Struct RingBufferCapture 

pub struct RingBufferCapture { /* private fields */ }

In-memory packet capture with optional ring-buffer eviction.

Prefer crate::BusCapture for most use cases — it includes statistics counters and supports stats-only, bounded, and unbounded modes. Use RingBufferCapture only when you need a standalone ring buffer without statistics tracking.

Example

use oms_modbus::monitor::RingBufferCapture;
let capture = RingBufferCapture::new(10_000); // bounded, 10k records

Implementations

impl RingBufferCapture

pub fn new(capacity: usize) -> Self

Create a bounded ring buffer with the given capacity. When full, oldest records are evicted.

capacity is clamped to a minimum of 1. Passing 0 is equivalent to passing 1 — a single-record buffer.

pub fn unbounded() -> Self

Create an unbounded capture that never drops records. Use with caution — memory grows indefinitely.

pub fn len(&self) -> usize

Number of records currently buffered.

pub fn is_empty(&self) -> bool

Check if the buffer is empty.

pub fn dropped(&self) -> u64

Number of records dropped due to buffer overflow (bounded mode only).

pub fn drain(&self) -> Vec<PacketRecord>

Drain all records in chronological order. Clears the buffer.

pub fn snapshot(&self) -> Vec<PacketRecord>

Take a snapshot without clearing. Records are in chronological order.

Clones all records under the lock. For large buffers in hot paths, prefer Self::drain which swaps the buffer and releases the lock immediately.

pub fn set_unbounded(&self)

Switch to unbounded mode (existing records preserved).

pub fn set_bounded(&self)

Switch to bounded mode, stopping unbounded growth.

Capacity is fixed at construction time; this only prevents the ring buffer from growing without bound. Use RingBufferCapture::new to create a capture with a specific capacity.

Trait Implementations

impl Default for RingBufferCapture

fn default() -> Self

Returns the “default value” for a type.

impl WireTap for RingBufferCapture

fn on_write(&self, bytes: &[u8], ts: u64)

Bytes successfully written to the transport. Called once per poll_write that returns Ok(n) with n > 0.

fn on_read(&self, bytes: &[u8], ts: u64)

Bytes successfully read from the transport. Called once per poll_read that returns Ready(Ok(())) with new data.

fn on_error(&self, bytes: &[u8], error: &str, ts: u64)

Read returned an error, but partial data may have been received. Called when poll_read returns Ready(Err(e)) and the read buffer contains bytes that arrived before the error.