Struct Tail 

pub struct Tail { /* private fields */ }

The complete records of a growing delimited or NDJSON file: where they end and how many rows. A partial last record counts once its newline lands.

Implementations

impl Tail

pub fn new(format: FileFormat, options: &OpenOptions, schema: &Schema) -> Tail

The tail of a file read as format with options, whose frame has schema, before anything is counted.

pub fn widening(self) -> Tail

Fields the schema does not have are columns to come rather than misfits: standard input’s NDJSON, read again with them once it ends.

pub fn new_fields(&self) -> Vec<Field>

The fields that arrived that the schema does not have, typed by their values.

pub fn path(&self) -> &Path

The file counted.

pub fn rows(&self) -> usize

Rows in the complete records.

pub fn misfits(&self) -> usize

Rows that arrived after the first count and did not fit the schema.

pub fn complete(&self) -> u64

Bytes through the end of the last complete record.

pub fn read_on(&mut self, file: &mut File, len: u64, check: bool) -> Result<()>

Count the records file completes between what was counted and len, checking each new row against the schema when check.

pub fn read_to_end( &mut self, file: &mut File, len: u64, check: bool, ) -> Result<()>

As Self::read_on, with nothing more to come: a last record with no newline is a record too. Text read as lines and streams wait for their ends as before.

Trait Implementations

impl Clone for Tail

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Tail

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

Formats the value using the given formatter.