From 50a635ed8e7ccf06f412bf2b8bfffaef448cff74 Mon Sep 17 00:00:00 2001
From: Eric Dattore <eric.dattore@gmail.com>
Date: Wed, 28 Nov 2018 13:01:21 -0700
Subject: [PATCH] Add support for MongoDB connection pooling in
 'rocket_contrib'.

---
 contrib/lib/Cargo.toml       |  3 +++
 contrib/lib/src/databases.rs | 17 +++++++++++++++++
 scripts/test.sh              |  1 +
 site/guide/6-state.md        |  3 +++
 4 files changed, 24 insertions(+)

diff --git a/contrib/lib/Cargo.toml b/contrib/lib/Cargo.toml
index 86ca1076..d8124977 100644
--- a/contrib/lib/Cargo.toml
+++ b/contrib/lib/Cargo.toml
@@ -33,6 +33,7 @@ mysql_pool = ["databases", "mysql", "r2d2_mysql"]
 sqlite_pool = ["databases", "rusqlite", "r2d2_sqlite"]
 cypher_pool = ["databases", "rusted_cypher", "r2d2_cypher"]
 redis_pool = ["databases", "redis", "r2d2_redis"]
+mongodb_pool = ["databases", "mongodb", "r2d2-mongodb"]
 
 [dependencies]
 # Global dependencies.
@@ -66,6 +67,8 @@ rusted_cypher = { version = "1", optional = true }
 r2d2_cypher = { version = "0.4", optional = true }
 redis = { version = "0.9", optional = true }
 r2d2_redis = { version = "0.8", optional = true }
+mongodb = { version = "0.3.12", optional = true }
+r2d2-mongodb = { version = "0.2.0", optional = true }
 
 # SpaceHelmet dependencies
 time = { version = "0.1.40", optional = true }
diff --git a/contrib/lib/src/databases.rs b/contrib/lib/src/databases.rs
index 148b06b0..277ed758 100644
--- a/contrib/lib/src/databases.rs
+++ b/contrib/lib/src/databases.rs
@@ -333,6 +333,7 @@
 //! | Sqlite   | [Rustqlite]           | [`rusqlite::Connection`]       | `sqlite_pool`          |
 //! | Neo4j    | [`rusted_cypher`]     | [`rusted_cypher::GraphClient`] | `cypher_pool`          |
 //! | Redis    | [`redis-rs`]          | [`redis::Connection`]          | `redis_pool`           |
+//! | MongoDB  | [`mongodb`]           | [`mongodb::db::Database`]      | `mongodb_pool`         |
 //!
 //! [Diesel]: https://diesel.rs
 //! [`redis::Connection`]: https://docs.rs/redis/0.9.0/redis/struct.Connection.html
@@ -349,6 +350,8 @@
 //! [Rust-Postgres]: https://github.com/sfackler/rust-postgres
 //! [`rust-mysql-simple`]: https://github.com/blackbeam/rust-mysql-simple
 //! [`diesel::PgConnection`]: http://docs.diesel.rs/diesel/pg/struct.PgConnection.html
+//! [`mongodb`]: https://github.com/mongodb-labs/mongo-rust-driver-prototype
+//! [`mongodb::db::Database`]: https://docs.rs/mongodb/0.3.12/mongodb/db/type.Database.html
 //!
 //! The above table lists all the supported database adapters in this library.
 //! In order to use particular `Poolable` type that's included in this library,
@@ -399,6 +402,9 @@ use self::r2d2::ManageConnection;
 #[cfg(feature = "redis_pool")] pub extern crate redis;
 #[cfg(feature = "redis_pool")] pub extern crate r2d2_redis;
 
+#[cfg(feature = "mongodb_pool")] pub extern crate mongodb;
+#[cfg(feature = "mongodb_pool")] pub extern crate r2d2_mongodb;
+
 /// A structure representing a particular database configuration.
 ///
 /// For the following configuration:
@@ -781,6 +787,17 @@ impl Poolable for redis::Connection {
     }
 }
 
+#[cfg(feature = "mongodb_pool")]
+impl Poolable for mongodb::db::Database {
+    type Manager = r2d2_mongodb::MongodbConnectionManager;
+    type Error = DbError<mongodb::Error>;
+
+    fn pool(config: DatabaseConfig) -> Result<r2d2::Pool<Self::Manager>, Self::Error> {
+        let manager = r2d2_mongodb::MongodbConnectionManager::new_with_uri(config.url).map_err(DbError::Custom)?;
+        r2d2::Pool::builder().max_size(config.pool_size).build(manager).map_err(DbError::PoolError)
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::collections::BTreeMap;
diff --git a/scripts/test.sh b/scripts/test.sh
index 41a219c1..f4686360 100755
--- a/scripts/test.sh
+++ b/scripts/test.sh
@@ -95,6 +95,7 @@ if [ "$1" = "--contrib" ]; then
     sqlite_pool
     cypher_pool
     redis_pool
+    mongodb_pool
   )
 
   pushd "${CONTRIB_LIB_ROOT}" > /dev/null 2>&1
diff --git a/site/guide/6-state.md b/site/guide/6-state.md
index aa10c06b..da3df46f 100644
--- a/site/guide/6-state.md
+++ b/site/guide/6-state.md
@@ -187,6 +187,7 @@ Presently, Rocket provides built-in support for the following databases:
 | Sqlite   | [`Rustqlite`]         | [`rusqlite::Connection`]       | `sqlite_pool`          |
 | Neo4j    | [`rusted_cypher`]     | [`rusted_cypher::GraphClient`] | `cypher_pool`          |
 | Redis    | [`redis-rs`]          | [`redis::Connection`]          | `redis_pool`           |
+| MongoDB  | [`mongodb`]           | [`mongodb::db::Database`]      | `mongodb_pool`         |
 
 [`r2d2`]: https://crates.io/crates/r2d2
 [Diesel]: https://diesel.rs
@@ -204,6 +205,8 @@ Presently, Rocket provides built-in support for the following databases:
 [Rust-Postgres]: https://github.com/sfackler/rust-postgres
 [`rust-mysql-simple`]: https://github.com/blackbeam/rust-mysql-simple
 [`diesel::PgConnection`]: http://docs.diesel.rs/diesel/pg/struct.PgConnection.html
+[`mongodb`]: https://github.com/mongodb-labs/mongo-rust-driver-prototype
+[`mongodb::db::Database`]: https://docs.rs/mongodb/0.3.12/mongodb/db/type.Database.html
 
 ### Usage