HDFS-16472. Make HDFS setrep tool cross platform (#4130)

* The source files for hdfs_setrep
   uses getopt for parsing the
   command line arguments.
* getopt is available only on Linux
   and thus, isn't cross platform.
* We need to replace getopt
  with boost::program_options
  to make this tool cross platform.

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/tools/CMakeLists.txt

@@ -38,6 +38,7 @@ add_executable(hdfs_tool_tests
                 hdfs-get-mock.cc
                 hdfs-find-mock.cc
                 hdfs-ls-mock.cc
+                hdfs-setrep-mock.cc
                 main.cc)
 target_include_directories(hdfs_tool_tests PRIVATE
                             ../tools
@@ -60,6 +61,7 @@ target_include_directories(hdfs_tool_tests PRIVATE
                             ../../tools/hdfs-get
                             ../../tools/hdfs-find
                             ../../tools/hdfs-ls
+                            ../../tools/hdfs-setrep
                             ../../tools/hdfs-cat)
 target_link_libraries(hdfs_tool_tests PRIVATE
                        gmock_main
@@ -81,5 +83,6 @@ target_link_libraries(hdfs_tool_tests PRIVATE
                        hdfs_get_lib
                        hdfs_find_lib
                        hdfs_ls_lib
+                       hdfs_setrep_lib
                        hdfs_cat_lib)
 add_test(hdfs_tool_tests hdfs_tool_tests)

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/tools/hdfs-setrep-mock.cc

@@ -0,0 +1,56 @@
+/**
+ * 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/licenses/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.
+ */
+
+#include <functional>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include "hdfs-setrep-mock.h"
+#include "hdfs-tool-tests.h"
+
+namespace hdfs::tools::test {
+SetrepMock::~SetrepMock() = default;
+
+void SetrepMock::SetExpectations(
+    std::function<std::unique_ptr<SetrepMock>()> test_case,
+    const std::vector<std::string> &args) const {
+  // Get the pointer to the function that defines the test case
+  const auto test_case_func =
+      test_case.target<std::unique_ptr<SetrepMock> (*)()>();
+  ASSERT_NE(test_case_func, nullptr);
+
+  // Set the expected method calls and their corresponding arguments for each
+  // test case
+  if (*test_case_func == &CallHelp<SetrepMock>) {
+    EXPECT_CALL(*this, HandleHelp()).Times(1).WillOnce(testing::Return(true));
+    return;
+  }
+
+  if (*test_case_func == &PassPermissionsAndAPath<SetrepMock>) {
+    const auto number = args[0];
+    const auto path = args[1];
+    EXPECT_CALL(*this, HandlePath(path, number))
+        .Times(1)
+        .WillOnce(testing::Return(true));
+  }
+}
+} // namespace hdfs::tools::test

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/tools/hdfs-setrep-mock.h

@@ -0,0 +1,68 @@
+/**
+ * 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/licenses/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.
+ */
+
+#ifndef LIBHDFSPP_TOOLS_HDFS_SETREP_MOCK
+#define LIBHDFSPP_TOOLS_HDFS_SETREP_MOCK
+
+#include <functional>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <gmock/gmock.h>
+
+#include "hdfs-setrep.h"
+
+namespace hdfs::tools::test {
+/**
+ * {@class SetrepMock} is an {@class Setrep} whereby it mocks the
+ * HandleHelp and HandlePath methods for testing their functionality.
+ */
+class SetrepMock : public hdfs::tools::Setrep {
+public:
+  /**
+   * {@inheritdoc}
+   */
+  SetrepMock(const int argc, char **argv) : Setrep(argc, argv) {}
+
+  // Abiding to the Rule of 5
+  SetrepMock(const SetrepMock &) = delete;
+  SetrepMock(SetrepMock &&) = delete;
+  SetrepMock &operator=(const SetrepMock &) = delete;
+  SetrepMock &operator=(SetrepMock &&) = delete;
+  ~SetrepMock() override;
+
+  /**
+   * Defines the methods and the corresponding arguments that are expected
+   * to be called on this instance of {@link HdfsTool} for the given test case.
+   *
+   * @param test_case An {@link std::function} object that points to the
+   * function defining the test case
+   * @param args The arguments that are passed to this test case
+   */
+  void SetExpectations(std::function<std::unique_ptr<SetrepMock>()> test_case,
+                       const std::vector<std::string> &args = {}) const;
+
+  MOCK_METHOD(bool, HandleHelp, (), (const, override));
+
+  MOCK_METHOD(bool, HandlePath, (const std::string &, const std::string &),
+              (const, override));
+};
+} // namespace hdfs::tools::test
+
+#endif

