dataclasses import dataclass, field
from datetime import datetime
from pathlib import Path
from typing import Any, Callable, Collection, Generator, Protocol, TypedDict, cast
from weakref import WeakValueDictionary
from filelock import FileLock
from loguru import logger
from nanobot.config.paths import get_legacy_sessions_dir, get_runtime_subdir
from nanobot.providers.base import ProviderConversationState
from nanobot.runtime_context import (
RUNTIME_CONTEXT_HISTORY_META,
public_history_message,
)
from nanobot.session.model_selection import SESSION_MODEL_PRESET_METADATA_KEY
from nanobot.utils.helpers import (
content_with_media_breadcrumbs,
ensure_dir,
estimate_message_tokens,
find_legal_message_start,
recent_message_start_index,
safe_filename,
strip_think,
)
from nanobot.utils.subagent_channel_display import scrub_subagent_announce_body
SESSION_CACHE_MAX_SIZE = 128
MIN_COMPACTED_REPLAY_MESSAGES = 8
_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*$')
_SESSION_PREVIEW_MAX_CHARS = 120
_SESSION_LIST_PREVIEW_MAX_RECORDS = 200
_SESSION_LIST_PREVIEW_MAX_CHARS = 1_000_000
_SESSION_DATA_ERRORS = (ValueError, TypeError, AttributeError, KeyError)
_PROVIDER_STATE_RECORD_TYPE = "provider_state"
_PROVIDER_STATE_RECORD_PREFIX_RE = re.compile(
r'^\s*\{\s*"_type"\s*:\s*"provider_state"\s*(?:,|\})'
)
_FORK_VOLATILE_METADATA_KEYS = {
"goal_state",
"pending_user_turn",
"runtime_checkpoint",
"session_handle",
"thread_goal",
"title",
"title_user_edited",
}
_WORKSPACE_STATE_DIR = ".nanobot"
_WORKSPACE_ID_FILE = "workspace-id"
_WORKSPACE_ID_RE = re.compile(r"^[0-9a-f]{32}$")
_SESSION_MIGRATION_LOCK_TIMEOUT_SECONDS = 30
_SESSION_FILES_LOCK_FILENAME = ".session-files.lock"
_COPY_CHUNK_SIZE = 1024 * 1024
def _json_object(value: object) -> dict[str, Any]:
"""Narrow a decoded JSON object while preserving its original values."""
if not isinstance(value, dict):
raise ValueError("session records must be JSON objects")
return cast(dict[str, Any], value)
def _is_provider_state_record_line(line: str) -> bool:
"""Recognize the canonical private record without decoding its opaque payload."""
return _PROVIDER_STATE_RECORD_PREFIX_RE.match(line) is not None
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: object) -> str:
"""Return compact display text for session lists."""
if isinstance(content, str):
text = content
elif isinstance(content, list):
parts: list[str] = []
for block in cast(list[object], content):
if isinstance(block, dict):
block_data = cast(dict[object, object], block)
if block_data.get("type") != "text":
continue
value = block_data.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."""
message = public_history_message(message)
content = cast(object, 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: object) -> str:
if not isinstance(metadata, dict):
return ""
metadata_data = cast(dict[object, object], metadata)
title = metadata_data.get("title")
if not isinstance(title, str):
return ""
if metadata_data.get("title_user_edited") is True:
return title
return strip_think(title)
@dataclass
class RetentionResult:
dropped: list[dict[str, Any]]
already_consolidated_count: int
@dataclass(frozen=True)
class SessionPolicy:
"""Runtime rules that do not belong in durable session data."""
persist: bool = True
log_content: bool = True
disabled_tools: frozenset[str] = frozenset()
@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
provider_state: ProviderConversationState | None = field(default=None, repr=False)
policy: SessionPolicy = field(default_factory=SessionPolicy, repr=False, compare=False)
def __post_init__(self) -> None:
if not isinstance(cast(object, self.metadata), dict):
self.metadata = {}
if not isinstance(cast(object, self.provider_state), ProviderConversationState):
self.provider_state = None
# An out-of-range offset (corrupt metadata) would hide all history; reset it.
last_consolidated = cast(object, self.last_consolidated)
if (
isinstance(last_consolidated, bool)
or not isinstance(last_consolidated, int)
or not 0 <= last_consolidated <= len(self.messages)
):
self.last_consolidated = 0
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 = 0,
*,
max_tokens: int = 0,
extend_to_user: bool = False,
include_runtime_context: bool = True,
) -> list[dict[str, Any]]:
"""Return recent replayable messages for LLM input.
A positive ``max_messages`` applies an explicit caller-owned count
limit. The normal model path relies on ``max_tokens`` instead.
"""
replay_start = self.last_consolidated
if replay_start:
# ``last_consolidated`` is archive progress, not a replay boundary.
# Keep a small raw suffix for continuity, extending back to the user
# that started an assistant/tool sequence when necessary.
recent_start = recent_message_start_index(
self.messages,
MIN_COMPACTED_REPLAY_MESSAGES,
extend_to_user=True,
)
replay_start = min(replay_start, recent_start)
replayable = self.messages[replay_start:]
if max_messages <= 0:
start_idx = 0
else:
unarchived_count = len(self.messages) - self.last_consolidated
if replay_start < self.last_consolidated and unarchived_count < max_messages:
# The archived replay suffix can exceed the nominal count when one
# tool-heavy turn spans the boundary. Preserve that complete turn.
start_idx = 0
else:
start_idx = recent_message_start_index(
replayable,
max_messages,
extend_to_user=extend_to_user,
)
sliced = replayable[start_idx:]
# 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
has_persisted_runtime_context = isinstance(
message.get(RUNTIME_CONTEXT_HISTORY_META),
dict,
)
if not include_runtime_context:
message = public_history_message(message)
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.
