hermes-agent/hermes_cli/session_recovery.py

817 lines
29 KiB
Python

"""Offline, non-destructive recovery for a damaged Hermes session database.
The recovery path deliberately avoids in-place repair:
* the supplied source database is never opened by SQLite;
* the source file and any WAL/SHM/rollback-journal sidecars are copied into a
disposable working directory first;
* canonical rows are copied into a newly initialized current-schema database;
* derived FTS tables and migration bookkeeping are rebuilt, not copied; and
* the recovered database is never installed over the active database.
"""
from __future__ import annotations
import json
import os
import shutil
import sqlite3
import tempfile
from pathlib import Path
from typing import Any, Callable, Optional
from hermes_state import (
FTS_STORAGE_VERSION,
SCHEMA_VERSION,
SessionDB,
_db_opens_cleanly,
)
ProgressCallback = Callable[[dict[str, Any]], None]
_CANONICAL_TABLES = (
"sessions",
"messages",
"session_model_usage",
"compression_locks",
"gateway_routing",
"async_delegations",
)
_TOPIC_TABLES = (
"telegram_dm_topic_mode",
"telegram_dm_topic_bindings",
)
# These values describe derived indexes or the schema that owns an optional
# table. A fresh destination must generate them from its own current schema.
_GENERATED_META_KEYS = frozenset({
"fts_storage_version",
"fts_optimize_available",
"fts_rebuild_high_water",
"fts_rebuild_progress",
"fts_cjk_stale",
"fts_cjk_rebuild_high_water",
"fts_cjk_rebuild_progress",
"telegram_dm_topic_schema_version",
})
_SIDECAR_SUFFIXES = ("", "-wal", "-shm", "-journal")
_MINIMUM_SPACE_HEADROOM = 256 * 1024 * 1024
class SessionRecoveryError(RuntimeError):
"""Base error for offline session recovery."""
class SessionRecoverySafetyError(SessionRecoveryError):
"""Raised before recovery when a path or overwrite guard fails."""
class SessionRecoverySourceError(SessionRecoveryError):
"""Raised when the source cannot provide the required canonical tables."""
def _sidecar_path(db_path: Path, suffix: str) -> Path:
return db_path if not suffix else db_path.with_name(db_path.name + suffix)
def _resolved_output_path(path: Path) -> Path:
"""Resolve a not-yet-created output path without requiring it to exist."""
parent = path.expanduser().parent.resolve(strict=True)
return parent / path.name
def _validate_paths(
source_path: Path,
output_path: Optional[Path] = None,
work_dir: Optional[Path] = None,
) -> tuple[Path, Optional[Path], Path]:
source = source_path.expanduser().resolve(strict=True)
if not source.is_file():
raise SessionRecoverySafetyError(f"Source is not a file: {source}")
output: Optional[Path] = None
if output_path is not None:
output = _resolved_output_path(output_path)
protected = {
_sidecar_path(source, suffix).resolve(strict=False)
for suffix in _SIDECAR_SUFFIXES
}
if output.resolve(strict=False) in protected:
raise SessionRecoverySafetyError(
"The recovery output must not be the source database or one of "
"its journal sidecars."
)
for suffix in _SIDECAR_SUFFIXES:
candidate = _sidecar_path(output, suffix)
if os.path.lexists(candidate):
raise SessionRecoverySafetyError(
f"Refusing to overwrite existing recovery output: {candidate}"
)
work_root = (
work_dir.expanduser().resolve(strict=True)
if work_dir is not None
else (output.parent if output is not None else source.parent)
)
if not work_root.is_dir():
raise SessionRecoverySafetyError(
f"Recovery work directory is not a directory: {work_root}"
)
return source, output, work_root
def _source_fingerprint(source: Path) -> dict[str, dict[str, int]]:
fingerprint: dict[str, dict[str, int]] = {}
for suffix in _SIDECAR_SUFFIXES:
path = _sidecar_path(source, suffix)
if not path.exists():
continue
stat = path.stat()
fingerprint[suffix or "main"] = {
"size": stat.st_size,
"mtime_ns": stat.st_mtime_ns,
}
return fingerprint
def _format_bytes(value: int) -> str:
units = ("B", "KiB", "MiB", "GiB", "TiB")
amount = float(value)
for unit in units:
if amount < 1024 or unit == units[-1]:
return f"{amount:.1f} {unit}"
amount /= 1024
return f"{value} B"
def _same_filesystem(left: Path, right: Path) -> bool:
try:
return os.stat(left).st_dev == os.stat(right).st_dev
except OSError:
