persistence_std_derive/
lib.rs

1use itertools::Itertools;
2use proc_macro::TokenStream;
3use proc_macro2::TokenTree;
4use quote::quote;
5use syn::{parse_macro_input, DeriveInput};
6
7macro_rules! match_kv_attr {
8    ($key:expr, $value_type:tt) => {
9        |tt| {
10            if let [TokenTree::Ident(key), TokenTree::Punct(eq), TokenTree::$value_type(value)] =
11                &tt[..]
12            {
13                if (key == $key) && (eq.as_char() == '=') {
14                    Some(quote!(#value))
15                } else {
16                    None
17                }
18            } else {
19                None
20            }
21        }
22    };
23}
24
25#[proc_macro_derive(CosmwasmExt, attributes(proto_message, proto_query))]
26pub fn derive_cosmwasm_ext(input: TokenStream) -> TokenStream {
27    let input = parse_macro_input!(input as DeriveInput);
28    let ident = input.ident;
29
30    let type_url = get_type_url(&input.attrs);
31
32    // `EncodeError` always indicates that a message failed to encode because the
33    // provided buffer had insufficient capacity. Message encoding is otherwise
34    // infallible.
35
36    let (query_request_conversion, cosmwasm_query) = if get_attr("proto_query", &input.attrs)
37        .is_some()
38    {
39        let path = get_query_attrs(&input.attrs, match_kv_attr!("path", Literal));
40        let res = get_query_attrs(&input.attrs, match_kv_attr!("response_type", Ident));
41
42        let query_request_conversion = quote! {
43            impl <Q: cosmwasm_std::CustomQuery> From<#ident> for cosmwasm_std::QueryRequest<Q> {
44                fn from(msg: #ident) -> Self {
45                    cosmwasm_std::QueryRequest::<Q>::Stargate {
46                        path: #path.to_string(),
47                        data: msg.into(),
48                    }
49                }
50            }
51        };
52
53        let cosmwasm_query = quote! {
54            pub fn query(self, querier: &cosmwasm_std::QuerierWrapper<impl cosmwasm_std::CustomQuery>) -> cosmwasm_std::StdResult<#res> {
55                querier.query::<#res>(&self.into())
56            }
57        };
58
59        (query_request_conversion, cosmwasm_query)
60    } else {
61        (quote!(), quote!())
62    };
63
64    (quote! {
65        impl #ident {
66            pub const TYPE_URL: &'static str = #type_url;
67            #cosmwasm_query
68
69            pub fn to_proto_bytes(&self) -> Vec<u8> {
70                let mut bytes = Vec::new();
71                prost::Message::encode(self, &mut bytes)
72                    .expect("Message encoding must be infallible");
73                bytes
74            }
75            pub fn to_any(&self) -> crate::shim::Any {
76                crate::shim::Any {
77                    type_url: Self::TYPE_URL.to_string(),
78                    value: self.to_proto_bytes(),
79                }
80            }
81        }
82
83        #query_request_conversion
84
85        impl From<#ident> for cosmwasm_std::Binary {
86            fn from(msg: #ident) -> Self {
87                cosmwasm_std::Binary(msg.to_proto_bytes())
88            }
89        }
90
91        impl<T> From<#ident> for cosmwasm_std::CosmosMsg<T> {
92            fn from(msg: #ident) -> Self {
93                cosmwasm_std::CosmosMsg::<T>::Stargate {
94                    type_url: #type_url.to_string(),
95                    value: msg.into(),
96                }
97            }
98        }
99
100        impl TryFrom<cosmwasm_std::Binary> for #ident {
101            type Error = cosmwasm_std::StdError;
102
103            fn try_from(binary: cosmwasm_std::Binary) -> ::std::result::Result<Self, Self::Error> {
104                use ::prost::Message;
105                Self::decode(&binary[..]).map_err(|e| {
106                    cosmwasm_std::StdError::parse_err(
107                        stringify!(#ident),
108                        format!(
109                            "Unable to decode binary: \n  - base64: {}\n  - bytes array: {:?}\n\n{:?}",
110                            binary,
111                            binary.to_vec(),
112                            e
113                        )
114                    )
115                })
116            }
117        }
118
119        impl TryFrom<cosmwasm_std::SubMsgResult> for #ident {
120            type Error = cosmwasm_std::StdError;
121
122            fn try_from(result: cosmwasm_std::SubMsgResult) -> ::std::result::Result<Self, Self::Error> {
123                result
124                    .into_result()
125                    .map_err(|e| cosmwasm_std::StdError::generic_err(e))?
