Implement a diesel connection based on the pure rust postgres crate

.travis.yml

@@ -49,12 +49,12 @@ matrix:
   allow_failures:
     - rust: nightly
   include:
-  - rust: nightly-2019-08-01
+  - rust: nightly-2019-12-29
     name: "Compile tests"
     env: RUSTFLAGS="--cap-lints=warn"
     script:
     - (cd diesel_compile_tests && cargo test)
-  - rust: 1.37.0
+  - rust: 1.40.0
     name: "Rustfmt && Clippy"
     script:
     - rustup component add rustfmt clippy
@@ -66,8 +66,8 @@ matrix:
     - SQLITE_DATABASE_URL=/tmp/test.db
     script:
     - (cd diesel_cli && cargo test --no-default-features --features "sqlite-bundled")
-  - rust: 1.37.0
-     name: "Minimal supported rust version == 1.37.0"
+  - rust: 1.40.0
+    name: "Minimal supported rust version == 1.40.0"
     script:
     - cargo check --all
 

CHANGELOG.md

@@ -27,6 +27,8 @@ for Rust libraries in [RFC #1105](https://github.com/rust-lang/rfcs/blob/master/
 * The `MacAddr` SQL type can now be used without enabling the `network-address`
   feature.
 
+* A unstable pure rust postgresql connection implementation (`PostgresConnection`) was added behind the `unstable_pure_rust_postgres` feature flag. It is based on the `postgres` crate
+
 ### Removed
 
 * All previously deprecated items have been removed.
@@ -47,7 +49,7 @@ for Rust libraries in [RFC #1105](https://github.com/rust-lang/rfcs/blob/master/
   `Mysql::TypeMetadata`, you will need to take the new struct
   `MysqlTypeMetadata` instead.
 
-* The minimal officially supported rustc version is now 1.36.0
+* The minimal officially supported rustc version is now 1.37.0
 
 * The `RawValue` types for the `Mysql` and `Postgresql` backend where changed
   from `[u8]` to distinct opaque types. If you used the concrete `RawValue` type

_build/install-rust.yml

@@ -1,14 +1,14 @@
 steps:
   # Linux and Windows
   - bash: |
-      rustup install $RUSTUP_TOOLCHAIN
+      rustup install --force $RUSTUP_TOOLCHAIN
     env:
       RUSTUP_TOOLCHAIN: ${{parameters.rust_version}}
     displayName: Install rust
     condition: not(eq(variables['Agent.OS'], 'Darwin'))
   # Macos
   - script: |
-      curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain $RUSTUP_TOOLCHAIN
+      curl https://sh.rustup.rs -sSf | sh -s -- -y --default-toolchain  $RUSTUP_TOOLCHAIN --profile minimal
       echo "##vso[task.setvariable variable=PATH;]$PATH:$HOME/.cargo/bin"
     env:
       RUSTUP_TOOLCHAIN: ${{parameters.rust_version}}

azure-pipelines.yml

@@ -178,7 +178,7 @@ jobs:
     - template: _build/install-rust.yml
       parameters:
         platform: Linux
-        rust_version: nightly-2019-08-01
+        rust_version: nightly-2019-12-29
     - bash: |
         sudo apt-get update &&
         sudo apt-get -y install libsqlite3-dev libpq-dev libmysqlclient-dev
@@ -197,7 +197,7 @@ jobs:
     - template: _build/install-rust.yml
       parameters:
         platform: Linux
-        rust_version: 1.36.0
+        rust_version: 1.40.0
     - bash: |
         sudo apt-get update &&
         sudo apt-get -y install libsqlite3-dev libpq-dev libmysqlclient-dev
@@ -241,11 +241,29 @@ jobs:
     - template: _build/install-rust.yml
       parameters:
         platform: Linux
-        rust_version: 1.36.0
+        rust_version: 1.37.0
     - bash: |
         sudo apt-get update &&
         sudo apt-get -y install libsqlite3-dev libpq-dev libmysqlclient-dev
       displayName: Install build dependencies
     - bash: |
         cargo check --all
-      displayName: Check building with rust 1.36.0
+      displayName: Check building with rust 1.37.0
+
+- job: PURE_RUST_POSTGRES
+  displayName: Test pure rust postgres connection implementation
+  pool:
+    vmImage: ubuntu-16.04
+  variables:
+    PG_DATABASE_URL: postgres://postgres@localhost/
+  steps:
+    - template: _build/install-rust.yml
+      parameters:
+        platform: Linux
+        rust_version: 1.40.0
+    - bash: |
+        (cd diesel && cargo test --no-default-features --features "extras unstable_pure_rust_postgres")
+      displayName: Test diesel
+    - bash: |
+        (cd diesel_tests && cargo test --no-default-features --features "unstable_pure_rust_postgres")
+      displayName: Run diesel tests

diesel/Cargo.toml

@@ -20,6 +20,8 @@ libc = { version = "0.2.0", optional = true }
 libsqlite3-sys = { version = ">=0.8.0, <0.17.0", optional = true, features = ["min_sqlite_version_3_7_16"] }
 mysqlclient-sys = { version = ">=0.1.0, <0.3.0", optional = true }
 pq-sys = { version = ">=0.3.0, <0.5.0", optional = true }
+postgresql = {version = "0.17", optional = true, package = "postgres" }
+bytes = {version = "0.5", optional = true}
 quickcheck = { version = "0.4", optional = true }
 serde_json = { version = ">=0.8.0, <2.0", optional = true }
 time = { version = "0.1", optional = true }
@@ -41,7 +43,7 @@ dotenv = ">=0.8, <0.11"
 quickcheck = "0.4"
 