# Existing directories were already required by _validate_paths. This
# fallback is defensive for platforms with incomplete st_dev support.
return left.anchor.casefold() == right.anchor.casefold()
def _disk_space_preflight(
source: Path,
work_root: Path,
output_parent: Optional[Path],
) -> dict[str, Any]:
"""Require space for the disposable bundle, output, and safety headroom."""
bundle_bytes = sum(
_sidecar_path(source, suffix).stat().st_size
for suffix in _SIDECAR_SUFFIXES
if _sidecar_path(source, suffix).exists()
)
# The v23 external-content rebuild is normally substantially smaller than
# a legacy database, but using the complete source bundle as the estimate
# avoids betting the user's disk on that expectation.
output_allowance = bundle_bytes if output_parent is not None else 0
headroom = max(
_MINIMUM_SPACE_HEADROOM,
int((bundle_bytes + output_allowance) * 0.05),
)
work_free = int(shutil.disk_usage(work_root).free)
report: dict[str, Any] = {
"source_bundle_bytes": bundle_bytes,
"estimated_output_bytes": output_allowance,
"headroom_bytes": headroom,
"work_dir": str(work_root),
"work_dir_free_bytes": work_free,
}
if output_parent is None or _same_filesystem(work_root, output_parent):
required = bundle_bytes + output_allowance + headroom
report["shared_filesystem"] = True
report["work_dir_required_bytes"] = required
if work_free < required:
raise SessionRecoverySafetyError(
"Not enough free disk space for a safe recovery copy: "
f"{_format_bytes(work_free)} available at {work_root}, "
f"{_format_bytes(required)} required "
f"({_format_bytes(bundle_bytes)} source bundle + "
f"{_format_bytes(output_allowance)} output allowance + "
f"{_format_bytes(headroom)} headroom). Use --work-dir or "
"--output on a filesystem with more free space."
)
return report
output_free = int(shutil.disk_usage(output_parent).free)
work_required = bundle_bytes + headroom
output_required = output_allowance + headroom
report.update({
"shared_filesystem": False,
"work_dir_required_bytes": work_required,
"output_dir": str(output_parent),
"output_dir_free_bytes": output_free,
"output_dir_required_bytes": output_required,
})
shortages: list[str] = []
if work_free < work_required:
shortages.append(
f"{work_root}: {_format_bytes(work_free)} available, "
f"{_format_bytes(work_required)} required"
)
if output_free < output_required:
shortages.append(
f"{output_parent}: {_format_bytes(output_free)} available, "
f"{_format_bytes(output_required)} required"
)
if shortages:
raise SessionRecoverySafetyError(
"Not enough free disk space for safe recovery: "
+ "; ".join(shortages)
+ ". Choose work/output filesystems with more free space."
)
return report
def _copy_source_bundle(source: Path, snapshot_dir: Path) -> tuple[Path, list[str]]:
snapshot_source = snapshot_dir / source.name
copied: list[str] = []
for suffix in _SIDECAR_SUFFIXES:
source_part = _sidecar_path(source, suffix)
if not source_part.exists():
continue
destination_part = _sidecar_path(snapshot_source, suffix)
shutil.copy2(source_part, destination_part)
copied.append(destination_part.name)
return snapshot_source, copied
def _table_columns(conn: sqlite3.Connection, table: str) -> list[str]:
return [str(row[1]) for row in conn.execute(f'PRAGMA table_info("{table}")')]
def _table_inventory(
conn: sqlite3.Connection,
table: str,
) -> dict[str, Any]:
result: dict[str, Any] = {"available": False, "columns": [], "rows": None}
try:
columns = _table_columns(conn, table)
if not columns:
return result
result["available"] = True
result["columns"] = columns
result["rows"] = int(
conn.execute(f'SELECT COUNT(*) FROM "{table}"').fetchone()[0]
)
except sqlite3.DatabaseError as exc:
result["error"] = str(exc)
return result
def _inspect_connection(conn: sqlite3.Connection) -> dict[str, Any]:
conn.execute("PRAGMA writable_schema=ON")
report: dict[str, Any] = {"tables": {}, "errors": [], "warnings": []}
try:
row = conn.execute("PRAGMA journal_mode").fetchone()
report["journal_mode"] = str(row[0]).lower() if row else None
except sqlite3.DatabaseError as exc:
