feat(nns): Avoid cloning large fields when listing proposals (dfinity#3505)

# Why

When converting from `ProposalData` to `ProposalInfo`, the large fields
(e.g. canister WASMs, logos) are "omitted" in a way that those fields
are first cloned then cleared. It indeed saves space in the response by
not including them, but the instructions are nevertheless wasted for the
clone, and this can be significant for certain queries (e.g. listing
only proposals including canister WASMs).

# What

* Make `ProposalInfo`/`ListProposalInfoResponse` pure API types, by
removing its corresponding internal type
* Add conversion method `proposal_data_to_info` from the `ProposalData`
internal type to `ProposalInfo` API type
* Implement the equivalent behavior of `omit_large_fields` in the
conversion code
* Let `Governance::list_proposals` use the new conversion method and
return `ListProposalInfoResponse`(API type)
* Update benchmark results (98% improvement on list_proposals)

# Tests

`rs/nns/governance/tests/governance.rs` already tests various cases for
`omit_large_fields`

Author: jasonz-dfinity

rs/nns/governance/api/src/ic_nns_governance.pb.v1.rs

@@ -2158,61 +2158,41 @@ pub struct WaitForQuietState {
 /// This is a view of the ProposalData returned by API queries and is NOT used
 /// for storage. The ballots are restricted to those of the caller's neurons and
 /// additionally it has the computed fields, topic, status, and reward_status.
-#[derive(candid::CandidType, candid::Deserialize, serde::Serialize, comparable::Comparable)]
-#[allow(clippy::derive_partial_eq_without_eq)]
-#[derive(Clone, PartialEq, ::prost::Message)]
+#[derive(candid::CandidType, candid::Deserialize, serde::Serialize, Clone, Debug, PartialEq)]
 pub struct ProposalInfo {
     /// The unique id for this proposal.
-    #[prost(message, optional, tag = "1")]
     pub id: Option<::ic_nns_common::pb::v1::ProposalId>,
     /// The ID of the neuron that made this proposal.
-    #[prost(message, optional, tag = "2")]
     pub proposer: Option<NeuronId>,
     /// The amount of ICP in E8s to be charged to the proposer if the proposal is
     /// rejected.
-    #[prost(uint64, tag = "3")]
     pub reject_cost_e8s: u64,
     /// The proposal originally submitted.
-    #[prost(message, optional, tag = "4")]
     pub proposal: Option<Proposal>,
     /// The timestamp, in seconds from the Unix epoch, when this proposal was made.
-    #[prost(uint64, tag = "5")]
     pub proposal_timestamp_seconds: u64,
     /// See \[ProposalData::ballots\].
-    #[prost(map = "fixed64, message", tag = "6")]
     pub ballots: ::std::collections::HashMap<u64, Ballot>,
     /// See \[ProposalData::latest_tally\].
-    #[prost(message, optional, tag = "7")]
     pub latest_tally: Option<Tally>,
     /// See \[ProposalData::decided_timestamp_seconds\].
-    #[prost(uint64, tag = "8")]
     pub decided_timestamp_seconds: u64,
     /// See \[ProposalData::executed_timestamp_seconds\].
-    #[prost(uint64, tag = "12")]
     pub executed_timestamp_seconds: u64,
     /// See \[ProposalData::failed_timestamp_seconds\].
-    #[prost(uint64, tag = "13")]
     pub failed_timestamp_seconds: u64,
     /// See \[ProposalData::failure_reason\].
-    #[prost(message, optional, tag = "18")]
     pub failure_reason: Option<GovernanceError>,
     /// See \[ProposalData::reward_event_round\].
-    #[prost(uint64, tag = "14")]
     pub reward_event_round: u64,
     /// Derived - see \[Topic\] for more information
-    #[prost(enumeration = "Topic", tag = "15")]
     pub topic: i32,
     /// Derived - see \[ProposalStatus\] for more information
-    #[prost(enumeration = "ProposalStatus", tag = "16")]
     pub status: i32,
     /// Derived - see \[ProposalRewardStatus\] for more information
-    #[prost(enumeration = "ProposalRewardStatus", tag = "17")]
     pub reward_status: i32,
-    #[prost(uint64, optional, tag = "19")]
     pub deadline_timestamp_seconds: Option<u64>,
-    #[prost(message, optional, tag = "20")]
     pub derived_proposal_information: Option<DerivedProposalInformation>,
-    #[prost(uint64, optional, tag = "21")]
     pub total_potential_voting_power: ::core::option::Option<u64>,
 }
 