 [features]
-default = ["with-deprecated", "32-column-tables"]
+default = ["postgres", "unstable_pure_rust_postgres"]
 extras = ["chrono", "serde_json", "uuidv07", "deprecated-time", "network-address", "numeric", "r2d2"]
 unstable = ["diesel_derives/nightly"]
 large-tables = ["32-column-tables"]
@@ -50,6 +52,7 @@ huge-tables = ["64-column-tables"]
 64-column-tables = ["32-column-tables"]
 128-column-tables = ["64-column-tables"]
 postgres = ["pq-sys", "bitflags", "diesel_derives/postgres"]
+unstable_pure_rust_postgres = ["bitflags", "diesel_derives/postgres", "postgresql", "bytes"]
 sqlite = ["libsqlite3-sys", "diesel_derives/sqlite"]
 mysql = ["mysqlclient-sys", "url", "percent-encoding", "diesel_derives/mysql"]
 with-deprecated = []

diesel/src/data_types.rs

@@ -3,5 +3,5 @@
 //! confusing (such as date and time types). This module will re-export
 //! all backend specific data structures when compiled against that
 //! backend.
-#[cfg(feature = "postgres")]
+#[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
 pub use crate::pg::data_types::*;

diesel/src/doctest_setup.rs

@@ -1,20 +1,27 @@
 extern crate dotenv;
-#[macro_use] extern crate cfg_if;
+#[macro_use]
+extern crate cfg_if;
 
-use diesel::prelude::*;
 use self::dotenv::dotenv;
+use diesel::prelude::*;
 
 cfg_if! {
-    if #[cfg(feature = "postgres")] {
+    if #[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))] {
         #[allow(dead_code)]
         type DB = diesel::pg::Pg;
 
-        fn connection_no_transaction() -> PgConnection {
+        #[cfg(feature = "postgres")]
+        type DbConnection = PgConnection;
+
+        #[cfg(feature = "unstable_pure_rust_postgres")]
+        type DbConnection = PostgresConnection;
+
+        fn connection_no_transaction() -> DbConnection {
             let connection_url = database_url_from_env("PG_DATABASE_URL");
-            PgConnection::establish(&connection_url).unwrap()
+            DbConnection::establish(&connection_url).unwrap()
         }
 
-        fn connection_no_data() -> PgConnection {
+        fn connection_no_data() -> DbConnection {
             let connection = connection_no_transaction();
             connection.begin_test_transaction().unwrap();
             connection.execute("DROP TABLE IF EXISTS users CASCADE").unwrap();
@@ -26,7 +33,7 @@ cfg_if! {
         }
 
         #[allow(dead_code)]
-        fn establish_connection() -> PgConnection {
+        fn establish_connection() -> DbConnection {
             let connection = connection_no_data();
 
             connection.execute("CREATE TABLE users (
@@ -104,7 +111,7 @@ cfg_if! {
                 (1, 'My first post'),
                 (1, 'About Rust'),
                 (2, 'My first post too')").unwrap();
-            
+
             connection.execute("CREATE TABLE comments (
                 id INTEGER PRIMARY KEY AUTOINCREMENT,
                 post_id INTEGER NOT NULL,
@@ -161,7 +168,7 @@ cfg_if! {
                 (1, 'My first post'),
                 (1, 'About Rust'),
                 (2, 'My first post too')").unwrap();
-            
+
             connection.execute("CREATE TABLE comments (
                 id INTEGER PRIMARY KEY AUTO_INCREMENT,
                 post_id INTEGER NOT NULL,
@@ -195,7 +202,6 @@ fn database_url_from_env(backend_specific_env_var: &str) -> String {
         .expect("DATABASE_URL must be set in order to run tests")
 }
 
-
 mod schema {
     table! {
         animals {

diesel/src/expression/functions/date_and_time.rs

@@ -54,7 +54,7 @@ impl AsExpression<Nullable<Timestamp>> for now {
     }
 }
 
-#[cfg(feature = "postgres")]
+#[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
 impl AsExpression<Timestamptz> for now {
     type Expression = Coerce<now, Timestamptz>;
 
@@ -63,7 +63,7 @@ impl AsExpression<Timestamptz> for now {
     }
 }
 
-#[cfg(feature = "postgres")]
+#[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
 impl AsExpression<Nullable<Timestamptz>> for now {
     type Expression = Coerce<now, Nullable<Timestamptz>>;
 

diesel/src/expression/mod.rs

@@ -66,7 +66,7 @@ pub mod dsl {
     #[doc(inline)]
     pub use super::sql_literal::sql;
 
