Trait exonum::storage::StorageValue

pub trait StorageValue: Sized {
    fn hash(&self) -> Hash;
    fn into_bytes(self) -> Vec<u8>;
    fn from_bytes(value: Cow<[u8]>) -> Self;
}

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

For compatibility with modern architectures the little-endian encoding is used.

Examples

Implementing StorageValue for the type:

use std::borrow::Cow;

use exonum::storage::StorageValue;
use exonum::crypto::{self, Hash};
use byteorder::{LittleEndian, ByteOrder};

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

impl StorageValue for Data {
    fn into_bytes(self) -> Vec<u8> {
        let mut buffer = vec![0; 6];
        LittleEndian::write_i16(&mut buffer[0..2], self.a);
        LittleEndian::write_u32(&mut buffer[2..6], self.b);
        buffer
    }

    fn from_bytes(value: Cow<[u8]>) -> Self {
        let a = LittleEndian::read_i16(&value[0..2]);
        let b = LittleEndian::read_u32(&value[2..6]);
        Data { a, b }
    }

    fn hash(&self) -> Hash {
        let mut buffer = [0; 6];
        LittleEndian::write_i16(&mut buffer[0..2], self.a);
        LittleEndian::write_u32(&mut buffer[2..6], self.b);
        crypto::hash(&buffer)
    }
}

Required Methods

fn hash(&self) -> Hash

Returns a hash of the value.

This method is actively used to build indices, so the hashing strategy must satisfy the basic requirements of cryptographic hashing: equal values must have the same hash and not equal values must have different hashes.

fn into_bytes(self) -> Vec<u8>

Serialize a value into a vector of bytes.

fn from_bytes(value: Cow<[u8]>) -> Self

Deserialize a value from bytes.

Implementations on Foreign Types

impl StorageValue for ()

fn into_bytes(self) -> Vec<u8>

fn from_bytes(_value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for u8

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for u16

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for u32

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for u64

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for i8

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for i16

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for i32

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for i64

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for Vec<u8>

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

impl StorageValue for String

fn into_bytes(self) -> Vec<u8>

fn from_bytes(value: Cow<[u8]>) -> Self

fn hash(&self) -> Hash

Implementors

• impl StorageValue for Connect
• impl StorageValue for Propose
• impl StorageValue for Prevote
• impl StorageValue for Precommit
• impl StorageValue for Status
• impl StorageValue for BlockResponse
• impl StorageValue for ProposeRequest
• impl StorageValue for TransactionsRequest
• impl StorageValue for PrevotesRequest
• impl StorageValue for PeersRequest
• impl StorageValue for BlockRequest
• impl StorageValue for Hash
• impl StorageValue for PublicKey
• impl StorageValue for RawMessage
• impl StorageValue for Block
• impl StorageValue for TxLocation
• impl StorageValue for StoredConfiguration