HDFS-10787: libhdfs++: Public API should expose configuration parser. Original patch contributed by Mitchell Tracy, followup work and compile warning fixes contributed by Anatoli Shein.

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

@@ -30,6 +30,8 @@ cmake_minimum_required(VERSION 2.8)
 
 enable_testing()
 include (CTest)
+
+SET(BUILD_SHARED_HDFSPP TRUE CACHE STRING "BUILD_SHARED_HDFSPP defaulting to 'TRUE'")
 SET(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMake" ${CMAKE_MODULE_PATH})
 
 # If there's a better way to inform FindCyrusSASL.cmake, let's make this cleaner:
@@ -246,6 +248,7 @@ if(NEED_LINK_DL)
    set(LIB_DL dl)
 endif()
 
+set(LIBHDFSPP_VERSION "0.1.0")
 set(LIBHDFSPP_ALL_OBJECTS $<TARGET_OBJECTS:bindings_c_obj> $<TARGET_OBJECTS:fs_obj> $<TARGET_OBJECTS:rpc_obj> $<TARGET_OBJECTS:reader_obj> $<TARGET_OBJECTS:proto_obj> $<TARGET_OBJECTS:connection_obj> $<TARGET_OBJECTS:common_obj> $<TARGET_OBJECTS:uriparser2_obj>)
 if (HADOOP_BUILD)
   hadoop_add_dual_library(hdfspp ${EMPTY_FILE_CC} ${LIBHDFSPP_ALL_OBJECTS})
@@ -256,6 +259,7 @@ if (HADOOP_BUILD)
     ${SASL_LIBRARIES}
     ${CMAKE_THREAD_LIBS_INIT}
   )
+  set_target_properties(hdfspp PROPERTIES SOVERSION ${LIBHDFSPP_VERSION})
 else (HADOOP_BUILD)
   add_library(hdfspp_static STATIC ${EMPTY_FILE_CC} ${LIBHDFSPP_ALL_OBJECTS})
   target_link_libraries(hdfspp_static
@@ -265,18 +269,11 @@ else (HADOOP_BUILD)
     ${SASL_LIBRARIES}
     ${CMAKE_THREAD_LIBS_INIT}
     )
-  add_library(hdfspp SHARED ${EMPTY_FILE_CC} ${LIBHDFSPP_ALL_OBJECTS})
+  if(BUILD_SHARED_HDFSPP)
-  target_link_libraries(hdfspp_static
+    add_library(hdfspp SHARED ${EMPTY_FILE_CC} ${LIBHDFSPP_ALL_OBJECTS})
-    ${LIB_DL}
+    set_target_properties(hdfspp PROPERTIES SOVERSION ${LIBHDFSPP_VERSION})
-    ${PROTOBUF_LIBRARY}
+  endif(BUILD_SHARED_HDFSPP)
-    ${OPENSSL_LIBRARIES}
-    ${SASL_LIBRARIES}
-    ${CMAKE_THREAD_LIBS_INIT}
-    )
 endif (HADOOP_BUILD)
-set(LIBHDFSPP_VERSION "0.1.0")
-set_target_properties(hdfspp PROPERTIES
-  SOVERSION ${LIBHDFSPP_VERSION})
 
 # Set up make install targets
 # Can be installed to a particular location via "make DESTDIR=... install"
@@ -286,7 +283,9 @@ install(FILES ${LIBHDFSPP_HEADER_FILES} DESTINATION include/hdfspp)
 install(FILES ${LIBHDFS_HEADER_FILES} DESTINATION include/hdfs)
 
 install(TARGETS hdfspp_static ARCHIVE DESTINATION lib)
-install(TARGETS hdfspp LIBRARY DESTINATION lib)
+if(BUILD_SHARED_HDFSPP)
+  install(TARGETS hdfspp LIBRARY DESTINATION lib)
+endif(BUILD_SHARED_HDFSPP)
 
 add_custom_target(
     InstallToBuildDirectory

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

@@ -16,6 +16,8 @@
 # limitations under the License.
 #
 
+include_directories( ../../tools )
+
 add_subdirectory(cat)
 add_subdirectory(gendirs)
 add_subdirectory(find)

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/examples/cc/cat/CMakeLists.txt

@@ -24,4 +24,4 @@ include_directories( ${LIBHDFSPP_DIR}/include )
 link_directories( ${LIBHDFSPP_DIR}/lib )
 
 add_executable(cat cat.cc)
-target_link_libraries(cat hdfspp_static)
+target_link_libraries(cat tools_common hdfspp_static)

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

@@ -31,10 +31,8 @@
    **/
 
 #include "hdfspp/hdfspp.h"
-#include "common/hdfs_configuration.h"
-#include "common/configuration_loader.h"
-
 #include <google/protobuf/stubs/common.h>
+#include "tools_common.h"
 
 const std::size_t BUF_SIZE = 1048576; //1 MB
 static char input_buffer[BUF_SIZE];
@@ -46,35 +44,17 @@ int main(int argc, char *argv[]) {
   }
   std::string path = argv[1];
 