@@ -3479,11 +3459,8 @@ pub struct ListProposalInfo {
     #[prost(bool, optional, tag = "7")]
     pub omit_large_fields: Option<bool>,
 }
-#[derive(candid::CandidType, candid::Deserialize, serde::Serialize, comparable::Comparable)]
-#[allow(clippy::derive_partial_eq_without_eq)]
-#[derive(Clone, PartialEq, ::prost::Message)]
+#[derive(candid::CandidType, candid::Deserialize, serde::Serialize, Clone, Debug, PartialEq)]
 pub struct ListProposalInfoResponse {
-    #[prost(message, repeated, tag = "1")]
     pub proposal_info: Vec<ProposalInfo>,
 }
 /// A request to list neurons. The "requested list", i.e., the list of

rs/nns/governance/canbench/canbench_results.yml

@@ -1,67 +1,67 @@
 benches:
   add_neuron_active_maximum:
     total:
-      instructions: 42749552
+      instructions: 42752796
       heap_increase: 1
       stable_memory_increase: 0
     scopes: {}
   add_neuron_active_typical:
     total:
-      instructions: 2170522
+      instructions: 2170658
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   add_neuron_inactive_maximum:
     total:
-      instructions: 112621390
+      instructions: 112624375
       heap_increase: 1
       stable_memory_increase: 0
     scopes: {}
   add_neuron_inactive_typical:
     total:
-      instructions: 8497159
+      instructions: 8497036
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   cascading_vote_all_heap:
     total:
-      instructions: 35650914
+      instructions: 35676146
       heap_increase: 0
       stable_memory_increase: 128
     scopes: {}
   cascading_vote_heap_neurons_stable_index:
     total:
-      instructions: 61785953
+      instructions: 61811185
       heap_increase: 0
       stable_memory_increase: 128
     scopes: {}
   cascading_vote_stable_everything:
     total:
-      instructions: 188618691
+      instructions: 188611915
       heap_increase: 0
       stable_memory_increase: 128
     scopes: {}
   cascading_vote_stable_neurons_with_heap_index:
     total:
-      instructions: 162350256
+      instructions: 162343480
       heap_increase: 0
       stable_memory_increase: 128
     scopes: {}
   centralized_following_all_stable:
     total:
-      instructions: 78266711
+      instructions: 78265237
       heap_increase: 0
       stable_memory_increase: 128
     scopes: {}
   compute_ballots_for_new_proposal_with_stable_neurons:
     total:
-      instructions: 2223231
+      instructions: 2223431
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   draw_maturity_from_neurons_fund_heap:
     total:
-      instructions: 7643198
+      instructions: 7656798
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
@@ -85,7 +85,7 @@ benches:
     scopes: {}
   list_neurons_heap:
     total:
-      instructions: 4947095
+      instructions: 4988540
       heap_increase: 9
       stable_memory_increase: 0
     scopes: {}
@@ -103,13 +103,13 @@ benches:
     scopes: {}
   list_neurons_stable:
     total:
-      instructions: 113659672
+      instructions: 113606723
       heap_increase: 5
       stable_memory_increase: 0
     scopes: {}
   list_proposals:
     total:
-      instructions: 6477035
+      instructions: 128658
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
@@ -127,37 +127,37 @@ benches:
     scopes: {}
   neuron_data_validation_heap:
     total:
-      instructions: 406842391
+      instructions: 406853184
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   neuron_data_validation_stable:
     total:
-      instructions: 362640286
+      instructions: 362648372
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   neuron_metrics_calculation_heap:
     total:
-      instructions: 1498269
+      instructions: 1498869
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   neuron_metrics_calculation_stable:
     total:
-      instructions: 3026795
+      instructions: 3027495
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   range_neurons_performance:
     total:
-      instructions: 56448740
+      instructions: 56447340
       heap_increase: 0
       stable_memory_increase: 0
     scopes: {}
   single_vote_all_stable:
     total:
-      instructions: 2805835
+      instructions: 2805871
       heap_increase: 0
       stable_memory_increase: 128
     scopes: {}

rs/nns/governance/canister/canister.rs

@@ -774,9 +774,7 @@ fn get_neuron_info_by_id_or_subaccount(
 #[query]
 fn get_proposal_info(id: ProposalId) -> Option<ProposalInfo> {
     debug_log("get_proposal_info");
-    governance()
-        .get_proposal_info(&caller(), id)
-        .map(ProposalInfo::from)
+    GOVERNANCE.with_borrow(|governance| governance.get_proposal_info(&caller(), id))
 }
 
