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fix(compression): retire completed todo snapshots safely

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This commit is contained in:
Screaming Sun
2026-08-19 01:02:16 +02:00
committed by Teknium
parent 1762d3788c
commit 989e48cc85
2 changed files with 364 additions and 6 deletions
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agent/conversation_compression.py
+76 -5
View File
@@ -2450,6 +2450,29 @@ def _strip_stale_todo_snapshot(content: Any) -> Any:
return content
def _todo_snapshot_is_only_content(content: Any, stripped: Any) -> bool:
"""Return whether stripping the snapshot leaves no structured content.
Text snapshots are appended at the end of a string. Structured snapshots
occupy their own text part, so only an empty remainder proves that the row
was synthetic scaffolding alone. Text extraction is deliberately not used:
image, audio, and future non-text parts are content that must survive.
"""
if isinstance(content, str) and isinstance(stripped, str):
return not stripped.strip()
if isinstance(content, list) and isinstance(stripped, list):
return not stripped
return False
def _replace_message_content(message: dict, content: Any) -> None:
"""Rewrite message content without allowing an old API sidecar to replay."""
from agent.turn_context import drop_stale_api_content
message["content"] = content
drop_stale_api_content(message)
# Retention-parity notice (#84718): compaction re-injects the todo list
# verbatim while skill instructions are pruned to [SKILL_PRUNED: ...] markers,
# so the imperative crosses the boundary without the policy that governed it.
@@ -2521,10 +2544,10 @@ def _merge_anchor_into_user_message(target: dict, anchor: dict) -> None:
if isinstance(target_content, list)
else [{"type": "text", "text": str(target_content or "")}]
)
target["content"] = anchor_parts + target_parts
_replace_message_content(target, anchor_parts + target_parts)
else:
merged = f"{anchor_content or ''}\n\n{target_content or ''}".strip()
target["content"] = merged
_replace_message_content(target, merged)
for flag in _SYNTHETIC_USER_FLAGS:
target.pop(flag, None)
@@ -3824,6 +3847,53 @@ def compress_context(
)
todo_snapshot = agent._todo_store.format_for_injection()
# A non-empty store is authoritative even when every item is already
# completed/cancelled and format_for_injection() therefore returns an
# empty string. In that case remove the previous snapshot so completed
# work is not resurrected. A truly empty store is different: fresh
# gateway agents may be unable to rehydrate todo tool results after a
# prior compaction, so the retained snapshot is the only surviving
# record of pending work and must stay in place.
_todo_has_items = getattr(agent._todo_store, "has_items", None)
try:
_todo_store_is_authoritative = bool(
_todo_has_items()
) if callable(_todo_has_items) else False
except Exception:
# A plugin/test double may implement only format_for_injection().
# Unknown authority must preserve pending snapshot state rather than
# risk deleting it during compression.
_todo_store_is_authoritative = False
if _todo_store_is_authoritative:
for _todo_idx in range(len(compressed) - 1, -1, -1):
_todo_message = compressed[_todo_idx]
if not isinstance(_todo_message, dict) or _todo_message.get("role") != "user":
continue
_todo_content = _todo_message.get("content")
_todo_stripped = _strip_stale_todo_snapshot(_todo_content)
if _todo_stripped == _todo_content:
continue
if (
_todo_message.get("_todo_snapshot_synthetic")
and _todo_snapshot_is_only_content(
_todo_content, _todo_stripped
)
):
compressed.pop(_todo_idx)
if _todo_idx < len(compressed):
# A standalone snapshot can move away from the tail
# after later turns arrive. Deleting it may expose two
# assistant rows; use the normal replay repair so their
# content/tool-call metadata is preserved consistently.
agent._repair_message_sequence(compressed)
else:
_replace_message_content(_todo_message, _todo_stripped)
# The row is no longer todo-only scaffolding. Other
# synthetic flags, if any, remain authoritative and
# _is_real_user_message() recomputes provenance from the
# surviving content plus those flags.
_todo_message.pop("_todo_snapshot_synthetic", None)
break
if todo_snapshot:
# Retention parity (#84718): the snapshot below re-injects the
# imperative verbatim. If this same boundary pruned skill bodies
@@ -3865,8 +3935,9 @@ def compress_context(
if isinstance(_stripped, str) and _stripped
else todo_snapshot
)
_tail["content"] = _append_text_to_content(
_stripped, _snapshot_text
_replace_message_content(
_tail,
_append_text_to_content(_stripped, _snapshot_text),
)
merged = True
elif _stripped != _tail.get("content") and not _message_text(
@@ -3874,7 +3945,7 @@ def compress_context(
).strip():