-  hdfs::Options options;
+  //Building a URI object from the given uri path
-  //Setting the config path to the default: "$HADOOP_CONF_DIR" or "/etc/hadoop/conf"
+  hdfs::URI uri = hdfs::parse_path_or_exit(path);
-  hdfs::ConfigurationLoader loader;
+
-  //Loading default config files core-site.xml and hdfs-site.xml from the config path
+  std::shared_ptr<hdfs::FileSystem> fs = hdfs::doConnect(uri, false);
-  hdfs::optional<hdfs::HdfsConfiguration> config = loader.LoadDefaultResources<hdfs::HdfsConfiguration>();
-  //TODO: HDFS-9539 - after this is resolved, valid config will always be returned.
-  if(config){
-    //Loading options from the config
-    options = config->GetOptions();
-  }
-  hdfs::IoService * io_service = hdfs::IoService::New();
-  //Wrapping fs into a shared pointer to guarantee deletion
-  std::shared_ptr<hdfs::FileSystem> fs(hdfs::FileSystem::New(io_service, "", options));
   if (!fs) {
-    std::cerr << "Could not connect the file system." << std::endl;
+    std::cerr << "Could not connect the file system. " << std::endl;
-    exit(EXIT_FAILURE);
-  }
-  hdfs::Status status = fs->ConnectToDefaultFs();
-  if (!status.ok()) {
-    if(!options.defaultFS.get_host().empty()){
-      std::cerr << "Error connecting to " << options.defaultFS << ". " << status.ToString() << std::endl;
-    } else {
-      std::cerr << "Error connecting to the cluster: defaultFS is empty. " << status.ToString() << std::endl;
-    }
     exit(EXIT_FAILURE);
   }
 
   hdfs::FileHandle *file_raw = nullptr;
-  status = fs->Open(path, &file_raw);
+  hdfs::Status status = fs->Open(path, &file_raw);
   if (!status.ok()) {
     std::cerr << "Could not open file " << path << ". " << status.ToString() << std::endl;
     exit(EXIT_FAILURE);

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/examples/cc/find/CMakeLists.txt

@@ -24,4 +24,4 @@ include_directories( ${LIBHDFSPP_DIR}/include )
 link_directories( ${LIBHDFSPP_DIR}/lib )
 
 add_executable(find find.cc)
-target_link_libraries(find hdfspp_static)
+target_link_libraries(find tools_common hdfspp_static)

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/examples/cc/find/find.cc

@@ -38,11 +38,9 @@
    **/
 
 #include "hdfspp/hdfspp.h"
-#include "common/hdfs_configuration.h"
-#include "common/configuration_loader.h"
-
 #include <google/protobuf/stubs/common.h>
 #include <future>
+#include "tools_common.h"
 
 void SyncFind(std::shared_ptr<hdfs::FileSystem> fs, const std::string &path, const std::string &name){
   std::vector<hdfs::StatInfo> results;
@@ -119,32 +117,12 @@ int main(int argc, char *argv[]) {
   std::string name = argv[2];
   bool use_async = (std::stoi(argv[3]) != 0);
 
-  hdfs::Options options;
+  //Building a URI object from the given uri path
-  //Setting the config path to the default: "$HADOOP_CONF_DIR" or "/etc/hadoop/conf"
+  hdfs::URI uri = hdfs::parse_path_or_exit(path);
-  hdfs::ConfigurationLoader loader;
+
-  //Loading default config files core-site.xml and hdfs-site.xml from the config path
+  std::shared_ptr<hdfs::FileSystem> fs = hdfs::doConnect(uri, true);
-  hdfs::optional<hdfs::HdfsConfiguration> config = loader.LoadDefaultResources<hdfs::HdfsConfiguration>();
-  //TODO: HDFS-9539 - after this is resolved, valid config will always be returned.
-  if(config){
-    //Loading options from the config
-    options = config->GetOptions();
-  }
-  //TODO: HDFS-9539 - until then we increase the time-out to allow all recursive async calls to finish
-  options.rpc_timeout = std::numeric_limits<int>::max();
-  hdfs::IoService * io_service = hdfs::IoService::New();
-  //Wrapping fs into a unique pointer to guarantee deletion
-  std::shared_ptr<hdfs::FileSystem> fs(hdfs::FileSystem::New(io_service, "", options));
   if (!fs) {
-    std::cerr << "Could not connect the file system." << std::endl;
+    std::cerr << "Could not connect the file system. " << std::endl;
-    exit(EXIT_FAILURE);
-  }
-  hdfs::Status status = fs->ConnectToDefaultFs();
-  if (!status.ok()) {
-    if(!options.defaultFS.get_host().empty()){
-      std::cerr << "Error connecting to " << options.defaultFS << ". " << status.ToString() << std::endl;
-    } else {
-      std::cerr << "Error connecting to the cluster: defaultFS is empty. " << status.ToString() << std::endl;
-    }
     exit(EXIT_FAILURE);
   }
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/examples/cc/gendirs/CMakeLists.txt

