/// Creates a `ConnectionPoolConfiguration`.

public init() { }

/// The maximum number of connections in the `ConnectionPool`. Defaults to `10`.

public var maximumConnections = 10

/// The maximum size of the backlog of requests for connections, or `nil` for no limit.

/// Defaults to `nil`.

public var maximumPendingRequests: Int? = nil

/// The maximum time, in seconds, that requests for connections will wait before timing out,

/// or `nil` for no timeout. Defaults to `nil`.

public var pendingRequestTimeout: Int? = nil

/// The maximum time, in seconds, that connections allocated to requests can be used before

/// timing out, or `nil` for no timeout. Defaults to `nil`.

public var allocatedConnectionTimeout: Int? = nil

/// The `DispatchQueue` on which completion handlers for

/// `ConnectionPool.acquireConnection(completionHandler:)` and

/// `ConnectionPool.withConnection(completionHandler:)` are executed.

///

/// This dispatch queue is also used for asynchronous tasks internally performed by the

/// `ConnectionPool`, such as managing timeouts and periodic logging of performance metrics.

///

/// Defaults to `DispatchQueue.global()`.

public var dispatchQueue = DispatchQueue.global()

/// The interval, in seconds, between periodic logging of `ConnectionPool` performance metrics,

/// or `nil` to not log performance metrics.

///

/// For example, a value of `3600` causes metrics to be logged once an hour (at the start of

/// the hour). A value of `21600` causes metrics to be logged every 6 hours (at midnight,

/// 06:00, noon, and 18:00 UTC).

///

/// Metrics are logged with `LogLevel.info`.

///

/// Defaults to `3600`.

///

/// - SeeAlso: `ConnectionPool.computeMetrics(reset:)`

public var metricsLoggingInterval: Int? = 3600

/// Whether the `ConnectionPool` performance metrics are reset each time they are logged.

/// Defaults to `true`.

public var metricsResetWhenLogged = true