asset: add asset.v1.Metadata.priority_score

This is intended to help support clients that need to display lists of assets.
An asset registry can assign rankings to tokens, and frontend software can
consume them without needing to have its own opinions about what the ranking
should be. For instance, a registry could have hardcoded "tiers" or priorities,
or priorities assigned by market cap, or the user's balances, etc.

crates/core/asset/src/asset/denom_metadata.rs

@@ -39,6 +39,7 @@ pub(super) struct Inner {
     // For now, don't bother with a domain type here,
     // since we don't render images from Rust code.
     images: Vec<pb::AssetImage>,
+    priority_score: u64,
 
     /// Sorted by priority order.
     pub(super) units: Vec<BareDenomUnit>,
@@ -64,6 +65,7 @@ impl From<&Inner> for pb::Metadata {
             penumbra_asset_id: Some(inner.id.into()),
             denom_units: inner.units.clone().into_iter().map(|x| x.into()).collect(),
             images: inner.images.clone(),
+            priority_score: inner.priority_score,
         }
     }
 }
@@ -129,6 +131,7 @@ impl TryFrom<pb::Metadata> for Inner {
             name: value.name,
             symbol: value.symbol,
             images: value.images,
+            priority_score: value.priority_score,
         })
     }
 }
@@ -250,6 +253,7 @@ impl Inner {
             name: String::new(),
             symbol: String::new(),
             images: Vec::new(),
+            priority_score: 0,
         }
     }
 }
@@ -416,13 +420,15 @@ impl Debug for Metadata {
             display_index,
             name,
             symbol,
+            priority_score,
         } = inner.as_ref();
 
         f.debug_struct("Metadata")
             .field("id", id)
             .field("base_denom", base_denom)
             .field("description", description)
             .field("images", images)
+            .field("priority_score", priority_score)
             .field("units", units)
             .field("display_index", display_index)
             .field("name", name)

crates/proto/src/gen/penumbra.core.asset.v1.rs

@@ -84,6 +84,11 @@ pub struct Metadata {
     pub penumbra_asset_id: ::core::option::Option<AssetId>,
     #[prost(message, repeated, tag = "1985")]
     pub images: ::prost::alloc::vec::Vec<AssetImage>,
+    /// An optional "score" used to prioritize token lists.
+    ///
+    /// This is solely for use in client-side registries.
+    #[prost(uint64, tag = "1986")]
+    pub priority_score: u64,
 }
 impl ::prost::Name for Metadata {
     const NAME: &'static str = "Metadata";

crates/proto/src/gen/penumbra.core.asset.v1.serde.rs

@@ -1036,6 +1036,9 @@ impl serde::Serialize for Metadata {
         if !self.images.is_empty() {
             len += 1;
         }
+        if self.priority_score != 0 {
+            len += 1;
+        }
         let mut struct_ser = serializer.serialize_struct("penumbra.core.asset.v1.Metadata", len)?;
         if !self.description.is_empty() {
             struct_ser.serialize_field("description", &self.description)?;
@@ -1061,6 +1064,10 @@ impl serde::Serialize for Metadata {
         if !self.images.is_empty() {
             struct_ser.serialize_field("images", &self.images)?;
         }
+        if self.priority_score != 0 {
+            #[allow(clippy::needless_borrow)]
+            struct_ser.serialize_field("priorityScore", ToString::to_string(&self.priority_score).as_str())?;
+        }
         struct_ser.end()
     }
 }
@@ -1081,6 +1088,8 @@ impl<'de> serde::Deserialize<'de> for Metadata {
             "penumbra_asset_id",
             "penumbraAssetId",
             "images",
+            "priority_score",
+            "priorityScore",
         ];
 
         #[allow(clippy::enum_variant_names)]
@@ -1093,6 +1102,7 @@ impl<'de> serde::Deserialize<'de> for Metadata {
             Symbol,
             PenumbraAssetId,
             Images,
+            PriorityScore,
             __SkipField__,
         }
         impl<'de> serde::Deserialize<'de> for GeneratedField {
@@ -1123,6 +1133,7 @@ impl<'de> serde::Deserialize<'de> for Metadata {
                             "symbol" => Ok(GeneratedField::Symbol),
                             "penumbraAssetId" | "penumbra_asset_id" => Ok(GeneratedField::PenumbraAssetId),
                             "images" => Ok(GeneratedField::Images),
+                            "priorityScore" | "priority_score" => Ok(GeneratedField::PriorityScore),
                             _ => Ok(GeneratedField::__SkipField__),
                         }
                     }
@@ -1150,6 +1161,7 @@ impl<'de> serde::Deserialize<'de> for Metadata {
                 let mut symbol__ = None;
                 let mut penumbra_asset_id__ = None;
                 let mut images__ = None;
+                let mut priority_score__ = None;
                 while let Some(k) = map_.next_key()? {
                     match k {
                         GeneratedField::Description => {
@@ -1200,6 +1212,14 @@ impl<'de> serde::Deserialize<'de> for Metadata {
                             }
                             images__ = Some(map_.next_value()?);
                         }
+                        GeneratedField::PriorityScore => {
+                            if priority_score__.is_some() {
+                                return Err(serde::de::Error::duplicate_field("priorityScore"));
+                            }
+                            priority_score__ = 
+                                Some(map_.next_value::<::pbjson::private::NumberDeserialize<_>>()?.0)
+                            ;
+                        }
                         GeneratedField::__SkipField__ => {
                             let _ = map_.next_value::<serde::de::IgnoredAny>()?;
                         }
@@ -1214,6 +1234,7 @@ impl<'de> serde::Deserialize<'de> for Metadata {
                     symbol: symbol__.unwrap_or_default(),
                     penumbra_asset_id: penumbra_asset_id__,
                     images: images__.unwrap_or_default(),
+                    priority_score: priority_score__.unwrap_or_default(),
                 })
             }
         }

proto/penumbra/penumbra/core/asset/v1/asset.proto

@@ -62,6 +62,11 @@ message Metadata {
   AssetId penumbra_asset_id = 1984;
 
   repeated AssetImage images = 1985;
+
+  // An optional "score" used to prioritize token lists.
+  //
+  // This is solely for use in client-side registries.
+  uint64 priority_score = 1986;
 }
 
 // DenomUnit represents a struct that describes a given denomination unit of the basic token.