content = content_with_media_breadcrumbs(
role,
content,
message.get("media"),
)
cli_apps = cast(object, message.get("cli_apps"))
if (
include_runtime_context
and not has_persisted_runtime_context
and role == "user"
and isinstance(cli_apps, list)
and cli_apps
and isinstance(content, str)
):
cli_lines: list[str] = []
for item in cast(list[object], cli_apps[:8]):
if not isinstance(item, dict):
continue
item_data = cast(dict[object, object], item)
name = str(item_data.get("name") or "").strip().lower()
if not name:
continue
entry_point = (
str(item_data.get("entry_point") or "unknown").strip() or "unknown"
)
cli_lines.append(
f"[CLI App Attachment: @{name}; tool=run_cli_app; entry_point={entry_point}; "
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
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.provider_state = None
self.updated_at = datetime.now()
self.metadata.pop("_last_summary", None)
def retain_recent_legal_suffix(
self,
max_messages: int,
*,
extend_to_user: bool = False,
) -> RetentionResult:
"""Keep a legal recent suffix, optionally extending it back to a user turn.
Returns a RetentionResult with dropped messages and how many of those
were in the already-consolidated prefix. This method mutates
self.messages and self.last_consolidated in place.
"""
if max_messages <= 0:
dropped = list(self.messages)
lc = self.last_consolidated
self.clear()
return RetentionResult(
dropped=dropped,
already_consolidated_count=min(lc, len(dropped)),
)
if len(self.messages) <= max_messages:
return RetentionResult(
dropped=[],
already_consolidated_count=0,
)
original = list(self.messages)
before_lc = self.last_consolidated
start_idx = max(0, len(self.messages) - max_messages)
if extend_to_user:
recovered_user = next(
(i for i in range(start_idx, -1, -1) if self.messages[i].get("role") == "user"),
None,
)
if recovered_user is not None:
start_idx = recovered_user
if start_idx > 0 and self.messages[start_idx - 1].get("_channel_delivery"):
start_idx -= 1
retained = self.messages[start_idx:]
# Prefer starting at a user turn (or its preceding _channel_delivery) when one exists within the retained window.
first_user = next((i for i, m in enumerate(retained) if m.get("role") == "user"), None)
if first_user is not None:
if first_user > 0 and retained[first_user - 1].get("_channel_delivery"):
retained = retained[first_user - 1:]
else:
retained = retained[first_user:]
elif not extend_to_user:
# If the hard-capped tail is assistant/tool-only, anchor to the
# latest user in the full session and take a capped forward window.
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 = 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 unless the caller requested user-turn extension.
if not extend_to_user and 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
if dropped:
self.provider_state = None
self.updated_at = datetime.now()
return RetentionResult(
dropped=dropped,
already_consolidated_count=already_consolidated,
)
class SessionPayload(TypedDict):
key: str
created_at: str | None
updated_at: str | None
metadata: dict[str, Any]
messages: list[dict[str, Any]]
class SessionMetadataPayload(TypedDict):
key: str
created_at: str | None
updated_at: str | None
metadata: dict[str, Any]
class SessionInfo(TypedDict):
key: str
created_at: str
updated_at: str
title: str
preview: str
path: str
@dataclass(frozen=True)
class _SessionFileSnapshot:
digest: str
size: int
mtime_ns: int
updated_at: float
device: int
inode: int
@dataclass(frozen=True)
class SessionRestoreResult:
restored: int
unchanged: int
conflicts: tuple[Path, ...]
class SessionStore(Protocol):
def load(self, key: str) -> Session | None: ...
def save(self, session: Session, *, fsync: bool = False) -> None: ...
def delete(self, key: str) -> bool: ...
def read(self, key: str) -> SessionPayload | None: ...
def read_metadata(self, key: str) -> SessionMetadataPayload | None: ...
def update_metadata(
self,
key: str,
updates: dict[str, Any],
*,
fsync: bool = False,
) -> bool: ...
def list_sessions(self) -> list[SessionInfo]: ...
class JsonlSessionStore:
"""JSONL implementation of session persistence."""
def __init__(self, workspace: Path, *, sessions_root: Path | None = None):
canonical_workspace = Path(workspace).expanduser().resolve(strict=False)
ensure_dir(canonical_workspace)
root = (
Path(sessions_root).expanduser().resolve(strict=False)
if sessions_root is not None
else get_runtime_subdir("sessions").resolve(strict=False)
)
if root == canonical_workspace or root.is_relative_to(canonical_workspace):
raise RuntimeError(
"session storage must be outside the agent workspace; "
"move --config outside --workspace or choose a nested workspace directory"
)
ensure_dir(root)
with suppress(OSError):
os.chmod(root, 0o700)
self.workspace = canonical_workspace
self._migration_lock = FileLock(
str(root / ".workspace-migration.lock"),
timeout=_SESSION_MIGRATION_LOCK_TIMEOUT_SECONDS,
)
with self._migration_lock:
workspace_id = self._load_or_create_workspace_id(canonical_workspace, root)
workspace_id = self._claim_workspace_namespace(
root,
canonical_workspace,
workspace_id,
)
self.sessions_dir = ensure_dir(root / workspace_id)
self.legacy_sessions_dir = get_legacy_sessions_dir()
self._session_files_lock = FileLock(
str(self.sessions_dir / _SESSION_FILES_LOCK_FILENAME)
)
with self._session_files_lock:
self._migrate_from_workspace(canonical_workspace)
@contextmanager
def locked_session_files(self) -> Generator[Path, None, None]:
"""Guard direct access to canonical session files in this directory."""
