Method append

nodedb-wal/src/uring_writer.rs:148–191

Append a record to the in-memory buffer. Returns the assigned LSN. The record is NOT durable until `submit_and_sync()` is called. `database_id` is stored in header bytes 34-41. Pass `0` for the default database (backward-compatible with pre-existing records).

(
        &mut self,
        record_type: u32,
        tenant_id: u64,
        vshard_id: u32,
        database_id: u64,
        payload: &[u8],
    )

    /// `database_id` is stored in header bytes 34-41. Pass `0` for the
    /// default database (backward-compatible with pre-existing records).
    pub fn append(
        &mut self,
        record_type: u32,
        tenant_id: u64,
        vshard_id: u32,
        database_id: u64,
        payload: &[u8],
    ) -> Result<u64> {
        if self.sealed {
            return Err(WalError::Sealed);
        }

        let lsn = self.next_lsn.fetch_add(1, Ordering::Relaxed);
        let preamble_bytes = self.segment_preamble.as_ref().map(|p| p.to_bytes());
        let record = WalRecord::new(
            record_type,
            lsn,
            tenant_id,
            vshard_id,
            database_id,
            payload.to_vec(),
            self.encryption_key.as_ref(),
            preamble_bytes.as_ref(),
        )?;

        let header_bytes = record.header.to_bytes();
        let total_size = HEADER_SIZE + record.payload.len();

        if self.buffer.remaining() < total_size {
            self.submit_and_wait_write()?;
        }

        if total_size > self.buffer.capacity() {
            return Err(WalError::PayloadTooLarge {
                size: record.payload.len(),
                max: self.buffer.capacity() - HEADER_SIZE,
            });
        }

        self.buffer.write(&header_bytes);
        self.buffer.write(&record.payload);

        Ok(lsn)
    }

    /// Submit the buffered data via io_uring write + fsync, and wait for completion.
    ///