126                    .data
127                    .ok_or_else(|| cosmwasm_std::StdError::not_found("cosmwasm_std::SubMsgResult::<T>"))?
128                    .try_into()
129            }
130        }
131    })
132    .into()
133}
134
135fn get_type_url(attrs: &[syn::Attribute]) -> proc_macro2::TokenStream {
136    let proto_message = get_attr("proto_message", attrs).and_then(|a| a.parse_meta().ok());
137
138    if let Some(syn::Meta::List(meta)) = proto_message.clone() {
139        match meta.nested[0].clone() {
140            syn::NestedMeta::Meta(syn::Meta::NameValue(meta)) => {
141                if meta.path.is_ident("type_url") {
142                    match meta.lit {
143                        syn::Lit::Str(s) => quote!(#s),
144                        _ => proto_message_attr_error(meta.lit),
145                    }
146                } else {
147                    proto_message_attr_error(meta.path)
148                }
149            }
150            t => proto_message_attr_error(t),
151        }
152    } else {
153        proto_message_attr_error(proto_message)
154    }
155}
156
157fn get_query_attrs<F>(attrs: &[syn::Attribute], f: F) -> proc_macro2::TokenStream
158where
159    F: FnMut(&Vec<TokenTree>) -> Option<proc_macro2::TokenStream>,
160{
161    let proto_query = get_attr("proto_query", attrs);
162
163    if let Some(attr) = proto_query {
164        if attr.tokens.clone().into_iter().count() != 1 {
165            return proto_query_attr_error(proto_query);
166        }
167
168        if let Some(TokenTree::Group(group)) = attr.tokens.clone().into_iter().next() {
169            let kv_groups = group.stream().into_iter().group_by(|t| {
170                if let TokenTree::Punct(punct) = t {
171                    punct.as_char() != ','
172                } else {
173                    true
174                }
175            });
176            let mut key_values: Vec<Vec<TokenTree>> = vec![];
177
178            for (non_sep, g) in &kv_groups {
179                if non_sep {
180                    key_values.push(g.collect());
181                }
182            }
183
184            return key_values
185                .iter()
186                .find_map(f)
187                .unwrap_or_else(|| proto_query_attr_error(proto_query));
188        }
189
190        proto_query_attr_error(proto_query)
191    } else {
192        proto_query_attr_error(proto_query)
193    }
194}
195
196fn get_attr<'a>(attr_ident: &str, attrs: &'a [syn::Attribute]) -> Option<&'a syn::Attribute> {
197    attrs
198        .iter()
199        .find(|&attr| attr.path.segments.len() == 1 && attr.path.segments[0].ident == attr_ident)
200}
201
202fn proto_message_attr_error<T: quote::ToTokens>(tokens: T) -> proc_macro2::TokenStream {
203    syn::Error::new_spanned(tokens, "expected `proto_message(type_url = \"...\")`")
204        .to_compile_error()
205}
206
207fn proto_query_attr_error<T: quote::ToTokens>(tokens: T) -> proc_macro2::TokenStream {
208    syn::Error::new_spanned(
209        tokens,
210        "expected `proto_query(path = \"...\", response_type = ...)`",
211    )
212    .to_compile_error()
213}
persistence_std_derive/lib.rs

persistence_std_derive/
lib.rs
