Struct obkv::KvReader

pub struct KvReader<'a, K> { /* private fields */ }

A reader of obkv databases.

Implementations

impl<'a, K> KvReader<'a, K>

pub fn new(bytes: &[u8]) -> KvReader<'_, K>

Construct a reader on top of a memory area.

use obkv::KvReaderU16;

let mut iter = KvReaderU16::new(&[]).iter();
assert_eq!(iter.next(), None);

pub fn get(&self, requested_key: K) -> Option<&'a [u8]>where K: Key + PartialOrd,

Returns the value associated with the given key or None if the key is not present.

use obkv::{KvWriterU16, KvReaderU16};

let mut writer = KvWriterU16::memory();
writer.insert(0, b"hello").unwrap();
writer.insert(1, b"blue").unwrap();
writer.insert(255, b"world").unwrap();
let obkv = writer.into_inner().unwrap();

let reader = KvReaderU16::new(&obkv);
assert_eq!(reader.get(0), Some(&b"hello"[..]));
assert_eq!(reader.get(1), Some(&b"blue"[..]));
assert_eq!(reader.get(10), None);
assert_eq!(reader.get(255), Some(&b"world"[..]));

pub fn iter(&self) -> Fuse<KvIter<'a, K>>where K: Key,

Returns an iterator over all the keys in the key-value store.

use obkv::{KvWriterU16, KvReaderU16};

let mut writer = KvWriterU16::memory();
writer.insert(0, b"hello").unwrap();
writer.insert(1, b"blue").unwrap();
writer.insert(255, b"world").unwrap();
let obkv = writer.into_inner().unwrap();

let mut iter = KvReaderU16::new(&obkv).iter();
assert_eq!(iter.next(), Some((0, &b"hello"[..])));
assert_eq!(iter.next(), Some((1, &b"blue"[..])));
assert_eq!(iter.next(), Some((255, &b"world"[..])));
assert_eq!(iter.next(), None);
assert_eq!(iter.next(), None); // is it fused?

Trait Implementations

impl<'a, K: Clone> Clone for KvReader<'a, K>

fn clone(&self) -> KvReader<'a, K>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<'a, K: Debug> Debug for KvReader<'a, K>

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

Formats the value using the given formatter.

impl<'a, K: Default> Default for KvReader<'a, K>

fn default() -> KvReader<'a, K>

Returns the “default value” for a type.

impl<'a, K: Hash> Hash for KvReader<'a, K>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'a, K: Key> IntoIterator for KvReader<'a, K>

type Item = (K, &'a [u8])

The type of the elements being iterated over.

type IntoIter = Fuse<KvIter<'a, K>>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl<'a, K: PartialEq> PartialEq for KvReader<'a, K>

fn eq(&self, other: &KvReader<'a, K>) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<'a, K: Copy> Copy for KvReader<'a, K>

impl<'a, K: Eq> Eq for KvReader<'a, K>

impl<'a, K> StructuralEq for KvReader<'a, K>

impl<'a, K> StructuralPartialEq for KvReader<'a, K>