HDFS-16251. Make hdfs_cat tool cross platform (#3523)

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

@@ -16,7 +16,7 @@
 # limitations under the License.
 #
 
-add_executable(hdfs_allowSnapshot_test hdfs-allow-snapshot-mock.cc hdfs-tool-test.cc main.cc)
-target_include_directories(hdfs_allowSnapshot_test PRIVATE ../tools ../../tools ../../tools/hdfs-allow-snapshot)
-target_link_libraries(hdfs_allowSnapshot_test PRIVATE gmock_main hdfs_allowSnapshot_lib)
-add_test(hdfs_allowSnapshot_test hdfs_allowSnapshot_test)
+add_executable(hdfs_tool_test hdfs-allow-snapshot-mock.cc hdfs-cat-mock.cc hdfs-tool-test.cc main.cc)
+target_include_directories(hdfs_tool_test PRIVATE ../tools ../../tools ../../tools/hdfs-allow-snapshot ../../tools/hdfs-cat)
+target_link_libraries(hdfs_tool_test PRIVATE gmock_main hdfs_allowSnapshot_lib hdfs_cat_lib)
+add_test(hdfs_tool_test hdfs_tool_test)

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

@@ -0,0 +1,23 @@
+/**
+ * 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 "hdfs-cat-mock.h"
+
+namespace hdfs::tools::test {
+CatMock::~CatMock() {}
+} // namespace hdfs::tools::test

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

@@ -0,0 +1,53 @@
+/**
+ * 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_CAT_MOCK
+#define LIBHDFSPP_TOOLS_HDFS_CAT_MOCK
+
+#include <string>
+
+#include <gmock/gmock.h>
+
+#include "hdfs-cat.h"
+
+namespace hdfs::tools::test {
+/**
+ * {@class CatMock} is an {@class Cat} whereby it mocks the
+ * HandleHelp and HandlePath methods for testing their functionality.
+ */
+class CatMock : public hdfs::tools::Cat {
+public:
+  /**
+   * {@inheritdoc}
+   */
+  CatMock(const int argc, char **argv) : Cat(argc, argv) {}
+
+  // Abiding to the Rule of 5
+  CatMock(const CatMock &) = delete;
+  CatMock(CatMock &&) = delete;
+  CatMock &operator=(const CatMock &) = delete;
+  CatMock &operator=(CatMock &&) = delete;
+  ~CatMock() override;
+
+  MOCK_METHOD(bool, HandleHelp, (), (const, override));
+
+  MOCK_METHOD(bool, HandlePath, (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-test.cc

@@ -20,6 +20,7 @@
 #include <gtest/gtest.h>
 
 #include "hdfs-allow-snapshot-mock.h"
+#include "hdfs-cat-mock.h"
 #include "hdfs-tool-test.h"
 
 HdfsToolBasicTest::~HdfsToolBasicTest() {}
@@ -30,6 +31,14 @@ INSTANTIATE_TEST_SUITE_P(
     testing::Values(PassAPath<hdfs::tools::test::AllowSnapshotMock>,
                     CallHelp<hdfs::tools::test::AllowSnapshotMock>));
 
+INSTANTIATE_TEST_SUITE_P(HdfsCat, HdfsToolBasicTest,
+                         testing::Values(PassAPath<hdfs::tools::test::CatMock>,
+                                         CallHelp<hdfs::tools::test::CatMock>));
+
 INSTANTIATE_TEST_SUITE_P(
     HdfsAllowSnapshot, HdfsToolNegativeTest,
-    testing::Values(Pass2Paths<hdfs::tools::test::AllowSnapshotMock>));
+    testing::Values(Pass2Paths<hdfs::tools::test::AllowSnapshotMock>));
+
+INSTANTIATE_TEST_SUITE_P(
+    HdfsCat, HdfsToolNegativeTest,
+    testing::Values(Pass2Paths<hdfs::tools::test::CatMock>));

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

@@ -31,9 +31,7 @@ add_library(tools_common $<TARGET_OBJECTS:tools_common_obj>)
 add_library(hdfs_tool_obj OBJECT hdfs-tool.cc)
 target_include_directories(hdfs_tool_obj PRIVATE ../tools)
 
-
-add_executable(hdfs_cat hdfs_cat.cc)
-target_link_libraries(hdfs_cat tools_common hdfspp_static)
+add_subdirectory(hdfs-cat)
 
 add_executable(hdfs_chgrp hdfs_chgrp.cc)
 target_link_libraries(hdfs_chgrp tools_common hdfspp_static)
@@ -81,14 +79,13 @@ add_executable(hdfs_setrep hdfs_setrep.cc)
 target_link_libraries(hdfs_setrep tools_common hdfspp_static)
 
 add_library(hdfs_allowSnapshot_lib STATIC  $<TARGET_OBJECTS:hdfs_tool_obj> hdfs-allow-snapshot/hdfs-allow-snapshot.cc)
-target_include_directories(hdfs_allowSnapshot_lib PRIVATE ../tools allow-snapshot ${Boost_INCLUDE_DIRS})
+target_include_directories(hdfs_allowSnapshot_lib PRIVATE ../tools hdfs-allow-snapshot ${Boost_INCLUDE_DIRS})
 target_link_libraries(hdfs_allowSnapshot_lib PRIVATE Boost::boost Boost::program_options tools_common hdfspp_static)
 
 add_executable(hdfs_allowSnapshot hdfs-allow-snapshot/main.cc)
 target_include_directories(hdfs_allowSnapshot PRIVATE ../tools)
 target_link_libraries(hdfs_allowSnapshot PRIVATE hdfs_allowSnapshot_lib)
 
