[#78] policy: Introduce ListTargets method for Policy contract

* Introduce a new method ListTargets that lists targets by kind.
* Slightly fix key mapping - also concatenate kind to prefix.
* Write unit-tests.
* Regenerate rpcclient.

Signed-off-by: Airat Arifullin <a.arifullin@yadro.com>

policy/config.yml

@@ -4,5 +4,6 @@ safemethods:
   - "listChains"
   - "getChain"
   - "listChainsByPrefix"
+  - "listTargets"
   - "iteratorChainsByPrefix"
   - "version"

policy/doc.go

@@ -8,6 +8,7 @@
  | 'n' + uint16(len(namespace)) + namespace | []byte | Container chain                   |
  | 'm' + entity name (namespace/container)  | []byte | Mapped name to an encoded number  |
  | 'counter'                                | uint64 | Integer counter used for mapping  |
+ | 'rc'                                     | uint64 | Actvie rules count for a target   |
 
 */
 

policy/policy_contract.go

@@ -23,6 +23,7 @@ const (
 )
 
 const (
+	activeRulesCounterKeyPrefix = "rc"
 	mappingKeyPrefix            = 'm'
 	counterKey                  = "counter"
 )
@@ -90,11 +91,15 @@ func storageKey(prefix Kind, counter int, name []byte) []byte {
 	return append(key, name...)
 }
 
+func numericMapKeyPrefix(kind Kind) []byte {
+	return []byte{mappingKeyPrefix, byte(kind)}
+}
+
 // mapToNumeric maps a name to a number. That allows to keep more space in
 // a storage key shortening long names. Short entity
 // names are also mapped to prevent collisions in the map.
-func mapToNumeric(ctx storage.Context, name []byte) (mapped int, mappingExists bool) {
-	mKey := append([]byte{mappingKeyPrefix}, name...)
+func mapToNumeric(ctx storage.Context, kind Kind, name []byte) (mapped int, mappingExists bool) {
+	mKey := append(numericMapKeyPrefix(kind), name...)
 	numericID := storage.Get(ctx, mKey)
 	if numericID == nil {
 		return
@@ -109,8 +114,8 @@ func mapToNumeric(ctx storage.Context, name []byte) (mapped int, mappingExists b
 // names are also mapped to prevent collisions in the map.
 // If a mapping cannot be found, then the method creates and returns it.
 // mapToNumericCreateIfNotExists is NOT applicable for a read-only context.
-func mapToNumericCreateIfNotExists(ctx storage.Context, name []byte) int {
-	mKey := append([]byte{mappingKeyPrefix}, name...)
+func mapToNumericCreateIfNotExists(ctx storage.Context, kind Kind, name []byte) int {
+	mKey := append(numericMapKeyPrefix(kind), name...)
 	numericID := storage.Get(ctx, mKey)
 	if numericID == nil {
 		counter := storage.Get(ctx, counterKey).(int)
@@ -126,15 +131,17 @@ func AddChain(entity Kind, entityName string, name []byte, chain []byte) {
 	ctx := storage.GetContext()
 	checkAuthorization(ctx)
 
-	entityNameBytes := mapToNumericCreateIfNotExists(ctx, []byte(entityName))
+	entityNameBytes := mapToNumericCreateIfNotExists(ctx, entity, []byte(entityName))
 	key := storageKey(entity, entityNameBytes, name)
 	storage.Put(ctx, key, chain)
+
+	incTargetRulesCount(ctx, append(numericMapKeyPrefix(entity), entityName...))
 }
 
 func GetChain(entity Kind, entityName string, name []byte) []byte {
 	ctx := storage.GetReadOnlyContext()
 
-	entityNameBytes, exists := mapToNumeric(ctx, []byte(entityName))
+	entityNameBytes, exists := mapToNumeric(ctx, entity, []byte(entityName))
 	if !exists {
 		panic("not found")
 	}
@@ -152,20 +159,21 @@ func RemoveChain(entity Kind, entityName string, name []byte) {
 	ctx := storage.GetContext()
 	checkAuthorization(ctx)
 