with self._session_files_lock:
yield self.sessions_dir
@staticmethod
def _fsync_directory(path: Path) -> None:
with suppress(PermissionError, NotImplementedError):
fd = os.open(path, os.O_RDONLY)
try:
os.fsync(fd)
except OSError as exc:
if exc.errno != errno.EINVAL:
raise
finally:
os.close(fd)
@classmethod
def _write_text_atomic(cls, path: Path, content: str, *, mode: int = 0o600) -> None:
tmp = path.with_name(f".{path.name}.{secrets.token_hex(8)}.tmp")
try:
with open(tmp, "x", encoding="utf-8") as handle:
os.chmod(tmp, mode)
handle.write(content)
handle.flush()
os.fsync(handle.fileno())
os.replace(tmp, path)
cls._fsync_directory(path.parent)
finally:
tmp.unlink(missing_ok=True)
@classmethod
def _read_workspace_id(cls, marker: Path) -> str:
if marker.is_symlink():
raise RuntimeError(f"workspace identity marker must not be a symlink: {marker}")
value = marker.read_text(encoding="utf-8").strip()
if not _WORKSPACE_ID_RE.fullmatch(value):
raise RuntimeError(
f"workspace identity marker is invalid: {marker}; "
"restore its original 32-character identifier before starting nanobot"
)
return value
@staticmethod
def _workspace_id_path(workspace: Path) -> Path:
state_dir = workspace / _WORKSPACE_STATE_DIR
if state_dir.is_symlink():
raise RuntimeError(f"workspace state directory must not be a symlink: {state_dir}")
ensure_dir(state_dir)
return state_dir / _WORKSPACE_ID_FILE
@classmethod
def _find_workspace_namespace(cls, workspace: Path, root: Path) -> str | None:
"""Recover an identity marker removed by cleanup at the same workspace path."""
matches: list[str] = []
for sessions_dir in root.iterdir():
if (
not _WORKSPACE_ID_RE.fullmatch(sessions_dir.name)
or sessions_dir.is_symlink()
or not sessions_dir.is_dir()
):
continue
marker = sessions_dir / ".workspace"
if marker.is_symlink() or not marker.is_file():
continue
try:
recorded = Path(marker.read_text(encoding="utf-8").strip()).expanduser()
recorded = recorded.resolve(strict=False)
same_workspace = recorded == workspace or (
recorded.exists() and recorded.samefile(workspace)
)
except (OSError, UnicodeError, ValueError):
continue
if same_workspace:
matches.append(sessions_dir.name)
if len(matches) > 1:
raise RuntimeError(
f"multiple session namespaces claim workspace {workspace}; "
"remove the stale namespace marker before starting nanobot"
)
return matches[0] if matches else None
@classmethod
def _load_or_create_workspace_id(cls, workspace: Path, root: Path) -> str:
marker = cls._workspace_id_path(workspace)
if marker.exists() or marker.is_symlink():
return cls._read_workspace_id(marker)
recovered = cls._find_workspace_namespace(workspace, root)
if recovered is not None:
cls._write_text_atomic(marker, f"{recovered}\n")
return recovered
workspace_id = secrets.token_hex(16)
flags = os.O_WRONLY | os.O_CREAT | os.O_EXCL
flags |= getattr(os, "O_NOFOLLOW", 0)
try:
fd = os.open(marker, flags, 0o600)
except FileExistsError:
return cls._read_workspace_id(marker)
try:
payload = f"{workspace_id}\n".encode("ascii")
view = memoryview(payload)
while view:
written = os.write(fd, view)
view = view[written:]
os.fsync(fd)
except BaseException:
with suppress(OSError):
marker.unlink()
raise
finally:
os.close(fd)
cls._fsync_directory(marker.parent)
return workspace_id
@classmethod
def _replace_workspace_id(cls, workspace: Path, workspace_id: str) -> None:
cls._write_text_atomic(cls._workspace_id_path(workspace), f"{workspace_id}\n")
@classmethod
def _write_workspace_marker(cls, sessions_dir: Path, workspace: Path) -> None:
cls._write_text_atomic(sessions_dir / ".workspace", f"{workspace}\n")
@classmethod
def _claim_workspace_namespace(
cls,
root: Path,
workspace: Path,
workspace_id: str,
) -> str:
"""Bind a stable workspace ID, rotating copied live workspaces apart."""
