Struct LogGuard 

pub struct LogGuard {
    pub log_buffer: VecDeque<LogEntry>,
    pub log_level: LogLevel,
    pub log_limit: usize,
}

Log monitoring state.

Buffers recent Tor log messages and provides functionality to dump them when circuits are closed for debugging purposes.

Buffer Behavior

The log buffer operates as a ring buffer with a configurable maximum size. When the buffer is full, the oldest entries are discarded to make room for new ones.

Example

use vanguards_rs::logguard::LogGuard;
use vanguards_rs::config::LogguardConfig;

let config = LogguardConfig::default();
let mut guard = LogGuard::new(&config);

// Buffer log entries
guard.log_event("NOTICE", "Circuit 123 built");
guard.log_event("INFO", "Stream attached");
assert_eq!(guard.buffer_len(), 2);

// Dump logs before circuit close
guard.dump_log_queue("123", "Pre");
assert_eq!(guard.buffer_len(), 0);

Event Handling

The guard responds to circuit events:

• On CLOSED or FAILED with reason REQUESTED: Dumps buffered logs
• This captures context around intentional circuit closures

See Also

• LogEntry - Individual log entries
• crate::config::LogguardConfig - Configuration options
• crate::logger - Main logging infrastructure

Fields

log_buffer: VecDeque<LogEntry>

Buffered log entries.

log_level: LogLevel

Minimum log level to buffer.

log_limit: usize

Maximum number of entries to buffer.

Implementations

impl LogGuard

pub fn new(config: &LogguardConfig) -> Self

Creates a new LogGuard with the specified configuration.

pub fn log_event(&mut self, runlevel: &str, message: &str)

Handles a log event from Tor.

Buffers the log entry if it meets the minimum log level requirement. Automatically trims the buffer if it exceeds the configured limit.

Arguments

• runlevel - The log level (DEBUG, INFO, NOTICE, WARN, ERR)
• message - The log message content

pub fn log_event_with_timestamp( &mut self, runlevel: &str, message: &str, arrived_at: f64, )

Handles a log event with a specific timestamp.

pub fn log_warn_event(&self, message: &str)

Handles a WARN-level log event.

Logs the warning at NOTICE level for visibility.

pub fn dump_log_queue(&mut self, circ_id: &str, when: &str)

Dumps the log buffer for a circuit close event.

This is called before and after circuit close. The “when” argument is “Pre” before we close a circuit and “Post” after.

Arguments

• circ_id - The circuit ID being closed
• when - “Pre” for before close, “Post” for after close

pub fn circ_event(&mut self, circ_id: &str, status: &str, reason: Option<&str>)

Handles a circuit event for post-close log dumping.

Dumps buffered logs after a circuit is closed with REQUESTED reason.

Arguments

• circ_id - The circuit ID
• status - The circuit status (CLOSED, FAILED, etc.)
• reason - The close reason

pub fn buffer_len(&self) -> usize

Returns the number of buffered log entries.

pub fn clear(&mut self)

Clears the log buffer.

pub fn get_log_event_types(dump_level: LogLevel) -> Vec<&'static str>

Returns the log levels that should be subscribed to based on dump_level.

Returns a list of Tor event types to subscribe to.

Trait Implementations

impl Clone for LogGuard

fn clone(&self) -> LogGuard

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LogGuard

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

Formats the value using the given formatter.