Add bitvec-like generic support to the scale-bits type for use in codegen (#718)

* Add bitvec-like generic support to the scale-bits type for use in codegen * Use nightly 1.66 formatting * Fix reading input while decoding bit sequences * Add tests for our DecodedBits wrapper * Add convenience DecodedBits::(in)to_bits functions * Don't expose DecodedBits::bit_format * Re-export scale_bits as peer dependency * Move subxt::utils into a separate file * Hide DecodedBits internals * Don't re-export types from the `bits` module * Update subxt/src/utils/bits.rs Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com> * Update subxt/src/utils/bits.rs Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com> * Address review feedback * Clarify the byte needed calculation in DecodedBits encoding * Remove remaining dbg! invocations Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com>
2026-06-12 17:01:09 +00:00 · 2022-11-24 15:09:20 +01:00
parent a80d6cfd30
commit f0ce26db7b
9 changed files with 273 additions and 28 deletions
@@ -0,0 +1,100 @@
+// Copyright 2019-2022 Parity Technologies (UK) Ltd.
+// This file is dual-licensed as Apache-2.0 or GPL-3.0.
+// see LICENSE for license details.
+
+//! Miscellaneous utility helpers.
+
+pub mod bits;
+
+use codec::{
+    Decode,
+    DecodeAll,
+    Encode,
+};
+use derivative::Derivative;
+
+/// Wraps an already encoded byte vector, prevents being encoded as a raw byte vector as part of
+/// the transaction payload
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct Encoded(pub Vec<u8>);
+
+impl codec::Encode for Encoded {
+    fn encode(&self) -> Vec<u8> {
+        self.0.to_owned()
+    }
+}
+
+/// A wrapper for any type `T` which implement encode/decode in a way compatible with `Vec<u8>`.
+///
+/// [`WrapperKeepOpaque`] stores the type only in its opaque format, aka as a `Vec<u8>`. To
+/// access the real type `T` [`Self::try_decode`] needs to be used.
+#[derive(Derivative, Encode, Decode)]
+#[derivative(
+    Debug(bound = ""),
+    Clone(bound = ""),
+    PartialEq(bound = ""),
+    Eq(bound = ""),
+    Default(bound = ""),
+    Hash(bound = "")
+)]
+pub struct WrapperKeepOpaque<T> {
+    data: Vec<u8>,
+    _phantom: PhantomDataSendSync<T>,
+}
+
+impl<T: Decode> WrapperKeepOpaque<T> {
+    /// Try to decode the wrapped type from the inner `data`.
+    ///
+    /// Returns `None` if the decoding failed.
+    pub fn try_decode(&self) -> Option<T> {
+        T::decode_all(&mut &self.data[..]).ok()
+    }
+
+    /// Returns the length of the encoded `T`.
+    pub fn encoded_len(&self) -> usize {
+        self.data.len()
+    }
+
+    /// Returns the encoded data.
+    pub fn encoded(&self) -> &[u8] {
+        &self.data
+    }
+
+    /// Create from the given encoded `data`.
+    pub fn from_encoded(data: Vec<u8>) -> Self {
+        Self {
+            data,
+            _phantom: PhantomDataSendSync::new(),
+        }
+    }
+}
+
+/// A version of [`std::marker::PhantomData`] that is also Send and Sync (which is fine
+/// because regardless of the generic param, it is always possible to Send + Sync this
+/// 0 size type).
+#[derive(Derivative, Encode, Decode, scale_info::TypeInfo)]
+#[derivative(
+    Clone(bound = ""),
+    PartialEq(bound = ""),
+    Debug(bound = ""),
+    Eq(bound = ""),
+    Default(bound = ""),
+    Hash(bound = "")
+)]
+#[scale_info(skip_type_params(T))]
+#[doc(hidden)]
+pub struct PhantomDataSendSync<T>(core::marker::PhantomData<T>);
+
+impl<T> PhantomDataSendSync<T> {
+    pub(crate) fn new() -> Self {
+        Self(core::marker::PhantomData)
+    }
+}
+
+unsafe impl<T> Send for PhantomDataSendSync<T> {}
+unsafe impl<T> Sync for PhantomDataSendSync<T> {}
+
+/// This represents a key-value collection and is SCALE compatible
+/// with collections like BTreeMap. This has the same type params
+/// as `BTreeMap` which allows us to easily swap the two during codegen.
+pub type KeyedVec<K, V> = Vec<(K, V)>;