for _attempt in range(3):
sessions_dir = root / workspace_id
marker = sessions_dir / ".workspace"
if sessions_dir.is_symlink():
raise RuntimeError(f"session namespace must not be a symlink: {sessions_dir}")
if not sessions_dir.exists():
ensure_dir(sessions_dir)
cls._write_workspace_marker(sessions_dir, workspace)
return workspace_id
if marker.is_symlink():
raise RuntimeError(f"session workspace marker must not be a symlink: {marker}")
if not marker.exists():
if any(sessions_dir.iterdir()):
raise RuntimeError(
f"session namespace has data but no workspace marker: {sessions_dir}"
)
cls._write_workspace_marker(sessions_dir, workspace)
return workspace_id
recorded_text = marker.read_text(encoding="utf-8").strip()
if not recorded_text:
raise RuntimeError(f"session workspace marker is empty: {marker}")
recorded = Path(recorded_text).expanduser().resolve(strict=False)
if recorded == workspace:
return workspace_id
try:
same_workspace = recorded.exists() and recorded.samefile(workspace)
except OSError:
same_workspace = False
if same_workspace:
cls._write_workspace_marker(sessions_dir, workspace)
return workspace_id
if not recorded.exists():
# The identity marker travelled with a renamed or moved workspace.
cls._write_workspace_marker(sessions_dir, workspace)
return workspace_id
# Both paths exist and are different: this is a copy, not a move.
workspace_id = secrets.token_hex(16)
cls._replace_workspace_id(workspace, workspace_id)
raise RuntimeError(f"could not allocate an isolated session namespace for {workspace}")
@staticmethod
def _session_file_snapshot(path: Path) -> _SessionFileSnapshot | None:
flags = os.O_RDONLY | getattr(os, "O_NOFOLLOW", 0)
try:
fd = os.open(path, flags)
except OSError:
return None
try:
before = os.fstat(fd)
if not stat.S_ISREG(before.st_mode):
return None
digest = hashlib.sha256()
saw_record = False
updated_at: float | None = None
with os.fdopen(fd, "rb", closefd=False) as handle:
for raw_line in handle:
digest.update(raw_line)
if not raw_line.strip():
continue
value: object = json.loads(raw_line.decode("utf-8"))
data = _json_object(value)
saw_record = True
if data.get("_type") == "metadata":
raw_updated_at = cast(object, data.get("updated_at"))
if isinstance(raw_updated_at, str) and raw_updated_at:
updated_at = datetime.fromisoformat(raw_updated_at).timestamp()
after = os.fstat(fd)
if (
not saw_record
or before.st_dev != after.st_dev
or before.st_ino != after.st_ino
or before.st_size != after.st_size
or before.st_mtime_ns != after.st_mtime_ns
):
return None
return _SessionFileSnapshot(
digest=digest.hexdigest(),
size=after.st_size,
mtime_ns=after.st_mtime_ns,
updated_at=(updated_at if updated_at is not None else after.st_mtime_ns / 1e9),
device=after.st_dev,
inode=after.st_ino,
)
except (OSError, UnicodeDecodeError, json.JSONDecodeError, ValueError, TypeError):
return None
finally:
os.close(fd)
@classmethod
def _prepare_copy(
cls,
src: Path,
dst_dir: Path,
snapshot: _SessionFileSnapshot,
) -> Path:
tmp = dst_dir / f".{src.name}.{secrets.token_hex(8)}.tmp"
flags = os.O_RDONLY | getattr(os, "O_NOFOLLOW", 0)
src_fd = os.open(src, flags)
try:
before = os.fstat(src_fd)
if (
before.st_dev != snapshot.device
or before.st_ino != snapshot.inode
or before.st_size != snapshot.size
or before.st_mtime_ns != snapshot.mtime_ns
):
raise OSError("session source changed before migration")
digest = hashlib.sha256()
size = 0
with os.fdopen(src_fd, "rb", closefd=False) as source, open(tmp, "xb") as target:
os.chmod(tmp, 0o600)
while chunk := source.read(_COPY_CHUNK_SIZE):
digest.update(chunk)
size += len(chunk)
target.write(chunk)
target.flush()
os.fsync(target.fileno())
after = os.fstat(src_fd)
if (
digest.hexdigest() != snapshot.digest
or size != snapshot.size
or after.st_dev != snapshot.device
or after.st_ino != snapshot.inode
or after.st_size != snapshot.size
or after.st_mtime_ns != snapshot.mtime_ns
):
raise OSError("session source changed during migration")
return tmp
except BaseException:
tmp.unlink(missing_ok=True)
raise
finally:
os.close(src_fd)
@classmethod
def _install_snapshot(
cls,
src: Path,
dst: Path,
snapshot: _SessionFileSnapshot,
) -> None:
tmp = cls._prepare_copy(src, dst.parent, snapshot)
try:
os.replace(tmp, dst)
cls._fsync_directory(dst.parent)
installed = cls._session_file_snapshot(dst)
if installed is None or installed.digest != snapshot.digest:
raise OSError(f"session migration verification failed: {dst}")
finally:
tmp.unlink(missing_ok=True)
def _archive_conflict(
self,
src: Path,
snapshot: _SessionFileSnapshot,
label: str,
) -> Path:
conflict_dir = ensure_dir(self.sessions_dir / ".migration-conflicts")
conflict = conflict_dir / (
f"{src.stem}.{label}.{snapshot.digest[:12]}.{secrets.token_hex(4)}.jsonl"
)
self._install_snapshot(src, conflict, snapshot)
return conflict
@classmethod
def _remove_migrated_source(
cls,
src: Path,
snapshot: _SessionFileSnapshot,
) -> bool:
try:
current = src.stat(follow_symlinks=False)
if (
current.st_dev != snapshot.device
or current.st_ino != snapshot.inode
or current.st_size != snapshot.size
or current.st_mtime_ns != snapshot.mtime_ns
):
return False
src.unlink()
cls._fsync_directory(src.parent)
return True
except OSError:
return False
def _migrate_from_workspace(self, workspace: Path) -> None:
"""Durably copy legacy sessions out of the workspace, then remove the source."""
