Struct FileType 

pub struct FileType;

Arrow extension type for the Parquet FILE logical type.

A FILE value is a reference to a range of bytes, stored inline or in an external file. Its Arrow storage type is a struct whose fields are a subset of the following, each nullable, identified by name, in any order:

Field	Arrow type
uri	Utf8, LargeUtf8, or Utf8View
offset	Int64
size	Int64
content_type	Utf8, LargeUtf8, or Utf8View
checksum	Utf8, LargeUtf8, or Utf8View
inline	Binary, LargeBinary, or BinaryView

When reading, a FILE-annotated group is returned as a struct with this extension type. When writing, a struct field with this extension type is written as a FILE-annotated group.

If the file has an embedded Arrow schema, a reader takes each field’s metadata from it rather than from the Parquet annotation. A FILE-annotated group that the embedded schema describes as a plain struct is then read without this extension type. To get the extension type in that case, read with ArrowReaderOptions::with_skip_arrow_metadata set to true.

The extension name is arrow.parquet.file, which is the intended name for a canonical Arrow extension type; it is not yet standardized.

Trait Implementations

impl Clone for FileType

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for FileType

impl Debug for FileType

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

Formats the value using the given formatter.

impl Default for FileType

fn default() -> Self

Returns the “default value” for a type.

impl Eq for FileType

impl ExtensionType for FileType

const NAME: &'static str = "arrow.parquet.file"

The name identifying this extension type.

type Metadata = &'static str

The metadata type of this extension type.

fn metadata(&self) -> &Self::Metadata

Returns a reference to the metadata of this extension type, or &() if if this extension type defines no metadata (Self::Metadata=()).

fn serialize_metadata(&self) -> Option<String>

Returns the serialized representation of the metadata of this extension type, or None if this extension type defines no metadata (Self::Metadata=()).

fn deserialize_metadata( metadata: Option<&str>, ) -> Result<Self::Metadata, ArrowError>

Deserialize the metadata of this extension type from the serialized representation of the metadata. An extension type that defines no metadata should expect None for the serialized metadata and return Ok(()).

fn supports_data_type(&self, data_type: &DataType) -> Result<(), ArrowError>

Returns Ok(()) iff the given data type is supported by this extension type.

fn try_new( data_type: &DataType, _metadata: Self::Metadata, ) -> Result<Self, ArrowError>

Construct this extension type for a field with the given data type and metadata.

fn validate( data_type: &DataType, _metadata: Self::Metadata, ) -> Result<(), ArrowError>

Validate this extension type for a field with the given data type and metadata.

fn try_new_from_field_metadata( data_type: &DataType, metadata: &Metadata, ) -> Result<Self, ArrowError>

Construct this extension type from field metadata and data type.

impl PartialEq for FileType

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for FileType