From c7ea9c03e96a9f7d410dd13dfa23a949e50db75e Mon Sep 17 00:00:00 2001
From: jake <jake@sharnoth.com>
Date: Sat, 18 Nov 2023 23:27:14 -0700
Subject: [PATCH] add PSOPacketData derive to enums
---
psopacket/src/lib.rs | 84 +++++++++++++++++++++++++++++++++++++-------
1 file changed, 71 insertions(+), 13 deletions(-)
diff --git a/psopacket/src/lib.rs b/psopacket/src/lib.rs
index ef5a7a9..ff7c63c 100644
--- a/psopacket/src/lib.rs
+++ b/psopacket/src/lib.rs
@@ -647,19 +647,7 @@ pub fn pso_message(attr: TokenStream, item: TokenStream) -> TokenStream {
q.into()
}
-#[proc_macro_derive(PSOPacketData)]
-pub fn pso_packet_data(input: TokenStream) -> TokenStream {
- let derive = parse_macro_input!(input as DeriveInput);
-
- let name = derive.ident;
-
- let fields = if let syn::Data::Struct(strct) = derive.data {
- strct.fields
- }
- else {
- return syn::Error::new(name.span(), "PSOPacketData only works on structs").to_compile_error().into();
- };
-
+fn pso_packet_data_struct(name: syn::Ident, fields: syn::Fields) -> TokenStream {
let attrs = match get_struct_fields(fields.iter()) {
Ok(a) => a,
Err(err) => return err
@@ -695,3 +683,73 @@ pub fn pso_packet_data(input: TokenStream) -> TokenStream {
q.into()
}
+
+fn pso_packet_data_enum<'a>(name: syn::Ident, repr_type: syn::Ident, variants: impl Iterator<Item = &'a syn::Variant> + Clone) -> TokenStream {
+ let value_to_variant = variants
+ .clone()
+ .enumerate()
+ .map(|(i, variant)| {
+ quote! {
+ #i => #name::#variant,
+ }
+ })
+ .collect::<Vec<_>>();
+
+ let variant_to_value = variants
+ .enumerate()
+ .map(|(i, variant)| {
+ quote! {
+ #name::#variant => #repr_type::to_le_bytes(#i as #repr_type).to_vec(),
+ }
+ })
+ .collect::<Vec<_>>();
+ let impl_pso_data_packet = quote! {
+ impl PSOPacketData for #name {
+ fn from_bytes<R: std::io::Read + std::io::Seek>(mut cur: &mut R) -> Result<Self, PacketParseError> {
+ let mut buf = #repr_type::default().to_le_bytes();
+ cur.read_exact(&mut buf).unwrap();
+ let value = #repr_type::from_le_bytes(buf);
+
+ Ok(match value as usize {
+ #(#value_to_variant)*
+ _ => return Err(PacketParseError::InvalidValue)
+ })
+ }
+
+ fn as_bytes(&self) -> Vec<#repr_type> {
+ match self {
+ #(#variant_to_value)*
+ }
+ }
+ }
+ };
+
+ impl_pso_data_packet.into()
+}
+
+#[proc_macro_derive(PSOPacketData)]
+pub fn pso_packet_data(input: TokenStream) -> TokenStream {
+ let derive = parse_macro_input!(input as DeriveInput);
+
+ let name = derive.ident;
+
+ if let syn::Data::Struct(strct) = derive.data {
+ pso_packet_data_struct(name, strct.fields)
+ }
+ else if let syn::Data::Enum(enm) = derive.data {
+ let repr_type = derive.attrs.iter().fold(None, |mut repr_type, attr| {
+ if attr.path().is_ident("repr") {
+ attr.parse_nested_meta(|meta| {
+ repr_type = Some(meta.path.get_ident().cloned().unwrap());
+ Ok(())
+ }).unwrap();
+ }
+ repr_type
+ });
+
+ pso_packet_data_enum(name, repr_type.unwrap(), enm.variants.iter())
+ }
+ else {
+ syn::Error::new(name.span(), "PSOPacketData only works on structs and enums").to_compile_error().into()
+ }
+}