Merge pull request #89 from myaple/dev/diesel-postgis

Adds diesel support for Ewkb type for postgis

geozero/Cargo.toml

@@ -25,6 +25,7 @@ with-gpkg = ["with-wkb", "sqlx/sqlite"]
 with-gpx = ["gpx"]
 with-postgis-sqlx = ["with-wkb", "sqlx/postgres"]
 with-postgis-postgres = ["with-wkb", "postgres-types", "bytes"]
+with-postgis-diesel = ["with-wkb", "diesel", "byteorder"]
 with-mvt = ["prost", "prost-build"]
 with-tessellator = ["lyon"]
 
@@ -42,6 +43,8 @@ lyon = { version = "1.0", optional = true }
 log = "0.4.17"
 scroll = { version = "0.11", optional = true }
 sqlx = { version = "0.6", default-features = false, optional = true }
+diesel = { version = "2.0.2", default-features = false, optional = true }
+byteorder = { version = "1.4.3", default-features = false, optional = true }
 postgres-types = { version = "0.2", optional = true }
 bytes = { version = "1.0", optional = true }
 prost = { version = "0.11.0", optional = true }
@@ -59,6 +62,7 @@ flatgeobuf = "3.24.0"
 #flatgeobuf = { git = "https://github.com/pka/flatgeobuf", branch="geozero-0.9" }
 postgres = "0.19"
 sqlx = { version = "0.6", default-features = false, features = [ "runtime-tokio-native-tls", "macros", "time", "postgres", "sqlite" ] }
+diesel = { version = "2.0.2", default-features = false, features = [ "postgres" ] }
 tokio = { version = "1.17.0", default-features = false, features = ["macros"] }
 
 [build-dependencies]

geozero/src/lib.rs

@@ -78,7 +78,11 @@ pub mod gpkg;
 #[cfg(feature = "with-gpx")]
 pub mod gpx;
 
-#[cfg(any(feature = "with-postgis-postgres", feature = "with-postgis-sqlx"))]
+#[cfg(any(
+    feature = "with-postgis-postgres",
+    feature = "with-postgis-sqlx",
+    feature = "with-postgis-diesel"
+))]
 pub mod postgis;
 
 #[cfg(feature = "with-svg")]

geozero/src/postgis/mod.rs

@@ -3,6 +3,8 @@
 //! All geometry types implementing [GeozeroGeometry](crate::GeozeroGeometry) can be encoded as PostGIS EWKB geometry using [wkb::Encode](crate::wkb::Encode).
 //!
 //! Geometry types implementing [FromWkb](crate::wkb::FromWkb) can be decoded from PostGIS geometries using [wkb::Decode](crate::wkb::Decode).
+#[cfg(feature = "with-postgis-diesel")]
+mod postgis_diesel;
 #[cfg(feature = "with-postgis-postgres")]
 mod postgis_postgres;
 #[cfg(feature = "with-postgis-sqlx")]
@@ -89,3 +91,67 @@ pub mod postgres {
 pub mod sqlx {
     pub use super::postgis_sqlx::*;
 }
+
+/// Postgis geometry type encoding for Diesel.
+///
+/// # PostGIS usage example with Diesel
+///
+/// Declare model and select Ewkb types directly with GeoZero and Diesel
+///
+/// ```
+/// use diesel::pg::PgConnection;
+/// use diesel::{Connection, QueryDsl, RunQueryDsl};
+/// use diesel::prelude::*;
+///
+/// use geozero::wkb::Ewkb;
+///
+/// diesel::table! {
+///     use diesel::sql_types::*;
+///     use geozero::postgis::diesel::sql_types::*;
+///
+///     geometries (name) {
+///         name -> Varchar,
+///         geom -> Nullable<Geometry>,
+///     }
+/// }
+///
+/// #[derive(Queryable, Debug, Insertable)]
+/// #[diesel(table_name = geometries)]
+/// pub struct Geom {
+///     pub name: String,
+///     pub geom: Option<Ewkb>,
+/// }
+///
+/// pub fn establish_connection() -> PgConnection {
+///     let database_url = std::env::var("DATABASE_URL").expect("Unable to find database url.");
+///     PgConnection::establish(&database_url).unwrap()
+/// }
+///
+/// # async fn rust_geo_query() -> Result<(), diesel::result::Error> {
+/// let conn = &mut establish_connection();
+///
+/// let wkb = Ewkb(vec![
+///     1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 36, 64, 0, 0, 0, 0, 0, 0, 52, 192,
+/// ]);
+///
+/// let insert_geometry = Geom {
+///     name: "GeoZeroTest".to_string(),
+///     geom: Some(wkb),
+/// };
+///
+/// let inserted: Geom = diesel::insert_into(geometries::table)
+///     .values(&insert_geometry)
+///     .get_result(conn)
+///     .expect("Unable to insert into postgis");
+///
+/// let geometry_vec: Vec<Geom> = geometries::dsl::geometries
+///     .limit(10)
+///     .load::<Geom>(conn)
+///     .expect("Error loading geometries");
+/// # Ok(())
+/// # }
+/// ```
+#[cfg(feature = "with-postgis-diesel")]
+pub mod diesel {
+    pub use super::postgis_diesel::*;
+}

