Enum lance_io::ReadBatchParams

pub enum ReadBatchParams {
    Range(Range<usize>),
    RangeFull,
    RangeTo(RangeTo<usize>),
    RangeFrom(RangeFrom<usize>),
    Indices(UInt32Array),
}

Defines a selection of rows to read from a file/batch

Variants

Range(Range<usize>)

Select a contiguous range of rows

RangeFull

Select all rows (this is the default)

RangeTo(RangeTo<usize>)

Select all rows up to a given index

RangeFrom(RangeFrom<usize>)

Select all rows starting at a given index

Indices(UInt32Array)

Select scattered non-contiguous rows

Implementations

impl ReadBatchParams

pub fn valid_given_len(&self, len: usize) -> bool

Validate that the selection is valid given the length of the batch

pub fn slice(&self, start: usize, length: usize) -> Result<Self>

Slice the selection

For example, given ReadBatchParams::RangeFull and slice(10, 20), the output will be ReadBatchParams::Range(10..20)

Given ReadBatchParams::Range(10..20) and slice(5, 3), the output will be ReadBatchParams::Range(15..18)

Given ReadBatchParams::RangeTo(20) and slice(10, 5), the output will be ReadBatchParams::Range(10..15)

Given ReadBatchParams::RangeFrom(20) and slice(10, 5), the output will be ReadBatchParams::Range(30..35)

Given ReadBatchParams::Indices([1, 3, 5, 7, 9]) and slice(1, 3), the output will be ReadBatchParams::Indices([3, 5, 7])

You cannot slice beyond the bounds of the selection and an attempt to do so will return an error.

pub fn to_offsets(&self) -> Result<PrimitiveArray<UInt32Type>>

Convert a read range into a vector of row offsets

RangeFull and RangeFrom are unbounded and cannot be converted into row offsets and any attempt to do so will return an error. Call slice first

Trait Implementations

impl<'a, T: ByteArrayType> AsyncIndex<ReadBatchParams> for BinaryDecoder<'a, T>

type Output = Result<Arc<dyn Array>, Error>

fn get<'life0, 'async_trait>( &'life0 self, params: ReadBatchParams, ) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

impl<'a> AsyncIndex<ReadBatchParams> for DictionaryDecoder<'a>

type Output = Result<Arc<dyn Array>, Error>

fn get<'life0, 'async_trait>( &'life0 self, params: ReadBatchParams, ) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

impl AsyncIndex<ReadBatchParams> for PlainDecoder<'_>

type Output = Result<Arc<dyn Array>, Error>

fn get<'life0, 'async_trait>( &'life0 self, params: ReadBatchParams, ) -> Pin<Box<dyn Future<Output = Self::Output> + Send + 'async_trait>>

where Self: 'async_trait, 'life0: 'async_trait,

impl Clone for ReadBatchParams

fn clone(&self) -> ReadBatchParams

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ReadBatchParams

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for ReadBatchParams

fn default() -> Self

Returns the “default value” for a type.

impl Display for ReadBatchParams

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<&[u32]> for ReadBatchParams

fn from(value: &[u32]) -> Self

Converts to this type from the input type.

impl From<&ReadBatchParams> for ReadBatchParams

fn from(params: &Self) -> Self

Converts to this type from the input type.

impl From<PrimitiveArray<UInt32Type>> for ReadBatchParams

fn from(value: UInt32Array) -> Self

Converts to this type from the input type.

impl From<Range<usize>> for ReadBatchParams

fn from(r: Range<usize>) -> Self

Converts to this type from the input type.

impl From<RangeFrom<usize>> for ReadBatchParams

fn from(r: RangeFrom<usize>) -> Self

Converts to this type from the input type.

impl From<RangeFull> for ReadBatchParams

fn from(_: RangeFull) -> Self

Converts to this type from the input type.

impl From<RangeTo<usize>> for ReadBatchParams

fn from(r: RangeTo<usize>) -> Self

Converts to this type from the input type.