# The tail was nothing but an earlier snapshot row —
# refresh it in place instead of stacking a duplicate.
_tail["content"] = todo_snapshot
_replace_message_content(_tail, todo_snapshot)
_tail["_todo_snapshot_synthetic"] = True
merged = True
if not merged:
tests/agent/test_compression_rotation_state.py
+288 -1
View File
@@ -1566,7 +1566,11 @@ class TestTodoSnapshotScaffoldingTails:
agent = self._agent_with_todo(
db,
"PARENT_TODO_RESTRIP",
{"role": "user", "content": previously_merged},
{
"role": "user",
"content": previously_merged,
"api_content": "stale wire copy containing the old task",
},
)
compressed, _ = agent._compress_context(
@@ -1579,6 +1583,7 @@ class TestTodoSnapshotScaffoldingTails:
assert "task A" in tail["content"]
assert "old finished task" not in tail["content"]
assert tail["content"].count(TODO_INJECTION_HEADER) == 1
assert "api_content" not in tail
assert not any(
previous.get("role") == current.get("role") == "user"
for previous, current in zip(compressed, compressed[1:])
@@ -1620,6 +1625,288 @@ class TestTodoSnapshotScaffoldingTails:
for message in compressed
)
def test_empty_todo_store_removes_previous_compaction_snapshot(
self, tmp_path: Path
):
"""Completed items make the store authoritative and clear old work."""
from tools.todo_tool import TODO_INJECTION_HEADER
db = SessionDB(db_path=tmp_path / "state.db")
session_id = "PARENT_TODO_CLEARED"
db.create_session(session_id, source="cli")
agent = _build_agent_with_db(db, session_id, platform="cli")
stale_task = "- [ ] stale-task. This task was already cleared"
agent.context_compressor.compress.return_value = [
{"role": "user", "content": "[CONTEXT COMPACTION] summary"},
{"role": "assistant", "content": "acknowledged"},
{
"role": "user",
"content": (
"Keep this user context.\n\n"
f"{TODO_INJECTION_HEADER}\n{stale_task}"
),
"api_content": "stale wire copy containing the old snapshot",
},
]
agent._todo_store.write(
[{"id": "done", "content": "done thing", "status": "completed"}]
)
compressed, _ = agent._compress_context(
_msgs(), "sys", approx_tokens=120_000
)
combined = "\n".join(str(m.get("content") or "") for m in compressed)
assert "Keep this user context." in combined
assert TODO_INJECTION_HEADER not in combined
assert stale_task not in combined
retained = next(
message
for message in compressed
if "Keep this user context." in str(message.get("content") or "")
)
assert "api_content" not in retained
def test_cancelled_only_store_is_authoritative(self, tmp_path: Path):
"""Cancelled work retires the old snapshot just like completed work."""
from tools.todo_tool import TODO_INJECTION_HEADER
db = SessionDB(db_path=tmp_path / "state.db")
session_id = "PARENT_TODO_CANCELLED"
db.create_session(session_id, source="cli")
agent = _build_agent_with_db(db, session_id, platform="cli")
agent.context_compressor.compress.return_value = [
{"role": "user", "content": "Keep the request"},
{"role": "assistant", "content": "acknowledged"},
{
"role": "user",
"content": f"{TODO_INJECTION_HEADER}\n- [ ] obsolete task",
"_todo_snapshot_synthetic": True,
},
]
agent._todo_store.write(
[{"id": "nope", "content": "obsolete task", "status": "cancelled"}]
)
compressed, _ = agent._compress_context(
_msgs(), "sys", approx_tokens=120_000
)
assert [message.get("role") for message in compressed] == [
"user",
"assistant",
]
assert all(
TODO_INJECTION_HEADER not in str(message.get("content") or "")
for message in compressed
)
def test_structured_snapshot_only_tail_is_removed(self, tmp_path: Path):
"""A flagged list row is removable only when no other part remains."""
from tools.todo_tool import TODO_INJECTION_HEADER
db = SessionDB(db_path=tmp_path / "state.db")
session_id = "PARENT_TODO_STRUCTURED_ONLY"
db.create_session(session_id, source="cli")
agent = _build_agent_with_db(db, session_id, platform="cli")
agent.context_compressor.compress.return_value = [
{"role": "user", "content": "Keep the request"},
{"role": "assistant", "content": "acknowledged"},
{
"role": "user",
"content": [
{
"type": "text",
"text": f"{TODO_INJECTION_HEADER}\n- [ ] stale task",
}
],
"_todo_snapshot_synthetic": True,
},
]
agent._todo_store.write(
[{"id": "done", "content": "stale task", "status": "completed"}]
)
compressed, _ = agent._compress_context(
_msgs(), "sys", approx_tokens=120_000
)
assert [message.get("role") for message in compressed] == [
"user",
"assistant",
]
def test_non_tail_snapshot_deletion_repairs_assistant_alternation(
self, tmp_path: Path
):
from tools.todo_tool import TODO_INJECTION_HEADER
db = SessionDB(db_path=tmp_path / "state.db")
session_id = "PARENT_TODO_MIDDLE"
db.create_session(session_id, source="cli")
agent = _build_agent_with_db(db, session_id, platform="cli")
agent.context_compressor.compress.return_value = [
{"role": "user", "content": "Keep the request"},
{