@@ -24,4 +24,4 @@ include_directories( ${LIBHDFSPP_DIR}/include )
 link_directories( ${LIBHDFSPP_DIR}/lib )
 
 add_executable(gendirs gendirs.cc)
-target_link_libraries(gendirs hdfspp_static)
+target_link_libraries(gendirs tools_common hdfspp_static)

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/examples/cc/gendirs/gendirs.cc

@@ -37,11 +37,9 @@
    **/
 
 #include "hdfspp/hdfspp.h"
-#include "common/hdfs_configuration.h"
-#include "common/configuration_loader.h"
-
 #include <google/protobuf/stubs/common.h>
 #include <future>
+#include "tools_common.h"
 
 #define DEFAULT_PERMISSIONS 0755
 
@@ -80,32 +78,12 @@ int main(int argc, char *argv[]) {
   int depth = std::stoi(argv[2]);
   int fanout = std::stoi(argv[3]);
 
-  hdfs::Options options;
+  //Building a URI object from the given uri path
-  //Setting the config path to the default: "$HADOOP_CONF_DIR" or "/etc/hadoop/conf"
+  hdfs::URI uri = hdfs::parse_path_or_exit(path);
-  hdfs::ConfigurationLoader loader;
+
-  //Loading default config files core-site.xml and hdfs-site.xml from the config path
+  std::shared_ptr<hdfs::FileSystem> fs = hdfs::doConnect(uri, true);
-  hdfs::optional<hdfs::HdfsConfiguration> config = loader.LoadDefaultResources<hdfs::HdfsConfiguration>();
-  //TODO: HDFS-9539 - after this is resolved, valid config will always be returned.
-  if(config){
-    //Loading options from the config
-    options = config->GetOptions();
-  }
-  //TODO: HDFS-9539 - until then we increase the time-out to allow all recursive async calls to finish
-  options.rpc_timeout = std::numeric_limits<int>::max();
-  hdfs::IoService * io_service = hdfs::IoService::New();
-  //Wrapping fs into a unique pointer to guarantee deletion
-  std::shared_ptr<hdfs::FileSystem> fs(hdfs::FileSystem::New(io_service, "", options));
   if (!fs) {
-    std::cerr << "Could not connect the file system." << std::endl;
+    std::cerr << "Could not connect the file system. " << std::endl;
-    exit(EXIT_FAILURE);
-  }
-  hdfs::Status status = fs->ConnectToDefaultFs();
-  if (!status.ok()) {
-    if(!options.defaultFS.get_host().empty()){
-      std::cerr << "Error connecting to " << options.defaultFS << ". " << status.ToString() << std::endl;
-    } else {
-      std::cerr << "Error connecting to the cluster: defaultFS is empty. " << status.ToString() << std::endl;
-    }
     exit(EXIT_FAILURE);
   }
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/include/hdfspp/config_parser.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_CONFIGPARSER_H_
+#define LIBHDFSPP_CONFIGPARSER_H_
+
+#include "hdfspp/options.h"
+#include "hdfspp/uri.h"
+#include "hdfspp/status.h"
+
+#include <string>
+#include <memory>
+#include <vector>
+
+namespace hdfs {
+
+class ConfigParser {
+ public:
+  ConfigParser();
+  ConfigParser(const std::string& path);
+  ConfigParser(const std::vector<std::string>& configDirectories);
+  ~ConfigParser();
+  ConfigParser(ConfigParser&&);
+  ConfigParser& operator=(ConfigParser&&);
+
+  bool LoadDefaultResources();
+  std::vector<std::pair<std::string, Status> > ValidateResources() const;
+
+  // Return false if value couldn't be found or cast to desired type
+  bool get_int(const std::string& key, int& outval) const;
+  int get_int_or(const std::string& key, const int defaultval) const;
+
+  bool get_string(const std::string& key, std::string& outval) const;
+  std::string get_string_or(const std::string& key, const std::string& defaultval) const;
+
+  bool get_bool(const std::string& key, bool& outval) const;
+  bool get_bool_or(const std::string& key, const bool defaultval) const;
+
+  bool get_double(const std::string& key, double& outval) const;
+  double get_double_or(const std::string& key, const double defaultval) const;
+
+  bool get_uri(const std::string& key, URI& outval) const;
+  URI get_uri_or(const std::string& key, const URI& defaultval) const;
+
+  bool get_options(Options& outval) const;
+  Options get_options_or(const Options& defaultval) const;
+
+ private:
+  class impl;
+  std::unique_ptr<impl> pImpl;
+};
+
+}
+#endif