-
 add_executable(hdfs_disallowSnapshot hdfs_disallowSnapshot.cc)
 target_link_libraries(hdfs_disallowSnapshot tools_common hdfspp_static)
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tools/hdfs-cat/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_cat_lib STATIC  $<TARGET_OBJECTS:hdfs_tool_obj> hdfs-cat.cc)
+target_include_directories(hdfs_cat_lib PRIVATE ../../tools hdfs-cat ${Boost_INCLUDE_DIRS})
+target_link_libraries(hdfs_cat_lib PRIVATE Boost::boost Boost::program_options tools_common hdfspp_static)
+
+add_executable(hdfs_cat main.cc)
+target_include_directories(hdfs_cat PRIVATE ../../tools)
+target_link_libraries(hdfs_cat PRIVATE hdfs_cat_lib)
+
+install(TARGETS hdfs_cat RUNTIME DESTINATION bin)

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

@@ -0,0 +1,104 @@
+/**
+ * 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 <iostream>
+#include <memory>
+#include <ostream>
+#include <sstream>
+#include <string>
+
+#include "hdfs-cat.h"
+#include "tools_common.h"
+
+namespace hdfs::tools {
+Cat::Cat(const int argc, char **argv) : HdfsTool(argc, argv) {}
+
+bool Cat::Initialize() {
+  opt_desc_.add_options()("help,h", "Concatenate FILE to standard output.")(
+      "path", po::value<std::string>(),
+      "The path to the file that needs to be cat-ed");
+
+  // We allow only one argument to be passed to this tool. An exception is
+  // thrown if multiple arguments are passed.
+  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;
+}
+
+std::string Cat::GetDescription() const {
+  std::stringstream desc;
+  desc << "Usage: hdfs_cat [OPTION] FILE" << std::endl
+       << std::endl
+       << "Concatenate FILE to standard output." << std::endl
+       << std::endl
+       << "  -h  display this help and exit" << std::endl
+       << std::endl
+       << "Examples:" << std::endl
+       << "hdfs_cat hdfs://localhost.localdomain:8020/dir/file" << std::endl
+       << "hdfs_cat /dir/file" << std::endl;
+  return desc.str();
+}
+
+bool Cat::Do() {
+  if (!Initialize()) {
+    std::cerr << "Unable to initialize HDFS cat 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) {
+    const auto path = opt_val_["path"].as<std::string>();
+    return HandlePath(path);
+  }
+
+  return true;
+}
+
+bool Cat::HandleHelp() const {
+  std::cout << GetDescription();
+  return true;
+}
+
+bool Cat::HandlePath(const std::string &path) const {
+  // Building a URI object from the given uri_path
+  auto uri = hdfs::parse_path_or_exit(path);
+
+  const auto fs = hdfs::doConnect(uri, false);
+  if (fs == nullptr) {
+    std::cerr << "Could not connect the file system." << std::endl;
+    return false;
+  }
+
+  readFile(fs, uri.get_path(), 0, stdout, false);
+  return true;
+}
+} // namespace hdfs::tools

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

@@ -0,0 +1,90 @@
+/**
+ * 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_CAT
+#define LIBHDFSPP_TOOLS_HDFS_CAT
+
+#include <string>
+
+#include <boost/program_options.hpp>
+
+#include "hdfs-tool.h"
+
+namespace hdfs::tools {
+/**
+ * {@class Cat} is an {@class HdfsTool} that reads the contents of the file
+ * located at an HDFS path and writes to stdout.
+ */
+class Cat : public HdfsTool {
+public:
+  /**
+   * {@inheritdoc}
+   */
+  Cat(int argc, char **argv);
+
+  // Abiding to the Rule of 5
+  Cat(const Cat &) = default;
+  Cat(Cat &&) = default;
+  Cat &operator=(const Cat &) = delete;
+  Cat &operator=(Cat &&) = delete;
+  ~Cat() 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 { return argc_ > 1; }
+
+  /**
+   * {@inheritdoc}
+   */
+  [[nodiscard]] bool HandleHelp() const override;
+
+  /**
+   * Handle the path argument that's passed to this tool.
+   *
+   * @param path The path to the directory that needs to be made snapshot-able.
+   *
+   * @return A boolean indicating the result of this operation.
+   */
+  [[nodiscard]] virtual bool HandlePath(const std::string &path) 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-cat/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-cat.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 cat tool, exiting"
+        << std::endl;
+    std::exit(EXIT_FAILURE);
+  }
+
+  hdfs::tools::Cat cat(argc, argv);
+  auto success = false;
+
+  try {
+    success = cat.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_cat.cc

@@ -1,83 +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 "tools_common.h"
-
-void usage(){
-  std::cout << "Usage: hdfs_cat [OPTION] FILE"
-      << std::endl
-      << std::endl << "Concatenate FILE to standard output."
-      << std::endl
-      << std::endl << "  -h  display this help and exit"
-      << std::endl
-      << std::endl << "Examples:"
-      << std::endl << "hdfs_cat hdfs://localhost.localdomain:8020/dir/file"
-      << std::endl << "hdfs_cat /dir/file"
-      << std::endl;
-}
-
-#define BUF_SIZE 4096
-
-int main(int argc, char *argv[]) {
-  if (argc != 2) {
-    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 uri_path = argv[optind];
-
-  //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, false);
-  if (!fs) {
-    std::cerr << "Could not connect the file system. " << std::endl;
-    exit(EXIT_FAILURE);
-  }
-
-  readFile(fs, uri.get_path(), 0, stdout, false);
-
-  // Clean up static data and prevent valgrind memory leaks
-  google::protobuf::ShutdownProtobufLibrary();
-  return 0;
-}