From d1749f000955179a9e2cd02c2d226bde13fb8e47 Mon Sep 17 00:00:00 2001
From: Shaun Wang <spxwang@gmail.com>
Date: Wed, 7 Apr 2021 13:07:53 +1200
Subject: [PATCH] Update xtokens docs. (#438)
* Update xtokens docs.
* Fix typo.
* Update imbalances impl.
---
tokens/src/imbalances.rs | 38 +++++++++++++++++++++++++++++---------
xtokens/README.md | 8 --------
xtokens/src/lib.rs | 4 ++--
3 files changed, 31 insertions(+), 19 deletions(-)
diff --git a/tokens/src/imbalances.rs b/tokens/src/imbalances.rs
index 76faac8..084a3b9 100644
--- a/tokens/src/imbalances.rs
+++ b/tokens/src/imbalances.rs
@@ -1,7 +1,7 @@
// wrapping these imbalances in a private module is necessary to ensure absolute
// privacy of the inner member.
use crate::{Config, TotalIssuance};
-use frame_support::traits::{Get, Imbalance, TryDrop};
+use frame_support::traits::{Get, Imbalance, SameOrOther, TryDrop};
use sp_runtime::traits::{Saturating, Zero};
use sp_std::{marker, mem, result};
@@ -21,6 +21,12 @@ impl<T: Config, GetCurrencyId: Get<T::CurrencyId>> PositiveImbalance<T, GetCurre
}
}
+impl<T: Config, GetCurrencyId: Get<T::CurrencyId>> Default for PositiveImbalance<T, GetCurrencyId> {
+ fn default() -> Self {
+ Self::zero()
+ }
+}
+
/// Opaque, move-only struct with private fields that serves as a token
/// denoting that funds have been destroyed without any equal and opposite
/// accounting.
@@ -37,6 +43,12 @@ impl<T: Config, GetCurrencyId: Get<T::CurrencyId>> NegativeImbalance<T, GetCurre
}
}
+impl<T: Config, GetCurrencyId: Get<T::CurrencyId>> Default for NegativeImbalance<T, GetCurrencyId> {
+ fn default() -> Self {
+ Self::zero()
+ }
+}
+
impl<T: Config, GetCurrencyId: Get<T::CurrencyId>> TryDrop for PositiveImbalance<T, GetCurrencyId> {
fn try_drop(self) -> result::Result<(), Self> {
self.drop_zero()
@@ -73,14 +85,18 @@ impl<T: Config, GetCurrencyId: Get<T::CurrencyId>> Imbalance<T::Balance> for Pos
self.0 = self.0.saturating_add(other.0);
mem::forget(other);
}
- fn offset(self, other: Self::Opposite) -> result::Result<Self, Self::Opposite> {
+ // allow to make the impl same with `pallet-balances`
+ #[allow(clippy::comparison_chain)]
+ fn offset(self, other: Self::Opposite) -> SameOrOther<Self, Self::Opposite> {
let (a, b) = (self.0, other.0);
mem::forget((self, other));
- if a >= b {
- Ok(Self::new(a - b))
+ if a > b {
+ SameOrOther::Same(Self::new(a - b))
+ } else if b > a {
+ SameOrOther::Other(NegativeImbalance::new(b - a))
} else {
- Err(NegativeImbalance::new(b - a))
+ SameOrOther::None
}
}
fn peek(&self) -> T::Balance {
@@ -124,14 +140,18 @@ impl<T: Config, GetCurrencyId: Get<T::CurrencyId>> Imbalance<T::Balance> for Neg
self.0 = self.0.saturating_add(other.0);
mem::forget(other);
}
- fn offset(self, other: Self::Opposite) -> result::Result<Self, Self::Opposite> {
+ // allow to make the impl same with `pallet-balances`
+ #[allow(clippy::comparison_chain)]
+ fn offset(self, other: Self::Opposite) -> SameOrOther<Self, Self::Opposite> {
let (a, b) = (self.0, other.0);
mem::forget((self, other));
- if a >= b {
- Ok(Self::new(a - b))
+ if a > b {
+ SameOrOther::Same(Self::new(a - b))
+ } else if b > a {
+ SameOrOther::Other(PositiveImbalance::new(b - a))
} else {
- Err(PositiveImbalance::new(b - a))
+ SameOrOther::None
}
}
fn peek(&self) -> T::Balance {
diff --git a/xtokens/README.md b/xtokens/README.md
index 7032f29..4e12469 100644
--- a/xtokens/README.md
+++ b/xtokens/README.md
@@ -12,28 +12,20 @@ The xtokens module provides functions for
## Notes
-#### Unit tests
-
-Unit tests could be added once Polkadot has XCM simulator. https://github.com/paritytech/polkadot/issues/2544
-
#### Integration tests
Integration tests could be done manually after integrating xtokens into runtime. To cover the full features, set up at least 4 relay chain validators and 3 collators of different parachains, and use dispatchable calls to include all these scenarios:
- Transfer relay chain tokens to relay chain.
- - Use dispatchable call `transfer_to_relay_chain`.
- Transfer tokens issued by parachain A, from parachain A to parachain B.
- - Use dispatchable call `transfer_to_parachain`.
- Sending the tx from parachain A.
- Set the destination as Parachain B.
- Set the currency ID as parachain A token.
- Transfer tokens issued by parachain B, from parachain A to parachain B.
- - Use dispatchable call `transfer_to_parachain`.
- Sending the tx from parachain A.
- Set the destination as Parachain B.
- Set the currency ID as parachain B token.
- Transfer tokens issued by parachain C, from parachain A to parachain B.
- - Use dispatchable call `transfer_to_parachain`.
- Sending the tx from parachain A.
- Set the destination as Parachain B.
- Set the currency ID as parachain C token.
diff --git a/xtokens/src/lib.rs b/xtokens/src/lib.rs
index 801dad8..7df9796 100644
--- a/xtokens/src/lib.rs
+++ b/xtokens/src/lib.rs
@@ -14,8 +14,8 @@
//!
//! ### Dispatchable functions
//!
-//! - `transfer_to_relay_chain`: Transfer relay chain tokens to relay chain.
-//! - `transfer_to_parachain`: Transfer tokens to a sibling parachain.
+//! - `transfer`: Transfer local assets with given `CurrencyId` and `Amount`.
+//! - `transfer_multiasset`: Transfer `MultiAsset` assets.
#![cfg_attr(not(feature = "std"), no_std)]
#![allow(clippy::from_over_into)]
--
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