Draft for Repository

tbd-core/Cargo.toml

@@ -6,4 +6,5 @@ authors = ["Katharina Fey <[email protected]>"]
 [dependencies]
 
 # Remove this again soon
-rusqlite = "0.13.0"
+sqlite = "0.23.9"
+futures = "0.1"

tbd-core/src/lib.rs

@@ -1,8 +1,8 @@
 //! Shared code and data mapper
 
-extern crate rusqlite;
+extern crate sqlite;
+extern crate futures;
 
-mod mapping;
-mod db_tool;
+pub mod repository;
 
-pub use mapping::test_this;
+//pub use mapping::test_this;

tbd-core/src/repository.rs

@@ -0,0 +1,24 @@
+use futures::{Future, Stream};
+
+pub type Error = String;
+
+pub trait Queryable<Model> {
+    fn query(&self, q: Query) -> Box<Stream<Item = Model, Error = String>>;
+}
+
+pub enum Query {
+    All,
+}
+
+pub trait KVRespository {
+    type Error;
+
+    fn get<M: 'static>(pk: i64) -> Box<Future<Item = M, Error = Self::Error>>;
+}
+
+pub trait Repository {
+    fn query<M: 'static>(&self, q: Query) -> Box<Stream<Item = M, Error = Error>>
+    where
+        Self: Queryable<M>;
+}
+

tbd-core/tests/sqlite_repos.rs

@@ -0,0 +1,39 @@
+extern crate futures;
+extern crate sqlite;
+extern crate tbd_core;
+
+mod sqlite_repository;
+
+use sqlite_repository::*;
+
+use tbd_core::repository::{Query, Repository};
+
+use futures::{Future, Stream};
+
+#[test]
+fn test() {
+    let connection = sqlite::open(":memory:").unwrap();
+
+    connection
+        .execute(
+            "
+                CREATE TABLE users (name TEXT, age INTEGER);
+                INSERT INTO users (name, age) VALUES ('Alice', 42);
+                INSERT INTO users (name, age) VALUES ('Bob', 69);
+                ",
+        )
+        .unwrap();
+
+    let repo = SqliteRepository {
+        connection: connection,
+    };
+    let result = repo.query::<User>(Query::All);
+
+    result
+        .for_each(|u| {
+            println!("{:?}", u);
+            Ok(())
+        })
+        .wait()
+        .unwrap();
+}

tbd-core/tests/sqlite_repository/mod.rs

@@ -0,0 +1,46 @@
+use futures;
+use futures::Stream;
+use sqlite;
+use sqlite::Value;
+use tbd_core::repository::*;
+
+pub struct SqliteRepository {
+    pub connection: sqlite::Connection,
+}
+
+impl Repository for SqliteRepository {
+    fn query<M: 'static>(&self, q: Query) -> Box<Stream<Item = M, Error = String>>
+    where
+        Self: Queryable<M>,
+    {
+        <Self as Queryable<M>>::query(self, q)
+    }
+}
+
+#[derive(Debug)]
+pub struct User {
+    name: String,
+    age: i8,
+}
+
+impl Queryable<User> for SqliteRepository {
+    fn query(&self, _q: Query) -> Box<Stream<Item = User, Error = Error>> {
+        let mut cursor = self.connection
+            .prepare("SELECT * FROM users WHERE age > ?")
+            .unwrap()
+            .cursor();
+
+        cursor.bind(&[Value::Integer(50)]).unwrap();
+
+        let mut results = Vec::new();
+
+        while let Some(row) = cursor.next().unwrap() {
+            results.push(User {
+                name: row[0].as_string().unwrap().into(),
+                age: row[1].as_integer().unwrap() as i8,
+            });
+        }
+
+        Box::new(futures::stream::iter_ok(results.into_iter()))
+    }
+}