talos_agent/compaction/
policy.rs

1use super::constants::{
2    CIRCUIT_BREAKER_THRESHOLD, COLLAPSE_TURN_THRESHOLD, MAX_TOOL_RESULT_CHARS, PRESERVED_TURNS,
3    TRIM_TURN_THRESHOLD,
4};
5
6/// Configurable compaction policy documenting threshold math and limit sources.
7///
8/// All thresholds have documented defaults and source precedence. This struct
9/// makes the compaction decision boundary explicit and testable (MEM-005-A).
10#[derive(Debug, Clone)]
11pub struct CompactionPolicy {
12    /// Fraction of model_limit that triggers compaction (default: 0.8).
13    pub trigger_threshold: f32,
14    /// Maximum characters per tool result before budget truncation (default: 4000).
15    pub max_tool_result_chars: usize,
16    /// Number of recent turns preserved verbatim, never compacted by layers 4/5 (default: 10).
17    pub preserved_turns: usize,
18    /// Turn threshold for trim layer — tool results older than this are emptied (default: 20).
19    pub trim_turn_threshold: usize,
20    /// Turn threshold for collapse layer — turns older than this are summarized (default: 10).
21    pub collapse_turn_threshold: usize,
22    /// Maximum consecutive failures before circuit breaker trips (default: 3).
23    pub circuit_breaker_threshold: usize,
24    /// Tokens reserved for model output, reducing effective context budget (placeholder, default: 0).
25    pub output_reserve: u32,
26}
27
28impl Default for CompactionPolicy {
29    fn default() -> Self {
30        Self {
31            trigger_threshold: 0.8,
32            max_tool_result_chars: MAX_TOOL_RESULT_CHARS,
33            preserved_turns: PRESERVED_TURNS,
34            trim_turn_threshold: TRIM_TURN_THRESHOLD,
35            collapse_turn_threshold: COLLAPSE_TURN_THRESHOLD,
36            circuit_breaker_threshold: CIRCUIT_BREAKER_THRESHOLD,
37            output_reserve: 0,
38        }
39    }
40}
41
42impl CompactionPolicy {
43    /// Returns the token threshold at which compaction triggers.
44    ///
45    /// Source precedence: `model_limit * trigger_threshold - output_reserve`.
46    #[must_use]
47    pub fn trigger_tokens(&self, model_limit: u32) -> u32 {
48        let raw = (model_limit as f32 * self.trigger_threshold) as u32;
49        raw.saturating_sub(self.output_reserve)
50    }
51}
talos_agent/compaction/policy.rs

talos_agent/compaction/
policy.rs
