Struct lance_encoding::format::pb::List

pub struct List {
    pub offsets: Option<Box<ArrayEncoding>>,
}

An array encoding for variable-length list fields

Fields

offsets: Option<Box<ArrayEncoding>>

An array containing the offsets into an items array.

This array will have (num_rows + 1), will have a data type of uint64, and will never have nulls.

offsets[0] will always be 0.

If the incoming list at index i is not null then offsets[i+1] will contain offsets[i] + len(list)

If the incoming list at index i is null then offsets[i+1] will contain offsets[i] + num_items

The length of the list at index i can then be found from the calculation (offsets[i+1] - offsets[i]) % num_items. If the length is 0 the list is:

• offsets[i+1] == offsets[i] -> empty list
• offsets[i+1] == num_items + offsets[i+1] -> null list

The offsets array is always a uint64 array (even if the arrow type it maps to is using int32 or int64 offsets). However, this array is an unsigned integer array with range [0, 2 * num_items] and so it should be bit packed accordingly.

Trait Implementations

impl Clone for List

fn clone(&self) -> List

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for List

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

Formats the value using the given formatter.

impl Default for List

fn default() -> Self

Returns the “default value” for a type.

impl Message for List

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<B>(&self, buf: &mut B) -> Result<(), EncodeError>

where B: BufMut, 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<B>(&self, buf: &mut B) -> Result<(), EncodeError>

where B: BufMut, 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<B>(buf: B) -> Result<Self, DecodeError>

where B: Buf, Self: Default,

Decodes an instance of the message from a buffer.

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

where B: Buf, Self: Default,

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

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

where B: Buf, Self: Sized,

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

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

where B: Buf, Self: Sized,

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

impl Name for List

const NAME: &'static str = "List"

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.encodings"

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 with the [Any] type.

impl PartialEq for List

fn eq(&self, other: &List) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

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

impl StructuralPartialEq for List