feat(logic): introduce telemetry to track predicate call counts

Author: ccamel

x/logic/keeper/interpreter.go

@@ -105,6 +105,7 @@ func (k Keeper) newInterpreter(ctx context.Context, params types.Params) (*prolo
 		interpreter.WithHooks(
 			whitelistBlacklistHookFn(whitelistPredicates, blacklistPredicates),
 			gasMeterHookFn(sdkctx, params.GetGasPolicy()),
+			telemetryPredicateCallCounterHookFn(),
 		),
 		interpreter.WithPredicates(ctx, interpreter.RegistryNames),
 		interpreter.WithBootstrap(ctx, util.NonZeroOrDefault(interpreterParams.GetBootstrap(), bootstrap.Bootstrap())),
@@ -135,23 +136,20 @@ func whitelistBlacklistHookFn(whitelist, blacklist []string) engine.HookFunc {
 			return nil
 		}
 
-		predicateStringer, ok := operand.(fmt.Stringer)
+		predicate, ok := stringifyOperand(operand)
 		if !ok {
 			return engine.SyntaxError(operand, env)
 		}
 
-		predicate := predicateStringer.String()
-
-		if interpreter.IsRegistered(predicate) {
-			if _, found := allowed.Get(predicate); !found {
-				return engine.PermissionError(
-					prolog2.AtomOperationExecute,
-					prolog2.AtomPermissionForbiddenPredicate,
-					engine.NewAtom(predicate),
-					env,
-				)
-			}
+		if _, found := allowed.Get(predicate); !found {
+			return engine.PermissionError(
+				prolog2.AtomOperationExecute,
+				prolog2.AtomPermissionForbiddenPredicate,
+				engine.NewAtom(predicate),
+				env,
+			)
 		}
+
 		return nil
 	}
 }
@@ -166,13 +164,11 @@ func gasMeterHookFn(ctx context.Context, gasPolicy types.GasPolicy) engine.HookF
 			return nil
 		}
 
-		operandStringer, ok := operand.(fmt.Stringer)
+		predicate, ok := stringifyOperand(operand)
 		if !ok {
 			return engine.SyntaxError(operand, env)
 		}
 
-		predicate := operandStringer.String()
-
 		cost := lookupCost(predicate,
 			lo.CoalesceOrEmpty(gasPolicy.DefaultPredicateCost, defaultPredicateCost),
 			gasPolicy.PredicateCosts)

x/logic/keeper/metrics.go

@@ -0,0 +1,57 @@
+package keeper
+
+import (
+	"fmt"
+
+	"github.com/axone-protocol/prolog/engine"
+	"github.com/hashicorp/go-metrics"
+
+	"github.com/cosmos/cosmos-sdk/telemetry"
+
+	"github.com/axone-protocol/axoned/v10/x/logic/interpreter"
+	"github.com/axone-protocol/axoned/v10/x/logic/types"
+)
+
+var (
+	metricsKeys = []string{types.ModuleName, "vm", "predicate"}
+)
+
+const (
+	labelPredicate = "predicate"
+)
+
+func telemetryPredicateCallCounterHookFn() engine.HookFunc {
+	return func(opcode engine.Opcode, operand engine.Term, _ *engine.Env) error {
+		if opcode != engine.OpCall {
+			return nil
+		}
+
+		predicate, ok := stringifyOperand(operand)
+		if !ok {
+			return nil
+		}
+
+		if !interpreter.IsRegistered(predicate) {
+			return nil
+		}
+
+		telemetry.IncrCounterWithLabels(
+			metricsKeys,
+			1,
+			[]metrics.Label{
+				telemetry.NewLabel(labelPredicate, predicate),
+			},
+		)
+
+		return nil
+	}
+}
+
+// stringifyOperand returns the string representation of the operand if it implements fmt.Stringer.
+// It returns an empty string and false if the operand does not have a string representation.
+func stringifyOperand(operand engine.Term) (string, bool) {
+	if stringer, ok := operand.(fmt.Stringer); ok {
+		return stringer.String(), true
+	}
+	return "", false
+}