old_dir = workspace / "sessions"
if old_dir.is_symlink() or not old_dir.is_dir():
if old_dir.is_symlink():
logger.warning("Skipping symlinked legacy sessions directory: {}", old_dir)
return
for src in old_dir.glob("*.jsonl"):
if src.is_symlink() or not src.is_file():
logger.warning("Skipping unsafe legacy session file: {}", src)
continue
dst = self.sessions_dir / src.name
source_snapshot = self._session_file_snapshot(src)
if source_snapshot is None:
logger.warning("Skipping invalid or changing legacy session file: {}", src)
continue
try:
destination_snapshot = self._session_file_snapshot(dst) if dst.exists() else None
if dst.exists() and destination_snapshot is None:
logger.warning(
"Keeping legacy session because destination is invalid: {}",
dst,
)
continue
if destination_snapshot is None:
self._install_snapshot(src, dst, source_snapshot)
elif destination_snapshot.digest == source_snapshot.digest:
pass
elif source_snapshot.updated_at > destination_snapshot.updated_at:
archived = self._archive_conflict(dst, destination_snapshot, "destination")
self._install_snapshot(src, dst, source_snapshot)
logger.warning("Archived older session migration conflict at {}", archived)
else:
archived = self._archive_conflict(src, source_snapshot, "workspace")
logger.warning("Archived older session migration conflict at {}", archived)
installed = self._session_file_snapshot(dst)
if installed is None:
raise OSError(f"session migration destination is unreadable: {dst}")
selected_digest = (
source_snapshot.digest
if destination_snapshot is None
or source_snapshot.updated_at > destination_snapshot.updated_at
else destination_snapshot.digest
)
if installed.digest != selected_digest:
raise OSError(f"session migration selected unexpected data: {dst}")
if not self._remove_migrated_source(src, source_snapshot):
logger.warning(
"Session migrated but legacy source changed or could not be removed: {}",
src,
)
except OSError as exc:
logger.warning("Failed to migrate session {}: {}", src, exc)
def restore_to_workspace(self) -> SessionRestoreResult:
"""Copy canonical sessions back for an explicit downgrade or rollback."""
restored = 0
unchanged = 0
conflicts: list[Path] = []
old_dir = self.workspace / "sessions"
if old_dir.is_symlink():
raise RuntimeError(f"refusing to restore into symlinked sessions directory: {old_dir}")
ensure_dir(old_dir)
with self._migration_lock, self._session_files_lock:
for src in self.sessions_dir.glob("*.jsonl"):
if self.session_key_from_path(src) is None:
continue
source_snapshot = self._session_file_snapshot(src)
if source_snapshot is None:
conflicts.append(src)
continue
dst = old_dir / src.name
if dst.exists():
destination_snapshot = self._session_file_snapshot(dst)
if (
destination_snapshot is not None
and destination_snapshot.digest == source_snapshot.digest
):
unchanged += 1
else:
conflicts.append(dst)
continue
self._install_snapshot(src, dst, source_snapshot)
restored += 1
return SessionRestoreResult(
restored=restored,
unchanged=unchanged,
conflicts=tuple(conflicts),
)
@staticmethod
def safe_key(key: str) -> str:
return safe_filename(key.replace(":", "_"))
@staticmethod
def storage_key(key: str) -> str:
return base64.urlsafe_b64encode(key.encode()).decode().rstrip("=")
@staticmethod
def decode_storage_key(stem: str) -> str | None:
try:
padding = 4 - len(stem) % 4
if padding != 4:
stem += "=" * padding
return base64.urlsafe_b64decode(stem).decode("utf-8")
except _SESSION_DATA_ERRORS:
return None
@classmethod
def session_key_from_path(cls, path: Path) -> str | None:
key = cls.decode_storage_key(path.stem)
if key is None or cls.storage_key(key) != path.stem:
return None
return key
def get_session_path(self, key: str) -> Path:
return self.sessions_dir / f"{self.storage_key(key)}.jsonl"
def get_legacy_lossy_path(self, key: str) -> Path:
return self.sessions_dir / f"{safe_filename(key.replace(':', '_'))}.jsonl"
def get_legacy_session_path(self, key: str) -> Path:
return self.legacy_sessions_dir / f"{self.safe_key(key)}.jsonl"
def load(self, key: str) -> Session | None:
with self._session_files_lock:
return self._load_unlocked(key)
def _load_unlocked(self, key: str) -> Session | None:
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
provider_state: ProviderConversationState | None = None
with open(path, encoding="utf-8") as f:
for line in f:
line = line.strip()
if not line:
continue
raw_data: object = json.loads(line)
data = _json_object(raw_data)
record_type = data.get("_type")
if record_type == "metadata":
metadata_value = cast(object, data.get("metadata", {}))
metadata = (
cast(dict[str, Any], metadata_value)
if isinstance(metadata_value, dict)
else {}
)
created_at_value = cast(object, data.get("created_at"))
updated_at_value = cast(object, data.get("updated_at"))
created_at = (
datetime.fromisoformat(created_at_value)
if isinstance(created_at_value, str) and created_at_value
else None
)
updated_at = (
datetime.fromisoformat(updated_at_value)
if isinstance(updated_at_value, str) and updated_at_value
else None
)
offset = cast(object, data.get("last_consolidated", 0))
last_consolidated = (
offset
if isinstance(offset, int) and not isinstance(offset, bool)
else 0
)
elif record_type == _PROVIDER_STATE_RECORD_TYPE:
provider_state = ProviderConversationState.from_private_record(
data.get("state")
)
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,
provider_state=provider_state,
)
except _SESSION_DATA_ERRORS as e:
