Simulate: Enable on follower node & allow specifying starting round (a…

…lgorand#5685)

cmd/goal/clerk.go

@@ -69,6 +69,7 @@ var (
 	requestFilename    string
 	requestOutFilename string
 
+	simulateStartRound            uint64
 	simulateAllowEmptySignatures  bool
 	simulateAllowMoreLogging      bool
 	simulateAllowMoreOpcodeBudget bool
@@ -164,6 +165,7 @@ func init() {
 	simulateCmd.Flags().StringVar(&requestFilename, "request", "", "Simulate request object to run. Mutually exclusive with --txfile")
 	simulateCmd.Flags().StringVar(&requestOutFilename, "request-only-out", "", "Filename for writing simulate request object. If provided, the command will only write the request object and exit. No simulation will happen")
 	simulateCmd.Flags().StringVarP(&outFilename, "result-out", "o", "", "Filename for writing simulation result")
+	simulateCmd.Flags().Uint64Var(&simulateStartRound, "round", 0, "Specify the round after which the simulation will take place. If not specified, the simulation will take place after the latest round.")
 	simulateCmd.Flags().BoolVar(&simulateAllowEmptySignatures, "allow-empty-signatures", false, "Allow transactions without signatures to be simulated as if they had correct signatures")
 	simulateCmd.Flags().BoolVar(&simulateAllowMoreLogging, "allow-more-logging", false, "Lift the limits on log opcode during simulation")
 	simulateCmd.Flags().BoolVar(&simulateAllowMoreOpcodeBudget, "allow-more-opcode-budget", false, "Apply max extra opcode budget for apps per transaction group (default 320000) during simulation")
@@ -1285,6 +1287,7 @@ var simulateCmd = &cobra.Command{
 						Txns: txgroup,
 					},
 				},
+				Round:                 basics.Round(simulateStartRound),
 				AllowEmptySignatures:  simulateAllowEmptySignatures,
 				AllowMoreLogging:      simulateAllowMoreLogging,
 				AllowUnnamedResources: simulateAllowUnnamedResources,
@@ -1310,6 +1313,7 @@ var simulateCmd = &cobra.Command{
 						Txns: txgroup,
 					},
 				},
+				Round:                 basics.Round(simulateStartRound),
 				AllowEmptySignatures:  simulateAllowEmptySignatures,
 				AllowMoreLogging:      simulateAllowMoreLogging,
 				AllowUnnamedResources: simulateAllowUnnamedResources,

daemon/algod/api/algod.oas2.json

@@ -3629,6 +3629,10 @@
             "$ref": "#/definitions/SimulateRequestTransactionGroup"
           }
         },
+        "round": {
+          "description": "If provided, specifies the round preceding the simulation. State changes through this round will be used to run this simulation. Usually only the 4 most recent rounds will be available (controlled by the node config value MaxAcctLookback). If not specified, defaults to the latest available round.",
+          "type": "integer"
+        },
         "allow-empty-signatures": {
           "description": "Allows transactions without signatures to be simulated as if they had correct signatures.",
           "type": "boolean"

daemon/algod/api/algod.oas3.yml

@@ -2088,6 +2088,10 @@
             "description": "Applies extra opcode budget during simulation for each transaction group.",
             "type": "integer"
           },
+          "round": {
+            "description": "If provided, specifies the round preceding the simulation. State changes through this round will be used to run this simulation. Usually only the 4 most recent rounds will be available (controlled by the node config value MaxAcctLookback). If not specified, defaults to the latest available round.",
+            "type": "integer"
+          },
           "txn-groups": {
             "description": "The transaction groups to simulate.",
             "items": {

daemon/algod/api/server/v2/handlers.go

@@ -1013,6 +1013,7 @@ type PreEncodedSimulateRequestTransactionGroup struct {
 // PreEncodedSimulateRequest mirrors model.SimulateRequest
 type PreEncodedSimulateRequest struct {
 	TxnGroups             []PreEncodedSimulateRequestTransactionGroup `codec:"txn-groups"`
+	Round                 basics.Round                                `codec:"round,omitempty"`
 	AllowEmptySignatures  bool                                        `codec:"allow-empty-signatures,omitempty"`
 	AllowMoreLogging      bool                                        `codec:"allow-more-logging,omitempty"`
 	AllowUnnamedResources bool                                        `codec:"allow-unnamed-resources,omitempty"`

daemon/algod/api/server/v2/utils.go

@@ -550,6 +550,7 @@ func convertSimulationRequest(request PreEncodedSimulateRequest) simulation.Requ
 	}
 	return simulation.Request{
 		TxnGroups:             txnGroups,
+		Round:                 request.Round,
 		AllowEmptySignatures:  request.AllowEmptySignatures,
 		AllowMoreLogging:      request.AllowMoreLogging,
 		AllowUnnamedResources: request.AllowUnnamedResources,

ledger/acctupdates.go

@@ -692,6 +692,13 @@ func (au *accountUpdates) LatestTotals() (basics.Round, ledgercore.AccountTotals
 	return au.latestTotalsImpl()
 }
 
+// Totals returns the totals of all accounts for the given round
+func (au *accountUpdates) Totals(rnd basics.Round) (ledgercore.AccountTotals, error) {
+	au.accountsMu.RLock()
+	defer au.accountsMu.RUnlock()
+	return au.totalsImpl(rnd)
+}
+
 // ReadCloseSizer interface implements the standard io.Reader and io.Closer as well
 // as supporting the Size() function that let the caller know what the size of the stream would be (in bytes).
 type ReadCloseSizer interface {
@@ -722,6 +729,15 @@ func (au *accountUpdates) latestTotalsImpl() (basics.Round, ledgercore.AccountTo
 	return rnd, au.roundTotals[offset], nil
 }
 
+// totalsImpl returns the totals of all accounts for the given round
+func (au *accountUpdates) totalsImpl(rnd basics.Round) (ledgercore.AccountTotals, error) {
+	offset, err := au.roundOffset(rnd)
+	if err != nil {
+		return ledgercore.AccountTotals{}, err
+	}
+	return au.roundTotals[offset], nil
+}
+
 // initializeFromDisk performs the atomic operation of loading the accounts data information from disk
 // and preparing the accountUpdates for operation.
 func (au *accountUpdates) initializeFromDisk(l ledgerForTracker, lastBalancesRound basics.Round) error {

ledger/ledger.go

@@ -632,6 +632,13 @@ func (l *Ledger) LatestTotals() (basics.Round, ledgercore.AccountTotals, error)
 	return l.accts.LatestTotals()
 }
 
+// Totals returns the totals of all accounts for the given round.
+func (l *Ledger) Totals(rnd basics.Round) (ledgercore.AccountTotals, error) {
+	l.trackerMu.RLock()
+	defer l.trackerMu.RUnlock()
+	return l.accts.Totals(rnd)
+}
+
 // OnlineCirculation returns the online totals of all accounts at the end of round rnd.
 // It implements agreement's calls for Circulation(rnd)
 func (l *Ledger) OnlineCirculation(rnd basics.Round, voteRnd basics.Round) (basics.MicroAlgos, error) {