1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
// This file is part of Substrate.

// Copyright (C) 2020-2021 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// 	http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use codec::{Decode, Encode};
use sp_core::RuntimeDebug;
use sp_std::vec::Vec;

/// A string that wraps a `&'static str` in the runtime and `String`/`Vec<u8>` on decode.
#[derive(Eq, RuntimeDebug, Clone)]
pub enum RuntimeString {
	/// The borrowed mode that wraps a `&'static str`.
	Borrowed(&'static str),
	/// The owned mode that wraps a `String`.
	#[cfg(feature = "std")]
	Owned(String),
	/// The owned mode that wraps a `Vec<u8>`.
	#[cfg(not(feature = "std"))]
	Owned(Vec<u8>),
}

/// Convenience macro to use the format! interface to get a `RuntimeString::Owned`
#[macro_export]
macro_rules! format_runtime_string {
	($($args:tt)*) => {{
		#[cfg(feature = "std")]
		{
			sp_runtime::RuntimeString::Owned(format!($($args)*))
		}
		#[cfg(not(feature = "std"))]
		{
			sp_runtime::RuntimeString::Owned(sp_std::alloc::format!($($args)*).as_bytes().to_vec())
		}
	}};
}

impl From<&'static str> for RuntimeString {
	fn from(data: &'static str) -> Self {
		Self::Borrowed(data)
	}
}

#[cfg(feature = "std")]
impl From<RuntimeString> for String {
	fn from(string: RuntimeString) -> Self {
		match string {
			RuntimeString::Borrowed(data) => data.to_owned(),
			RuntimeString::Owned(data) => data,
		}
	}
}

impl Default for RuntimeString {
	fn default() -> Self {
		Self::Borrowed(Default::default())
	}
}

impl PartialEq for RuntimeString {
	fn eq(&self, other: &Self) -> bool {
		self.as_ref() == other.as_ref()
	}
}

impl AsRef<[u8]> for RuntimeString {
	fn as_ref(&self) -> &[u8] {
		match self {
			Self::Borrowed(val) => val.as_ref(),
			Self::Owned(val) => val.as_ref(),
		}
	}
}

impl Encode for RuntimeString {
	fn encode(&self) -> Vec<u8> {
		match self {
			Self::Borrowed(val) => val.encode(),
			Self::Owned(val) => val.encode(),
		}
	}
}

impl Decode for RuntimeString {
	fn decode<I: codec::Input>(value: &mut I) -> Result<Self, codec::Error> {
		Decode::decode(value).map(Self::Owned)
	}
}

#[cfg(feature = "std")]
impl std::fmt::Display for RuntimeString {
	fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
		match self {
			Self::Borrowed(val) => write!(f, "{}", val),
			Self::Owned(val) => write!(f, "{}", val),
		}
	}
}

#[cfg(feature = "std")]
impl serde::Serialize for RuntimeString {
	fn serialize<S: serde::Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
		match self {
			Self::Borrowed(val) => val.serialize(serializer),
			Self::Owned(val) => val.serialize(serializer),
		}
	}
}

#[cfg(feature = "std")]
impl<'de> serde::Deserialize<'de> for RuntimeString {
	fn deserialize<D: serde::Deserializer<'de>>(de: D) -> Result<Self, D::Error> {
		String::deserialize(de).map(Self::Owned)
	}
}

/// Create a const [`RuntimeString`].
#[macro_export]
macro_rules! create_runtime_str {
	( $y:expr ) => {{
		$crate::RuntimeString::Borrowed($y)
	}};
}