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/tools/hdfs-tool-tests.cc

@@ -38,6 +38,7 @@
 #include "hdfs-move-to-local-mock.h"
 #include "hdfs-rename-snapshot-mock.h"
 #include "hdfs-rm-mock.h"
+#include "hdfs-setrep-mock.h"
 #include "hdfs-tool-test-fixtures.h"
 #include "hdfs-tool-tests.h"
 
@@ -156,6 +157,11 @@ INSTANTIATE_TEST_SUITE_P(
                     PassMOptPermissionsAndAPath<hdfs::tools::test::FindMock>,
                     PassNOptAndAPath<hdfs::tools::test::FindMock>));
 
+INSTANTIATE_TEST_SUITE_P(
+    HdfsSetrep, HdfsToolBasicTest,
+    testing::Values(CallHelp<hdfs::tools::test::SetrepMock>,
+                    PassPermissionsAndAPath<hdfs::tools::test::SetrepMock>));
+
 // Negative tests
 INSTANTIATE_TEST_SUITE_P(
     HdfsAllowSnapshot, HdfsToolNegativeTestThrows,
@@ -245,6 +251,20 @@ INSTANTIATE_TEST_SUITE_P(
                     PassMOpt<hdfs::tools::test::FindMock>,
                     PassNOpt<hdfs::tools::test::FindMock>));
 
+INSTANTIATE_TEST_SUITE_P(
+    HdfsChgrp, HdfsToolNegativeTestThrows,
+    testing::Values(PassNOptAndAPath<hdfs::tools::test::ChgrpMock>));
+
+INSTANTIATE_TEST_SUITE_P(
+    HdfsSetrep, HdfsToolNegativeTestThrows,
+    testing::Values(
+        Pass3Paths<hdfs::tools::test::SetrepMock>,
+        PassRecursiveOwnerAndAPath<hdfs::tools::test::SetrepMock>,
+        PassRecursive<hdfs::tools::test::SetrepMock>,
+        PassMPOptsPermissionsAndAPath<hdfs::tools::test::SetrepMock>,
+        PassMOpt<hdfs::tools::test::SetrepMock>,
+        PassNOpt<hdfs::tools::test::SetrepMock>));
+
 INSTANTIATE_TEST_SUITE_P(
     HdfsRm, HdfsToolNegativeTestNoThrow,
     testing::Values(PassRecursive<hdfs::tools::test::RmMock>));
@@ -302,5 +322,5 @@ INSTANTIATE_TEST_SUITE_P(
     testing::Values(PassAPath<hdfs::tools::test::ChgrpMock>));
 
 INSTANTIATE_TEST_SUITE_P(
-    HdfsChgrp, HdfsToolNegativeTestThrows,
-    testing::Values(PassNOptAndAPath<hdfs::tools::test::ChgrpMock>));
+    HdfsSetrep, HdfsToolNegativeTestNoThrow,
+    testing::Values(PassAPath<hdfs::tools::test::SetrepMock>));

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/CMakeLists.txt

@@ -64,8 +64,7 @@ add_subdirectory(hdfs-copy-to-local)
 
 add_subdirectory(hdfs-move-to-local)
 
