- User-turn predicates reuse _is_context_summary_message (single detection path).
- _serialize_for_summary hoists the shared head/tail truncation.
- __init__ initialises per-session state via _reset_session_compaction_state.
- Timeout cooldown ladder (60/300/900s) is one module helper used by both
record_timeout_failure and the summary failure path; module-level so a real
method bound onto a stub compressor still exercises it.
Hunk-by-hunk audit of the compaction commit found 14 dropped WHY/invariant
statements (route-pin scope, persistence-marker sweep failure mode, stamp
asymmetry, reasoning-replay boundary, size-class parity with preflight,
small-context floor cap, tail-anchor ordering rules, defer-baseline backstops).
Each is restored as a compact 1-3 line comment at its anchor.
- Nine near-identical durable-row getters/setters -> _durable_read/_durable_write
(also used for parent-lineage lookups in on_session_start).
- on_session_reset/on_session_end share _reset_session_compaction_state.
- _find_tail_cut_by_tokens: the two backward token walks become one _walk_back
(randomized parity vs. the previous version: 1500 transcripts identical).
- _strip_context_summary_handoff_message: one _unwrapped() helper for all paths
(parity: 1296 content shapes identical).
- ruff SIM102/SIM108/SIM114 collapses.
The 15 rolling micro-compaction methods (cursor resolution, exchange
serialization, one-exchange summarization, defrag, splice, DB sync, telemetry)
move verbatim into MicroCompactionMixin, mixed into ContextCompressor
(MRO: ContextCompressor -> MicroCompactionMixin -> ContextEngine). Origin
constants and call_llm are imported lazily so tests patching
agent.context_compressor.X still apply; logger name parity is kept.
- _generate_summary(): prompt assembly lifted into _build_summary_prompt, the
exception path into _on_summary_failure; the two identical main-model retry
branches are merged behind a reason lookup.
- compress(): terminal summary-failure abort classes are table-driven via
_TERMINAL_SUMMARY_FAILURES (same precedence, log text and telemetry class;
flag reads stay lazy so __new__-built test doubles keep working).
_summarize_tool_result_unguarded routed on tool_name through ~20 if-branches; each
branch is now a small _sum_* function in _TOOL_RESULT_SUMMARIZERS with the generic
fallback unchanged. Output verified byte-identical against the previous version
across 1288 name/args/content combinations.
- delete _cached_prompt_reflects_builtin_memory + _builtin_memory_prompt_snapshot
(zero callers since the commit site moved to byte-equality; the only test
reference asserts their ABSENCE from the commit window)
- delete CompressionExecutorSaturatedError (never raised or caught anywhere)
- _compress_context_via_codex_app_server: three near-identical skip branches
collapse into one skip_reason + single log line (same message text)
Hand-reviewed compaction: non-obvious rules, ordering constraints, invariants,
failure modes and WHY are kept in 1-3 line form; narrative, issue-number history
and code restatements are dropped.
_candidate_rejected(): compressor abort, no-progress, empty transcript and
superseded-attempt checks in their original order; caller handles the
shared release + unchanged-return. Aborted-branch try/finally collapsed
(the finally only released the lease, which the caller now does).
- _fold_todo_snapshot(): stale-snapshot strip + live todo fold into the tail
- _rebuild_system_prompt_at_boundary(): tool refresh + byte-equal keep-prompt
- _salvage_or_refuse_grown_transcript(): commit-site anti-growth guard
- _publish_rotated_compaction(): parent flush, child publish, id re-point,
goal/heartbeat/loop/title carry-over
- old_session_id is now an explicit Optional local instead of locals().get()
compress_context 1181 -> 794 lines; bodies moved verbatim.
Teknium