cosmwasm_std/
iterator.rs

1use crate::StdError;
2use schemars::JsonSchema;
3use serde::{Deserialize, Serialize};
4
5/// A record of a key-value storage that is created through an iterator API.
6/// The first element (key) is always raw binary data. The second element
7/// (value) is binary by default but can be changed to a custom type. This
8/// allows contracts to reuse the type when deserializing database records.
9pub type Record<V = Vec<u8>> = (Vec<u8>, V);
10
11#[derive(Serialize, Deserialize, Clone, Copy, Debug, PartialEq, Eq, JsonSchema)]
12#[serde(rename_all = "snake_case")]
13// We assign these to integers to provide a stable API for passing over FFI (to wasm and Go)
14pub enum Order {
15    Ascending = 1,
16    Descending = 2,
17}
18
19impl TryFrom<i32> for Order {
20    type Error = StdError;
21
22    fn try_from(value: i32) -> Result<Self, Self::Error> {
23        match value {
24            1 => Ok(Order::Ascending),
25            2 => Ok(Order::Descending),
26            _ => Err(StdError::generic_err("Order must be 1 or 2")),
27        }
28    }
29}
30
31impl From<Order> for i32 {
32    fn from(original: Order) -> i32 {
33        original as _
34    }
35}
36
37#[cfg(test)]
38mod tests {
39    use crate::{from_json, to_json_vec};
40
41    use super::*;
42
43    #[test]
44    fn order_serde() {
45        let ascending_bytes = br#""ascending""#;
46        let descending_bytes = br#""descending""#;
47
48        assert_eq!(to_json_vec(&Order::Ascending).unwrap(), ascending_bytes);
49        assert_eq!(to_json_vec(&Order::Descending).unwrap(), descending_bytes);
50
51        assert_eq!(
52            from_json::<Order>(ascending_bytes).unwrap(),
53            Order::Ascending
54        );
55
56        assert_eq!(
57            from_json::<Order>(descending_bytes).unwrap(),
58            Order::Descending
59        );
60    }
61}
cosmwasm_std/iterator.rs

cosmwasm_std/
iterator.rs