-add_executable(hdfs_setrep hdfs_setrep.cc)
-target_link_libraries(hdfs_setrep tools_common hdfspp_static)
+add_subdirectory(hdfs-setrep)
 
 add_subdirectory(hdfs-allow-snapshot)
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/hdfs-setrep/CMakeLists.txt

@@ -0,0 +1,27 @@
+#
+# 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/licenses/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.
+#
+
+add_library(hdfs_setrep_lib STATIC $<TARGET_OBJECTS:hdfs_tool_obj> hdfs-setrep.cc)
+target_include_directories(hdfs_setrep_lib PRIVATE ../../tools ${Boost_INCLUDE_DIRS})
+target_link_libraries(hdfs_setrep_lib PRIVATE Boost::boost Boost::program_options tools_common hdfspp_static)
+
+add_executable(hdfs_setrep main.cc)
+target_include_directories(hdfs_setrep PRIVATE ../../tools)
+target_link_libraries(hdfs_setrep PRIVATE hdfs_setrep_lib)
+
+install(TARGETS hdfs_setrep RUNTIME DESTINATION bin)

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/hdfs-setrep/hdfs-setrep.cc

@@ -0,0 +1,220 @@
+/**
+ * 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/licenses/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.
+ */
+
+#include <future>
+#include <iostream>
+#include <memory>
+#include <ostream>
+#include <sstream>
+#include <string>
+
+#include "hdfs-setrep.h"
+#include "internal/set-replication-state.h"
+#include "tools_common.h"
+
+namespace hdfs::tools {
+Setrep::Setrep(const int argc, char **argv) : HdfsTool(argc, argv) {}
+
+bool Setrep::Initialize() {
+  auto add_options = opt_desc_.add_options();
+  add_options("help,h",
+              "Changes the replication factor of a file at PATH. If PATH is a "
+              "directory then the command recursively changes the replication "
+              "factor of all files under the directory tree rooted at PATH.");
+  add_options(
+      "replication-factor", po::value<std::string>(),
+      "The replication factor to set for the given path and its children.");
+  add_options("path", po::value<std::string>(),
+              "The path for which the replication factor needs to be set.");
+
+  // We allow only one positional argument to be passed to this tool. An
+  // exception is thrown if multiple arguments are passed.
+  pos_opt_desc_.add("replication-factor", 1);
+  pos_opt_desc_.add("path", 1);
+
+  po::store(po::command_line_parser(argc_, argv_)
+                .options(opt_desc_)
+                .positional(pos_opt_desc_)
+                .run(),
+            opt_val_);
+  po::notify(opt_val_);
+  return true;
+}
+
+bool Setrep::ValidateConstraints() const {
+  // Only "help" is allowed as single argument.
+  if (argc_ == 2) {
+    return opt_val_.count("help");
+  }
+
+  // Rest of the cases must contain more than 2 arguments on the command line.
+  return argc_ > 2;
+}
+
+std::string Setrep::GetDescription() const {
+  std::stringstream desc;
+  desc << "Usage: hdfs_setrep [OPTION] NUM_REPLICAS PATH" << std::endl
+       << std::endl
+       << "Changes the replication factor of a file at PATH. If PATH is a "
+          "directory then the command"
+       << std::endl
+       << "recursively changes the replication factor of all files under the "
+          "directory tree rooted at PATH."
+       << std::endl
+       << std::endl
+       << "  -h  display this help and exit" << std::endl
+       << std::endl
+       << "Examples:" << std::endl
+       << "hdfs_setrep 5 hdfs://localhost.localdomain:8020/dir/file"
+       << std::endl
+       << "hdfs_setrep 3 /dir1/dir2" << std::endl;
+  return desc.str();
+}
+
+bool Setrep::Do() {
+  if (!Initialize()) {
+    std::cerr << "Unable to initialize HDFS setrep tool" << std::endl;
+    return false;
+  }
+
+  if (!ValidateConstraints()) {
+    std::cout << GetDescription();
+    return false;
+  }
+
+  if (opt_val_.count("help") > 0) {
+    return HandleHelp();
+  }
+
+  if (opt_val_.count("path") > 0 && opt_val_.count("replication-factor") > 0) {
+    const auto replication_factor =
+        opt_val_["replication-factor"].as<std::string>();
