NodeWeight ergonomics

lib/dal-macros/Cargo.toml

@@ -19,4 +19,6 @@ quote = { workspace = true }
 syn = { workspace = true }
 
 [dev-dependencies]
+dal = { path = "../dal" }
+si-events = { path = "../si-events-rs" }
 trybuild = { version = "1.0.99", features = ["diff"] }

lib/dal-macros/src/lib.rs

@@ -10,3 +10,12 @@ pub fn si_versioned_node_weight(
 ) -> manyhow::Result<proc_macro::TokenStream> {
     node_weight::versioned::derive_si_versioned_node_weight(input, errors)
 }
+
+#[manyhow]
+#[proc_macro_derive(SiNodeWeight, attributes(si_node_weight))]
+pub fn si_node_weight(
+    input: proc_macro::TokenStream,
+    errors: &mut manyhow::Emitter,
+) -> manyhow::Result<proc_macro::TokenStream> {
+    node_weight::derive_si_node_weight(input, errors)
+}

lib/dal-macros/src/node_weight.rs

@@ -1 +1,299 @@
+use std::collections::HashSet;
+
+use darling::{util::IdentString, FromAttributes, FromMeta};
+use manyhow::{bail, emit};
+use proc_macro2::TokenStream;
+use quote::{quote, ToTokens};
+use syn::{Data, DeriveInput, Expr, Path};
+
 pub(crate) mod versioned;
+
+#[derive(Debug, PartialEq, Eq, Hash)]
+enum SkipOption {
+    ContentHash,
+    Id,
+    LineageId,
+    MerkleTreeHash,
+    NodeHash,
+    NodeWeightDiscriminants,
+    SetId,
+    SetLineageId,
+    SetMerkleTreeHash,
+}
+
+impl FromMeta for SkipOption {
+    fn from_string(value: &str) -> darling::Result<Self> {
+        match value {
+            "content_hash" => Ok(Self::ContentHash),
+            "id" => Ok(Self::Id),
+            "lineage_id" => Ok(Self::LineageId),
+            "merkle_tree_hash" => Ok(Self::MerkleTreeHash),
+            "node_hash" => Ok(Self::NodeHash),
+            "node_weight_discriminants" => Ok(Self::NodeWeightDiscriminants),
+            "set_id" => Ok(Self::SetId),
+            "set_lineage_id" => Ok(Self::SetLineageId),
+            "set_merkle_tree_hash" => Ok(Self::SetMerkleTreeHash),
+            v => Err(darling::Error::unknown_value(v)),
+        }
+    }
+}
+
+#[derive(Debug, Default)]
+struct SkipOptionSet {
+    options: HashSet<SkipOption>,
+}
+
+impl SkipOptionSet {
+    fn should_skip(&self, option: SkipOption) -> bool {
+        self.options.contains(&option)
+    }
+
+    fn add_skip_option(&mut self, option: SkipOption) {
+        self.options.insert(option);
+    }
+}
+
+impl FromMeta for SkipOptionSet {
+    fn from_list(items: &[darling::ast::NestedMeta]) -> darling::Result<Self> {
+        let mut new_option_set = SkipOptionSet::default();
+        for item in items {
+            new_option_set.add_skip_option(SkipOption::from_nested_meta(item)?);
+        }
+
+        Ok(new_option_set)
+    }
+}
+
+#[derive(FromAttributes)]
+#[darling(attributes(si_node_weight))]
+struct SiNodeWeightOptions {
+    discriminant: Option<Path>,
+    #[darling(default)]
+    skip: SkipOptionSet,
+}
+
+#[derive(Debug, Default)]
+struct NodeHashParticipation {
+    participant: bool,
+    custom_code: Option<String>,
+}
+
+impl FromMeta for NodeHashParticipation {
+    fn from_word() -> darling::Result<Self> {
+        Ok(Self {
+            participant: true,
+            custom_code: None,
+        })
+    }
+
+    fn from_value(value: &syn::Lit) -> darling::Result<Self> {
+        match value {
+            syn::Lit::Str(custom_str) => Ok(Self {
+                participant: true,
+                custom_code: Some(custom_str.value()),
+            }),
+            _ => Err(darling::Error::unexpected_lit_type(value)),
+        }
+    }
+}
+
+#[derive(Debug, Default, FromAttributes)]
+#[darling(attributes(si_node_weight))]
+struct NodeWeightFieldAttrs {
+    #[darling(default, rename = "node_hash")]
+    node_hash_participation: NodeHashParticipation,
+}
+
+pub fn derive_si_node_weight(
+    input: proc_macro::TokenStream,
+    errors: &mut manyhow::Emitter,
+) -> manyhow::Result<proc_macro::TokenStream> {
+    let input = syn::parse::<DeriveInput>(input)?;
+    let DeriveInput {
+        ident,
+        data: type_data,
+        attrs,
+        ..
+    } = input.clone();
+    let struct_options = SiNodeWeightOptions::from_attributes(&attrs)?;
+
+    let node_weight_discriminant = if let Some(discriminant) = struct_options.discriminant {
+        discriminant
+    } else {
+        emit!(errors, input, "No NodeWeightDiscriminants was specified.");
+        syn::parse_str::<Path>("")?
+    };
+
+    let struct_data = match &type_data {
+        Data::Struct(data) => data,
+        _ => {
+            bail!(input, "SiNodeWeight must be derived on a struct.");
+        }
+    };
+    let mut struct_has_content_address = false;
+    let mut node_hash_parts = Vec::new();
+    for field in &struct_data.fields {
+        if let Some(field_ident) = &field.ident {
+            let ident_string: IdentString = field_ident.clone().into();
+            if ident_string == "content_address" {
