Struct cw_storage_plus::SnapshotMap

pub struct SnapshotMap<'a, K, T> { /* private fields */ }

Map that maintains a snapshots of one or more checkpoints. We can query historical data as well as current state. What data is snapshotted depends on the Strategy.

Implementations

impl<'a, K, T> SnapshotMap<'a, K, T>

pub const fn new(
    pk: &'a str,
    checkpoints: &'a str,
    changelog: &'a str,
    strategy: Strategy
) -> Self

Example:

use cw_storage_plus::{SnapshotMap, Strategy};

SnapshotMap::<&[u8], &str>::new(
    "never",
    "never__check",
    "never__change",
    Strategy::EveryBlock
);

pub fn changelog(&self) -> &Map<'a, (K, u64), ChangeSet<T>>

impl<'a, K, T> SnapshotMap<'a, K, T>where
    T: Serialize + DeserializeOwned + Clone,
    K: PrimaryKey<'a> + Prefixer<'a>,

pub fn add_checkpoint(
    &self,
    store: &mut dyn Storage,
    height: u64
) -> StdResult<()>

pub fn remove_checkpoint(
    &self,
    store: &mut dyn Storage,
    height: u64
) -> StdResult<()>

impl<'a, K, T> SnapshotMap<'a, K, T>where
    T: Serialize + DeserializeOwned + Clone,
    K: PrimaryKey<'a> + Prefixer<'a> + KeyDeserialize,

pub fn key(&self, k: K) -> Path<T>

pub fn save(
    &self,
    store: &mut dyn Storage,
    k: K,
    data: &T,
    height: u64
) -> StdResult<()>

pub fn remove(&self, store: &mut dyn Storage, k: K, height: u64) -> StdResult<()>

pub fn load(&self, store: &dyn Storage, k: K) -> StdResult<T>

load will return an error if no data is set at the given key, or on parse error

pub fn may_load(&self, store: &dyn Storage, k: K) -> StdResult<Option<T>>

may_load will parse the data stored at the key if present, returns Ok(None) if no data there. returns an error on issues parsing

pub fn may_load_at_height(
    &self,
    store: &dyn Storage,
    k: K,
    height: u64
) -> StdResult<Option<T>>

pub fn assert_checkpointed(
    &self,
    store: &dyn Storage,
    height: u64
) -> StdResult<()>

pub fn update<A, E>(
    &self,
    store: &mut dyn Storage,
    k: K,
    height: u64,
    action: A
) -> Result<T, E>where
    A: FnOnce(Option<T>) -> Result<T, E>,
    E: From<StdError>,

Loads the data, perform the specified action, and store the result in the database. This is shorthand for some common sequences, which may be useful.

If the data exists, action(Some(value)) is called. Otherwise action(None) is called.

This is a bit more customized than needed to only read “old” value 1 time, not 2 per naive approach

impl<'a, K, T> SnapshotMap<'a, K, T>where
    T: Serialize + DeserializeOwned + Clone,
    K: PrimaryKey<'a> + Prefixer<'a> + KeyDeserialize,

pub fn range_raw<'c>(
    &self,
    store: &'c dyn Storage,
    min: Option<Bound<'a, K>>,
    max: Option<Bound<'a, K>>,
    order: Order
) -> Box<dyn Iterator<Item = StdResult<Record<T>>> + 'c>where
    T: 'c,

pub fn keys_raw<'c>(
    &self,
    store: &'c dyn Storage,
    min: Option<Bound<'a, K>>,
    max: Option<Bound<'a, K>>,
    order: Order
) -> Box<dyn Iterator<Item = Vec<u8>> + 'c>where
    T: 'c,

impl<'a, K, T> SnapshotMap<'a, K, T>where
    T: Serialize + DeserializeOwned,
    K: PrimaryKey<'a> + KeyDeserialize,

pub fn prefix_range<'c>(
    &self,
    store: &'c dyn Storage,
    min: Option<PrefixBound<'a, K::Prefix>>,
    max: Option<PrefixBound<'a, K::Prefix>>,
    order: Order
) -> Box<dyn Iterator<Item = StdResult<(K::Output, T)>> + 'c>where
    T: 'c,
    'a: 'c,
    K: 'c,
    K::Output: 'static,

While range over a prefix fixes the prefix to one element and iterates over the remaining, prefix_range accepts bounds for the lowest and highest elements of the Prefix itself, and iterates over those (inclusively or exclusively, depending on PrefixBound). There are some issues that distinguish these two, and blindly casting to Vec<u8> doesn’t solve them.

pub fn range<'c>(
    &self,
    store: &'c dyn Storage,
    min: Option<Bound<'a, K>>,
    max: Option<Bound<'a, K>>,
    order: Order
) -> Box<dyn Iterator<Item = StdResult<(K::Output, T)>> + 'c>where
    T: 'c,
    K::Output: 'static,

pub fn keys<'c>(
    &self,
    store: &'c dyn Storage,
    min: Option<Bound<'a, K>>,
    max: Option<Bound<'a, K>>,
    order: Order
) -> Box<dyn Iterator<Item = StdResult<K::Output>> + 'c>where
    T: 'c,
    K::Output: 'static,

pub fn prefix(&self, p: K::Prefix) -> Prefix<K::Suffix, T, K::Suffix>

pub fn sub_prefix(
    &self,
    p: K::SubPrefix
) -> Prefix<K::SuperSuffix, T, K::SuperSuffix>