feat: add store name in tracekv-emitted store traces (backport #11646)

* feature: Clone and Merge methods on TraceContext

* chore: use TraceContext.Merge method in SetTracingContext

* feature: add Store name in TraceContext during execution

* chore: update rootmulti Store TraceContext on *Store after Merge()

store/cachemulti/store.go

@@ -13,6 +13,10 @@ import (
 	"github.com/cosmos/cosmos-sdk/store/types"
 )
 
+// storeNameCtxKey is the TraceContext metadata key that identifies
+// the store which emitted a given trace.
+const storeNameCtxKey = "store_name"
+
 //----------------------------------------
 // Store
 
@@ -52,7 +56,11 @@ func NewFromKVStore(
 
 	for key, store := range stores {
 		if cms.TracingEnabled() {
-			store = tracekv.NewStore(store.(types.KVStore), cms.traceWriter, cms.traceContext)
+			tctx := cms.traceContext.Clone().Merge(types.TraceContext{
+				storeNameCtxKey: key.Name(),
+			})
+
+			store = tracekv.NewStore(store.(types.KVStore), cms.traceWriter, tctx)
 		}
 		if cms.ListeningEnabled(key) {
 			store = listenkv.NewStore(store.(types.KVStore), key, listeners[key])

store/rootmulti/store.go

@@ -330,13 +330,7 @@ func (rs *Store) SetTracer(w io.Writer) types.MultiStore {
 func (rs *Store) SetTracingContext(tc types.TraceContext) types.MultiStore {
 	rs.traceContextMutex.Lock()
 	defer rs.traceContextMutex.Unlock()
-	if rs.traceContext != nil {
-		for k, v := range tc {
-			rs.traceContext[k] = v
-		}
-	} else {
-		rs.traceContext = tc
-	}
+	rs.traceContext = rs.traceContext.Merge(tc)
 
 	return rs
 }

store/types/store.go

@@ -418,6 +418,29 @@ type KVPair kv.Pair
 // every trace operation.
 type TraceContext map[string]interface{}
 
+// Clone clones tc into another instance of TraceContext.
+func (tc TraceContext) Clone() TraceContext {
+	ret := TraceContext{}
+	for k, v := range tc {
+		ret[k] = v
+	}
+
+	return ret
+}
+
+// Merge merges value of newTc into tc.
+func (tc TraceContext) Merge(newTc TraceContext) TraceContext {
+	if tc == nil {
+		tc = TraceContext{}
+	}
+
+	for k, v := range newTc {
+		tc[k] = v
+	}
+
+	return tc
+}
+
 // MultiStorePersistentCache defines an interface which provides inter-block
 // (persistent) caching capabilities for multiple CommitKVStores based on StoreKeys.
 type MultiStorePersistentCache interface {

store/types/store_test.go

@@ -90,3 +90,120 @@ func TestTransientStoreKey(t *testing.T) {
 	require.Equal(t, key.name, key.Name())
 	require.Equal(t, fmt.Sprintf("TransientStoreKey{%p, test}", key), key.String())
 }
+
+func TestTraceContext_Clone(t *testing.T) {
+	tests := []struct {
+		name string
+		tc   TraceContext
+		want TraceContext
+	}{
+		{
+			"nil TraceContext yields empty TraceContext",
+			nil,
+			TraceContext{},
+		},
+		{
+			"non-nil TraceContext yields equal TraceContext",
+			TraceContext{
+				"value": 42,
+			},
+			TraceContext{
+				"value": 42,
+			},
+		},
+		{
+			"non-nil TraceContext yields equal TraceContext, for more than one key",
+			TraceContext{
+				"value":   42,
+				"another": 24,
+				"weird":   "string",
+			},
+			TraceContext{
+				"value":   42,
+				"another": 24,
+				"weird":   "string",
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.want, tt.tc.Clone())
+		})
+	}
+}
+
+func TestTraceContext_Clone_is_deep(t *testing.T) {
+	original := TraceContext{
+		"value":   42,
+		"another": 24,
+		"weird":   "string",
+	}
+
+	clone := original.Clone()
+
+	clone["other"] = true
+
+	require.NotEqual(t, original, clone)
+}
+
+func TestTraceContext_Merge(t *testing.T) {
+	tests := []struct {
+		name  string
+		tc    TraceContext
+		other TraceContext
+		want  TraceContext
+	}{
+		{
+			"tc is nil, other is empty, yields an empty TraceContext",
+			nil,
+			TraceContext{},
+			TraceContext{},
+		},
+		{
+			"tc is nil, other is nil, yields an empty TraceContext",
+			nil,
+			nil,
+			TraceContext{},
+		},
+		{
+			"tc is not nil, other is nil, yields tc",
+			TraceContext{
+				"data": 42,
+			},
+			nil,
+			TraceContext{
+				"data": 42,
+			},
+		},
+		{
+			"tc is not nil, other is not nil, yields tc + other",
+			TraceContext{
+				"data": 42,
+			},
+			TraceContext{
+				"data2": 42,
+			},
+			TraceContext{
+				"data":  42,
+				"data2": 42,
+			},
+		},
+		{
+			"tc is not nil, other is not nil, other updates value in tc, yields tc updated with value from other",
+			TraceContext{
+				"data": 42,
+			},
+			TraceContext{
+				"data": 24,
+			},
+			TraceContext{
+				"data": 24,
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			require.Equal(t, tt.want, tt.tc.Merge(tt.other))
+		})
+	}
+}