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/include/hdfspp/hdfspp.h

@@ -26,6 +26,7 @@
 #include "hdfspp/fsinfo.h"
 #include "hdfspp/content_summary.h"
 #include "hdfspp/uri.h"
+#include "hdfspp/config_parser.h"
 #include "hdfspp/locks.h"
 
 #include <functional>

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/bindings/c/hdfs.cc

@@ -1295,13 +1295,13 @@ tOffset hdfsTell(hdfsFS fs, hdfsFile file) {
       return -1;
     }
 
-    ssize_t offset = 0;
+    off_t offset = 0;
     Status stat = file->get_impl()->Seek(&offset, std::ios_base::cur);
     if (!stat.ok()) {
       return Error(stat);
     }
 
-    return offset;
+    return (tOffset)offset;
   } catch (const std::exception & e) {
     return ReportException(e);
   } catch (...) {

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

@@ -19,6 +19,6 @@ if(NEED_LINK_DL)
    set(LIB_DL dl)
 endif()
 
-add_library(common_obj OBJECT status.cc sasl_digest_md5.cc hdfs_ioservice.cc options.cc configuration.cc configuration_loader.cc hdfs_configuration.cc uri.cc util.cc retry_policy.cc cancel_tracker.cc logging.cc libhdfs_events_impl.cc auth_info.cc namenode_info.cc statinfo.cc fsinfo.cc content_summary.cc locks.cc)
+add_library(common_obj OBJECT status.cc sasl_digest_md5.cc hdfs_ioservice.cc options.cc configuration.cc configuration_loader.cc hdfs_configuration.cc uri.cc util.cc retry_policy.cc cancel_tracker.cc logging.cc libhdfs_events_impl.cc auth_info.cc namenode_info.cc statinfo.cc fsinfo.cc content_summary.cc locks.cc config_parser.cc)
 add_library(common $<TARGET_OBJECTS:common_obj> $<TARGET_OBJECTS:uriparser2_obj>)
 target_link_libraries(common ${LIB_DL})

