Struct Session 

pub struct Session {
    pub id: String,
    pub model: String,
    pub messages: VecDeque<Message>,
    pub total_tokens: usize,
    pub max_context_tokens: usize,
    pub created_at: Instant,
    pub last_active: Instant,
}

A conversation session with bounded context-window management.

Fields

id: String

Unique session identifier.

model: String

Model associated with this session.

messages: VecDeque<Message>

Ordered message history (oldest first).

total_tokens: usize

Running sum of tokens across all messages currently in messages.

max_context_tokens: usize

Hard ceiling on context tokens; messages are trimmed to stay below this.

created_at: Instant

Wall-clock time at which the session was created.

last_active: Instant

Wall-clock time of the last add_message call.

Implementations

impl Session

pub fn add_message(&mut self, role: String, content: String, tokens: usize)

Append a message and update the running token total.

Trims the oldest messages first if adding tokens would overflow the context window.

pub fn trim_to_fit(&mut self, new_tokens: usize)

Drop the oldest messages until total_tokens + new_tokens fits within max_context_tokens.

pub fn token_utilization(&self) -> f64

Fraction of the context window currently occupied (0.0–1.0).

pub fn is_expired(&self, timeout_secs: u64) -> bool

Returns true if the session has not been active for longer than timeout_secs seconds.

Trait Implementations

impl Debug for Session

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.