-	entityNameBytes, exists := mapToNumeric(ctx, []byte(entityName))
+	entityNameBytes, exists := mapToNumeric(ctx, entity, []byte(entityName))
 	if !exists {
 		return
 	}
 
 	key := storageKey(entity, entityNameBytes, name)
 	storage.Delete(ctx, key)
+	decTargetRulesCount(ctx, append(numericMapKeyPrefix(entity), entityName...))
 }
 
 func RemoveChainsByPrefix(entity Kind, entityName string, name []byte) {
 	ctx := storage.GetContext()
 	checkAuthorization(ctx)
 
-	entityNameBytes, exists := mapToNumeric(ctx, []byte(entityName))
+	entityNameBytes, exists := mapToNumeric(ctx, entity, []byte(entityName))
 	if !exists {
 		return
 	}
@@ -174,6 +182,7 @@ func RemoveChainsByPrefix(entity Kind, entityName string, name []byte) {
 	it := storage.Find(ctx, key, storage.KeysOnly)
 	for iterator.Next(it) {
 		storage.Delete(ctx, iterator.Value(it).([]byte))
+		decTargetRulesCount(ctx, key)
 	}
 }
 
@@ -195,7 +204,7 @@ func ListChainsByPrefix(entity Kind, entityName string, prefix []byte) [][]byte
 
 	result := [][]byte{}
 
-	entityNameBytes, exists := mapToNumeric(ctx, []byte(entityName))
+	entityNameBytes, exists := mapToNumeric(ctx, entity, []byte(entityName))
 	if !exists {
 		return result
 	}
@@ -211,7 +220,63 @@ func ListChainsByPrefix(entity Kind, entityName string, prefix []byte) [][]byte
 
 func IteratorChainsByPrefix(entity Kind, entityName string, prefix []byte) iterator.Iterator {
 	ctx := storage.GetReadOnlyContext()
-	id, _ := mapToNumeric(ctx, []byte(entityName))
+	id, _ := mapToNumeric(ctx, entity, []byte(entityName))
 	keyPrefix := storageKey(entity, id, prefix)
 	return storage.Find(ctx, keyPrefix, storage.ValuesOnly)
 }
+
+// ListTargets lists targets for which rules are defined by kind.
+func ListTargets(entity Kind) [][]byte {
+	ctx := storage.GetReadOnlyContext()
+
+	targetNames := [][]byte{}
+
+	keyPrefix := numericMapKeyPrefix(entity)
+	it := storage.Find(ctx, keyPrefix, storage.KeysOnly)
+
+	for iterator.Next(it) {
+		key := iterator.Value(it).([]byte)
+		entityName := key[len(keyPrefix):]
+
+		if getTargetRulesCount(ctx, key) == 0 {
+			continue
+		}
+		targetNames = append(targetNames, entityName)
+	}
+
+	return targetNames
+}
+
+func incTargetRulesCount(ctx storage.Context, key []byte) {
+	ruleCounterKey := append([]byte(activeRulesCounterKeyPrefix), key...)
+	counter := storage.Get(ctx, ruleCounterKey)
+	if counter == nil {
+		storage.Put(ctx, ruleCounterKey, 1)
+	} else {
+		val := counter.(int)
+		val++
+		storage.Put(ctx, ruleCounterKey, val)
+	}
+}
+
+func decTargetRulesCount(ctx storage.Context, key []byte) {
+	ruleCounterKey := append([]byte(activeRulesCounterKeyPrefix), key...)
+	counter := storage.Get(ctx, ruleCounterKey)
+	if counter != nil {
+		val := counter.(int)
+		if val == 0 {
+			return
+		}
+		val--
+		storage.Put(ctx, ruleCounterKey, val)
+	}
+}
+
+func getTargetRulesCount(ctx storage.Context, key []byte) int {
+	ruleCounterKey := append([]byte(activeRulesCounterKeyPrefix), key...)
+	counter := storage.Get(ctx, ruleCounterKey)
+	if counter != nil {
+		return counter.(int)
+	}
+	return 0
+}

rpcclient/policy/client.go

@@ -90,6 +90,11 @@ func (c *ContractReader) ListChainsByPrefix(entity *big.Int, entityName string,
 	return unwrap.Array(c.invoker.Call(c.hash, "listChainsByPrefix", entity, entityName, prefix))
 }
 