+                struct_has_content_address = true;
+            }
+        } else {
+            emit!(errors, field, "No identifier found for field.");
+            continue;
+        }
+        let field_attrs = NodeWeightFieldAttrs::from_attributes(&field.attrs)?;
+        if field_attrs.node_hash_participation.participant {
+            let hasher_update =
+                if let Some(custom_code) = field_attrs.node_hash_participation.custom_code {
+                    match syn::parse_str::<Expr>(&custom_code) {
+                        Ok(expr) => expr.to_token_stream(),
+                        Err(e) => {
+                            emit!(
+                                errors,
+                                syn::Error::new_spanned(
+                                    field,
+                                    format!("Invalid custom code for node_hash calculation: {e}")
+                                )
+                            );
+                            continue;
+                        }
+                    }
+                } else {
+                    let field_ident = field.ident.clone();
+                    quote! {
+                        self.#field_ident.as_bytes()
+                    }
+                };
+            node_hash_parts.push(hasher_update);
+        }
+    }
+    errors.into_result()?;
+
+    let id_fn = if struct_options.skip.should_skip(SkipOption::Id) {
+        quote! {}
+    } else {
+        quote! {
+            fn id(&self) -> Ulid {
+                self.id
+            }
+        }
+    };
+
+    let lineage_id_fn = if struct_options.skip.should_skip(SkipOption::LineageId) {
+        quote! {}
+    } else {
+        quote! {
+            fn lineage_id(&self) -> Ulid {
+                self.lineage_id
+            }
+        }
+    };
+
+    let content_hash_fn = if struct_options.skip.should_skip(SkipOption::ContentHash) {
+        quote! {}
+    } else {
+        let content_hash_location = if struct_has_content_address {
+            quote! { self.content_address.content_hash() }
+        } else {
+            quote! { self.node_hash() }
+        };
+
+        quote! {
+            fn content_hash(&self) -> ContentHash {
+                #content_hash_location
+            }
+        }
+    };
+
+    let merkle_tree_hash_fn = if struct_options.skip.should_skip(SkipOption::MerkleTreeHash) {
+        quote! {}
+    } else {
+        quote! {
+            fn merkle_tree_hash(&self) -> MerkleTreeHash {
+                self.merkle_tree_hash
+            }
+        }
+    };
+
+    let node_hash_fn = if struct_options.skip.should_skip(SkipOption::NodeHash) {
+        quote! {}
+    } else {
+        let mut hash_updates = TokenStream::new();
+        for update in node_hash_parts {
+            let full_update = quote! { content_hasher.update(#update); };
+            hash_updates.extend(full_update);
+        }
+
+        quote! {
+            fn node_hash(&self) -> ContentHash {
+                let mut content_hasher = ContentHash::hasher();
+                #hash_updates
+
+                content_hasher.finalize()
+            }
+        }
+    };
+
+    let node_weight_discriminant_fn = if struct_options
+        .skip
+        .should_skip(SkipOption::NodeWeightDiscriminants)
+    {
+        quote! {}
+    } else {
+        quote! {
+            fn node_weight_discriminant(&self) -> NodeWeightDiscriminants {
+                #node_weight_discriminant
+            }
+        }
+    };
+
+    let set_id_fn = if struct_options.skip.should_skip(SkipOption::SetId) {
+        quote! {}
+    } else {
+        quote! {
+            fn set_id(&mut self, new_id: Ulid) {
+                self.id = new_id;
+            }
+        }
+    };
+
+    let set_lineage_id_fn = if struct_options.skip.should_skip(SkipOption::SetLineageId) {
+        quote! {}
+    } else {
+        quote! {
+            fn set_lineage_id(&mut self, new_lineage_id: Ulid) {
+                self.lineage_id = new_lineage_id;
+            }
+        }
+    };
+
+    let set_merkle_tree_hash_fn = if struct_options
+        .skip
+        .should_skip(SkipOption::SetMerkleTreeHash)
+    {
+        quote! {}
+    } else {
+        quote! {
+            fn set_merkle_tree_hash(&mut self, new_merkle_tree_hash: MerkleTreeHash) {
+                self.merkle_tree_hash = new_merkle_tree_hash;
+            }
+        }
+    };
+
+    let output = quote! {
+        impl SiNodeWeight for #ident {
+            #id_fn
+            #lineage_id_fn
+            #content_hash_fn
+            #merkle_tree_hash_fn
+            #node_hash_fn
+            #node_weight_discriminant_fn
+            #set_id_fn
+            #set_lineage_id_fn
+            #set_merkle_tree_hash_fn
+        }
+    };
+
+    Ok(output.into())
+}