report["journal_mode"] = None
# Journal metadata is useful context but not canonical session data.
# A damaged journal pragma must not block rows that are still readable.
report["warnings"].append(f"journal mode: {exc}")
for table in (*_CANONICAL_TABLES, "state_meta", *_TOPIC_TABLES):
report["tables"][table] = _table_inventory(conn, table)
for required in ("sessions", "messages"):
table_report = report["tables"][required]
if not table_report.get("available") or table_report.get("rows") is None:
report["errors"].append(
f"required table {required} is not completely readable"
)
report["recoverable"] = not report["errors"]
return report
def _snapshot_and_inspect(
source: Path,
work_root: Path,
) -> tuple[tempfile.TemporaryDirectory[str], Path, dict[str, Any]]:
before = _source_fingerprint(source)
temp_dir = tempfile.TemporaryDirectory(
prefix="hermes-session-recovery-",
dir=str(work_root),
)
snapshot_dir = Path(temp_dir.name)
try:
snapshot_source, copied = _copy_source_bundle(source, snapshot_dir)
after = _source_fingerprint(source)
if before != after:
raise SessionRecoverySafetyError(
"The source database bundle changed while it was being copied. "
"Stop every Hermes process using this profile and retry."
)
conn = sqlite3.connect(
str(snapshot_source),
isolation_level=None,
timeout=1.0,
)
try:
inspection = _inspect_connection(conn)
finally:
conn.close()
inspection["source_bundle"] = copied
inspection["source_fingerprint"] = before
return temp_dir, snapshot_source, inspection
except BaseException:
temp_dir.cleanup()
raise
def inspect_session_database(
source_path: Path,
*,
work_dir: Optional[Path] = None,
) -> dict[str, Any]:
"""Inspect canonical table readability without opening the source itself."""
source, _, work_root = _validate_paths(source_path, work_dir=work_dir)
disk_space = _disk_space_preflight(source, work_root, None)
temp_dir, _, inspection = _snapshot_and_inspect(source, work_root)
try:
return {
"operation": "inspect",
"source": str(source),
"disk_space": disk_space,
**inspection,
"source_unchanged": _source_fingerprint(source)
== inspection["source_fingerprint"],
}
finally:
temp_dir.cleanup()
def _copy_table(
source: sqlite3.Connection,
destination: sqlite3.Connection,
table: str,
*,
chunk_size: int,
progress_cb: Optional[ProgressCallback],
source_rows: Optional[int],
) -> dict[str, Any]:
source_columns = _table_columns(source, table)
destination_columns = _table_columns(destination, table)
columns = [column for column in destination_columns if column in source_columns]
result: dict[str, Any] = {
"source_rows": source_rows,
"copied_rows": 0,
"columns": columns,
}
if not source_columns:
result["status"] = "missing"
return result
if not columns:
result["status"] = "failed"
result["error"] = "source and destination have no compatible columns"
return result
quoted = ", ".join(f'"{column}"' for column in columns)
placeholders = ", ".join("?" for _ in columns)
select_sql = f'SELECT {quoted} FROM "{table}"'
insert_prefix = "INSERT OR REPLACE" if table == "state_meta" else "INSERT"
insert_sql = f'{insert_prefix} INTO "{table}" ({quoted}) VALUES ({placeholders})'
try:
cursor = source.execute(select_sql)
while True:
rows = cursor.fetchmany(chunk_size)
if not rows:
break
destination.execute("BEGIN IMMEDIATE")
try:
destination.executemany(insert_sql, rows)
destination.execute("COMMIT")
except BaseException:
destination.execute("ROLLBACK")
raise
result["copied_rows"] += len(rows)
if progress_cb is not None:
progress_cb({
"table": table,
"copied_rows": result["copied_rows"],
"source_rows": source_rows,
})
except sqlite3.DatabaseError as exc:
result["status"] = "partial" if result["copied_rows"] else "failed"
