Support multiple scoring chains (#39)

## Motivation

Add flexibility in how we use scoring chain(s)

## Proposal

* Support several scoring chains
* Let frontends pick the one their user should use (possibly none)

## Test Plan

CI + manual tests

Author: ma2bd

backend/README.md

@@ -43,9 +43,9 @@ CHAIN="${INFO[0]}"
 OWNER="${INFO[1]}"
 ```
 
-### Creating the scoring chain
+### Creating the scoring chains
 
-Let's create another wallet and the scoring chain. The app wallet will be accessible with `linera -w1`.
+Let's create another wallet and two scoring chains. The app wallet will be accessible with `linera -w1`.
 
 ```bash
 export LINERA_WALLET_1="$LINERA_TMP_DIR/wallet_1.json"
@@ -57,6 +57,10 @@ linera -w1 wallet init --faucet $FAUCET_URL
 INFO_1=($(linera -w1 wallet request-chain --faucet $FAUCET_URL))
 CHAIN_1="${INFO_1[0]}"
 OWNER_1="${INFO_1[1]}"
+
+INFO_2=($(linera -w1 wallet request-chain --faucet $FAUCET_URL))
+CHAIN_2="${INFO_1[0]}"
+OWNER_2="${INFO_1[1]}"
 ```
 
 ### Creating the GoL challenge application
@@ -66,8 +70,7 @@ node service.
 
 ```bash
 APP_ID=$(linera --wait-for-outgoing-messages \
-  project publish-and-create backend gol_challenge $CHAIN \
-    --json-parameters "{ \"scoring_chain_id\": \"$CHAIN_1\" }")
+  project publish-and-create backend gol_challenge $CHAIN)
 ```
 
 ### Creating a new puzzle
@@ -80,18 +83,18 @@ BLOB_ID=$(linera publish-data-blob "$LINERA_TMP_DIR/02_beehive_pattern_puzzle.bc
 
 ### Publishing puzzles and running code-generation
 
-Run the node service for the scoring chain.
+Run the node service for the scoring chains.
 ```bash
 linera -w1 service --port 8081 &
 sleep 1
 ```
 
 The following script creates puzzles with the `gol` tool, then it uses the user wallet to
-publish them. At the same time, it also sends GraphQL queries to the scoring chain to register
+publish them. At the same time, it also sends GraphQL queries to the scoring chain(s) to register
 the puzzles.
 
 ```bash
-./publish-puzzles.sh http://localhost:8081/chains/$CHAIN_1/applications/$APP_ID
+./publish-puzzles.sh http://localhost:8081/chains/$CHAIN_1/applications/$APP_ID http://localhost:8081/chains/$CHAIN_2/applications/$APP_ID
 ```
 
 Note that we never unregister puzzles.
@@ -121,7 +124,7 @@ query {
 
 ```gql,uri=http://localhost:8080/chains/$CHAIN/applications/$APP_ID
 mutation {
-    submitSolution(puzzleId: "$BLOB_ID", board: {
+    submitSolution(puzzleId: "$BLOB_ID", scoringChainId: "$CHAIN_1", board: {
         size: 9,
         liveCells: [{x: 3, y: 2}, {x: 4, y: 2}, {x: 2, y: 3}, {x: 5, y: 3}, {x: 3, y: 4}, {x: 4, y: 4}]
     })
@@ -133,6 +136,7 @@ mutation {
 To debug GraphQL APIs, uncomment the line with `read` and run `bash -x -e <(linera extract-script-from-markdown backend/README.md)`.
 ```bash
 echo http://localhost:8081/chains/$CHAIN_1/applications/$APP_ID
+echo http://localhost:8081/chains/$CHAIN_2/applications/$APP_ID
 # read
 ```
 
@@ -161,6 +165,7 @@ Restart the service with the scoring chain followed in read-only:
 kill $PID
 
 linera wallet follow-chain "$CHAIN_1"
+linera wallet follow-chain "$CHAIN_2"
 
