perf(core,memory): reduce heap allocations in message processing#913
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perf(core,memory): reduce heap allocations in message processing#913
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- remove_tool_responses_middle_out: take Vec<Message> by value to eliminate one redundant clone per progressive-compaction iteration - middle-out removal tracking: replace HashSet<usize> with Vec::with_capacity(to_remove); linear scan is faster for N <= 20 - consolidate_summaries: replace collect::<Vec<_>>().join() with String::with_capacity + write! loop to skip intermediate allocation - load_history / load_history_filtered / message_by_id / messages_by_ids: skip serde_json::from_str when parts_json == "[]" (common case) Closes #884, #886, #887, #888. #885 was already handled.
…anges (#861) - remove_tool_responses_middle_out: add fraction=0.0 edge case and ToolOutput part compaction tests - messages.rs: add explicit fast-path coverage for load_history, load_history_filtered, message_by_id, messages_by_ids when parts_json == "[]" and non-empty parts round-trip test
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Summary
remove_tool_responses_middle_out: takeVec<Message>by value — eliminates one redundant full-vec clone per progressive-compaction iteration (was cloned on both early-return path and result construction path)HashSet<usize>withVec::with_capacity(to_remove)— linearcontainsis faster for N ≤ 20 and avoids hash table overheadconsolidate_summaries: replace.collect::<Vec<_>>().join("\n\n")withString::with_capacity+write!loop — eliminates intermediateVec<String>allocationload_history/load_history_filtered/message_by_id/messages_by_ids: skipserde_json::from_strwhenparts_json == "[]"— fast-paths the common empty-parts casepersist_messagefast-path (Fast-path empty-parts serialization in persist_message #885) was already in place via.filter(|m| !m.parts.is_empty())Test plan
cargo +nightly fmt --check— cleancargo clippy --workspace -- -D warnings— 0 warningscargo nextest run --workspace --lib --bins— 2797/2797 passedremove_tool_responses_middle_outtests verifiedload_historytests verifiedCloses #884, #885, #886, #887, #888
Part of epic #861