lib/dal-macros/tests/ui/06-node_weight-basic-tests-pass.rs

@@ -0,0 +1,25 @@
+use dal::workspace_snapshot::{
+    edge_weight::EdgeWeightKindDiscriminants,
+    node_weight::{
+        traits::{CorrectExclusiveOutgoingEdge, CorrectTransforms, SiNodeWeight},
+        NodeWeightDiscriminants,
+    },
+};
+use si_events::{merkle_tree_hash::MerkleTreeHash, ulid::Ulid, ContentHash};
+
+#[derive(dal_macros::SiNodeWeight)]
+#[si_node_weight(discriminant = NodeWeightDiscriminants::InputSocket)]
+pub struct TestingNodeWeight {
+    id: Ulid,
+    lineage_id: Ulid,
+    merkle_tree_hash: MerkleTreeHash,
+}
+
+impl CorrectTransforms for TestingNodeWeight {}
+impl CorrectExclusiveOutgoingEdge for TestingNodeWeight {
+    fn exclusive_outgoing_edges(&self) -> &[EdgeWeightKindDiscriminants] {
+        todo!()
+    }
+}
+
+fn main() {}

lib/dal-macros/tests/ui/07-node_weight-no-discriminant-specified-fail.rs

@@ -0,0 +1,25 @@
+use dal::workspace_snapshot::{
+    edge_weight::EdgeWeightKindDiscriminants,
+    node_weight::{
+        traits::{CorrectExclusiveOutgoingEdge, CorrectTransforms, SiNodeWeight},
+        NodeWeightDiscriminants,
+    },
+};
+use si_events::{merkle_tree_hash::MerkleTreeHash, ulid::Ulid, ContentHash};
+
+#[derive(dal_macros::SiNodeWeight)]
+#[si_node_weight]
+pub struct TestingNodeWeight {
+    id: Ulid,
+    lineage_id: Ulid,
+    merkle_tree_hash: MerkleTreeHash,
+}
+
+impl CorrectTransforms for TestingNodeWeight {}
+impl CorrectExclusiveOutgoingEdge for TestingNodeWeight {
+    fn exclusive_outgoing_edges(&self) -> &[EdgeWeightKindDiscriminants] {
+        &[]
+    }
+}
+
+fn main() {}