Remove codec::Encode and codec::Decode derives from generated APIs by default
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jsdw
changed the title
codec::Encode and codec::Decode from generated APIs by defaultcodec::Encode and codec::Decode derives from generated APIs by default
lexnv
reviewed
May 27, 2025
lexnv
reviewed
May 27, 2025
lexnv
reviewed
May 27, 2025
| if key.hasher.ends_with_key() { | ||
| let arg = &key.arg_name; | ||
| let keys = quote!(#static_storage_key::new(#arg.borrow())); | ||
| let keys = quote!(#static_storage_key::new(#arg)); |
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We don't use references anymore because we need the self of the key to work with EncodeAsType and DecodeAsType?
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The basic reason was just because previously we would SCALE encode the key before doing anything with it, but now we want to avoid SCALE encoding and so we keep the key itself, requiring us to have ownership of the key.
It might be that we can allow the stored key to be a reference as well or something like that, because we only need it for long enough to encode it given actual metadata!
pkhry
approved these changes
May 29, 2025
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Most APIs in Subxt haven't used
codec::Encodeorcodec::Decodein a while; these traits encode and decode bytes from/to a chain based on the precise shape of our generated types and don't take into account any changes in the chain metadata. Nevertheless, our codegen spits out these derives and the associatedcodecattributes by default.One of the issues we recently hit was #2006, whereby
EncodeandDecodederives in our generated APIs were not playing nicely with compact encoded generics.One solution from that issue is to migrate our generated APIs away from using
codec::Encodeorcodec::Decodeand relying only onEncodeAsTypeandDecodeAstype, which take the chain metadata into account and handle things like encoding and decoding compact encoded values transparently. This PR takes this path.As a nice side effect, the generated code size is reduced in line count by ~10%.
Users can still derive
EncodeandDecodethemselves on types that they want these traits on, or on everything (potentially running into issues like this again which would require workarounds like in the linked issue), but all of the main Subxt interfaces no longer have any reliance on them, and so they do not need to be derviced by default.Closes #2006