Lib.rs

Mavryk Smart Rollup 内核的事务型存储。

此 crate 支持处理更新存储的对象。所有对象都存储在持久存储中。

要使用此 crate，提供对象的定义。对象结构应遵循以下指南

• 可以从 OwnedPath 创建，即，它实现了 From<OwnedPath>
• 它有直接在持久存储上操作的获取器和设置器，每个获取器和设置器都应接受一个 Runtime 作为参数以执行操作（在设置器的情况下为 mut）。

注意 对象必须只查看以其 OwnedPath 为前缀的持久存储。

要使用此 crate，创建所需的价值结构和存储对象，如下所示

use mavryk_smart_rollup_host::runtime::Runtime;
use mavryk_smart_rollup_host::path::{concat, RefPath, OwnedPath};
use mavryk_smart_rollup_storage::storage::Storage;
use mavryk_smart_rollup_mock::MockHost;

struct MyValue {
  path: OwnedPath,
}

const VALUE_PATH: RefPath = RefPath::assert_from(b"/value");

impl MyValue {
  pub fn setter(&mut self, host: &mut impl Runtime, v: &str) {
    let value_path = concat(&self.path, &VALUE_PATH)
        .expect("Could not get path for value");
    host.store_write(&value_path, v.as_bytes(), 0)
        .expect("Could not set value");
  }

  pub fn getter(
      &mut self,
      host: &impl Runtime,
  ) -> Vec<u8> {
    let value_path = concat(&self.path, &VALUE_PATH)
        .expect("Could not get path for value");
    host.store_read(&value_path, 0, 1024)
        .expect("Could not read value")
  }
}

impl From<OwnedPath> for MyValue {
  fn from(path: OwnedPath) -> Self {
    Self { path }
  }
}

const VALUES_PATH: RefPath = RefPath::assert_from(b"/values");

let mut host = MockHost::default();

let mut storage = Storage::<MyValue>::init(&VALUES_PATH)
    .expect("Could not create storage interface");

storage.begin_transaction(&mut host)
    .expect("Could not begin transaction");

let value_id = RefPath::assert_from(b"/my.value.id");

let mut value = storage.create_new(&mut host, &value_id)
    .expect("Could not create new value")
    .expect("Value already exists");

value.setter(&mut host, "some value");

storage.commit_transaction(&mut host)
    .expect("Could not commit transaction");