-    #[cfg(feature = "postgres")]
+    #[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
     pub use crate::pg::expression::dsl::*;
 
     /// The return type of [`count(expr)`](../dsl/fn.count.html)

diesel/src/expression_methods/mod.rs

@@ -21,6 +21,6 @@ pub use self::global_expression_methods::{ExpressionMethods, NullableExpressionM
 #[doc(inline)]
 pub use self::text_expression_methods::TextExpressionMethods;
 
-#[cfg(feature = "postgres")]
+#[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
 #[doc(inline)]
 pub use crate::pg::expression::expression_methods::*;

diesel/src/lib.rs

@@ -125,9 +125,6 @@
     clippy::used_underscore_binding
 )]
 
-#[cfg(feature = "postgres")]
-#[macro_use]
-extern crate bitflags;
 extern crate byteorder;
 #[macro_use]
 extern crate diesel_derives;
@@ -168,7 +165,7 @@ pub mod row;
 
 #[cfg(feature = "mysql")]
 pub mod mysql;
-#[cfg(feature = "postgres")]
+#[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
 pub mod pg;
 #[cfg(feature = "sqlite")]
 pub mod sqlite;
@@ -280,7 +277,7 @@ pub mod helper_types {
     pub type Distinct<Source> = <Source as DistinctDsl>::Output;
 
     /// Represents the return type of `.distinct_on(expr)`
-    #[cfg(feature = "postgres")]
+    #[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
     pub type DistinctOn<Source, Expr> = <Source as DistinctOnDsl<Expr>>::Output;
 
     /// Represents the return type of `.single_value()`
@@ -316,6 +313,8 @@ pub mod prelude {
     pub use crate::mysql::MysqlConnection;
     #[cfg(feature = "postgres")]
     pub use crate::pg::PgConnection;
+    #[cfg(feature = "unstable_pure_rust_postgres")]
+    pub use crate::pg::PostgresConnection;
     #[cfg(feature = "sqlite")]
     pub use crate::sqlite::SqliteConnection;
 }

diesel/src/macros/mod.rs

@@ -1117,7 +1117,7 @@ mod tests {
     }
 
     #[test]
-    #[cfg(feature = "postgres")]
+    #[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
     fn table_with_custom_schema() {
         use crate::pg::Pg;
         let expected_sql = r#"SELECT "foo"."bars"."baz" FROM "foo"."bars" -- binds: []"#;
@@ -1158,7 +1158,7 @@ mod tests {
     );
 
     #[test]
-    #[cfg(feature = "postgres")]
+    #[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
     fn table_with_column_renaming_postgres() {
         use crate::pg::Pg;
         let expected_sql =
@@ -1205,7 +1205,7 @@ mod tests {
     );
 
     #[test]
-    #[cfg(feature = "postgres")]
+    #[cfg(any(feature = "postgres", feature = "unstable_pure_rust_postgres"))]
     fn table_renaming_postgres() {
         use crate::pg::Pg;
         let expected_sql = r#"SELECT "mod"."id" FROM "mod" -- binds: []"#;

diesel/src/migration/mod.rs

@@ -87,6 +87,14 @@ impl MigrationConnection for crate::pg::PgConnection {
     }
 }
 
+#[cfg(feature = "unstable_pure_rust_postgres")]
+impl MigrationConnection for crate::pg::PostgresConnection {
+    fn setup(&self) -> QueryResult<usize> {
+        use crate::RunQueryDsl;
+        crate::sql_query(CREATE_MIGRATIONS_TABLE).execute(self)
+    }
+}
+
 #[cfg(feature = "mysql")]
 impl MigrationConnection for crate::mysql::MysqlConnection {
     fn setup(&self) -> QueryResult<usize> {

diesel/src/pg/connection/mod.rs

@@ -132,7 +132,7 @@ impl PgConnection {
     ///     .run(|| Ok(()))
     /// # }
     /// ```
-    pub fn build_transaction(&self) -> TransactionBuilder {
+    pub fn build_transaction(&self) -> TransactionBuilder<Self> {
         TransactionBuilder::new(self)
     }
 

diesel/src/pg/expression/extensions/interval_dsl.rs

@@ -248,14 +248,19 @@ mod tests {
     use crate::prelude::*;
     use crate::{select, sql_types};
 
+    #[cfg(feature = "postgres")]
+    type DbConnection = PgConnection;
+    #[cfg(feature = "unstable_pure_rust_postgres")]
+    type DbConnection = PostgresConnection;
+
     thread_local! {
-        static CONN: PgConnection = {
+        static CONN: DbConnection = {
             dotenv().ok();
 
             let connection_url = ::std::env::var("PG_DATABASE_URL")
                 .or_else(|_| ::std::env::var("DATABASE_URL"))
                 .expect("DATABASE_URL must be set in order to run tests");
-            PgConnection::establish(&connection_url).unwrap()
+            DbConnection::establish(&connection_url).unwrap()
         }
     }