 linera service --port 8080 &
 ```

backend/src/contract.rs

@@ -8,7 +8,7 @@ mod state;
 use async_graphql::ComplexObject;
 use gol_challenge::{game::Puzzle, GolChallengeAbi, Operation};
 use linera_sdk::{
-    linera_base_types::{AccountOwner, ChainId, DataBlobHash, Timestamp, WithContractAbi},
+    linera_base_types::{AccountOwner, DataBlobHash, Timestamp, WithContractAbi},
     views::{RootView, View},
     Contract, ContractRuntime,
 };
@@ -22,12 +22,6 @@ pub struct GolChallengeContract {
 
 linera_sdk::contract!(GolChallengeContract);
 
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub struct Parameters {
-    /// Where to report puzzles for scoring.
-    scoring_chain_id: ChainId,
-}
-
 impl WithContractAbi for GolChallengeContract {
     type Abi = GolChallengeAbi;
 }
@@ -45,7 +39,7 @@ pub struct Message {
 impl Contract for GolChallengeContract {
     type Message = Message;
     type InstantiationArgument = ();
-    type Parameters = Parameters;
+    type Parameters = ();
     type EventValue = ();
 
     async fn load(runtime: ContractRuntime<Self>) -> Self {
@@ -68,6 +62,7 @@ impl Contract for GolChallengeContract {
                 puzzle_id,
                 board,
                 owner,
+                scoring_chain_id,
             } => {
                 let owner = owner.unwrap_or_else(|| {
                     self.runtime
@@ -88,18 +83,19 @@ impl Contract for GolChallengeContract {
                     .insert(&puzzle_id, solution)
                     .expect("Store solution");
 
-                let Parameters { scoring_chain_id } = self.runtime.application_parameters();
-                let message = Message {
-                    puzzle_id,
-                    timestamp,
-                    owner,
-                };
-                self.runtime
-                    .prepare_message(message)
-                    .send_to(scoring_chain_id);
+                if let Some(scoring_chain_id) = scoring_chain_id {
+                    let message = Message {
+                        puzzle_id,
+                        timestamp,
+                        owner,
+                    };
+                    self.runtime
+                        .prepare_message(message)
+                        .send_to(scoring_chain_id);
+                }
             }
             Operation::RegisterPuzzle { puzzle_id } => {
-                self.assert_scoring_chain("Puzzles are only registered on the scoring chain.");
+                // Puzzles are only registered on a scoring chain.
                 self.state.registered_puzzles.insert(&puzzle_id).unwrap();
             }
         }
@@ -112,35 +108,30 @@ impl Contract for GolChallengeContract {
             timestamp,
             owner,
         } = message;
-        self.assert_scoring_chain("Messages are sent to the scoring chain.");
         let is_registered = self
             .state
             .registered_puzzles
             .contains(&puzzle_id)
             .await
             .unwrap();
-        assert!(is_registered, "Puzzle must be registered");
-        let map = self
-            .state
-            .reported_solutions
-            .load_entry_mut(&owner)
-            .await
-            .unwrap();
-        map.insert(&puzzle_id, timestamp).unwrap();
+        if is_registered {
+            let map = self
+                .state
+                .reported_solutions
+                .load_entry_mut(&owner)
+                .await
+                .unwrap();
+            map.insert(&puzzle_id, timestamp).unwrap();
+        } else {
+            log::trace!("Ignoring unregistered puzzle");
+        }
     }
 
     async fn store(mut self) {
         self.state.save().await.expect("Failed to save state");
     }
 }
 
-impl GolChallengeContract {
-    fn assert_scoring_chain(&mut self, error: &str) {
-        let Parameters { scoring_chain_id } = self.runtime.application_parameters();
-        assert_eq!(self.runtime.chain_id(), scoring_chain_id, "{}", error);
-    }
-}
-
 /// This implementation is only nonempty in the service.
 #[ComplexObject]
 impl GolChallengeState {}

backend/src/lib.rs

@@ -11,7 +11,7 @@ pub mod game;
 use async_graphql::{Request, Response};
 use linera_sdk::{
     graphql::GraphQLMutationRoot,
-    linera_base_types::{AccountOwner, ContractAbi, DataBlobHash, ServiceAbi},
+    linera_base_types::{AccountOwner, ChainId, ContractAbi, DataBlobHash, ServiceAbi},
 };
 use serde::{Deserialize, Serialize};
 
@@ -31,6 +31,8 @@ pub enum Operation {
         board: Board,
         /// Optional owner to credit instead of the current authenticated owner.
         owner: Option<AccountOwner>,
+        /// The scoring chain to use.
+        scoring_chain_id: Option<ChainId>,
     },
     // Scoring appchain only
     /// Register a puzzle to activate scoring for it.

backend/src/state.rs

@@ -14,11 +14,12 @@ use serde::{Deserialize, Serialize};
 #[graphql(complex)]
 #[view(context = ViewStorageContext)]
 pub struct GolChallengeState {
+    // User chains only.
     /// The local solutions previously submitted by an owner of the chain. Puzzles do not
     /// need to be registered.
     pub solutions: MapView<DataBlobHash, Solution>,
 
-    // Scoring chain only.
+    // Scoring chains only.
     /// The set of registered puzzles.
     pub registered_puzzles: SetView<DataBlobHash>,
     /// The set of all solutions reported to us, indexed by owner, then by puzzle_id. We only track

publish-puzzles.sh

@@ -5,9 +5,11 @@
 
 set -e
 
-# Expecting some URI to query the node service of the scoring chain.
+# Expecting some URIs to query the node service of the scoring chain.
 # If absent, puzzles will be published but not registered for scoring.
-URI="$1"
+URIS=("$@")
+
+echo "Using ${#URIS[@]} scoring chains"
 
 # Create temporary directory
 TEMP_DIR=$(mktemp -d)
@@ -63,12 +65,12 @@ for i in "${!PUZZLE_FILES[@]}"; do
             echo "  \"$PUZZLE\": \"$BLOB_ID\"," >> "$BLOB_MAP_FILE"
         fi
 
-        if [ -n "$URI" ]; then
+        for URI in "${URIS[@]}"; do
             QUERY="mutation { registerPuzzle(puzzleId: \"$BLOB_ID\")}"
             JSON_QUERY=$( jq -n --arg q "$QUERY" '{"query": $q}' )
             # Use js to parse the result and fail otherwise.
             curl -w '\n' -g -X POST -H "Content-Type: application/json" -d "$JSON_QUERY" "$URI" | tee /dev/stderr | jq -e .data
-        fi
+        done
     else
         echo "  Error: Could not extract blob ID for $PUZZLE"
         exit 1