+    const auto path = opt_val_["path"].as<std::string>();
+    return HandlePath(path, replication_factor);
+  }
+
+  return false;
+}
+
+bool Setrep::HandleHelp() const {
+  std::cout << GetDescription();
+  return true;
+}
+
+bool Setrep::HandlePath(const std::string &path,
+                        const std::string &replication_factor) const {
+  // Building a URI object from the given path.
+  auto uri = hdfs::parse_path_or_exit(path);
+
+  const auto fs = hdfs::doConnect(uri, true);
+  if (!fs) {
+    std::cerr << "Could not connect to the file system." << std::endl;
+    return false;
+  }
+
+  /*
+   * Wrap async FileSystem::SetReplication with promise to make it a blocking
+   * call.
+   */
+  auto promise = std::make_shared<std::promise<hdfs::Status>>();
+  std::future future(promise->get_future());
+  auto handler = [promise](const hdfs::Status &s) { promise->set_value(s); };
+
+  const auto replication = static_cast<uint16_t>(
+      std::strtol(replication_factor.c_str(), nullptr, 8));
+  /*
+   * Allocating shared state, which includes:
+   * replication to be set, handler to be called, request counter, and a boolean
+   * to keep track if find is done
+   */
+  auto state =
+      std::make_shared<SetReplicationState>(replication, handler, 0, false);
+
+  /*
+   * Keep requesting more from Find until we process the entire listing. Call
+   * handler when Find is done and request counter is 0. Find guarantees that
+   * the handler will only be called once at a time so we do not need locking in
+   * handler_find.
+   */
+  auto handler_find = [fs, state](const hdfs::Status &status_find,
+                                  const std::vector<hdfs::StatInfo> &stat_infos,
+                                  const bool has_more_results) -> bool {
+    /*
+     * For each result returned by Find we call async SetReplication with the
+     * handler below. SetReplication DOES NOT guarantee that the handler will
+     * only be called once at a time, so we DO need locking in
+     * handler_set_replication.
+     */
+    auto handler_set_replication =
+        [state](const hdfs::Status &status_set_replication) {
+          std::lock_guard guard(state->lock);
+
+          // Decrement the counter once since we are done with this async call.
+          if (!status_set_replication.ok() && state->status.ok()) {
+            // We make sure we set state->status only on the first error.
+            state->status = status_set_replication;
+          }
+          state->request_counter--;
+          if (state->request_counter == 0 && state->find_is_done) {
+            state->handler(state->status); // Exit.
+          }
+        };
+    if (!stat_infos.empty() && state->status.ok()) {
+      for (hdfs::StatInfo const &stat_info : stat_infos) {
+        // Launch an asynchronous call to SetReplication for every returned
+        // file.
+        if (stat_info.file_type == hdfs::StatInfo::IS_FILE) {
+          state->request_counter++;
+          fs->SetReplication(stat_info.full_path, state->replication,
+                             handler_set_replication);
+        }
+      }
+    }
+
+    /*
+     * Lock this section because handlerSetReplication might be accessing the
+     * same shared variables simultaneously.
+     */
+    std::lock_guard guard(state->lock);
+    if (!status_find.ok() && state->status.ok()) {
+      // We make sure we set state->status only on the first error.
+      state->status = status_find;
+    }
+    if (!has_more_results) {
+      state->find_is_done = true;
+      if (state->request_counter == 0) {
+        state->handler(state->status); // Exit.
+      }
+      return false;
+    }
+    return true;
+  };
+
+  // Asynchronous call to Find.
+  fs->Find(uri.get_path(), "*", hdfs::FileSystem::GetDefaultFindMaxDepth(),
+           handler_find);
+
+  // Block until promise is set.
+  const auto status = future.get();
+  if (!status.ok()) {
+    std::cerr << "Error: " << status.ToString() << std::endl;
+    return false;
+  }
+  return true;
+}
+} // namespace hdfs::tools

