Struct HyperMap

pub struct HyperMap<K, V> { /* private fields */ }

An non-iterable implementation of a map that stores its content directly on the trie.

Implementations

impl<K, V> HyperMap<K, V>

pub fn new() -> Self

Make a new, empty HyperMap,

It should be called when contract init.

Examples

Basic usage:

use fvm_std::collections::hyper_map::HyperMap;
use fvm_macros::contract;
use fvm_macros::storage;

#[storage]
pub struct HyperMapDemo {
    map: HyperMap<String, String>,
}

#[contract]
impl HyperMapDemo {
    /// used in construct method
    fn new() -> Self {
        Self { map: HyperMap::new() }
    }
}

impl<K, V> HyperMap<K, V>

where K: Ord + Hash + Encode + Decode, V: Encode + Decode,

pub fn get<Q>(&mut self, k: &Q) -> Option<&V>

where K: Borrow<Q> + Ord, Q: Hash + Ord + Encode + ToOwned<Owned = K> + ?Sized,

Returns a reference to the value corresponding to the key.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

pub fn get_mut<Q>(&mut self, k: &Q) -> Option<&mut V>

where K: Borrow<Q> + Ord, Q: Hash + Ord + Encode + ToOwned<Owned = K> + ?Sized,

Returns a mutable reference to the value corresponding to the key.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

All get_mut result we wil think it to be changed.

pub fn insert(&mut self, key: K, value: V) -> Option<V>

where K: Clone,

Inserts a key-value pair into the map.

If the map did not have this key present, None is returned.

If the map did have this key present, the value is updated, and the old value is returned. The key is not updated, though; this matters for types that can be == without being identical. See the [module-level documentation] for more.

pub fn remove<Q>(&mut self, k: &Q) -> Option<V>

where K: Borrow<Q>, Q: Hash + Eq + Ord + Encode + ToOwned<Owned = K> + ?Sized,

Removes a key from the map, returning the stored key and value if the key was previously in the map.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

pub fn len(&self) -> u64

Returns the number of elements in the map.

pub fn is_empty(&self) -> bool

Returns true if the map contains no elements.

pub fn get_key_value<Q>(&mut self, k: &Q) -> Option<(&K, &V)>

where K: Borrow<Q> + Ord, Q: Hash + Ord + Encode + ToOwned<Owned = K> + ?Sized,

Returns the key-value pair corresponding to the supplied key.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

pub fn contains_key<Q>(&self, k: &Q) -> bool

where K: Borrow<Q> + Ord, Q: Hash + Ord + Encode + ToOwned<Owned = K> + ?Sized,

Returns true if the map contains a value for the specified key.

The key may be any borrowed form of the map’s key type, but the ordering on the borrowed form must match the ordering on the key type.

Trait Implementations

impl<K, V> Default for HyperMap<K, V>

fn default() -> Self

Returns the “default value” for a type.

impl<K, V> SpreadLayout for HyperMap<K, V>

where K: Ord + Hash + Encode + Decode, V: Encode + Decode,

fn read_ledger(key_prefix: &[u8], _: &[u8]) -> Self

从账本读数据接口

fn write_ledger(&self, key_prefix: &[u8], deploy_flag: &[u8])

写入账本数据接口，key为属性名