result["error"] = str(exc)
return result
result["status"] = (
"complete"
if source_rows is None or result["copied_rows"] == source_rows
else "partial"
)
if result["status"] == "partial":
result["error"] = (
f"copied {result['copied_rows']} of {source_rows} readable rows"
)
return result
def _copy_state_meta(
source: sqlite3.Connection,
destination: sqlite3.Connection,
*,
chunk_size: int,
progress_cb: Optional[ProgressCallback],
source_rows: Optional[int],
) -> dict[str, Any]:
source_columns = _table_columns(source, "state_meta")
destination_columns = _table_columns(destination, "state_meta")
result: dict[str, Any] = {
"source_meta_rows": source_rows,
"copied_rows": 0,
"columns": ["key", "value"],
"excluded_keys": sorted(_GENERATED_META_KEYS),
}
if not {"key", "value"}.issubset(source_columns):
result["status"] = "missing"
return result
if not {"key", "value"}.issubset(destination_columns):
result["status"] = "failed"
result["error"] = "destination state_meta schema is incomplete"
return result
placeholders = ", ".join("?" for _ in _GENERATED_META_KEYS)
filtered_source_rows: Optional[int] = None
try:
filtered_source_rows = int(
source.execute(
f"SELECT COUNT(*) FROM state_meta WHERE key NOT IN ({placeholders})",
tuple(_GENERATED_META_KEYS),
).fetchone()[0]
)
except sqlite3.DatabaseError:
# The copy loop below will return the concrete read error.
pass
try:
cursor = source.execute(
f"SELECT key, value FROM state_meta WHERE key NOT IN ({placeholders})",
tuple(_GENERATED_META_KEYS),
)
while True:
rows = cursor.fetchmany(chunk_size)
if not rows:
break
destination.execute("BEGIN IMMEDIATE")
try:
destination.executemany(
"INSERT OR REPLACE INTO state_meta(key, value) VALUES (?, ?)",
rows,
)
destination.execute("COMMIT")
except BaseException:
destination.execute("ROLLBACK")
raise
result["copied_rows"] += len(rows)
if progress_cb is not None:
progress_cb({
"table": "state_meta",
"copied_rows": result["copied_rows"],
"source_rows": filtered_source_rows,
})
except sqlite3.DatabaseError as exc:
result["status"] = "partial" if result["copied_rows"] else "failed"
result["error"] = str(exc)
return result
result["status"] = (
"complete"
if filtered_source_rows is None or result["copied_rows"] == filtered_source_rows
else "partial"
)
if result["status"] == "partial":
result["error"] = (
f"copied {result['copied_rows']} of {filtered_source_rows} readable rows"
)
return result
def _verify_recovered_database(
output: Path,
*,
expected_counts: dict[str, Optional[int]],
copy_report: dict[str, dict[str, Any]],
) -> dict[str, Any]:
verification: dict[str, Any] = {"errors": []}
open_error = _db_opens_cleanly(output)
verification["opens_cleanly"] = open_error is None
if open_error is not None:
verification["errors"].append(f"database health probe: {open_error}")
conn = sqlite3.connect(str(output), isolation_level=None)
try:
integrity_rows = [
str(row[0]) for row in conn.execute("PRAGMA integrity_check").fetchall()
]
verification["integrity_check"] = integrity_rows
if integrity_rows != ["ok"]:
verification["errors"].append(
"PRAGMA integrity_check did not return exactly 'ok'"
)
foreign_key_rows = [
list(row) for row in conn.execute("PRAGMA foreign_key_check").fetchall()
]
verification["foreign_key_check"] = foreign_key_rows
if foreign_key_rows:
verification["errors"].append("foreign key violations remain")
journal_row = conn.execute("PRAGMA journal_mode").fetchone()
verification["journal_mode"] = (
str(journal_row[0]).lower() if journal_row else None
)
schema_row = conn.execute(
"SELECT version FROM schema_version LIMIT 1"
).fetchone()
verification["schema_version"] = int(schema_row[0]) if schema_row else None
