Struct DefaultBlockCompaction 

pub struct DefaultBlockCompaction;

Default block-based compaction strategy.

Stateless — all parameters come from CompactionConfig.

• keep_first: returns turn range 0..keep_first_turns
• keep_compacted: one-liner summaries of the middle section, bounded by max_summary_tokens
• keep_recent: truncates tool outputs in the recent section to tool_output_max_lines

Trait Implementations

impl BlockCompactionStrategy for DefaultBlockCompaction

fn keep_compacted<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, record: &'life1 LoopRecord, turn_map: &'life2 TurnMap, config: &'life3 CompactionConfig, is_most_recent: bool, ) -> Pin<Box<dyn Future<Output = Option<CompactedSection>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait,

Basic implementation: generates per-turn one-liner summaries until max_summary_tokens is exhausted. Remaining turns are dropped.

More sophisticated strategies (e.g. LLM-based) should produce a holistic summary of ALL turns within the budget rather than dropping turns.

Summaries use Message::User role to maintain valid LLM message alternation (user→assistant→user→…). A summary replaces a full turn sequence (user + assistant + tool results) with a single user-role “[Summary]” message.

fn keep_first<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, _record: &'life1 LoopRecord, turn_map: &'life2 TurnMap, config: &'life3 CompactionConfig, ) -> Pin<Box<dyn Future<Output = Option<TurnRange>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait,

Determine the keep_first section: turns kept verbatim from the start. Only called for the most recent loop.

fn keep_recent<'life0, 'life1, 'life2, 'life3, 'async_trait>( &'life0 self, record: &'life1 LoopRecord, turn_map: &'life2 TurnMap, config: &'life3 CompactionConfig, ) -> Pin<Box<dyn Future<Output = Option<CompactedSection>> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait, 'life3: 'async_trait,

Create the keep_recent section: recent turns with truncated tool outputs. Only called for the most recent loop.

fn compact<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, record: &'life1 LoopRecord, config: &'life2 CompactionConfig, is_most_recent: bool, ) -> Pin<Box<dyn Future<Output = CompactionBlock> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait, 'life1: 'async_trait, 'life2: 'async_trait,

Assemble a CompactionBlock from the three sections. Default implementation calls the three methods above.