lightstream 0.6.0

Composable, zero-copy Arrow IPC and native data streaming for Rust with SIMD-aligned I/O, async support, and memory-mapping.
Documentation 
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// Copyright Peter G. Bower 2025-2026.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.

//! # Transport writer trait
//!
//! Common interface for all transport-level table writers i.e. TCP, WebSocket,
//! UDS, QUIC, WebTransport, and stdio.
//!
//! Every transport writer wraps an inner [`TableSink`] and delegates the same
//! set of write methods. This trait captures that contract so new transports get
//! compile-time enforcement instead of copy-paste.
//!
//! [`TableSink`]: crate::models::sinks::table_sink::TableSink

use std::future::Future;
use std::io;

use minarrow::{Field, TableV};

/// Shared writing interface for all transport-level Arrow IPC writers.
pub trait IPCTransportWriter {
    /// Get the schema used for this writer.
    fn schema(&self) -> &[Field];

    /// Register a dictionary for categorical columns.
    fn register_dictionary(&mut self, dict_id: i64, values: Vec<String>);

    /// Write a single table and flush.
    fn write_table(
        &mut self,
        table: impl Into<TableV> + Send,
    ) -> impl Future<Output = io::Result<()>> + Send;

    /// Write all tables and close.
    fn write_all_tables(
        &mut self,
        tables: Vec<impl Into<TableV> + Send>,
    ) -> impl Future<Output = io::Result<()>> + Send;

    /// Finalise the stream. Must be called after writing all tables.
    fn finish(&mut self) -> impl Future<Output = io::Result<()>> + Send;
}