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/config_parser.cc

@@ -0,0 +1,219 @@
+/**
+ * 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 "hdfspp/config_parser.h"
+#include "common/hdfs_configuration.h"
+#include "common/configuration_loader.h"
+
+#include <string>
+#include <memory>
+#include <vector>
+#include <numeric>
+
+namespace hdfs {
+
+static const char kSearchPathSeparator = ':';
+
+HdfsConfiguration LoadDefault(ConfigurationLoader & loader)
+{
+  optional<HdfsConfiguration> result = loader.LoadDefaultResources<HdfsConfiguration>();
+  if (result)
+  {
+    return result.value();
+  }
+  else
+  {
+    return loader.NewConfig<HdfsConfiguration>();
+  }
+}
+
+class ConfigParser::impl {
+ public:
+  impl() :
+      config_(loader_.NewConfig<HdfsConfiguration>()) {
+  }
+
+  impl(const std::vector<std::string>& dirs) :
+      config_(loader_.NewConfig<HdfsConfiguration>()) {
+
+      // Convert vector of paths into ':' separated path
+      std::string path = std::accumulate(dirs.begin(), dirs.end(), std::string(""),
+        [](std::string cumm, std::string elem) {return cumm + kSearchPathSeparator + elem;});
+      loader_.SetSearchPath(path);
+      config_ = LoadDefault(loader_);
+  }
+
+  impl(const std::string& path) :
+      config_(loader_.NewConfig<HdfsConfiguration>()) {
+
+      loader_.SetSearchPath(path);
+      config_ = LoadDefault(loader_);
+  }
+
+  bool LoadDefaultResources() {
+    config_ = LoadDefault(loader_);
+    return true;
+  }
+
+  std::vector<std::pair<std::string, Status> > ValidateResources() const {
+    return loader_.ValidateDefaultResources<HdfsConfiguration>();
+  }
+
+  bool get_int(const std::string& key, int& outval) const {
+    auto ret = config_.GetInt(key);
+    if (!ret) {
+      return false;
+    } else {
+      outval = *ret;
+      return true;
+    }
+  }
+
+  bool get_string(const std::string& key, std::string& outval) const {
+    auto ret = config_.Get(key);
+    if (!ret) {
+      return false;
+    } else {
+      outval = *ret;
+      return true;
+    }
+  }
+
+  bool get_bool(const std::string& key, bool& outval) const {
+    auto ret = config_.GetBool(key);
+    if (!ret) {
+      return false;
+    } else {
+      outval = *ret;
+      return true;
+    }
+  }
+
+  bool get_double(const std::string& key, double& outval) const {
+    auto ret = config_.GetDouble(key);
+    if (!ret) {
+      return false;
+    } else {
+      outval = *ret;
+      return true;
+    }
+  }
+
+  bool get_uri(const std::string& key, URI& outval) const {
+    auto ret = config_.GetUri(key);
+    if (!ret) {
+      return false;
+    } else {
+      outval = *ret;
+      return true;
+    }
+  }
+
+  bool get_options(Options& outval) {
+    outval = config_.GetOptions();
+    return true;
+  }
+
+ private:
+  ConfigurationLoader loader_;
+  HdfsConfiguration config_;
+};
+
+
+ConfigParser::ConfigParser() {
+  pImpl.reset(new ConfigParser::impl());
+}
+
+ConfigParser::ConfigParser(const std::vector<std::string>& configDirectories) {
+  pImpl.reset(new ConfigParser::impl(configDirectories));
+}
+
+ConfigParser::ConfigParser(const std::string& path) {
+  pImpl.reset(new ConfigParser::impl(path));
+}
+
+ConfigParser::~ConfigParser() = default;
+ConfigParser::ConfigParser(ConfigParser&&) = default;
+ConfigParser& ConfigParser::operator=(ConfigParser&&) = default;
+
+bool ConfigParser::LoadDefaultResources() { return pImpl->LoadDefaultResources(); }
+std::vector<std::pair<std::string, Status> > ConfigParser::ValidateResources() const { return pImpl->ValidateResources();}
+
+bool ConfigParser::get_int(const std::string& key, int& outval) const { return pImpl->get_int(key, outval); }
+int ConfigParser::get_int_or(const std::string& key, const int defaultval) const {
+  int res = 0;
+  if(get_int(key, res)) {
+    return res;
+  } else {
+    return defaultval;
+  }
+}
+
+bool ConfigParser::get_string(const std::string& key, std::string& outval) const { return pImpl->get_string(key, outval); }
+std::string ConfigParser::get_string_or(const std::string& key, const std::string& defaultval) const {
+  std::string res;
+  if(get_string(key, res)) {
+    return res;
+  } else {
+    return defaultval;
+  }
+}
+
+bool ConfigParser::get_bool(const std::string& key, bool& outval) const { return pImpl->get_bool(key, outval); }
+bool ConfigParser::get_bool_or(const std::string& key, const bool defaultval) const {
+  bool res = false;
+  if(get_bool(key, res)) {
+    return res;
+  } else {
+    return defaultval;
+  }
+}
+
+bool ConfigParser::get_double(const std::string& key, double& outval) const { return pImpl->get_double(key, outval); }
+double ConfigParser::get_double_or(const std::string& key, const double defaultval) const {
+  double res = 0;
+  if(get_double(key, res)) {
+    return res;
+  } else {
+    return defaultval;
+  }
+}
+
+bool ConfigParser::get_uri(const std::string& key, URI& outval) const { return pImpl->get_uri(key, outval); }
+URI ConfigParser::get_uri_or(const std::string& key, const URI& defaultval) const {
+  URI res;
+  if(get_uri(key, res)) {
+    return res;
+  } else {
+    res = defaultval;
+    return res;
+  }
+}
+
+bool ConfigParser::get_options(Options& outval) const { return pImpl->get_options(outval); }
+Options ConfigParser::get_options_or(const Options& defaultval) const {
+  Options res;
+  if(get_options(res)) {
+    return res;
+  } else {
+    res = defaultval;
+    return res;
+  }
+}
+
+} // end namespace hdfs

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/configuration.cc

@@ -72,8 +72,8 @@ optional<int64_t> Configuration::GetInt(const std::string& key) const {
   if (raw) {
     errno = 0;
     char* end = nullptr;
-    auto result =
+    optional<int64_t> result =
-        std::experimental::make_optional(strtol(raw->c_str(), &end, 10));
+        std::experimental::make_optional(static_cast<int64_t>(strtol(raw->c_str(), &end, 10)));
     if (end == raw->c_str()) {
       /* strtoll will set end to input if no conversion was done */
       return optional<int64_t>();

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/configuration_loader.cc

@@ -17,6 +17,7 @@
  */
 
 #include "configuration_loader.h"
+#include "common/logging.h"
 
 #include <fstream>
 #include <strings.h>
@@ -74,7 +75,11 @@ void ConfigurationLoader::SetDefaultSearchPath() {
   //    /etc/hadoop/conf
   const char * hadoop_conf_dir_env = getenv("HADOOP_CONF_DIR");
   if (hadoop_conf_dir_env) {
-    AddToSearchPath(hadoop_conf_dir_env);
+    std::stringstream ss(hadoop_conf_dir_env);
+    std::string path;
+    while (std::getline(ss, path, kSearchPathSeparator)) {
+      AddToSearchPath(path);
+    }
   } else {
     AddToSearchPath("/etc/hadoop/conf");
   }
@@ -136,6 +141,63 @@ std::string ConfigurationLoader::GetSearchPath()
   return result.str();
 }
 
