Struct Schema

pub struct Schema {
    column_schemas: Vec<ColumnSchema>,
    name_to_index: HashMap<String, usize>,
    arrow_schema: Arc<Schema>,
    timestamp_index: Option<usize>,
    version: u32,
}

A common schema, should be immutable.

Fields

column_schemas: Vec<ColumnSchema>

name_to_index: HashMap<String, usize>

arrow_schema: Arc<Schema>

timestamp_index: Option<usize>

version: u32

Implementations

impl Schema

pub const INITIAL_VERSION: u32 = 0u32

Initial version of the schema.

pub fn new(column_schemas: Vec<ColumnSchema>) -> Schema

Create a schema from a vector of ColumnSchema.

Panics

Panics when ColumnSchema’s default_constraint can’t be serialized into json.

pub fn try_new(column_schemas: Vec<ColumnSchema>) -> Result<Schema, Error>

Try to Create a schema from a vector of ColumnSchema.

pub fn arrow_schema(&self) -> &Arc<Schema>

pub fn column_schemas(&self) -> &[ColumnSchema]

pub fn column_schema_by_name(&self, name: &str) -> Option<&ColumnSchema>

pub fn column_name_by_index(&self, idx: usize) -> &str

Retrieve the column’s name by index

Panics

This method may panic if the index is out of range of column schemas.

pub fn column_index_by_name(&self, name: &str) -> Option<usize>

pub fn contains_column(&self, name: &str) -> bool

pub fn num_columns(&self) -> usize

pub fn is_empty(&self) -> bool

pub fn timestamp_index(&self) -> Option<usize>

Returns index of the timestamp key column.

pub fn timestamp_column(&self) -> Option<&ColumnSchema>

pub fn version(&self) -> u32

pub fn metadata(&self) -> &HashMap<String, String>

pub fn try_project(&self, indices: &[usize]) -> Result<Schema, Error>

Generate a new projected schema

Panic

If the index out ouf bound

Trait Implementations

impl Clone for Schema

fn clone(&self) -> Schema

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Schema

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

Formats the value using the given formatter.

impl PartialEq for Schema

fn eq(&self, other: &Schema) -> 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 TryFrom<Arc<DFSchema>> for Schema

type Error = Error

The type returned in the event of a conversion error.

fn try_from(value: Arc<DFSchema>) -> Result<Schema, Error>

Performs the conversion.

impl TryFrom<Arc<Schema>> for Schema

type Error = Error

The type returned in the event of a conversion error.

fn try_from(arrow_schema: Arc<Schema>) -> Result<Schema, Error>

Performs the conversion.

impl TryFrom<RawSchema> for Schema

type Error = Error

The type returned in the event of a conversion error.

fn try_from(raw: RawSchema) -> Result<Schema, Error>

Performs the conversion.

impl TryFrom<Schema> for Schema

type Error = Error

The type returned in the event of a conversion error.

fn try_from(arrow_schema: Schema) -> Result<Schema, Error>

Performs the conversion.

impl Eq for Schema

impl StructuralPartialEq for Schema