Struct TruncateStrategy 

pub struct TruncateStrategy;

Default CompactionStrategy: drop the oldest unpinned messages until the preserved tail starts at a safe User-without- ToolResult boundary. Pinned messages from the dropped prefix survive verbatim at their relative position; the cut never strands a ToolResult from its ToolCall. Reports under CompactionStrategy::name as "truncate".

Trait Implementations

impl CompactionStrategy for TruncateStrategy

fn name(&self) -> &'static str

Stable, machine-readable name of the strategy. Used by HistoryCompacted events so callers can attribute compaction to a specific algorithm in logs/metrics.

fn compact<'life0, 'life1, 'life2, 'async_trait>( &'life0 self, messages: &'life1 [Message], pinned: &'life2 [bool], preserve_n_last: usize, ) -> Pin<Box<dyn Future<Output = Result<CompactionOutput, CompactionError>> + Send + 'async_trait>>

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

Compact messages into a smaller history.