Trait exonum::storage::StorageKey

pub trait StorageKey {
    fn size(&self) -> usize;
    fn write(&self, buffer: &mut [u8]);
    fn read(buffer: &[u8]) -> Self;
}

A trait that defines serialization of corresponding types as storage keys.

Since internally the keys are sorted in a serialized form, the big-endian encoding is used.

Examples

Implementing StorageKey for the type:

use std::mem;

use exonum::storage::StorageKey;
use byteorder::{LittleEndian, ByteOrder};

struct Key {
    a: i16,
    b: u32,
}

impl StorageKey for Key {
    fn size(&self) -> usize {
        mem::size_of_val(&self.a) + mem::size_of_val(&self.b)
    }

    fn write(&self, buffer: &mut [u8]) {
        LittleEndian::write_i16(&mut buffer[0..2], self.a);
        LittleEndian::write_u32(&mut buffer[2..6], self.b);
    }

    fn read(buffer: &[u8]) -> Self {
        let a = LittleEndian::read_i16(&buffer[0..2]);
        let b = LittleEndian::read_u32(&buffer[2..6]);
        Key { a, b }
    }
}

Required Methods

fn size(&self) -> usize

Returns the size of the serialized key in bytes.

fn write(&self, buffer: &mut [u8])

Serialize a key into the specified buffer of bytes.

The caller must guarantee that the size of the buffer is equal to the precalculated size of the serialized key.

fn read(buffer: &[u8]) -> Self

Deserialize a key from the specified buffer of bytes.

Implementations on Foreign Types

impl StorageKey for ()

fn size(&self) -> usize

fn write(&self, _buffer: &mut [u8])

fn read(_buffer: &[u8]) -> Self

impl StorageKey for u8

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for u16

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for u32

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for u64

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for i8

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for i16

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for i32

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for i64

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for Vec<u8>

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for String

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

impl StorageKey for [u8; 32]

fn size(&self) -> usize

fn write(&self, buffer: &mut [u8])

fn read(buffer: &[u8]) -> Self

Implementors

• impl StorageKey for Hash
• impl StorageKey for PublicKey
• impl StorageKey for DBKey