 #[query]
@@ -792,17 +790,13 @@ fn get_neurons_fund_audit_info(
 #[query]
 fn get_pending_proposals() -> Vec<ProposalInfo> {
     debug_log("get_pending_proposals");
-    governance()
-        .get_pending_proposals(&caller())
-        .into_iter()
-        .map(ProposalInfo::from)
-        .collect()
+    GOVERNANCE.with_borrow(|governance| governance.get_pending_proposals(&caller()))
 }
 
 #[query]
 fn list_proposals(req: ListProposalInfo) -> ListProposalInfoResponse {
     debug_log("list_proposals");
-    governance().list_proposals(&caller(), &(req.into())).into()
+    GOVERNANCE.with_borrow(|governance| governance.list_proposals(&caller(), &req.into()))
 }
 
 #[query]

rs/nns/governance/proto/ic_nns_governance/pb/v1/governance.proto

@@ -1642,64 +1642,6 @@ message WaitForQuietState {
   uint64 current_deadline_timestamp_seconds = 1;
 }
 
-// This is a view of the ProposalData returned by API queries and is NOT used
-// for storage. The ballots are restricted to those of the caller's neurons and
-// additionally it has the computed fields, topic, status, and reward_status.
-message ProposalInfo {
-  // The unique id for this proposal.
-  ic_nns_common.pb.v1.ProposalId id = 1;
-
-  // The ID of the neuron that made this proposal.
-  ic_nns_common.pb.v1.NeuronId proposer = 2;
-
-  // The amount of ICP in E8s to be charged to the proposer if the proposal is
-  // rejected.
-  uint64 reject_cost_e8s = 3;
-
-  // The proposal originally submitted.
-  Proposal proposal = 4;
-
-  // The timestamp, in seconds from the Unix epoch, when this proposal was made.
-  uint64 proposal_timestamp_seconds = 5;
-
-  // See [ProposalData::ballots].
-  map<fixed64, Ballot> ballots = 6;
-
-  // See [ProposalData::latest_tally].
-  Tally latest_tally = 7;
-
-  // See [ProposalData::decided_timestamp_seconds].
-  uint64 decided_timestamp_seconds = 8;
-
-  // See [ProposalData::executed_timestamp_seconds].
-  uint64 executed_timestamp_seconds = 12;
-
-  // See [ProposalData::failed_timestamp_seconds].
-  uint64 failed_timestamp_seconds = 13;
-
-  // See [ProposalData::failure_reason].
-  GovernanceError failure_reason = 18;
-
-  // See [ProposalData::reward_event_round].
-  uint64 reward_event_round = 14;
-
-  // Derived - see [Topic] for more information
-  Topic topic = 15;
-
-  // Derived - see [ProposalStatus] for more information
-  ProposalStatus status = 16;
-
-  // Derived - see [ProposalRewardStatus] for more information
-  ProposalRewardStatus reward_status = 17;
-
-  optional uint64 deadline_timestamp_seconds = 19;
-
-  DerivedProposalInformation derived_proposal_information = 20;
-
-  // See [ProposalData::total_potential_voting_power].
-  optional uint64 total_potential_voting_power = 21;
-}
-
 // Network economics contains the parameters for several operations related
 // to the economy of the network. When submitting a NetworkEconomics proposal
 // default values (0) are considered unchanged, so a valid proposal only needs
@@ -2492,10 +2434,6 @@ message ListProposalInfo {
   optional bool omit_large_fields = 7;
 }
 
-message ListProposalInfoResponse {
-  repeated ProposalInfo proposal_info = 1;
-}
-
 // A response to "ListKnownNeurons"
 message ListKnownNeuronsResponse {
   // List of known neurons.