fix: cleanups and comments

Author: FGoessler

schema-engine/commands/src/commands/create_migration.rs

@@ -31,15 +31,14 @@ pub async fn create_migration(
     let previous_migrations = list_migrations(input.migrations_list.migration_directories.clone());
     let sources: Vec<_> = input.schema.to_psl_input();
     let dialect = connector.schema_dialect();
-
+    // We need to start with the 'to', which is the Schema, in order to grab the
+    // namespaces, in case we've got MultiSchema enabled.
     let to = dialect.schema_from_datamodel(sources.clone())?;
 
     let from = migration_schema_cache
         .get_or_insert(&input.migrations_list.migration_directories, || async {
             let namespaces = dialect.extract_namespaces(&to);
-            // TODO(MultiSchema): we may need to do something similar to
-            // namespaces_and_preview_features_from_diff_targets here as well,
-            // particularly if it's not correctly setting the preview features flags.
+            // We pass the namespaces here, because we want to describe all of these namespaces.
             connector.schema_from_migrations(&previous_migrations, namespaces).await
         })
         .await?;

schema-engine/commands/src/commands/diagnose_migration_history.rs

@@ -147,7 +147,6 @@ pub async fn diagnose_migration_history(
                         .await
                 })
                 .await;
-
             let to = connector.schema_from_database(namespaces.clone()).await;
             let drift = match from.and_then(|from| to.map(|to| dialect.diff(from, to))).map(|mig| {
                 if dialect.migration_is_empty(&mig) {

schema-engine/commands/src/migration_schema_cache.rs

@@ -4,7 +4,7 @@ use std::hash::{Hash, Hasher};
 
 use schema_connector::DatabaseSchema;
 
-/// A cache for migrations to avoid redundant work during `prisma migrate dev`.
+/// A cache for DatabaseSchemas based on the migration directories to avoid redundant work during `prisma migrate dev`.
 pub struct MigrationSchemaCache {
     migrations: HashMap<String, DatabaseSchema>,
 }
@@ -17,7 +17,7 @@ impl MigrationSchemaCache {
         }
     }
 
-    /// Gets a migration from the cache, or computes it using the provided async closure if not found.
+    /// Gets a DatabaseSchema from the cache, or calls the provided async closure if not found and stores its result in the cache.
     pub async fn get_or_insert<F, Fut, E, T>(
         &mut self,
         migration_directories: &Vec<T>,
@@ -28,25 +28,16 @@ impl MigrationSchemaCache {
         Fut: std::future::Future<Output = Result<DatabaseSchema, E>>,
         T: Hash,
     {
-        let key = self.cache_key(migration_directories);
+        let mut hasher = DefaultHasher::new();
+        migration_directories.hash(&mut hasher);
+        let cache_key = hasher.finish().to_string();
 
-        if !self.migrations.contains_key(&key) {
-            println!("Cache miss for key: {}", key);
+        if !self.migrations.contains_key(&cache_key) {
             let schema = f().await?;
-            self.migrations.insert(key.clone(), schema);
-        } else {
-            println!("Cache hit for key: {}", key);
+            self.migrations.insert(cache_key.clone(), schema);
         }
 
-        Ok(self.migrations.get(&key).unwrap().clone())
-    }
-
-    fn cache_key<T: Hash>(&self, migration_directories: &Vec<T>) -> String {
-        let mut hasher = DefaultHasher::new();
-
-        migration_directories.hash(&mut hasher);
-
-        hasher.finish().to_string()
+        Ok(self.migrations.get(&cache_key).unwrap().clone())
     }
 }
 

schema-engine/core/src/state.rs

@@ -36,7 +36,7 @@ pub(crate) struct EngineState {
     //
     // To a channel leading to a spawned MigrationConnector.
     connectors: Mutex<HashMap<ConnectorRequestType, mpsc::Sender<ErasedConnectorRequest>>>,
-    /// The cache for migrations to avoid redundant work during `prisma migrate dev`.
+    /// The cache for DatabaseSchemas based of migration directories to avoid redundant work during `prisma migrate dev`.
     migration_schema_cache: Arc<Mutex<MigrationSchemaCache>>,
 }
 

schema-engine/schema-engine-wasm/src/wasm/engine.rs

@@ -72,7 +72,7 @@ pub struct SchemaEngine {
     /// The dispatcher for tracing.
     dispatch: Dispatch,
 
-    /// The cache for migrations to avoid redundant work during `prisma migrate dev`.
+    /// The cache for DatabaseSchemas based of migration directories to avoid redundant work during `prisma migrate dev`.
     migration_schema_cache: MigrationSchemaCache,
 }
 

schema-engine/sql-schema-describer/src/connector_data.rs

@@ -41,7 +41,7 @@ impl<'de> Deserialize<'de> for ConnectorData {
 
 impl Clone for ConnectorData {
     fn clone(&self) -> Self {
-        let cloned_data = self.data.as_ref().map(|d| (&**d).clone_box());
+        let cloned_data = self.data.as_ref().map(|d| (**d).clone_box());
 
         ConnectorData { data: cloned_data }
     }