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/hdfs-setrep/hdfs-setrep.h

@@ -0,0 +1,96 @@
+/**
+ * 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/licenses/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.
+ */
+
+#ifndef LIBHDFSPP_TOOLS_HDFS_SETREP
+#define LIBHDFSPP_TOOLS_HDFS_SETREP
+
+#include <string>
+
+#include <boost/program_options.hpp>
+
+#include "hdfs-tool.h"
+
+namespace hdfs::tools {
+/**
+ * {@class Setrep} is an {@class HdfsTool} that changes the replication factor
+ * of a file at a given path. If the path is a directory, then it recursively
+ * changes the replication factor of all files under the directory tree rooted
+ * at the given path.
+ */
+class Setrep : public HdfsTool {
+public:
+  /**
+   * {@inheritdoc}
+   */
+  Setrep(int argc, char **argv);
+
+  // Abiding to the Rule of 5
+  Setrep(const Setrep &) = default;
+  Setrep(Setrep &&) = default;
+  Setrep &operator=(const Setrep &) = delete;
+  Setrep &operator=(Setrep &&) = delete;
+  ~Setrep() override = default;
+
+  /**
+   * {@inheritdoc}
+   */
+  [[nodiscard]] std::string GetDescription() const override;
+
+  /**
+   * {@inheritdoc}
+   */
+  [[nodiscard]] bool Do() override;
+
+protected:
+  /**
+   * {@inheritdoc}
+   */
+  [[nodiscard]] bool Initialize() override;
+
+  /**
+   * {@inheritdoc}
+   */
+  [[nodiscard]] bool ValidateConstraints() const override;
+
+  /**
+   * {@inheritdoc}
+   */
+  [[nodiscard]] bool HandleHelp() const override;
+
+  /**
+   * Handle the path argument that's passed to this tool.
+   *
+   * @param path The path to the directory for which we need setrep info.
+   * @param replication_factor The replication factor to set to given path and
+   * its children.
+   *
+   * @return A boolean indicating the result of this operation.
+   */
+  [[nodiscard]] virtual bool
+  HandlePath(const std::string &path,
+             const std::string &replication_factor) const;
+
+private:
+  /**
+   * A boost data-structure containing the description of positional arguments
+   * passed to the command-line.
+   */
+  po::positional_options_description pos_opt_desc_;
+};
+} // namespace hdfs::tools
+#endif

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/hdfs-setrep/main.cc

@@ -0,0 +1,52 @@
+/**
+ * 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/licenses/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.
+ */
+
+#include <cstdlib>
+#include <exception>
+#include <iostream>
+
+#include <google/protobuf/stubs/common.h>
+
+#include "hdfs-setrep.h"
+
+int main(int argc, char *argv[]) {
+  const auto result = std::atexit([]() -> void {
+    // Clean up static data on exit and prevent valgrind memory leaks
+    google::protobuf::ShutdownProtobufLibrary();
+  });
+  if (result != 0) {
+    std::cerr << "Error: Unable to schedule clean-up tasks for HDFS setrep "
+                 "tool, exiting"
+              << std::endl;
+    std::exit(EXIT_FAILURE);
+  }
+
+  hdfs::tools::Setrep setrep(argc, argv);
+  auto success = false;
+
+  try {
+    success = setrep.Do();
+  } catch (const std::exception &e) {
+    std::cerr << "Error: " << e.what() << std::endl;
+  }
+
+  if (!success) {
+    std::exit(EXIT_FAILURE);
+  }
+  return 0;
+}

