Struct VecHistory 

pub struct VecHistory { /* private fields */ }

A History implementation backed by Vec<Message> + Mutex, with token accounting.

Implementations

impl VecHistory

pub fn new() -> Self

pub fn from_messages(messages: Vec<Message>) -> Self

Trait Implementations

impl Default for VecHistory

fn default() -> VecHistory

Returns the “default value” for a type.

impl History for VecHistory

fn append(&self, msg: Message)

Appends a message.

fn snapshot(&self) -> Vec<Message>

A snapshot of the current history, to be fed into the next LLM call.

fn replace(&self, messages: Vec<Message>)

Replace the entire message list after compression. The turn main loop calls this to write back the new list consisting of a summary plus the retained tail. The implementation should also reset the token estimation baseline, since the old actual token counts no longer apply to the new list.

fn splice_prefix(&self, drop_count: usize, summary: Message) -> usize

Prefix splice: replaces the first drop_count messages in the current list with the single summary message, preserving everything after them. Returns the actual number of messages dropped (drop_count is clamped to the current length).

fn len(&self) -> usize

Number of messages currently held. Used to record a rollback boundary before a turn appends its prompt, so Self::truncate can undo it if the turn fails permanently.

fn truncate(&self, len: usize)

Truncates the message list to at most len messages, dropping any tail beyond it. A no-op when len >= current length.

fn record_input_tokens(&self, tokens: u64)

Records the actual input token count from the last LLM call (input + cache_read + cache_creation). Serves as the precise baseline for Self::token_estimate; subsequent Self::append messages are accumulated incrementally using a character heuristic.

fn token_estimate(&self) -> Option<u64>

Estimates the token count for the current history. None indicates the history is empty or no estimate is available.

fn is_empty(&self) -> bool

Returns whether the history holds no messages.