Context compaction controller

Monitors token usage and dispatches the appropriate compaction level. Includes a circuit breaker that silences compaction after 3 consecutive failures to prevent infinite compaction loops.

Methods

Public methods

• CompactionController$maybe_compact()

• CompactionController$compact_now()

• CompactionController$handle_ptl_error()

• CompactionController$reset_failures()

• CompactionController$failure_count()

• CompactionController$clone()

---

CompactionController$maybe_compact()

Check token usage and compact if needed.

Usage

CompactionController$maybe_compact(
  chat,
  model_limit = 200000L,
  compact_model = .HAIKU_MODEL
)

Arguments

chat

An ellmer::Chat object.

model_limit

Integer. Model context window token limit.

compact_model

Character. Model for compaction tasks (haiku).

Returns

Invisibly NULL.

---

CompactionController$compact_now()

Run the two-level compaction now (snip -> session-memory -> full 9-section), guarded by the circuit breaker. Unlike maybe_compact() this skips the token-threshold check, so callers that have already decided to compact (e.g. mid-loop) can reuse the exact same Claude Code-aligned flow.

Usage

CompactionController$compact_now(chat, compact_model = .HAIKU_MODEL)

Arguments

chat

An ellmer::Chat object.

compact_model

Character. Model for compaction tasks (haiku).

Returns

Invisibly TRUE on success, FALSE if skipped or failed.

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CompactionController$handle_ptl_error()

Handle a prompt-too-long (PTL) error by dropping turns.

Usage

CompactionController$handle_ptl_error(chat, error = NULL)

Arguments

chat

An ellmer::Chat object.

error

An error condition or message string (parsed for a real context limit when present).

---

CompactionController$reset_failures()

Reset the failure counter (e.g. after a successful turn).

Usage

CompactionController$reset_failures()

---

CompactionController$failure_count()

Return current failure count.

Usage

CompactionController$failure_count()

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CompactionController$clone()

The objects of this class are cloneable with this method.

Usage

CompactionController$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.