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/hdfs_setrep.cc

@@ -1,172 +0,0 @@
-/*
-  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/licenses/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.
-*/
-
-#include <google/protobuf/stubs/common.h>
-#include <unistd.h>
-#include <future>
-#include "tools_common.h"
-
-void usage(){
-  std::cout << "Usage: hdfs_setrep [OPTION] NUM_REPLICAS PATH"
-      << std::endl
-      << std::endl << "Changes the replication factor of a file at PATH. If PATH is a directory then the command"
-      << std::endl << "recursively changes the replication factor of all files under the directory tree rooted at PATH."
-      << std::endl
-      << std::endl << "  -h  display this help and exit"
-      << std::endl
-      << std::endl << "Examples:"
-      << std::endl << "hdfs_setrep 5 hdfs://localhost.localdomain:8020/dir/file"
-      << std::endl << "hdfs_setrep 3 /dir1/dir2"
-      << std::endl;
-}
-
-struct SetReplicationState {
-  const uint16_t replication;
-  const std::function<void(const hdfs::Status &)> handler;
-  //The request counter is incremented once every time SetReplication async call is made
-  uint64_t request_counter;
-  //This boolean will be set when find returns the last result
-  bool find_is_done;
-  //Final status to be returned
-  hdfs::Status status;
-  //Shared variables will need protection with a lock
-  std::mutex lock;
-  SetReplicationState(const uint16_t replication_, const std::function<void(const hdfs::Status &)> & handler_,
-              uint64_t request_counter_, bool find_is_done_)
-      : replication(replication_),
-        handler(handler_),
-        request_counter(request_counter_),
-        find_is_done(find_is_done_),
-        status(),
-        lock() {
-  }
-};
-
-int main(int argc, char *argv[]) {
-  //We should have 3 or 4 parameters
-  if (argc < 3) {
-    usage();
-    exit(EXIT_FAILURE);
-  }
-
-  int input;
-
-  //Using GetOpt to read in the values
-  opterr = 0;
-  while ((input = getopt(argc, argv, "h")) != -1) {
-    switch (input)
-    {
-    case 'h':
-      usage();
-      exit(EXIT_SUCCESS);
-    case '?':
-      if (isprint(optopt))
-        std::cerr << "Unknown option `-" << (char) optopt << "'." << std::endl;
-      else
-        std::cerr << "Unknown option character `" << (char) optopt << "'." << std::endl;
-      usage();
-      exit(EXIT_FAILURE);
-    default:
-      exit(EXIT_FAILURE);
-    }
-  }
-  std::string repl = argv[optind];
-  std::string uri_path = argv[optind + 1];
-
-  //Building a URI object from the given uri_path
-  hdfs::URI uri = hdfs::parse_path_or_exit(uri_path);
-
-  std::shared_ptr<hdfs::FileSystem> fs = hdfs::doConnect(uri, true);
-  if (!fs) {
-    std::cerr << "Could not connect the file system. " << std::endl;
-    exit(EXIT_FAILURE);
-  }
-
-  /* wrap async FileSystem::SetReplication with promise to make it a blocking call */
-  std::shared_ptr<std::promise<hdfs::Status>> promise = std::make_shared<std::promise<hdfs::Status>>();
-  std::future<hdfs::Status> future(promise->get_future());
-  auto handler = [promise](const hdfs::Status &s) {
-    promise->set_value(s);
-  };
-
-  uint16_t replication = std::stoi(repl.c_str(), NULL, 8);
-  //Allocating shared state, which includes:
-  //replication to be set, handler to be called, request counter, and a boolean to keep track if find is done
-  std::shared_ptr<SetReplicationState> state = std::make_shared<SetReplicationState>(replication, handler, 0, false);
-
-  // Keep requesting more from Find until we process the entire listing. Call handler when Find is done and reques counter is 0.
-  // Find guarantees that the handler will only be called once at a time so we do not need locking in handlerFind.
-  auto handlerFind = [fs, state](const hdfs::Status &status_find, const std::vector<hdfs::StatInfo> & stat_infos, bool has_more_results) -> bool {
-
-    //For each result returned by Find we call async SetReplication with the handler below.
-    //SetReplication DOES NOT guarantee that the handler will only be called once at a time, so we DO need locking in handlerSetReplication.
-    auto handlerSetReplication = [state](const hdfs::Status &status_set_replication) {
-      std::lock_guard<std::mutex> guard(state->lock);
-
-      //Decrement the counter once since we are done with this async call
-      if (!status_set_replication.ok() && state->status.ok()){
-        //We make sure we set state->status only on the first error.
-        state->status = status_set_replication;
-      }
-      state->request_counter--;
-      if(state->request_counter == 0 && state->find_is_done){
-        state->handler(state->status); //exit
-      }
-    };
-    if(!stat_infos.empty() && state->status.ok()) {
-      for (hdfs::StatInfo const& s : stat_infos) {
-        //Launch an asynchronous call to SetReplication for every returned file
-        if(s.file_type == hdfs::StatInfo::IS_FILE){
-          state->request_counter++;
-          fs->SetReplication(s.full_path, state->replication, handlerSetReplication);
-        }
-      }
-    }
-
-    //Lock this section because handlerSetReplication might be accessing the same
-    //shared variables simultaneously
-    std::lock_guard<std::mutex> guard(state->lock);
-    if (!status_find.ok() && state->status.ok()){
-      //We make sure we set state->status only on the first error.
-      state->status = status_find;
-    }
-    if(!has_more_results){
-      state->find_is_done = true;
-      if(state->request_counter == 0){
-        state->handler(state->status); //exit
-      }
-      return false;
-    }
-    return true;
-  };
-
-  //Asynchronous call to Find
-  fs->Find(uri.get_path(), "*", hdfs::FileSystem::GetDefaultFindMaxDepth(), handlerFind);
-
-  /* block until promise is set */
-  hdfs::Status status = future.get();
-  if (!status.ok()) {
-    std::cerr << "Error: " << status.ToString() << std::endl;
-    exit(EXIT_FAILURE);
-  }
-
-  // Clean up static data and prevent valgrind memory leaks
-  google::protobuf::ShutdownProtobufLibrary();
-  return 0;
-}

