Enum PoolError 

pub enum PoolError {
    Exhausted,
    Timeout,
    AlreadyAcquired,
    NotAcquired,
    InvalidConfig(String),
    Internal(String),
    Closed,
    ConnectionFailed(String),
    CircuitOpen,
    RateLimited {
        remaining: u64,
        reset_at: i64,
    },
}

连接池特有错误

Variants

Exhausted

连接池耗尽

Timeout

获取连接超时

AlreadyAcquired

连接已被获取

NotAcquired

连接未被获取

InvalidConfig(String)

配置非法

Internal(String)

内部错误

Closed

连接池已关闭（close_all 后拒绝新 acquire）

ConnectionFailed(String)

连接创建失败（保留原始错误信息）

CircuitOpen

#88 修复：断路器已跳闸，拒绝请求以防级联失败

当 circuit-breaker feature 启用且 CircuitBreaker 处于 Open 状态时， acquire/query_with_timeout 等方法会返回此错误，避免对下游数据库 造成更大压力。

RateLimited

#93 修复：限流器拒绝请求

当 rate-limit feature 启用且 RateLimiter 拒绝当前 key 时返回。 remaining 为本次窗口剩余配额（已为 0），reset_at 为窗口重置时间戳（毫秒）。

Fields

remaining: u64

reset_at: i64

Implementations

impl PoolError

pub fn error_code(&self) -> &'static str

Trait Implementations

impl Debug for PoolError

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

Formats the value using the given formatter.

impl Display for PoolError

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

Formats the value using the given formatter.

impl Error for PoolError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.