[GitHub] [nifi-minifi-cpp] adam-markovics commented on a diff in pull request #1447: MINIFICPP-1976 - Do not store a whole Relationship object for each transfer

[GitBox <gi...@apache.org>]

adam-markovics commented on code in PR #1447:
URL: https://github.com/apache/nifi-minifi-cpp/pull/1447#discussion_r1015197406


##########
libminifi/include/utils/ValueIdProvider.h:
##########
@@ -0,0 +1,61 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenseas/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <optional>
+#include <unordered_map>
+#include <vector>
+
+namespace org::apache::nifi::minifi::utils {
+
+template<typename T, typename IdType = size_t>
+class ValueIdProvider {
+ public:
+  using id_type = IdType;
+  static constexpr id_type INVALID_ID = static_cast<id_type>(-1);
+
+  [[nodiscard]]
+  id_type getId(const T& value) {
+    auto [it, inserted] = value_to_id_.insert({value, gsl::narrow<id_type>(values_.size())});

Review Comment:
   gsl needs to be included as well



##########
libminifi/include/core/ProcessSession.h:
##########
@@ -155,16 +156,25 @@ class ProcessSession : public ReferenceContainer {
     std::shared_ptr<FlowFile> snapshot;
   };
 
+  using Relationships = utils::ValueIdProvider<Relationship>;
+
+  Relationships relationships_;

Review Comment:
   Why isn't this a simple `unordered_set`, while references to `Relationship`s with `id_type`, could just be raw pointers to items stored here? Invalid ones are `nullptr`, if necessary. This could eliminate the need for `ValueIdProvider`.



##########
libminifi/include/utils/ValueIdProvider.h:
##########
@@ -0,0 +1,61 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenseas/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <optional>
+#include <unordered_map>
+#include <vector>
+
+namespace org::apache::nifi::minifi::utils {
+
+template<typename T, typename IdType = size_t>
+class ValueIdProvider {
+ public:
+  using id_type = IdType;
+  static constexpr id_type INVALID_ID = static_cast<id_type>(-1);
+
+  [[nodiscard]]
+  id_type getId(const T& value) {
+    auto [it, inserted] = value_to_id_.insert({value, gsl::narrow<id_type>(values_.size())});
+    if (inserted) {
+      values_.push_back(value);
+    }
+    return it->second;
+  }
+
+  [[nodiscard]]
+  std::optional<T> getValue(id_type id) const {
+    const auto idx = gsl::narrow<size_t>(id);
+    if (idx < values_.size()) {
+      return values_.at(idx);

Review Comment:
   `at` is checking boundaries for the second time after the condition, I think it's unnecessary



##########
libminifi/include/utils/ValueIdProvider.h:
##########
@@ -0,0 +1,61 @@
+/**
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenseas/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <optional>
+#include <unordered_map>
+#include <vector>
+
+namespace org::apache::nifi::minifi::utils {
+
+template<typename T, typename IdType = size_t>
+class ValueIdProvider {

Review Comment:
   I think a line of comment could explain what this class does, maybe a better name could also be found than overly generic "Provider".



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscribe@nifi.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org