use super::*;use time::Duration;use time::OffsetDateTime; impl Database {    pub async fn get_embeddings(        &self,        model: &str,        digests: &[Vec<u8>],    ) -> Result<HashMap<Vec<u8>, Vec<f32>>> {        self.weak_transaction(|tx| async move {            let embeddings = {                let mut db_embeddings = embedding::Entity::find()                    .filter(                        embedding::Column::Model.eq(model).and(                            embedding::Column::Digest                                .is_in(digests.iter().map(|digest| digest.as_slice())),                        ),                    )                    .stream(&*tx)                    .await?;                 let mut embeddings = HashMap::default();                while let Some(db_embedding) = db_embeddings.next().await {                    let db_embedding = db_embedding?;                    embeddings.insert(db_embedding.digest, db_embedding.dimensions);                }                embeddings            };             if !embeddings.is_empty() {                let now = OffsetDateTime::now_utc();                let retrieved_at = PrimitiveDateTime::new(now.date(), now.time());                 embedding::Entity::update_many()                    .filter(                        embedding::Column::Digest                            .is_in(embeddings.keys().map(|digest| digest.as_slice())),                    )                    .col_expr(embedding::Column::RetrievedAt, Expr::value(retrieved_at))                    .exec(&*tx)                    .await?;            }             Ok(embeddings)        })        .await    }     pub async fn save_embeddings(        &self,        model: &str,        embeddings: &HashMap<Vec<u8>, Vec<f32>>,    ) -> Result<()> {        self.weak_transaction(|tx| async move {            embedding::Entity::insert_many(embeddings.iter().map(|(digest, dimensions)| {                let now_offset_datetime = OffsetDateTime::now_utc();                let retrieved_at =                    PrimitiveDateTime::new(now_offset_datetime.date(), now_offset_datetime.time());                 embedding::ActiveModel {                    model: ActiveValue::set(model.to_string()),                    digest: ActiveValue::set(digest.clone()),                    dimensions: ActiveValue::set(dimensions.clone()),                    retrieved_at: ActiveValue::set(retrieved_at),                }            }))            .on_conflict(                OnConflict::columns([embedding::Column::Model, embedding::Column::Digest])                    .do_nothing()                    .to_owned(),            )            .exec_without_returning(&*tx)            .await?;            Ok(())        })        .await    }     pub async fn purge_old_embeddings(&self) -> Result<()> {        self.weak_transaction(|tx| async move {            embedding::Entity::delete_many()                .filter(                    embedding::Column::RetrievedAt                        .lte(OffsetDateTime::now_utc() - Duration::days(60)),                )                .exec(&*tx)                .await?;             Ok(())        })        .await    }}