geozero/src/postgis/postgis_diesel.rs

@@ -0,0 +1,51 @@
+use crate::postgis::postgis_diesel::sql_types::*;
+use crate::wkb::Ewkb;
+
+use byteorder::WriteBytesExt;
+
+use diesel::deserialize::{self, FromSql};
+use diesel::pg::{self, Pg};
+use diesel::serialize::{self, IsNull, Output, ToSql};
+
+pub mod sql_types {
+    use diesel::query_builder::QueryId;
+    use diesel::sql_types::SqlType;
+
+    #[derive(SqlType, QueryId)]
+    #[diesel(postgres_type(name = "geometry"))]
+    pub struct Geometry;
+
+    #[derive(SqlType, QueryId)]
+    #[diesel(postgres_type(name = "geography"))]
+    pub struct Geography;
+}
+
+impl ToSql<Geometry, Pg> for Ewkb {
+    fn to_sql(&self, out: &mut Output<Pg>) -> serialize::Result {
+        for ewkb_byte in &self.0 {
+            out.write_u8(*ewkb_byte)?;
+        }
+        Ok(IsNull::No)
+    }
+}
+
+impl ToSql<Geography, Pg> for Ewkb {
+    fn to_sql(&self, out: &mut Output<Pg>) -> serialize::Result {
+        for ewkb_byte in &self.0 {
+            out.write_u8(*ewkb_byte)?;
+        }
+        Ok(IsNull::No)
+    }
+}
+
+impl FromSql<Geometry, Pg> for Ewkb {
+    fn from_sql(bytes: pg::PgValue) -> deserialize::Result<Self> {
+        Ok(Self(bytes.as_bytes().to_vec()))
+    }
+}
+
+impl FromSql<Geography, Pg> for Ewkb {
+    fn from_sql(bytes: pg::PgValue) -> deserialize::Result<Self> {
+        Ok(Self(bytes.as_bytes().to_vec()))
+    }
+}

geozero/src/wkb/wkb_reader.rs

@@ -4,6 +4,11 @@ use crate::{GeomProcessor, GeozeroGeometry};
 use scroll::IOread;
 use std::io::Read;
 
+#[cfg(feature = "with-postgis-diesel")]
+use crate::postgis::diesel::sql_types::{Geography, Geometry};
+#[cfg(feature = "with-postgis-diesel")]
+use diesel::expression::AsExpression;
+
 /// WKB reader.
 pub struct Wkb(pub Vec<u8>);
 
@@ -14,6 +19,12 @@ impl GeozeroGeometry for Wkb {
 }
 
 /// EWKB reader.
+#[cfg_attr(
+    feature = "with-postgis-diesel",
+    derive(Debug, AsExpression, PartialEq)
+)]
+#[cfg_attr(feature = "with-postgis-diesel", diesel(sql_type = Geometry))]
+#[cfg_attr(feature = "with-postgis-diesel", diesel(sql_type = Geography))]
 pub struct Ewkb(pub Vec<u8>);
 
 impl GeozeroGeometry for Ewkb {