Trait VirtualServerHandler 

pub trait VirtualServerHandler {
    type Error: Error + Send + Sync + 'static;

    // Required methods
    fn get_hosted_tables(
        &self,
    ) -> VirtualServerFuture<'_, Result<Vec<HostedTable>, Self::Error>>;
    fn table_schema(
        &self,
        table_id: &str,
    ) -> VirtualServerFuture<'_, Result<IndexMap<String, ColumnType>, Self::Error>>;
    fn table_size(
        &self,
        table_id: &str,
    ) -> VirtualServerFuture<'_, Result<u32, Self::Error>>;
    fn table_make_view(
        &mut self,
        view_id: &str,
        view_id: &str,
        config: &mut ViewConfigUpdate,
    ) -> VirtualServerFuture<'_, Result<String, Self::Error>>;
    fn view_delete(
        &self,
        view_id: &str,
    ) -> VirtualServerFuture<'_, Result<(), Self::Error>>;
    fn view_get_data(
        &self,
        view_id: &str,
        config: &ViewConfig,
        schema: &IndexMap<String, ColumnType>,
        viewport: &ViewPort,
    ) -> VirtualServerFuture<'_, Result<VirtualDataSlice, Self::Error>>;

    // Provided methods
    fn table_column_size(
        &self,
        table_id: &str,
    ) -> VirtualServerFuture<'_, Result<u32, Self::Error>> { ... }
    fn view_size(
        &self,
        view_id: &str,
    ) -> VirtualServerFuture<'_, Result<u32, Self::Error>> { ... }
    fn view_column_size(
        &self,
        view_id: &str,
        config: &ViewConfig,
    ) -> VirtualServerFuture<'_, Result<u32, Self::Error>> { ... }
    fn view_schema(
        &self,
        view_id: &str,
        _config: &ViewConfig,
    ) -> VirtualServerFuture<'_, Result<IndexMap<String, ColumnType>, Self::Error>> { ... }
    fn table_validate_expression(
        &self,
        _table_id: &str,
        _expression: &str,
    ) -> VirtualServerFuture<'_, Result<ColumnType, Self::Error>> { ... }
    fn get_features(
        &self,
    ) -> VirtualServerFuture<'_, Result<Features<'_>, Self::Error>> { ... }
    fn table_make_port(
        &self,
        _req: &TableMakePortReq,
    ) -> VirtualServerFuture<'_, Result<u32, Self::Error>> { ... }
    fn view_get_min_max(
        &self,
        _view_id: &str,
        _column_name: &str,
        _config: &ViewConfig,
    ) -> VirtualServerFuture<'_, Result<(Scalar, Scalar), Self::Error>> { ... }
    fn make_table(
        &mut self,
        _table_id: &str,
        _data: &MakeTableData,
    ) -> VirtualServerFuture<'_, Result<(), Self::Error>> { ... }
}

Handler trait for implementing virtual server backends.

This trait defines the interface that must be implemented to provide a custom data source for the Perspective virtual server. Implementors handle table and view operations, translating them to their underlying data store.

Required Associated Types

type Error: Error + Send + Sync + 'static

The error type returned by handler methods.

Required Methods

fn get_hosted_tables( &self, ) -> VirtualServerFuture<'_, Result<Vec<HostedTable>, Self::Error>>

Returns a list of all tables hosted by this handler.

fn table_schema( &self, table_id: &str, ) -> VirtualServerFuture<'_, Result<IndexMap<String, ColumnType>, Self::Error>>

Returns the schema (column names and types) for a table.

fn table_size( &self, table_id: &str, ) -> VirtualServerFuture<'_, Result<u32, Self::Error>>

Returns the number of rows in a table.

fn table_make_view( &mut self, view_id: &str, view_id: &str, config: &mut ViewConfigUpdate, ) -> VirtualServerFuture<'_, Result<String, Self::Error>>

Creates a new view on a table with the given configuration.

The handler may modify the configuration to reflect any adjustments made during view creation.

fn view_delete( &self, view_id: &str, ) -> VirtualServerFuture<'_, Result<(), Self::Error>>

Deletes a view and releases its resources.

fn view_get_data( &self, view_id: &str, config: &ViewConfig, schema: &IndexMap<String, ColumnType>, viewport: &ViewPort, ) -> VirtualServerFuture<'_, Result<VirtualDataSlice, Self::Error>>

Retrieves data from a view within the specified viewport.

Provided Methods

fn table_column_size( &self, table_id: &str, ) -> VirtualServerFuture<'_, Result<u32, Self::Error>>

Return the column count of a Table

fn view_size( &self, view_id: &str, ) -> VirtualServerFuture<'_, Result<u32, Self::Error>>

Returns the number of rows in a View.

fn view_column_size( &self, view_id: &str, config: &ViewConfig, ) -> VirtualServerFuture<'_, Result<u32, Self::Error>>

Return the column count of a View

fn view_schema( &self, view_id: &str, _config: &ViewConfig, ) -> VirtualServerFuture<'_, Result<IndexMap<String, ColumnType>, Self::Error>>

Returns the schema of a view after applying its configuration.

fn table_validate_expression( &self, _table_id: &str, _expression: &str, ) -> VirtualServerFuture<'_, Result<ColumnType, Self::Error>>

Validates an expression against a table and returns its result type.

Default implementation returns Float for all expressions.

fn get_features( &self, ) -> VirtualServerFuture<'_, Result<Features<'_>, Self::Error>>

Returns the features supported by this handler.

Default implementation returns default features.

fn table_make_port( &self, _req: &TableMakePortReq, ) -> VirtualServerFuture<'_, Result<u32, Self::Error>>

Creates a new input port on a table.

Default implementation returns port ID 0.

fn view_get_min_max( &self, _view_id: &str, _column_name: &str, _config: &ViewConfig, ) -> VirtualServerFuture<'_, Result<(Scalar, Scalar), Self::Error>>

Returns the min and max values of a column in a view.

Default implementation panics with “not implemented”.

fn make_table( &mut self, _table_id: &str, _data: &MakeTableData, ) -> VirtualServerFuture<'_, Result<(), Self::Error>>

Creates a new table with the given data.

Default implementation panics with “not implemented”.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors