fix(engine): remove unnecessary allocations from GetNonFungibleIds (#861

)

Description
---
Remove unnecessary allocation when calling
`VaultAction::GetNonFungibleIds` and `BucketAction::GetNonFungibleIds`

Motivation and Context
---

Previously, when we were using borsh encoding, `BTreeSet`s would not
deserialize in the WASM (unfortunately, no specific details in my code
comment). Since the change to use CBOR this is no longer the case, which
allows us to encode a reference to the BTreeSet without the
into_iter/collect conversion to a Vec. Since Sets and Vecs are
represented in the same CBOR binary format, we can deserialize from a
BTreeSet to a Vec.

It is important to remove any unnecessary contract execution resource
usage.

How Has This Been Tested?
---
Modified existing test to call the bucket get_non_fungible_ids method.
Vault get_non_fungible is already tested.

What process can a PR reviewer use to test or verify this change?
---
Engine tests

Breaking Changes
---

- [x] None
- [ ] Requires data directory to be deleted
- [ ] Other - Please specify

dan_layer/engine/src/runtime/impl.rs

@@ -887,12 +887,7 @@ impl<TTemplateProvider: TemplateProvider<Template = LoadedTemplate>> RuntimeInte
 
                 self.tracker.write_with(|state| {
                     let vault_lock = state.lock_substate(&SubstateAddress::Vault(vault_id), LockFlag::Read)?;
-                    // NOTE: A BTreeSet does not decode when received in the WASM
-                    let non_fungible_ids = state
-                        .get_vault(&vault_lock)?
-                        .get_non_fungible_ids()
-                        .iter()
-                        .collect::<Vec<_>>();
+                    let non_fungible_ids = state.get_vault(&vault_lock)?.get_non_fungible_ids();
                     let result = InvokeResult::encode(&non_fungible_ids)?;
                     state.unlock_substate(vault_lock)?;
                     Ok(result)
@@ -1238,8 +1233,7 @@ impl<TTemplateProvider: TemplateProvider<Template = LoadedTemplate>> RuntimeInte
 
                 self.tracker.write_with(|state| {
                     let bucket = state.get_bucket(bucket_id)?;
-                    let non_fungible_ids = bucket.non_fungible_ids().iter().collect::<Vec<_>>();
-                    Ok(InvokeResult::encode(&non_fungible_ids)?)
+                    Ok(InvokeResult::encode(bucket.non_fungible_ids())?)
                 })
             },
         }

dan_layer/engine/tests/account_nfts.rs

@@ -2,7 +2,12 @@
 //   SPDX-License-Identifier: BSD-3-Clause
 
 use tari_engine_types::instruction::Instruction;
-use tari_template_lib::{args, models::ComponentAddress, prelude::Metadata, resource::TOKEN_SYMBOL};
+use tari_template_lib::{
+    args,
+    models::{ComponentAddress, NonFungibleId},
+    prelude::Metadata,
+    resource::TOKEN_SYMBOL,
+};
 use tari_template_test_tooling::TemplateTest;
 
 #[test]
@@ -57,6 +62,11 @@ fn basic_nft_mint() {
                 Instruction::PutLastInstructionOutputOnWorkspace {
                     key: b"my_nft".to_vec(),
                 },
+                Instruction::CallFunction {
+                    template_address: account_nft_template_test.get_template_address("Account"),
+                    function: "get_non_fungible_ids_for_bucket".to_string(),
+                    args: args![Variable("my_nft")],
+                },
                 Instruction::CallMethod {
                     component_address: owner_component_address,
                     method: "deposit".to_string(),
@@ -68,4 +78,9 @@ fn basic_nft_mint() {
         .unwrap();
 
     assert!(result.finalize.result.is_accept());
+
+    let bucket_nfts = result.finalize.execution_results[2]
+        .decode::<Vec<NonFungibleId>>()
+        .unwrap();
+    assert_eq!(bucket_nfts.len(), 1);
 }

dan_layer/engine_types/Cargo.toml

@@ -16,7 +16,7 @@ tari_template_lib = { workspace = true }
 tari_utilities = { workspace = true }
 
 borsh = { workspace = true }
-# if we set this version in the workspace it would break other crates
+# if we set this version in the workspace it would break other crates
 base64 = "0.21.0"
 blake2 = { workspace = true }
 rand = { workspace = true }
@@ -27,7 +27,6 @@ serde = { workspace = true, default-features = true }
 serde_json = { workspace = true }
 thiserror = { workspace = true }
 
-
 [features]
 default = ["debugging"]
 # Includes the ability to create free test coins

dan_layer/template_builtin/templates/account/src/lib.rs

@@ -26,6 +26,7 @@ use tari_template_lib::prelude::*;
 #[template]
 mod account_template {
     use super::*;
+
     pub struct Account {
         // TODO: Lazy key value map/store
         vaults: BTreeMap<ResourceAddress, Vault>,
@@ -234,5 +235,11 @@ mod account_template {
             let v = self.get_vault_mut(resource);
             v.create_proof_by_amount(amount)
         }
+
+        /// Utility function to allow bucket NFT content to be inspected. An empty vec is returned if the bucket does
+        /// not contain any NFTs or does not contain a NonFungible resource.
+        pub fn get_non_fungible_ids_for_bucket(bucket: Bucket) -> Vec<NonFungibleId> {
+            bucket.get_non_fungible_ids()
+        }
     }
 }