+Status validateStream(std::istream & stream) {
+  std::streampos start = stream.tellg();
+  stream.seekg(0, std::ios::end);
+  std::streampos end = stream.tellg();
+  stream.seekg(start, std::ios::beg);
+
+  int length = end - start;
+
+  if (length <= 0 || start == -1 || end == -1)
+    return Status::Error("The configuration file is empty");
+
+  LOG_DEBUG(kFileSystem, << "validateStream will read a config file of length " << length);
+
+  std::vector<char> raw_bytes((int64_t)length + 1);
+  stream.read(&raw_bytes[0], length);
+  raw_bytes[length] = 0;
+
+  try {
+    rapidxml::xml_document<> dom;
+    dom.parse<rapidxml::parse_trim_whitespace|rapidxml::parse_validate_closing_tags>(&raw_bytes[0]);
+
+    /* File must contain a single <configuration> stanza */
+    auto config_node = dom.first_node("configuration", 0, false);
+    if (!config_node) {
+      return Status::Error("The configuration file is missing a 'configuration' tag");
+    }
+    return Status::OK();
+  } catch (const rapidxml::parse_error &e) {
+    size_t location = e.where<char>() - &raw_bytes[0];
+    std::string msg = "The configuration file has invalid xml around character " + std::to_string(location);
+    return Status::Error(msg.c_str());
+  }
+}
+
+std::vector<std::pair<std::string, Status> > ConfigurationLoader::ValidateResources(std::vector<std::string> filenames) const
+{
+  std::vector<std::pair<std::string, Status> > stats;
+  bool found;
+  for(auto file: filenames) {
+    found = false;
+    for(auto dir: search_path_) {
+      std::ifstream stream(dir + file);
+      if ( stream.is_open() ) {
+        found = true;
+        stats.push_back(std::make_pair(file,validateStream(stream)));
+      } else {
+        LOG_DEBUG(kFileSystem, << dir << file << " was not found");
+      }
+    }
+    if(!found) {
+      std::string msg("No directory in the current search path contains the file [" + file + "]");
+      stats.push_back(std::make_pair(file,Status::PathNotFound(msg.c_str())));
+    }
+  }
+  return stats;
+}
+
 bool ConfigurationLoader::UpdateMapWithFile(ConfigMap & map, const std::string & path) const
 {
   if (path.front() == kFileSeparator) { // Absolute path

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/configuration_loader.h

@@ -20,6 +20,7 @@
 #define COMMON_CONFIGURATION_BUILDER_H_
 
 #include "configuration.h"
+#include "hdfspp/status.h"
 
 namespace hdfs {
 
@@ -75,6 +76,13 @@ public:
   optional<T> LoadDefaultResources();
 
 
+  // Returns a vector of filenames and the corresponding status when validation is attempted.
+  //    If the files can be successfully validated, then the status returned for that file is Status::OK
+  //    The files that are validated are those returned by T::GetDefaultFilenames().
+  //    T must be Configuration or a subclass
+  template<class T>
+  std::vector<std::pair<std::string, Status>> ValidateDefaultResources() const;
+
   /****************************************************************************
    *                    SEARCH PATH METHODS
    ***************************************************************************/
@@ -98,6 +106,8 @@ public:
 protected:
   using ConfigMap = Configuration::ConfigMap;
 
+  std::vector<std::pair<std::string, Status>> ValidateResources(std::vector<std::string> filenames) const;
+
   // Updates the src map with data from the XML in the path
   //   The search path will be searched for the filename
   bool UpdateMapWithFile(ConfigMap & map, const std::string & path) const;

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/configuration_loader_impl.h

@@ -111,6 +111,11 @@ optional<T> ConfigurationLoader::LoadDefaultResources() {
   }
 }
 
+template<class T>
+std::vector<std::pair<std::string, Status> > ConfigurationLoader::ValidateDefaultResources() const{
+  return ValidateResources(T::GetDefaultFilenames());
+}
+
 
 }
 

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/continuation/protobuf.h

@@ -49,6 +49,7 @@ struct ReadDelimitedPBMessageContinuation : public Continuation {
         uint32_t size = 0;
         bool v = is.ReadVarint32(&size);
         assert(v);
+        (void)v; //avoids unused variable warning
         is.PushLimit(size);
         msg_->Clear();
         v = msg_->MergeFromCodedStream(&is);