logger.warning("Failed to load session {}: {}", key, e)
repaired = self._repair_unlocked(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, *, path: Path | None = None) -> Session | None:
with self._session_files_lock:
return self._repair_unlocked(key, path=path)
def _repair_unlocked(self, key: str, *, path: Path | None = None) -> Session | None:
if path is None:
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
provider_state: ProviderConversationState | None = None
skipped = 0
with open(path, encoding="utf-8") as f:
for line in f:
line = line.strip()
if not line:
continue
try:
raw_data: object = json.loads(line)
except json.JSONDecodeError:
skipped += 1
continue
if not isinstance(raw_data, dict):
skipped += 1
continue
data = cast(dict[str, Any], raw_data)
record_type = data.get("_type")
if record_type == "metadata":
metadata_value = cast(object, data.get("metadata", {}))
metadata = (
cast(dict[str, Any], metadata_value)
if isinstance(metadata_value, dict)
else {}
)
created_at_value = cast(object, data.get("created_at"))
if isinstance(created_at_value, str) and created_at_value:
with suppress(ValueError):
created_at = datetime.fromisoformat(created_at_value)
updated_at_value = cast(object, data.get("updated_at"))
if isinstance(updated_at_value, str) and updated_at_value:
with suppress(ValueError):
updated_at = datetime.fromisoformat(updated_at_value)
offset = cast(object, data.get("last_consolidated", 0))
last_consolidated = (
offset
if isinstance(offset, int) and not isinstance(offset, bool)
else 0
)
elif record_type == _PROVIDER_STATE_RECORD_TYPE:
candidate = ProviderConversationState.from_private_record(
data.get("state")
)
if candidate is None:
skipped += 1
else:
provider_state = candidate
else:
messages.append(data)
if skipped:
logger.warning("Skipped {} corrupt lines in session {}", skipped, key)
if not messages and not metadata and provider_state is None:
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,
provider_state=provider_state,
)
except _SESSION_DATA_ERRORS as e:
logger.warning("Repair failed for session {}: {}", key, e)
return None
@staticmethod
def session_payload(session: Session) -> SessionPayload:
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:
with self._session_files_lock:
self._save_unlocked(session, fsync=fsync)
def _save_unlocked(self, session: Session, *, fsync: bool = False) -> None:
path = self.get_session_path(session.key)
tmp_path = path.with_name(f".{path.name}.{secrets.token_hex(8)}.tmp")
try:
with open(tmp_path, "x", 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")
if session.provider_state is not None:
provider_state_line = {
"_type": _PROVIDER_STATE_RECORD_TYPE,
"state": session.provider_state.to_private_record(),
}
f.write(json.dumps(provider_state_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:
with suppress(PermissionError):
fd = os.open(str(path.parent), os.O_RDONLY)
try:
os.fsync(fd)
except OSError as exc:
if exc.errno != errno.EINVAL:
raise
finally:
os.close(fd)
finally:
tmp_path.unlink(missing_ok=True)
def update_metadata(
self,
key: str,
updates: dict[str, Any],
*,
fsync: bool = False,
) -> bool:
"""Atomically replace only a session file's metadata record."""
with self._session_files_lock:
path = self.get_session_path(key)
if not path.exists():
return False
tmp_path = path.with_name(f".{path.name}.{secrets.token_hex(8)}.tmp")
try:
with open(path, encoding="utf-8") as source:
first_line = source.readline()
data = _json_object(json.loads(first_line))
if data.get("_type") != "metadata":
return False
raw_metadata = cast(object, data.get("metadata", {}))
metadata = (
dict(cast(dict[str, Any], raw_metadata))
if isinstance(raw_metadata, dict)
else {}
)
metadata.update(deepcopy(updates))
data["metadata"] = metadata
with open(tmp_path, "x", encoding="utf-8") as target:
target.write(json.dumps(data, ensure_ascii=False) + "\n")
shutil.copyfileobj(source, target)
if fsync:
target.flush()
os.fsync(target.fileno())
os.replace(tmp_path, path)
if fsync:
self._fsync_directory(path.parent)
return True
except _SESSION_DATA_ERRORS as exc:
logger.warning("Failed to update session metadata {}: {}", key, exc)
return False
finally:
tmp_path.unlink(missing_ok=True)
def delete(self, key: str) -> bool:
with self._session_files_lock:
return self._delete_unlocked(key)
def _delete_unlocked(self, key: str) -> bool:
paths = [
self.get_session_path(key),
self.get_legacy_lossy_path(key),
self.get_legacy_session_path(key),
]
deleted = False
for path in paths:
if not path.exists():
continue
try:
path.unlink()
deleted = True
except OSError as e:
logger.warning("Failed to delete session file {}: {}", path, e)
return deleted
def read(self, key: str) -> SessionPayload | None:
with self._session_files_lock:
return self._read_unlocked(key)
def _read_unlocked(self, key: str) -> SessionPayload | None:
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
raw_data: object = json.loads(line)
data = _json_object(raw_data)
record_type = data.get("_type")
if record_type == "metadata":
metadata_value = cast(object, data.get("metadata", {}))
metadata = (
cast(dict[str, Any], metadata_value)
if isinstance(metadata_value, dict)
else {}
)
created_at_value = cast(object, data.get("created_at"))
updated_at_value = cast(object, data.get("updated_at"))
stored_key_value = cast(object, data.get("key"))
created_at = (
created_at_value if isinstance(created_at_value, str) else None
)
updated_at = (
