Rearrange export structure to something a bit more convenient.

substrate/native-runtime/std/src/lib.rs

@@ -0,0 +1,203 @@
+// Copyright 2017 Parity Technologies (UK) Ltd.
+// This file is part of Polkadot.
+
+// Polkadot is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Polkadot is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Polkadot.  If not, see <http://www.gnu.org/licenses/>.
+
+//! The with-std support functions for the runtime.
+
+#[macro_use]
+extern crate environmental;
+extern crate polkadot_state_machine;
+extern crate polkadot_primitives as primitives;
+
+use std::fmt;
+use primitives::ed25519;
+
+pub use std::vec;
+pub use std::rc;
+pub use std::cell;
+pub use std::boxed;
+pub use std::slice;
+pub use std::mem;
+
+/// Prelude of common useful imports.
+///
+/// This should include only things which are in the normal std prelude.
+pub mod prelude {
+	pub use std::vec::Vec;
+	pub use std::boxed::Box;
+}
+
+pub use polkadot_state_machine::{Externalities, ExternalitiesError};
+use primitives::hexdisplay::HexDisplay;
+
+// TODO: use the real error, not NoError.
+
+#[derive(Debug)]
+/// As it says - an empty type we use for errors.
+pub struct NoError;
+impl fmt::Display for NoError {
+	fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "") }
+}
+
+environmental!(ext : trait Externalities);
+
+/// Get `key` from storage and return a `Vec`, empty if there's a problem.
+pub fn storage(key: &[u8]) -> Vec<u8> {
+	ext::with(|ext| ext.storage(key).ok().map(|s| s.to_vec()))
+		.expect("read_storage cannot be called outside of an Externalities-provided environment.")
+		.unwrap_or_else(Vec::new)
+}
+
+/// Get `key` from storage, placing the value into `value_out` (as much as possible) and return
+/// the number of bytes that the key in storage was.
+pub fn read_storage(key: &[u8], value_out: &mut [u8], value_offset: usize) -> usize {
+	ext::with(|ext| {
+		if let Ok(value) = ext.storage(key) {
+			let value = &value[value_offset..];
+			let written = ::std::cmp::min(value.len(), value_out.len());
+			value_out[0..written].copy_from_slice(&value[0..written]);
+			value.len()
+		} else {
+			// no-entry is treated as an empty vector of bytes.
+			// TODO: consider allowing empty-vector to exist separately to no-entry (i.e. return
+			// Option<usize>)
+			0
+		}
+	}).expect("read_storage cannot be called outside of an Externalities-provided environment.")
+}
+
+/// Set the storage to some particular key.
+pub fn set_storage(key: &[u8], value: &[u8]) {
+	ext::with(|ext|
+		ext.set_storage(key.to_vec(), value.to_vec())
+	);
+}
+
+/// The current relay chain identifier.
+pub fn chain_id() -> u64 {
+	ext::with(|ext|
+		ext.chain_id()
+	).unwrap_or(0)
+}
+
+/// Conduct a Keccak-256 hash of the given data.
+pub use primitives::{blake2_256, twox_128, twox_256};
+
+/// Verify a ed25519 signature.
+pub fn ed25519_verify(sig: &[u8; 64], msg: &[u8], pubkey: &[u8; 32]) -> bool {
+	ed25519::verify(&sig[..], msg, &pubkey[..])
+}
+
+/// Execute the given closure with global function available whose functionality routes into the
+/// externalities `ext`. Forwards the value that the closure returns.
+pub fn with_externalities<R, F: FnOnce() -> R>(ext: &mut Externalities, f: F) -> R {
+	ext::using(ext, f)
+}
+
+pub trait Printable {
+	fn print(self);
+}
+
+impl<'a> Printable for &'a [u8] {
+	fn print(self) {
+		println!("Runtime: {}", HexDisplay::from(&self));
+	}
+}
+
+impl<'a> Printable for &'a str {
+	fn print(self) {
+		println!("Runtime: {}", self);
+	}
+}
+
+impl Printable for u64 {
+	fn print(self) {
+		println!("Runtime: {}", self);
+	}
+}
+
+pub fn print<T: Printable + Sized>(value: T) {
+	value.print();
+}
+
+#[macro_export]
+macro_rules! impl_stubs {
+	($( $name:ident ),*) => {}
+}
+
+#[cfg(test)]
+mod tests {
+	use super::*;
+	use std::collections::HashMap;
+
+	#[derive(Debug, Default)]
+	struct TestExternalities {
+		storage: HashMap<Vec<u8>, Vec<u8>>,
+	}
+	impl Externalities for TestExternalities {
+		fn storage(&self, key: &[u8]) -> Result<&[u8], ExternalitiesError> {
+			Ok(self.storage.get(&key.to_vec()).map_or(&[] as &[u8], Vec::as_slice))
+		}
+
+		fn set_storage(&mut self, key: Vec<u8>, value: Vec<u8>) {
+			self.storage.insert(key, value);
+		}
+
+		fn chain_id(&self) -> u64 { 42 }
+	}
+
+	macro_rules! map {
+		($( $name:expr => $value:expr ),*) => (
+			vec![ $( ( $name, $value ) ),* ].into_iter().collect()
+		)
+	}
+
+	#[test]
+	fn storage_works() {
+		let mut t = TestExternalities { storage: map![], };
+		assert!(with_externalities(&mut t, || {
+			assert_eq!(storage(b"hello"), b"".to_vec());
+			set_storage(b"hello", b"world");
+			assert_eq!(storage(b"hello"), b"world".to_vec());
+			assert_eq!(storage(b"foo"), b"".to_vec());
+			set_storage(b"foo", &[1, 2, 3][..]);
+			true
+		}));
+
+		t.storage = map![b"foo".to_vec() => b"bar".to_vec()];
+
+		assert!(!with_externalities(&mut t, || {
+			assert_eq!(storage(b"hello"), b"".to_vec());
+			assert_eq!(storage(b"foo"), b"bar".to_vec());
+			false
+		}));
+	}
+
+	#[test]
+	fn read_storage_works() {
+		let mut t = TestExternalities { storage: map![
+			b":test".to_vec() => b"\x0b\0\0\0Hello world".to_vec()
+		], };
+
+		with_externalities(&mut t, || {
+			let mut v = [0u8; 4];
+			assert!(read_storage(b":test", &mut v[..], 0) >= 4);
+			assert_eq!(v, [11u8, 0, 0, 0]);
+			let mut w = [0u8; 11];
+			assert!(read_storage(b":test", &mut w[..], 4) >= 11);
+			assert_eq!(&w, b"Hello world");
+		});
+	}
+}