if verification["schema_version"] != SCHEMA_VERSION:
verification["errors"].append(
f"schema version is {verification['schema_version']}, "
f"expected {SCHEMA_VERSION}"
)
meta = {
str(row[0]): row[1]
for row in conn.execute(
"SELECT key, value FROM state_meta WHERE key LIKE 'fts_%'"
).fetchall()
}
verification["fts_meta"] = meta
if meta.get("fts_storage_version") != str(FTS_STORAGE_VERSION):
verification["errors"].append(
"fresh FTS storage version was not established"
)
pending_keys = sorted(
key
for key in (
"fts_optimize_available",
"fts_rebuild_high_water",
"fts_rebuild_progress",
"fts_cjk_stale",
"fts_cjk_rebuild_high_water",
"fts_cjk_rebuild_progress",
)
if key in meta
)
verification["pending_fts_keys"] = pending_keys
if pending_keys:
verification["errors"].append(
"derived FTS transition markers remain in the recovered database"
)
counts: dict[str, int] = {}
for table in (*_CANONICAL_TABLES, "state_meta", *_TOPIC_TABLES):
columns = _table_columns(conn, table)
if columns:
counts[table] = int(
conn.execute(f'SELECT COUNT(*) FROM "{table}"').fetchone()[0]
)
verification["table_counts"] = counts
for table in ("sessions", "messages"):
expected = expected_counts.get(table)
if expected is not None and counts.get(table) != expected:
verification["errors"].append(
f"{table} count is {counts.get(table)}, expected {expected}"
)
for table, table_report in copy_report.items():
if table_report.get("status") in {"failed", "partial"}:
verification["errors"].append(
f"{table} copy status is {table_report.get('status')}"
)
fts_checks: dict[str, str] = {}
for table in ("messages_fts", "messages_fts_trigram", "messages_fts_cjk"):
if not _table_columns(conn, table):
continue
try:
conn.execute(
f'INSERT INTO "{table}" ("{table}") VALUES (\'integrity-check\')'
)
conn.execute(
f'SELECT 1 FROM "{table}" WHERE "{table}" MATCH \'""\' LIMIT 1'
).fetchone()
fts_checks[table] = "ok"
except sqlite3.DatabaseError as exc:
fts_checks[table] = str(exc)
verification["errors"].append(f"{table} integrity check failed: {exc}")
verification["fts_checks"] = fts_checks
except sqlite3.DatabaseError as exc:
verification["errors"].append(f"verification query failed: {exc}")
finally:
conn.close()
verification["complete"] = not verification["errors"]
return verification
def _finalize_derived_metadata(destination: sqlite3.Connection) -> dict[str, Any]:
"""Stamp only metadata that the newly created destination actually owns."""
fts_tables = {
str(row[0])
for row in destination.execute(
"SELECT name FROM sqlite_master "
"WHERE type='table' AND name IN ('messages_fts', 'messages_fts_trigram')"
).fetchall()
}
result: dict[str, Any] = {"fts_tables": sorted(fts_tables), "finalized": False}
if fts_tables != {"messages_fts", "messages_fts_trigram"}:
result["error"] = "fresh destination is missing required FTS tables"
return result
fts_keys = tuple(key for key in _GENERATED_META_KEYS if key.startswith("fts_"))
placeholders = ", ".join("?" for _ in fts_keys)
destination.execute("BEGIN IMMEDIATE")
try:
destination.execute(
f"DELETE FROM state_meta WHERE key IN ({placeholders})",
fts_keys,
)
destination.execute(
"INSERT INTO state_meta(key, value) VALUES (?, ?) "
"ON CONFLICT(key) DO UPDATE SET value = excluded.value",
("fts_storage_version", str(FTS_STORAGE_VERSION)),
)
destination.execute("COMMIT")
except BaseException:
destination.execute("ROLLBACK")
raise
result["finalized"] = True
return result
def recover_session_database(
source_path: Path,
output_path: Path,
*,
work_dir: Optional[Path] = None,
chunk_size: int = 1_000,
progress_cb: Optional[ProgressCallback] = None,
) -> dict[str, Any]:
"""Recover canonical rows into a separate current-schema database.
