mongodb 3.6.0

pub mod session;

use super::Database;
use crate::{
    concern::{ReadConcern, WriteConcern},
    error::Result,
    options::{ClientOptions, DatabaseOptions, SelectionCriteria},
    Client as AsyncClient,
};

/// This is the main entry point for the synchronous API. A `Client` is used to connect to a MongoDB
/// cluster. By default, it will monitor the topology of the cluster, keeping track of any changes,
/// such as servers being added or removed.
///
/// `Client` is a wrapper around the asynchronous [`mongodb::Client`](../struct.Client.html), and it
/// starts up a tokio runtime internally to run that wrapped client on.
///
/// `Client` uses [`std::sync::Arc`](https://doc.rust-lang.org/std/sync/struct.Arc.html) internally,
/// so it can safely be shared across threads. For example:
///
/// ```rust
/// # use mongodb::{bson::Document, sync::Client, error::Result};
/// #
/// # fn start_workers() -> Result<()> {
/// let client = Client::with_uri_str("mongodb://example.com")?;
///
/// for i in 0..5 {
///     let client_ref = client.clone();
///
///     std::thread::spawn(move || {
///         let collection = client_ref.database("items").collection::<Document>(&format!("coll{}", i));
///
///         // Do something with the collection
///     });
/// }
/// #
/// # // Technically we should join the threads here, but for the purpose of the example, we'll just
/// # // sleep for a bit.
/// # std::thread::sleep(std::time::Duration::from_secs(3));
/// # Ok(())
/// # }
/// ```
///
/// ## TCP Keepalive
/// TCP keepalive is enabled by default with ``tcp_keepalive_time`` set to 120 seconds. The
/// driver does not set ``tcp_keepalive_intvl``. See the
/// [MongoDB Diagnostics FAQ keepalive section](https://www.mongodb.com/docs/manual/faq/diagnostics/#does-tcp-keepalive-time-affect-mongodb-deployments)
/// for instructions on setting these values at the system level.
///
/// ## Clean shutdown
/// Because Rust has no async equivalent of `Drop`, values that require server-side cleanup when
/// dropped spawn a new async task to perform that cleanup.  This can cause two potential issues:
///
/// * Drop tasks pending or in progress when the async runtime shuts down may not complete, causing
///   server-side resources to not be freed.
/// * Drop tasks may run at an arbitrary time even after no `Client` values exist, making it hard to
///   reason about associated resources (e.g. event handlers).
///
/// To address these issues, we highly recommend you use [`Client::shutdown`] in the termination
/// path of your application.  This will ensure that outstanding resources have been cleaned up and
/// terminate internal worker tasks before returning.  Please note that `shutdown` will wait for
/// _all_ outstanding resource handles to be dropped, so they must either have been dropped before
/// calling `shutdown` or in a concurrent task; see the documentation of `shutdown` for more
/// details.

#[derive(Clone, Debug)]
pub struct Client {
    pub(crate) async_client: AsyncClient,
}

impl From<AsyncClient> for Client {
    fn from(async_client: AsyncClient) -> Self {
        Self { async_client }
    }
}

impl Client {
    /// Creates a new `Client` connected to the cluster specified by `uri`. `uri` must be a valid
    /// MongoDB connection string.
    ///
    /// See the documentation on
    /// [`ClientOptions::parse`](../options/struct.ClientOptions.html#method.parse) for more
    /// details.
    pub fn with_uri_str(uri: impl AsRef<str>) -> Result<Self> {
        let async_client =
            crate::sync::TOKIO_RUNTIME.block_on(AsyncClient::with_uri_str(uri.as_ref()))?;
        Ok(Self { async_client })
    }

    /// Creates a new `Client` connected to the cluster specified by `options`.
    pub fn with_options(options: ClientOptions) -> Result<Self> {
        let async_client = AsyncClient::with_options(options)?;
        Ok(Self { async_client })
    }

    /// Gets the default selection criteria the `Client` uses for operations..
    pub fn selection_criteria(&self) -> Option<&SelectionCriteria> {
        self.async_client.selection_criteria()
    }

    /// Gets the default read concern the `Client` uses for operations.
    pub fn read_concern(&self) -> Option<&ReadConcern> {
        self.async_client.read_concern()
    }

    /// Gets the default write concern the `Client` uses for operations.
    pub fn write_concern(&self) -> Option<&WriteConcern> {
        self.async_client.write_concern()
    }

    /// Gets a handle to a database specified by `name` in the cluster the `Client` is connected to.
    /// The `Database` options (e.g. read preference and write concern) will default to those of the
    /// `Client`.
    ///
    /// This method does not send or receive anything across the wire to the database, so it can be
    /// used repeatedly without incurring any costs from I/O.
    pub fn database(&self, name: &str) -> Database {
        Database::new(self.async_client.database(name))
    }

    /// Gets a handle to a database specified by `name` in the cluster the `Client` is connected to.
    /// Operations done with this `Database` will use the options specified by `options` by default
    /// and will otherwise default to those of the `Client`.
    ///
    /// This method does not send or receive anything across the wire to the database, so it can be
    /// used repeatedly without incurring any costs from I/O.
    pub fn database_with_options(&self, name: &str, options: DatabaseOptions) -> Database {
        Database::new(self.async_client.database_with_options(name, options))
    }

    /// Gets a handle to the default database specified in the `ClientOptions` or MongoDB connection
    /// string used to construct this `Client`.
    ///
    /// If no default database was specified, `None` will be returned.
    pub fn default_database(&self) -> Option<Database> {
        self.async_client.default_database().map(Database::new)
    }
}