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/common/retry_policy.cc

@@ -54,6 +54,7 @@ RetryAction FixedDelayWithFailover::ShouldRetry(const Status &s, uint64_t retrie
     uint64_t failovers,
     bool isIdempotentOrAtMostOnce) const {
   (void)isIdempotentOrAtMostOnce;
+  (void)max_failover_conn_retries_;
   LOG_TRACE(kRPC, << "FixedDelayWithFailover::ShouldRetry(retries=" << retries << ", failovers=" << failovers << ")");
 
   if(failovers < max_failover_retries_ && (s.code() == ::asio::error::timed_out || s.get_server_exception_type() == Status::kStandbyException) )

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/filehandle.cc

@@ -52,7 +52,7 @@ void FileHandleImpl::PositionRead(
     const std::function<void(const Status &, size_t)> &handler) {
   LOG_DEBUG(kFileHandle, << "FileHandleImpl::PositionRead("
                          << FMT_THIS_ADDR << ", buf=" << buf
-                         << ", buf_size=" << buf_size << ") called");
+                         << ", buf_size=" << std::to_string(buf_size) << ") called");
 
   /* prevent usage after cancelation */
   if(cancel_state_->is_canceled()) {
@@ -78,7 +78,7 @@ void FileHandleImpl::PositionRead(
 Status FileHandleImpl::PositionRead(void *buf, size_t buf_size, off_t offset, size_t *bytes_read) {
   LOG_DEBUG(kFileHandle, << "FileHandleImpl::[sync]PositionRead("
                          << FMT_THIS_ADDR << ", buf=" << buf
-                         << ", buf_size=" << buf_size
+                         << ", buf_size=" << std::to_string(buf_size)
                          << ", offset=" << offset << ") called");
 
   auto callstate = std::make_shared<std::promise<std::tuple<Status, size_t>>>();
@@ -106,7 +106,7 @@ Status FileHandleImpl::PositionRead(void *buf, size_t buf_size, off_t offset, si
 Status FileHandleImpl::Read(void *buf, size_t buf_size, size_t *bytes_read) {
   LOG_DEBUG(kFileHandle, << "FileHandleImpl::Read("
                          << FMT_THIS_ADDR << ", buf=" << buf
-                         << ", buf_size=" << buf_size << ") called");
+                         << ", buf_size=" << std::to_string(buf_size) << ") called");
 
   Status stat = PositionRead(buf, buf_size, offset_, bytes_read);
   if(!stat.ok()) {
@@ -237,7 +237,7 @@ void FileHandleImpl::AsyncPreadSome(
 
   LOG_DEBUG(kFileHandle, << "FileHandleImpl::AsyncPreadSome("
             << FMT_THIS_ADDR << "), ...) Datanode hostname=" << dnHostName << ", IP Address=" << dnIpAddr
-            << ", file path=\"" << path_ << "\", offset=" << offset << ", read size=" << size_within_block);
+            << ", file path=\"" << path_ << "\", offset=" << std::to_string(offset) << ", read size=" << size_within_block);
 
   // This is where we will put the logic for re-using a DN connection; we can
   //    steal the FileHandle's dn and put it back when we're done

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/filesystem.h

@@ -203,9 +203,9 @@ public:
   /* all monitored events will need to lookup handlers */
   std::shared_ptr<LibhdfsEvents> get_event_handlers();
 
-  Options get_options();
+  Options get_options() override;
 
-  std::string get_cluster_name();
+  std::string get_cluster_name() override;
 
 private:
   /**

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/fs/namenode_operations.h

@@ -41,7 +41,7 @@ namespace hdfs {
 
 class NameNodeOperations {
 public:
-  MEMCHECKED_CLASS(NameNodeOperations);
+  MEMCHECKED_CLASS(NameNodeOperations)
   NameNodeOperations(::asio::io_service *io_service, const Options &options,
             const std::string &client_name, const std::string &user_name,
             const char *protocol_name, int protocol_version) :

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/reader/block_reader.cc

@@ -177,6 +177,7 @@ struct BlockReaderImpl::ReadPacketHeader : continuation::Continuation
         bool v = parent_->header_.ParseFromArray(&buf_[kHeaderStart],
                                                  header_length());
         assert(v && "Failed to parse the header");
+        (void)v; //avoids unused variable warning
         parent_->state_ = kReadChecksum;
       }
       if(parent_->event_handlers_) {

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/rpc/rpc_connection_impl.cc

@@ -31,8 +31,6 @@ namespace pbio = ::google::protobuf::io;
 using namespace ::hadoop::common;
 using namespace ::std::placeholders;
 
-static const int kNoRetry = -1;
-
 static void AddHeadersToPacket(
     std::string *res, std::initializer_list<const pb::MessageLite *> headers,
     const std::string *payload) {

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/rpc/rpc_connection_impl.h

@@ -38,14 +38,14 @@ namespace hdfs {
 template <class Socket>
 class RpcConnectionImpl : public RpcConnection {
 public:
-  MEMCHECKED_CLASS(RpcConnectionImpl);
+  MEMCHECKED_CLASS(RpcConnectionImpl)
 