updated_at_value if isinstance(updated_at_value, str) else None
)
stored_key = (
stored_key_value if isinstance(stored_key_value, str) else None
)
elif record_type == _PROVIDER_STATE_RECORD_TYPE:
continue
else:
messages.append(data)
return {
"key": stored_key or key,
"created_at": created_at,
"updated_at": updated_at,
"metadata": metadata,
"messages": messages,
}
except _SESSION_DATA_ERRORS as e:
logger.warning("Failed to read session {}: {}", key, e)
repaired = self._repair_unlocked(key, path=path)
if repaired is not None:
logger.info("Recovered read-only session view {} from corrupt file", key)
return self.session_payload(repaired)
return None
def read_metadata(self, key: str) -> SessionMetadataPayload | None:
with self._session_files_lock:
return self._read_metadata_unlocked(key)
def _read_metadata_unlocked(self, key: str) -> SessionMetadataPayload | None:
path = self.get_session_path(key)
if not path.exists():
return None
try:
with open(path, encoding="utf-8") as f:
for line in f:
line = line.strip()
if not line:
continue
raw_data: object = json.loads(line)
data = _json_object(raw_data)
if data.get("_type") != "metadata":
return None
metadata_value = cast(object, data.get("metadata", {}))
key_value = cast(object, data.get("key"))
created_at_value = cast(object, data.get("created_at"))
updated_at_value = cast(object, data.get("updated_at"))
return {
"key": key_value if isinstance(key_value, str) and key_value else key,
"created_at": (
created_at_value if isinstance(created_at_value, str) else None
),
"updated_at": (
updated_at_value if isinstance(updated_at_value, str) else None
),
"metadata": (
cast(dict[str, Any], metadata_value)
if isinstance(metadata_value, dict)
else {}
),
}
return None
except _SESSION_DATA_ERRORS as e:
logger.warning("Failed to read session metadata {}: {}", key, e)
repaired = self._repair_unlocked(key, path=path)
if repaired is not None:
logger.info("Recovered read-only session metadata {} from corrupt file", key)
return {
"key": repaired.key,
"created_at": repaired.created_at.isoformat(),
"updated_at": repaired.updated_at.isoformat(),
"metadata": repaired.metadata,
}
return None
def list_sessions(self) -> list[SessionInfo]:
with self._session_files_lock:
return self._list_sessions_unlocked()
def _list_sessions_unlocked(self) -> list[SessionInfo]:
sessions: list[SessionInfo] = []
for path in self.sessions_dir.glob("*.jsonl"):
storage_key = self.session_key_from_path(path)
if storage_key is None:
continue
try:
with open(path, encoding="utf-8") as f:
first_line = f.readline().strip()
if first_line:
raw_data: object = json.loads(first_line)
data = _json_object(raw_data)
if data.get("_type") == "metadata":
key_value = cast(object, data.get("key"))
key = (
key_value
if isinstance(key_value, str) and key_value
else storage_key
)
metadata = cast(object, 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
if _is_provider_state_record_line(line):
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
raw_item: object = json.loads(line)
item = _json_object(raw_item)
if item.get("_type") in {
"metadata",
_PROVIDER_STATE_RECORD_TYPE,
}:
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
fallback_time = datetime.fromtimestamp(path.stat().st_mtime).isoformat()
created_at = cast(object, data.get("created_at"))
updated_at = cast(object, data.get("updated_at"))
sessions.append(
{
"key": key,
"created_at": (
created_at
if isinstance(created_at, str) and created_at
else fallback_time
),
"updated_at": (
updated_at
if isinstance(updated_at, str) and updated_at
else fallback_time
),
"title": title,
"preview": preview,
"path": str(path),
}
)
except FileNotFoundError:
continue
except _SESSION_DATA_ERRORS:
repaired = self._repair_unlocked(storage_key, path=path)
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 item: item["updated_at"], reverse=True)
class SessionManager:
"""Manage session identity, caching, retention, and persistence."""
def __init__(
self,
workspace: Path,
*,
store: SessionStore | None = None,
sessions_root: Path | None = None,
):
self.workspace = workspace
self._jsonl_store = JsonlSessionStore(workspace, sessions_root=sessions_root)
self._store: SessionStore = store if store is not None else self._jsonl_store
self.sessions_dir = self._jsonl_store.sessions_dir
self.legacy_sessions_dir = self._jsonl_store.legacy_sessions_dir
self._cache: OrderedDict[str, Session] = OrderedDict()
# Preserve identity for sessions held by active callers without retaining idle ones.
self._overflow_cache: WeakValueDictionary[str, Session] = WeakValueDictionary()
self._max_cached_sessions = SESSION_CACHE_MAX_SIZE
self._delete_observer: Callable[[str], None] | None = None
def _remember(self, session: Session) -> None:
"""Keep recent sessions strongly cached without duplicating live objects."""
self._overflow_cache.pop(session.key, None)
self._cache[session.key] = session
self._cache.move_to_end(session.key)
while len(self._cache) > self._max_cached_sessions:
key, evicted = self._cache.popitem(last=False)
self._overflow_cache[key] = evicted
def _cached(self, key: str) -> Session | None:
session = self._cache.get(key)
if session is not None:
self._cache.move_to_end(key)
return session
session = self._overflow_cache.get(key)
if session is not None:
self._remember(session)
return session
def get_cached(self, key: str) -> Session | None:
"""Return a cached session without creating or loading one from disk."""
