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# Rust 原生接口

Apache IoTDB 提供官方 Rust 客户端 SDK：[apache/iotdb-client-rust](https://github.com/apache/iotdb-client-rust)。它基于 Thrift RPC 协议（默认端口 6667），同时支持 IoTDB 的两种数据模型：

- **树模型** — `Session` / `SessionPool`：设备/时间序列路径（`root.sg.d1.s1`），本文档主要介绍此模型
- **表模型** — `TableSession` / `TableSessionPool`：关系型 SQL 方言

## 1. 环境要求

- Rust 1.75+
- Apache IoTDB 2.x — 完整的服务端版本兼容矩阵见 [COMPATIBILITY.md](https://github.com/apache/iotdb-client-rust/blob/main/COMPATIBILITY.md)

## 2. 安装

发布到 crates.io 后：

```toml
[dependencies]
iotdb-client-rust = "0.1"
```

在此之前，可使用 git 依赖：

```toml
[dependencies]
iotdb-client = { git = "https://github.com/apache/iotdb-client-rust" }
```

两种方式的导入名均为 `iotdb_client`。

## 3. 快速上手

```rust
use iotdb_client::{Result, Session, SessionConfig, TSDataType, Tablet, Value};

fn main() -> Result<()> {
    let config = SessionConfig::default().with_node_urls(&["127.0.0.1:6667"])?;
    let mut session = Session::new(config);
    session.open()?;

    session.execute_non_query("CREATE DATABASE root.demo")?;
    session.execute_non_query(
        "CREATE TIMESERIES root.demo.d1.temperature WITH DATATYPE=DOUBLE, ENCODING=PLAIN",
    )?;

    // 通过列式 tablet 批量写入（允许 null）。
    let mut tablet = Tablet::new(
        "root.demo.d1",
        vec!["temperature".into()],
        vec![TSDataType::Double],
    )?;
    tablet.add_row(1_720_000_000_000, vec![Some(Value::Double(21.5))])?;
    tablet.add_row(1_720_000_001_000, vec![None])?; // null 单元格
    session.insert_tablet(&tablet)?;

    // 或通过 insertRecord 写入单行（还提供 aligned 变体以及
    // 多行的 insert_records / insert_records_of_one_device）。
    session.insert_record(
        "root.demo.d1",
        1_720_000_002_000,
        vec!["temperature".into()],
        &[Value::Double(22.0)],
        false, // is_aligned
    )?;

    // 逐行迭代查询结果；dataset 在 drop 前借用 session。
    {
        let mut dataset = session.execute_query("SELECT temperature FROM root.demo.d1")?;
        while let Some(row) = dataset.next_row()? {
            println!("ts={:?} values={:?}", row.timestamp, row.values);
        }
    }

    session.execute_non_query("DELETE DATABASE root.demo")?;
    session.close()
}
```

## 4. 会话池

`SessionPool` 是线程安全的会话池，适用于并发场景。`acquire()` 返回 RAII guard，drop 时自动将会话归还池中：

```rust
use std::sync::Arc;
use iotdb_client::{Result, SessionPool, SessionPoolConfig};

fn main() -> Result<()> {
    let config = SessionPoolConfig {
        max_size: 4,
        ..SessionPoolConfig::default()
    }
    .with_node_urls(&["127.0.0.1:6667"])?;
    let pool = Arc::new(SessionPool::new(config)?);

    let handles: Vec<_> = (0..4)
        .map(|_| {
            let pool = Arc::clone(&pool);
            std::thread::spawn(move || -> Result<()> {
                let mut session = pool.acquire()?;
                session.execute_non_query("SHOW DATABASES")?;
                Ok(())
            })
        })
        .collect();
    for handle in handles {
        handle.join().expect("thread panicked")?;
    }

    pool.close();
    Ok(())
}
```

## 5. TLS 与 RPC 压缩

**RPC 压缩**（即 Thrift compact 协议）必须与服务端配置 `dn_rpc_thrift_compression_enable`（默认 `false`）保持一致：

```rust
let config = SessionConfig { enable_rpc_compression: true, ..Default::default() };
```

**TLS** 通过 `tls` cargo feature 启用：

```toml
iotdb-client-rust = { version = "0.1", features = ["tls"] }
```

```rust
let config = SessionConfig {
    use_ssl: true,
    ca_cert_path: Some("ca.pem".into()),  // 信任私有 CA / 自签名证书
    accept_invalid_certs: false,          // true 跳过证书校验（仅限测试！）
    domain_override: None,                // 按 IP 连接时指定 SNI/校验主机名
    ..Default::default()
};
```

## 6. 示例

完整可运行示例见仓库 [`examples/`](https://github.com/apache/iotdb-client-rust/tree/main/examples) 目录：

```sh
cargo run --example tree_session
cargo run --example table_session
cargo run --example session_pool
```