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/internal/set-replication-state.h

@@ -0,0 +1,72 @@
+/**
+ * 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/licenses/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.
+ */
+
+#ifndef LIBHDFSPP_TOOLS_HDFS_SET_REPLICATION_STATE
+#define LIBHDFSPP_TOOLS_HDFS_SET_REPLICATION_STATE
+
+#include <functional>
+#include <mutex>
+
+#include "hdfspp/hdfspp.h"
+
+namespace hdfs::tools {
+/**
+ * {@class SetReplicationState} helps in handling the intermediate results while
+ * running {@link Setrep}.
+ */
+struct SetReplicationState {
+  SetReplicationState(const uint16_t replication,
+                      std::function<void(const hdfs::Status &)> handler,
+                      const uint64_t request_counter, const bool find_is_done)
+      : replication{replication}, handler{std::move(handler)},
+        request_counter{request_counter}, find_is_done{find_is_done} {}
+
+  /**
+   * The replication factor.
+   */
+  const uint16_t replication;
+
+  /**
+   * Handle the given {@link hdfs::Status}.
+   */
+  const std::function<void(const hdfs::Status &)> handler;
+
+  /**
+   * The request counter is incremented once every time SetReplication async
+   * call is made.
+   */
+  uint64_t request_counter;
+
+  /**
+   * This boolean will be set when find returns the last result.
+   */
+  bool find_is_done;
+
+  /**
+   * Final status to be returned.
+   */
+  hdfs::Status status;
+
+  /**
+   * Shared variables will need protection with a lock.
+   */
+  std::mutex lock;
+};
+} // namespace hdfs::tools
+
+#endif