The source path and its sidecars are copied before SQLite opens anything.
``output_path`` must not exist and is never swapped into place.
"""
if chunk_size <= 0:
raise SessionRecoverySafetyError("chunk_size must be greater than zero")
source, output, work_root = _validate_paths(
source_path,
output_path=output_path,
work_dir=work_dir,
)
assert output is not None
disk_space = _disk_space_preflight(source, work_root, output.parent)
temp_dir, snapshot_source, inspection = _snapshot_and_inspect(source, work_root)
try:
if not inspection.get("recoverable"):
reasons = "; ".join(inspection.get("errors") or ["unknown source error"])
raise SessionRecoverySourceError(
f"Required canonical tables are not readable: {reasons}"
)
source_conn = sqlite3.connect(
str(snapshot_source),
isolation_level=None,
timeout=1.0,
)
source_conn.execute("PRAGMA writable_schema=ON")
destination_db: Optional[SessionDB] = None
destination_conn: Optional[sqlite3.Connection] = None
try:
has_topic_tables = any(
inspection["tables"][table].get("available") for table in _TOPIC_TABLES
)
destination_db = SessionDB(db_path=output)
if has_topic_tables:
destination_db.apply_telegram_topic_migration()
destination_db.close()
destination_db = None
destination_conn = sqlite3.connect(
str(output),
isolation_level=None,
timeout=1.0,
)
destination_conn.execute("PRAGMA foreign_keys=OFF")
copy_report: dict[str, dict[str, Any]] = {}
for table in _CANONICAL_TABLES:
table_inspection = inspection["tables"][table]
copy_report[table] = _copy_table(
source_conn,
destination_conn,
table,
chunk_size=chunk_size,
progress_cb=progress_cb,
source_rows=table_inspection.get("rows"),
)
state_meta_inspection = inspection["tables"]["state_meta"]
if state_meta_inspection.get("available"):
copy_report["state_meta"] = _copy_state_meta(
source_conn,
destination_conn,
chunk_size=chunk_size,
progress_cb=progress_cb,
source_rows=state_meta_inspection.get("rows"),
)
else:
copy_report["state_meta"] = {"status": "missing", "copied_rows": 0}
for table in _TOPIC_TABLES:
table_inspection = inspection["tables"][table]
if not table_inspection.get("available"):
copy_report[table] = {
"status": "missing",
"copied_rows": 0,
}
continue
copy_report[table] = _copy_table(
source_conn,
destination_conn,
table,
chunk_size=chunk_size,
progress_cb=progress_cb,
source_rows=table_inspection.get("rows"),
)
derived_metadata = _finalize_derived_metadata(destination_conn)
finally:
source_conn.close()
if destination_conn is not None:
destination_conn.close()
if destination_db is not None:
destination_db.close()
verification = _verify_recovered_database(
output,
expected_counts={
table: inspection["tables"][table].get("rows")
for table in _CANONICAL_TABLES
},
copy_report=copy_report,
)
source_unchanged = (
_source_fingerprint(source) == inspection["source_fingerprint"]
)
if not source_unchanged:
verification["errors"].append(
"the source database bundle changed during recovery"
)
verification["complete"] = False
return {
"operation": "recover",
"source": str(source),
"output": str(output),
"source_bundle": inspection["source_bundle"],
"source_fingerprint": inspection["source_fingerprint"],
"source_unchanged": source_unchanged,
"disk_space": disk_space,
"inspection": {
"journal_mode": inspection.get("journal_mode"),
"tables": inspection["tables"],
"errors": inspection["errors"],
"warnings": inspection["warnings"],
},
"copy": copy_report,
"derived_metadata": derived_metadata,
"verification": verification,
"complete": bool(verification.get("complete") and source_unchanged),
"installed": False,
}
finally:
temp_dir.cleanup()
def write_recovery_report(path: Path, report: dict[str, Any]) -> Path:
"""Write a JSON report without overwriting an existing file."""
destination = _resolved_output_path(path)
with destination.open("x", encoding="utf-8") as handle:
json.dump(report, handle, indent=2, sort_keys=True)
handle.write("\n")
return destination