+// ListTargets invokes `listTargets` method of contract.
+func (c *ContractReader) ListTargets(entity *big.Int) ([]stackitem.Item, error) {
+	return unwrap.Array(c.invoker.Call(c.hash, "listTargets", entity))
+}
+
 // Version invokes `version` method of contract.
 func (c *ContractReader) Version() (*big.Int, error) {
 	return unwrap.BigInt(c.invoker.Call(c.hash, "version"))

tests/policy_test.go

@@ -39,19 +39,26 @@ func TestPolicy(t *testing.T) {
 	p33 := []byte("chain33")
 
 	e.Invoke(t, stackitem.Null{}, "addChain", policy.Namespace, "mynamespace", "ingress:123", p1)
+	checkTargets(t, e, policy.Namespace, [][]byte{[]byte("mynamespace")})
 	checkChains(t, e, "mynamespace", "", "ingress", [][]byte{p1})
 	checkChains(t, e, "mynamespace", "", "all", nil)
 
 	e.Invoke(t, stackitem.Null{}, "addChain", policy.Container, "cnr1", "ingress:myrule2", p2)
+	checkTargets(t, e, policy.Namespace, [][]byte{[]byte("mynamespace")})
+	checkTargets(t, e, policy.Container, [][]byte{[]byte("cnr1")})
 	checkChains(t, e, "mynamespace", "", "ingress", [][]byte{p1}) // Only namespace chains.
 	checkChains(t, e, "mynamespace", "cnr1", "ingress", [][]byte{p1, p2})
 	checkChains(t, e, "mynamespace", "cnr1", "all", nil)              // No chains attached to 'all'.
 	checkChains(t, e, "mynamespace", "cnr2", "ingress", [][]byte{p1}) // Only namespace, no chains for the container.
 
 	e.Invoke(t, stackitem.Null{}, "addChain", policy.Container, "cnr1", "ingress:myrule3", p3)
+	checkTargets(t, e, policy.Namespace, [][]byte{[]byte("mynamespace")})
+	checkTargets(t, e, policy.Container, [][]byte{[]byte("cnr1")})
 	checkChains(t, e, "mynamespace", "cnr1", "ingress", [][]byte{p1, p2, p3})
 
 	e.Invoke(t, stackitem.Null{}, "addChain", policy.Container, "cnr1", "ingress:myrule3", p33)
+	checkTargets(t, e, policy.Namespace, [][]byte{[]byte("mynamespace")})
+	checkTargets(t, e, policy.Container, [][]byte{[]byte("cnr1")})
 	checkChain(t, e, policy.Container, "cnr1", "ingress:myrule3", p33)
 	checkChains(t, e, "mynamespace", "cnr1", "ingress", [][]byte{p1, p2, p33}) // Override chain.
 	checkChainsByPrefix(t, e, policy.Container, "cnr1", "", [][]byte{p2, p33})
@@ -73,6 +80,9 @@ func TestPolicy(t *testing.T) {
 		// Remove by prefix.
 		e.Invoke(t, stackitem.Null{}, "removeChainsByPrefix", policy.Container, "cnr1", "ingress")
 		checkChains(t, e, "mynamespace", "cnr1", "ingress", nil)
+
+		checkTargets(t, e, policy.Namespace, [][]byte{})
+		checkTargets(t, e, policy.Container, [][]byte{})
 	})
 }
 
@@ -148,3 +158,21 @@ func checkChain(t *testing.T, e *neotest.ContractInvoker, kind byte, entityName,
 
 	require.True(t, bytes.Equal(expected, s.Pop().Bytes()))
 }
+
+func checkTargets(t *testing.T, e *neotest.ContractInvoker, kind byte, expected [][]byte) {
+	s, err := e.TestInvoke(t, "listTargets", kind)
+	require.NoError(t, err)
+
+	var targets [][]byte
+	for _, item := range s.Pop().Array() {
+		target, err := item.TryBytes()
+		require.NoError(t, err)
+		targets = append(targets, target)
+	}
+
+	require.Len(t, targets, len(expected))
+
+	for _, exp := range expected {
+		require.Contains(t, targets, exp)
+	}
+}