return self._cached(key)
def set_delete_observer(self, observer: Callable[[str], None]) -> None:
"""Observe explicit session deletion for process-local state cleanup."""
self._delete_observer = observer
@staticmethod
def safe_key(key: str) -> str:
"""Public helper used by HTTP handlers to map an arbitrary key to a stable filename stem."""
return JsonlSessionStore.safe_key(key)
@staticmethod
def _storage_key(key: str) -> str:
"""Collision-resistant encoding for internal session storage filenames."""
return JsonlSessionStore.storage_key(key)
@staticmethod
def _decode_storage_key(stem: str) -> str | None:
"""Reverse _storage_key(): decode a base64url (no-padding) stem back to the original key."""
return JsonlSessionStore.decode_storage_key(stem)
@staticmethod
def decode_storage_key(stem: str) -> str | None:
"""Public decoder for components that inspect canonical session filenames."""
return SessionManager._decode_storage_key(stem)
@classmethod
def _session_key_from_path(cls, path: Path) -> str | None:
"""Decode a session key only from a canonical collision-resistant filename."""
return JsonlSessionStore.session_key_from_path(path)
def _get_session_path(self, key: str) -> Path:
"""Get the collision-resistant workspace path for a session."""
return self._jsonl_store.get_session_path(key)
def _get_legacy_lossy_path(self, key: str) -> Path:
"""Previous workspace session path using lossy ':' to '_' replacement."""
return self._jsonl_store.get_legacy_lossy_path(key)
def _get_legacy_session_path(self, key: str) -> Path:
"""Legacy global session path (~/.nanobot/sessions/)."""
return self._jsonl_store.get_legacy_session_path(key)
@contextmanager
def locked_session_files(self) -> Generator[Path, None, None]:
"""Guard exceptional direct access to canonical JSONL files."""
with self._jsonl_store.locked_session_files() as sessions_dir:
yield sessions_dir
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.
"""
session = self._cached(key)
if session is not None:
return session
session = self._load(key)
if session is None:
session = Session(key=key)
self._remember(session)
return session
def get_or_create_transient(
self,
key: str,
*,
disabled_tools: Collection[str] = (),
) -> Session:
"""Return a fresh, non-persistent session without loading history."""
policy = SessionPolicy(
persist=False,
log_content=False,
disabled_tools=frozenset(disabled_tools),
)
session = self.get_cached(key)
if session is None or session.policy != policy:
session = Session(key=key, policy=policy)
self._remember(session)
return session
def _load(self, key: str) -> Session | None:
return self._store.load(key)
def _repair(self, key: str, *, path: Path | None = None) -> Session | None:
"""Attempt to recover a session from a corrupt JSONL file."""
return self._jsonl_store.repair(key, path=path)
def save(self, session: Session, *, fsync: bool = False) -> None:
"""Persist a session and retain it in the cache."""
if not session.policy.persist:
return
self._store.save(session, fsync=fsync)
self._remember(session)
def rename_model_preset(self, old_name: str, new_name: str) -> int:
"""Rename a session-scoped model preset across durable and live sessions."""
if old_name == new_name:
return 0
cached = dict(self._overflow_cache.items())
cached.update(self._cache)
keys = set(cached)
keys.update(item["key"] for item in self._store.list_sessions())
changed: list[Session] = []
try:
for key in sorted(keys):
session = cached.get(key) or self._load(key)
if (
session is None
or session.metadata.get(SESSION_MODEL_PRESET_METADATA_KEY) != old_name
):
continue
session.metadata[SESSION_MODEL_PRESET_METADATA_KEY] = new_name
changed.append(session)
if session.policy.persist:
self.save(session, fsync=True)
else:
self._remember(session)
except BaseException:
for session in reversed(changed):
session.metadata[SESSION_MODEL_PRESET_METADATA_KEY] = old_name
try:
if session.policy.persist:
self.save(session, fsync=True)
else:
self._remember(session)
except Exception:
logger.exception(
"Failed to roll back model preset rename for session {}",
session.key,
)
raise
return len(changed)
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
cached = dict(self._overflow_cache.items())
cached.update(self._cache)
for key, session in cached.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)
self._overflow_cache.pop(key, None)
def delete_session(self, key: str) -> bool:
"""Delete a persisted session and invalidate its cache entry."""
self.invalidate(key)
deleted = self._store.delete(key)
if self._delete_observer is not None:
self._delete_observer(key)
return deleted
def restore_sessions_to_workspace(self) -> SessionRestoreResult:
"""Restore session files to the pre-relocation path for an explicit rollback."""
return self._jsonl_store.restore_to_workspace()
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._cached(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(public_history_message(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:
"""Read a session without populating the cache."""
return cast(dict[str, Any] | None, self._store.read(key))
def read_session_snapshot(self, key: str) -> Session | None:
"""Load a detached session snapshot without populating the runtime cache."""
return self._store.load(key)
def read_session_metadata(self, key: str) -> dict[str, Any] | None:
"""Read session metadata without loading the transcript."""
return cast(dict[str, Any] | None, self._store.read_metadata(key))
def update_session_metadata(
self,
key: str,
updates: dict[str, Any],
*,
fsync: bool = False,
) -> bool:
"""Atomically update metadata without replacing session history."""
updated = self._store.update_metadata(key, updates, fsync=fsync)
if updated and (session := self.get_cached(key)) is not None:
session.metadata.update(deepcopy(updates))
return updated
def list_sessions(self) -> list[dict[str, Any]]:
return cast(list[dict[str, Any]], self._store.list_sessions())