RUST-1897 Fluent options parsing (#1061)

Author: abr-egn

src/action.rs

@@ -1,6 +1,7 @@
 //! Action builder types.
 
 mod aggregate;
+mod client_options;
 mod count;
 mod create_collection;
 mod create_index;
@@ -32,6 +33,7 @@ use std::{future::IntoFuture, marker::PhantomData, ops::Deref};
 
 pub use aggregate::Aggregate;
 use bson::Document;
+pub use client_options::ParseConnectionString;
 pub use count::{CountDocuments, EstimatedDocumentCount};
 pub use create_collection::CreateCollection;
 pub use create_index::CreateIndex;

src/action/client_options.rs

@@ -0,0 +1,104 @@
+use crate::{
+    client::options::{ClientOptions, ConnectionString, ResolverConfig},
+    error::{Error, Result},
+};
+
+impl ClientOptions {
+    /// Parses a MongoDB connection string (as either a `&str` or a [`ConnectionString`]) into a
+    /// [`ClientOptions`] struct. If the string is malformed or one of the options has an
+    /// invalid value, an error will be returned.
+    ///
+    /// In the case that "mongodb+srv" is used, SRV and TXT record lookups will be done as
+    /// part of this method.
+    ///
+    /// The format of a MongoDB connection string is described [here](https://www.mongodb.com/docs/manual/reference/connection-string/#connection-string-formats).
+    ///
+    /// Note that [default_database](ClientOptions::default_database) will be set from
+    /// `/defaultauthdb` in connection string.
+    ///
+    /// The following options are supported in the options query string:
+    ///
+    ///   * `appName`: maps to the `app_name` field
+    ///   * `authMechanism`: maps to the `mechanism` field of the `credential` field
+    ///   * `authSource`: maps to the `source` field of the `credential` field
+    ///   * `authMechanismProperties`: maps to the `mechanism_properties` field of the `credential`
+    ///     field
+    ///   * `compressors`: maps to the `compressors` field
+    ///   * `connectTimeoutMS`: maps to the `connect_timeout` field
+    ///   * `direct`: maps to the `direct` field
+    ///   * `heartbeatFrequencyMS`: maps to the `heartbeat_frequency` field
+    ///   * `journal`: maps to the `journal` field of the `write_concern` field
+    ///   * `localThresholdMS`: maps to the `local_threshold` field
+    ///   * `maxIdleTimeMS`: maps to the `max_idle_time` field
+    ///   * `maxStalenessSeconds`: maps to the `max_staleness` field of the `selection_criteria`
+    ///     field
+    ///   * `maxPoolSize`: maps to the `max_pool_size` field
+    ///   * `minPoolSize`: maps to the `min_pool_size` field
+    ///   * `readConcernLevel`: maps to the `read_concern` field
+    ///   * `readPreferenceField`: maps to the ReadPreference enum variant of the
+    ///     `selection_criteria` field
+    ///   * `readPreferenceTags`: maps to the `tags` field of the `selection_criteria` field. Note
+    ///     that this option can appear more than once; each instance will be mapped to a separate
+    ///     tag set
+    ///   * `replicaSet`: maps to the `repl_set_name` field
+    ///   * `retryWrites`: not yet implemented
+    ///   * `retryReads`: maps to the `retry_reads` field
+    ///   * `serverSelectionTimeoutMS`: maps to the `server_selection_timeout` field
+    ///   * `socketTimeoutMS`: unsupported, does not map to any field
+    ///   * `ssl`: an alias of the `tls` option
+    ///   * `tls`: maps to the TLS variant of the `tls` field`.
+    ///   * `tlsInsecure`: relaxes the TLS constraints on connections being made; currently is just
+    ///     an alias of `tlsAllowInvalidCertificates`, but more behavior may be added to this option
+    ///     in the future
+    ///   * `tlsAllowInvalidCertificates`: maps to the `allow_invalidCertificates` field of the
+    ///     `tls` field
+    ///   * `tlsCAFile`: maps to the `ca_file_path` field of the `tls` field
+    ///   * `tlsCertificateKeyFile`: maps to the `cert_key_file_path` field of the `tls` field
+    ///   * `w`: maps to the `w` field of the `write_concern` field
+    ///   * `waitQueueTimeoutMS`: unsupported, does not map to any field
+    ///   * `wTimeoutMS`: maps to the `w_timeout` field of the `write_concern` field
+    ///   * `zlibCompressionLevel`: maps to the `level` field of the `Compressor::Zlib` variant
+    ///     (which requires the `zlib-compression` feature flag) of the
+    ///     [`Compressor`](crate::compression::compressors::Compressor) enum
+    ///
+    /// `await` will return `Result<ClientOptions>`.
+    pub fn parse<C, E>(conn_str: C) -> ParseConnectionString
+    where
+        C: TryInto<ConnectionString, Error = E>,
+        E: Into<Error>,
+    {
+        ParseConnectionString {
+            conn_str: conn_str.try_into().map_err(Into::into),
+            resolver_config: None,
+        }
+    }
+}
+
+fn _assert_accept_str() {
+    let _ = ClientOptions::parse("foo");
+}
+
+#[allow(unreachable_code, clippy::diverging_sub_expression)]
+fn _assert_accept_conn_str() {
+    let _c: ConnectionString = todo!();
+    let _ = ClientOptions::parse(_c);
+}
+
+/// Parses a MongoDB connection string into a [`ClientOptions`] struct.  Construct with
+/// [`ClientOptions::parse`].
+#[must_use]
+pub struct ParseConnectionString {
+    pub(crate) conn_str: Result<ConnectionString>,
+    pub(crate) resolver_config: Option<ResolverConfig>,
+}
+
+impl ParseConnectionString {
+    /// In the case that "mongodb+srv" is used, SRV and TXT record lookups will be done using the
+    /// provided `ResolverConfig` as part of this method.
+    pub fn resolver_config(mut self, value: ResolverConfig) -> Self {
+        self.resolver_config = Some(value);
+        self
+    }
+}
+
+// Action impl in src/client/options/parse.rs.

src/client.rs

@@ -140,7 +140,7 @@ impl Client {
     /// See the documentation on
     /// [`ClientOptions::parse`](options/struct.ClientOptions.html#method.parse) for more details.
     pub async fn with_uri_str(uri: impl AsRef<str>) -> Result<Self> {
-        let options = ClientOptions::parse_uri(uri.as_ref(), None).await?;
+        let options = ClientOptions::parse(uri.as_ref()).await?;
 
         Client::with_options(options)
     }

src/client/csfle.rs

@@ -60,7 +60,7 @@ impl ClientState {
             let uri = opts
                 .extra_option(&EO_MONGOCRYPTD_URI)?
                 .unwrap_or(Self::MONGOCRYPTD_DEFAULT_URI);
-            let mut options = crate::options::ClientOptions::parse_uri(uri, None).await?;
+            let mut options = crate::options::ClientOptions::parse(uri).await?;
             options.server_selection_timeout = Some(Self::MONGOCRYPTD_SERVER_SELECTION_TIMEOUT);
             Some(Client::with_options(options)?)
         } else {