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,
        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 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, 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 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”.

Implementors