"role": "assistant",
"content": "before snapshot",
"api_content": "stale assistant wire copy",
},
{
"role": "user",
"content": f"{TODO_INJECTION_HEADER}\n- [ ] stale task",
"_todo_snapshot_synthetic": True,
},
{"role": "assistant", "content": "after snapshot"},
{"role": "user", "content": "new request"},
]
agent._todo_store.write(
[{"id": "done", "content": "stale task", "status": "completed"}]
)
compressed, _ = agent._compress_context(
_msgs(), "sys", approx_tokens=120_000
)
assert [message.get("role") for message in compressed] == [
"user",
"assistant",
"user",
]
repaired = compressed[1]
assert "before snapshot" in repaired["content"]
assert "after snapshot" in repaired["content"]
assert "api_content" not in repaired
assert not any(
previous.get("role") == current.get("role")
for previous, current in zip(compressed, compressed[1:])
)
def test_multimodal_content_survives_and_synthetic_provenance_clears(
self, tmp_path: Path
):
from tools.todo_tool import TODO_INJECTION_HEADER
db = SessionDB(db_path=tmp_path / "state.db")
session_id = "PARENT_TODO_MULTIMODAL_RETIRE"
db.create_session(session_id, source="cli")
agent = _build_agent_with_db(db, session_id, platform="cli")
surviving_parts = [
{"type": "text", "text": "Keep this caption"},
{
"type": "image_url",
"image_url": {"url": "https://example.com/context.png"},
},
{"type": "input_audio", "input_audio": {"data": "audio-data"}},
]
agent.context_compressor.compress.return_value = [
{"role": "user", "content": "summary"},
{"role": "assistant", "content": "acknowledged"},
{
"role": "user",
"content": surviving_parts
+ [
{
"type": "text",
"text": f"{TODO_INJECTION_HEADER}\n- [ ] stale task",
}
],
"api_content": "stale wire copy containing the snapshot",
"_todo_snapshot_synthetic": True,
"unrelated_metadata": "keep-me",
},
]
agent._todo_store.write(
[{"id": "done", "content": "stale task", "status": "completed"}]
)
input_msgs = [
{
"role": "user" if index % 2 == 0 else "assistant",
"content": f"message {index} " + "x" * 1000,
}
for index in range(40)
]
compressed, _ = agent._compress_context(
input_msgs, "sys", approx_tokens=120_000
)
retained = next(
message for message in compressed if isinstance(message.get("content"), list)
)
assert retained["content"] == surviving_parts
assert retained["unrelated_metadata"] == "keep-me"
assert "api_content" not in retained
assert "_todo_snapshot_synthetic" not in retained
@pytest.mark.parametrize("authority_mode", ["missing", "raises"])
def test_unknown_store_authority_preserves_snapshot(
self, tmp_path: Path, authority_mode: str
):
"""Legacy or broken stores fail conservative, never erasing pending work."""
from tools.todo_tool import TODO_INJECTION_HEADER
db = SessionDB(db_path=tmp_path / "state.db")
session_id = f"PARENT_TODO_COMPAT_{authority_mode.upper()}"
db.create_session(session_id, source="telegram")
agent = _build_agent_with_db(db, session_id, platform="telegram")
pending_task = "- [ ] pending-task. Preserve conservatively"
agent.context_compressor.compress.return_value = [
{"role": "user", "content": "Keep the request"},
{"role": "assistant", "content": "acknowledged"},
{
"role": "user",
"content": f"{TODO_INJECTION_HEADER}\n{pending_task}",
"_todo_snapshot_synthetic": True,
},
]
class LegacyStore:
def format_for_injection(self):
return None
store = LegacyStore()
if authority_mode == "raises":
store.has_items = MagicMock(side_effect=RuntimeError("store unavailable"))
agent._todo_store = store
compressed, _ = agent._compress_context(
_msgs(), "sys", approx_tokens=120_000
)
combined = "\n".join(str(message.get("content") or "") for message in compressed)
assert TODO_INJECTION_HEADER in combined
assert pending_task in combined
def test_unhydrated_empty_todo_store_preserves_pending_snapshot(
self, tmp_path: Path
):
"""A fresh empty store must not erase pending work retained by compression."""
from tools.todo_tool import TODO_INJECTION_HEADER
db = SessionDB(db_path=tmp_path / "state.db")
session_id = "PARENT_TODO_UNHYDRATED"
db.create_session(session_id, source="telegram")
agent = _build_agent_with_db(db, session_id, platform="telegram")
pending_task = "- [ ] pending-task. Continue after the next compaction"
getattr(agent, "context_compressor").compress.return_value = [
{"role": "user", "content": "[CONTEXT COMPACTION] summary"},
{"role": "assistant", "content": "acknowledged"},
{
"role": "user",
"content": f"{TODO_INJECTION_HEADER}\n{pending_task}",
"_todo_snapshot_synthetic": True,
},
]
compressed, _ = agent._compress_context(
_msgs(), "sys", approx_tokens=120_000
)
combined = "\n".join(str(m.get("content") or "") for m in compressed)
assert TODO_INJECTION_HEADER in combined
assert pending_task in combined
class TestArchivedParentActivityLabelsCleared:
def test_parent_labels_cleared_after_rotation_child_lineage_intact(