Struct ConstantLayout 

pub struct ConstantLayout {
    pub layers: Vec<i32>,
    pub inline_value: Option<Bytes>,
    pub rep_compression: Option<CompressiveEncoding>,
    pub def_compression: Option<CompressiveEncoding>,
    pub num_rep_values: u64,
    pub num_def_values: u64,
}

A layout used for pages where all (visible) values are the same scalar value.

This generalizes the prior AllNullLayout semantics for file_version >= 2.2.

There may be buffers of repetition and definition information if required in order to interpret what kind of nulls are present / which items are visible.

Fields

layers: Vec<i32>

The meaning of each repdef layer, used to interpret repdef buffers correctly

inline_value: Option<Bytes>

Inline fixed-width scalar value bytes.

This MUST only be used for types where a single non-null element is represented by a single fixed-width Arrow value buffer (i.e. no offsets buffer, no child data).

Constraints:

• MUST be absent for an all-null page
• MUST be <= 32 bytes if present

rep_compression: Option<CompressiveEncoding>

Optional compression algorithm used for the repetition buffer. If absent, repetition levels are stored as raw u16 values.

def_compression: Option<CompressiveEncoding>

Optional compression algorithm used for the definition buffer. If absent, definition levels are stored as raw u16 values.

num_rep_values: u64

Number of values in repetition buffer after decompression.

num_def_values: u64

Number of values in definition buffer after decompression.

Implementations

impl ConstantLayout

pub fn layers( &self, ) -> FilterMap<Cloned<Iter<'_, i32>>, fn(i32) -> Option<RepDefLayer>>

Returns an iterator which yields the valid enum values contained in layers.

pub fn push_layers(&mut self, value: RepDefLayer)

Appends the provided enum value to layers.

pub fn inline_value(&self) -> &[u8]

Returns the value of inline_value, or the default value if inline_value is unset.

Trait Implementations

impl Clone for ConstantLayout

fn clone(&self) -> ConstantLayout

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ConstantLayout

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

Formats the value using the given formatter.

impl Default for ConstantLayout

fn default() -> Self

Returns the “default value” for a type.

impl Message for ConstantLayout

fn encoded_len(&self) -> usize

Returns the encoded length of the message without a length delimiter.

fn clear(&mut self)

Clears the message, resetting all fields to their default.

fn encode(&self, buf: &mut impl BufMut) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message to a buffer.

fn encode_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message to a newly allocated buffer.

fn encode_length_delimited( &self, buf: &mut impl BufMut, ) -> Result<(), EncodeError>

where Self: Sized,

Encodes the message with a length-delimiter to a buffer.

fn encode_length_delimited_to_vec(&self) -> Vec<u8>

where Self: Sized,

Encodes the message with a length-delimiter to a newly allocated buffer.

fn decode(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes an instance of the message from a buffer.

fn decode_length_delimited(buf: impl Buf) -> Result<Self, DecodeError>

where Self: Default,

Decodes a length-delimited instance of the message from the buffer.

fn merge(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes an instance of the message from a buffer, and merges it into self.

fn merge_length_delimited(&mut self, buf: impl Buf) -> Result<(), DecodeError>

where Self: Sized,

Decodes a length-delimited instance of the message from buffer, and merges it into self.

impl Name for ConstantLayout

const NAME: &'static str = "ConstantLayout"

Simple name for this Message. This name is the same as it appears in the source .proto file, e.g. FooBar.

const PACKAGE: &'static str = "lance.encodings21"

Package name this message type is contained in. They are domain-like and delimited by ., e.g. google.protobuf.

fn full_name() -> String

Fully-qualified unique name for this Message. It’s prefixed with the package name and names of any parent messages, e.g. google.rpc.BadRequest.FieldViolation. By default, this is the package name followed by the message name. Fully-qualified names must be unique within a domain of Type URLs.

fn type_url() -> String

Type URL for this Message, which by default is the full name with a leading slash, but may also include a leading domain name, e.g. type.googleapis.com/google.profile.Person. This can be used when serializing into the google.protobuf.Any type.

impl PartialEq for ConstantLayout

fn eq(&self, other: &ConstantLayout) -> 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 StructuralPartialEq for ConstantLayout