Struct grenad::ReaderCursor

pub struct ReaderCursor<R> { /* private fields */ }

A cursor that can move forward backward and move on a specified key.

Implementations

impl<R> ReaderCursor<R>

pub fn current(&self) -> Option<(&[u8], &[u8])>

The currently pointed key and value pair.

pub fn into_reader(self) -> Reader<R>

Consumes the ReaderCursor and returns the underlying Reader type.

pub fn into_inner(self) -> R

Consumes the ReaderCursor and returns the underlying io::Read type.

The returned io::Read type has been io::Seeked which means that you must seek it back to the front to be read from the start.

pub fn get_ref(&self) -> &R

Gets a reference to the underlying reader.

pub fn reset(&mut self)

Resets the position of the cursor.

Useful when you want to be able to call move_on_next or move_on_prev in a loop and ensure that it will start from the first or the last value of the cursor.

impl<R: Read + Seek> ReaderCursor<R>

pub fn move_on_first(&mut self) -> Result<Option<(&[u8], &[u8])>, Error>

Moves the cursor on the first entry and returns it.

pub fn move_on_last(&mut self) -> Result<Option<(&[u8], &[u8])>, Error>

Moves the cursor on the last entry and returns it.

pub fn move_on_next(&mut self) -> Result<Option<(&[u8], &[u8])>, Error>

Moves the cursor on the entry following the current one and returns it.

pub fn move_on_prev(&mut self) -> Result<Option<(&[u8], &[u8])>, Error>

Moves the cursor on the entry preceding the current one and returns it.

pub fn move_on_key_lower_than_or_equal_to<A: AsRef<[u8]>>( &mut self, target_key: A ) -> Result<Option<(&[u8], &[u8])>, Error>

Moves the cursor on the entry with a key lower than or equal to the specified one and returns the corresponding entry.

pub fn move_on_key_greater_than_or_equal_to<A: AsRef<[u8]>>( &mut self, key: A ) -> Result<Option<(&[u8], &[u8])>, Error>

Moves the cursor on the entry with a key greater than or equal to the specified one and returns the corresponding entry.

pub fn move_on_key_equal_to<A: AsRef<[u8]>>( &mut self, key: A ) -> Result<Option<(&[u8], &[u8])>, Error>

Moves the cursor on the entry with a key equal to the key specified and returns the corresponding entry.

Methods from Deref<Target = Reader<R>>

pub fn file_version(&self) -> FileVersion

Returns the version of this file.

pub fn compression_type(&self) -> CompressionType

Returns the compression type of this file.

pub fn len(&self) -> u64

Returns the number of entries in this file.

pub fn is_empty(&self) -> bool

Returns weither this file contains entries or is empty.

pub fn get_ref(&self) -> &R

Gets a reference to the underlying reader.

Trait Implementations

impl<R: Clone> Clone for ReaderCursor<R>

fn clone(&self) -> ReaderCursor<R>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<R> Deref for ReaderCursor<R>

type Target = Reader<R>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<R, MF> Extend<ReaderCursor<R>> for MergerBuilder<R, MF>

fn extend<T: IntoIterator<Item = ReaderCursor<R>>>(&mut self, iter: T)

Extends a collection with the contents of an iterator.

fn extend_one(&mut self, item: A)

🔬This is a nightly-only experimental API. (extend_one)

Extends a collection with exactly one element.

fn extend_reserve(&mut self, additional: usize)

🔬This is a nightly-only experimental API. (extend_one)

Reserves capacity in a collection for the given number of additional elements.