Move crates to subdirectory

crates/database/src/lib.rs

@@ -0,0 +1,66 @@
+// Required for schema.rs
+#[macro_use]
+extern crate diesel;
+
+// Required for embed_migrations macro in database.rs
+#[macro_use]
+extern crate diesel_migrations;
+
+use diesel::prelude::*;
+use log::info;
+
+pub mod ensembles;
+pub use ensembles::*;
+
+pub mod error;
+pub use error::*;
+
+pub mod instruments;
+pub use instruments::*;
+
+pub mod medium;
+pub use medium::*;
+
+pub mod persons;
+pub use persons::*;
+
+pub mod recordings;
+pub use recordings::*;
+
+pub mod works;
+pub use works::*;
+
+mod schema;
+
+// This makes the SQL migration scripts accessible from the code.
+embed_migrations!();
+
+/// Generate a random string suitable as an item ID.
+pub fn generate_id() -> String {
+    uuid::Uuid::new_v4().simple().to_string()
+}
+
+/// Interface to a Musicus database.
+pub struct Database {
+    connection: SqliteConnection,
+}
+
+impl Database {
+    /// Create a new database interface and run migrations if necessary.
+    pub fn new(file_name: &str) -> Result<Database> {
+        info!("Opening database file '{}'", file_name);
+        let connection = SqliteConnection::establish(file_name)?;
+        diesel::sql_query("PRAGMA foreign_keys = ON").execute(&connection)?;
+
+        info!("Running migrations if necessary");
+        embedded_migrations::run(&connection)?;
+
+        Ok(Database { connection })
+    }
+
+    /// Defer all foreign keys for the next transaction.
+    fn defer_foreign_keys(&self) -> Result<()> {
+        diesel::sql_query("PRAGMA defer_foreign_keys = ON").execute(&self.connection)?;
+        Ok(())
+    }
+}