Struct Layout 

pub struct Layout<'a> {
    pub _tab: Table<'a>,
}

A Layout is a recursive data structure describing the physical layout of Vortex arrays in random access storage. As a starting, concrete example, the first three Layout encodings are defined as:

1. encoding == 1, Flat -> one buffer, zero child Layouts
2. encoding == 2, Chunked -> zero buffers, one or more child Layouts (used for chunks of rows)
3. encoding == 3, Columnar -> zero buffers, one or more child Layouts (used for columns of structs)

The row_count represents the number of rows represented by this Layout. This is very useful for pruning the Layout tree based on row filters.

The metadata field is fully opaque at this layer, and allows the Layout implementation corresponding to encoding to embed additional information that may be useful for the reader. For example, the ChunkedLayout uses the first byte of the metadata array as a boolean to indicate whether the first child Layout represents the statistics table for the other chunks.

Fields

_tab: Table<'a>

Implementations

impl<'a> Layout<'a>

pub const VT_ENCODING: VOffsetT = 4u16

pub const VT_ROW_COUNT: VOffsetT = 6u16

pub const VT_METADATA: VOffsetT = 8u16

pub const VT_CHILDREN: VOffsetT = 10u16

pub const VT_SEGMENTS: VOffsetT = 12u16

pub unsafe fn init_from_table(table: Table<'a>) -> Self

pub fn create<'bldr: 'args, 'args: 'mut_bldr, 'mut_bldr, A: Allocator + 'bldr>( _fbb: &'mut_bldr mut FlatBufferBuilder<'bldr, A>, args: &'args LayoutArgs<'args>, ) -> WIPOffset<Layout<'bldr>>

pub fn encoding(&self) -> u16

The ID of the encoding used for this Layout.

pub fn row_count(&self) -> u64

The number of rows of data represented by this Layout.

pub fn metadata(&self) -> Option<Vector<'a, u8>>

Any additional metadata this layout needs to interpret its children. This does not include data-specific metadata, which the layout should store in a segment.

pub fn children(&self) -> Option<Vector<'a, ForwardsUOffset<Layout<'a>>>>

The children of this Layout.

pub fn segments(&self) -> Option<Vector<'a, u32>>

Identifiers for each SegmentSpec of data required by this layout.

Trait Implementations

impl<'a> Clone for Layout<'a>

fn clone(&self) -> Layout<'a>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Layout<'_>

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

Formats the value using the given formatter.

impl<'a> Follow<'a> for Layout<'a>

type Inner = Layout<'a>

unsafe fn follow(buf: &'a [u8], loc: usize) -> Self::Inner

Safety

impl<'a> PartialEq for Layout<'a>

fn eq(&self, other: &Layout<'a>) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Verifiable for Layout<'_>

fn run_verifier( v: &mut Verifier<'_, '_>, pos: usize, ) -> Result<(), InvalidFlatbuffer>

Runs the verifier for this type, assuming its at position pos in the verifier’s buffer. Should not need to be called directly.

impl<'a> Copy for Layout<'a>

impl<'a> StructuralPartialEq for Layout<'a>