Struct dittolive_ditto::store::dql::QueryResultItem

pub struct QueryResultItem { /* private fields */ }

Represents a single match of a DQL query, similar to a “row” in SQL terms. It’s a reference type serving as a “cursor”, allowing for efficient access of the underlying data in various formats.

The row is lazily materialized and kept in memory until it goes out of scope. To reduce the memory footprint, access the items using the provided iterator.

let cars: Vec<Car> = all_cars_query_result
    .iter()
    .map(|query_result_item| query_result_item.deserialize_value().unwrap())
    .collect();

Implementations

impl QueryResultItem

pub fn value(&self) -> Arc<HashMap<Box<str>, Value>>

Returns the content as a materialized object.

The item’s value is .materialize()-ed on first access and subsequently on each access after performing .dematerialize(). Once materialized, the value is kept in memory until explicitly .dematerialize()-ed or the item goes out of scope.

pub fn is_materialized(&self) -> bool

Returns true if value is currently held materialized in memory, otherwise returns false.

See Also

• Self::materialize()
• Self::dematerialize()

pub fn materialize(&mut self)

Loads the CBOR representation of the item’s content, decodes it as a dictionary so it can be accessed via .value(). Keeps the dictionary in memory until .dematerialize() is called. No-op if value is already materialized.

pub fn dematerialize(&mut self)

Releases the materialized value from memory. No-op if item is not materialized.

pub fn cbor_data(&self) -> Vec<u8>

Return the content of the item as a CBOR slice.

Important: The returned CBOR slice is not cached, make sure to call this method once and keep it for as long as needed.

pub fn json_string(&self) -> String

Return the content of the item as a JSON string.

Important: The returned JSON string is not cached, make sure to call this method once and keep it for as long as needed.

pub fn deserialize_value<T: DeserializeOwned>(&self) -> Result<T, DittoError>

Convenience around Self::cbor_data() deserialize-ing the value.

Important: The returned value is not cached, make sure to call this method once and keep it for as long as needed.

Trait Implementations

impl From<Box<DqlResult>> for QueryResultItem

fn from(raw: Box<DqlResult>) -> Self

Converts to this type from the input type.