Struct FileReaderBuilder

pub struct FileReaderBuilder {
    projection: Option<Vec<usize>>,
    max_footer_fb_tables: usize,
    max_footer_fb_depth: usize,
}

Build an Arrow FileReader with custom options.

Fields

projection: Option<Vec<usize>>

Optional projection for which columns to load (zero-based column indices)

max_footer_fb_tables: usize

Passed through to construct [VerifierOptions]

max_footer_fb_depth: usize

Passed through to construct [VerifierOptions]

Implementations

impl FileReaderBuilder

pub fn new() -> Self

Options for creating a new FileReader.

To convert a builder into a reader, call FileReaderBuilder::build.

pub fn with_projection(self, projection: Vec<usize>) -> Self

Optional projection for which columns to load (zero-based column indices).

pub fn with_max_footer_fb_tables(self, max_footer_fb_tables: usize) -> Self

Flatbuffers option for parsing the footer. Controls the max number of fields and metadata key-value pairs that can be parsed from the schema of the footer.

By default this is set to 1_000_000 which roughly translates to a schema with no metadata key-value pairs but 499,999 fields.

This default limit is enforced to protect against malicious files with a massive amount of flatbuffer tables which could cause a denial of service attack.

If you need to ingest a trusted file with a massive number of fields and/or metadata key-value pairs and are facing the error "Unable to get root as footer: TooManyTables" then increase this parameter as necessary.

pub fn with_max_footer_fb_depth(self, max_footer_fb_depth: usize) -> Self

Flatbuffers option for parsing the footer. Controls the max depth for schemas with nested fields parsed from the footer.

By default this is set to 64 which roughly translates to a schema with a field nested 60 levels down through other struct fields.

This default limit is enforced to protect against malicious files with a extremely deep flatbuffer structure which could cause a denial of service attack.

If you need to ingest a trusted file with a deeply nested field and are facing the error "Unable to get root as footer: DepthLimitReached" then increase this parameter as necessary.

pub fn build<R: Read + Seek>( self, reader: R, ) -> Result<FileReader<R>, ArrowError>

Build FileReader with given reader.

Trait Implementations

impl Debug for FileReaderBuilder

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

Formats the value using the given formatter.

impl Default for FileReaderBuilder

fn default() -> Self

Returns the “default value” for a type.