   RpcConnectionImpl(RpcEngine *engine);
   virtual ~RpcConnectionImpl() override;
 
   virtual void Connect(const std::vector<::asio::ip::tcp::endpoint> &server,
                        const AuthInfo & auth_info,
-                       RpcCallback &handler);
+                       RpcCallback &handler) override;
   virtual void ConnectAndFlush(
       const std::vector<::asio::ip::tcp::endpoint> &server) override;
   virtual void SendHandshake(RpcCallback &handler) override;

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/rpc/rpc_engine.cc

@@ -68,7 +68,7 @@ void RpcEngine::Connect(const std::string &cluster_name,
   }
 
   // Construct retry policy after we determine if config is HA
-  retry_policy_ = std::move(MakeRetryPolicy(options_));
+  retry_policy_ = MakeRetryPolicy(options_);
 
   conn_ = InitializeConnection();
   conn_->Connect(last_endpoints_, auth_info_, handler);
@@ -133,7 +133,7 @@ std::string RpcEngine::getRandomClientId()
 
 void RpcEngine::TEST_SetRpcConnection(std::shared_ptr<RpcConnection> conn) {
   conn_ = conn;
-  retry_policy_ = std::move(MakeRetryPolicy(options_));
+  retry_policy_ = MakeRetryPolicy(options_);
 }
 
 void RpcEngine::TEST_SetRetryPolicy(std::unique_ptr<const RetryPolicy> policy) {
@@ -188,7 +188,7 @@ void RpcEngine::AsyncRpcCommsError(
     const Status &status,
     std::shared_ptr<RpcConnection> failedConnection,
     std::vector<std::shared_ptr<Request>> pendingRequests) {
-  LOG_ERROR(kRPC, << "RpcEngine::AsyncRpcCommsError called; status=\"" << status.ToString() << "\" conn=" << failedConnection.get() << " reqs=" << pendingRequests.size());
+  LOG_ERROR(kRPC, << "RpcEngine::AsyncRpcCommsError called; status=\"" << status.ToString() << "\" conn=" << failedConnection.get() << " reqs=" << std::to_string(pendingRequests.size()));
 
   io_service().post([this, status, failedConnection, pendingRequests]() {
     RpcCommsError(status, failedConnection, pendingRequests);
@@ -199,7 +199,7 @@ void RpcEngine::RpcCommsError(
     const Status &status,
     std::shared_ptr<RpcConnection> failedConnection,
     std::vector<std::shared_ptr<Request>> pendingRequests) {
-  LOG_WARN(kRPC, << "RpcEngine::RpcCommsError called; status=\"" << status.ToString() << "\" conn=" << failedConnection.get() << " reqs=" << pendingRequests.size());
+  LOG_WARN(kRPC, << "RpcEngine::RpcCommsError called; status=\"" << status.ToString() << "\" conn=" << failedConnection.get() << " reqs=" << std::to_string(pendingRequests.size()));
 
   std::lock_guard<std::mutex> state_lock(engine_state_lock_);
 
@@ -252,7 +252,7 @@ void RpcEngine::RpcCommsError(
           head_action && head_action->action != RetryAction::FAIL;
 
   if (haveRequests) {
-    LOG_TRACE(kRPC, << "Have " << pendingRequests.size() << " requests to resend");
+    LOG_TRACE(kRPC, << "Have " << std::to_string(pendingRequests.size()) << " requests to resend");
     bool needNewConnection = !conn_;
     if (needNewConnection) {
       LOG_DEBUG(kRPC, << "Creating a new NN conection");

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/lib/rpc/sasl_engine.cc

@@ -53,7 +53,7 @@ Status SaslEngine::SetPasswordInfo(const std::string &id,
 bool SaslEngine::ChooseMech(const std::vector<SaslMethod> &resp_auths) {
   Status status = Status::OK();
 
-  if (resp_auths.empty()) return NULL;
+  if (resp_auths.empty()) return false;
 
   for (SaslMethod auth: resp_auths) {
      if ( auth.mechanism != "GSSAPI") continue; // Hack: only GSSAPI for now
@@ -74,7 +74,7 @@ bool SaslEngine::ChooseMech(const std::vector<SaslMethod> &resp_auths) {
   // Clear out the chosen mech
   chosen_mech_ = SaslMethod();
 
-  return NULL;
+  return false;
 } // choose_mech()
 
 } // namespace hdfs

hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfspp/tests/configuration_test.h

@@ -18,6 +18,7 @@
 #ifndef TESTS_CONFIGURATION_H_
 #define TESTS_CONFIGURATION_H_
 
+#include "hdfspp/config_parser.h"
 #include "common/configuration.h"
 #include "common/configuration_loader.h"
 #include <cstdio>
@@ -50,6 +51,28 @@ void simpleConfigStream(std::stringstream& out, Args... args) {
   out << "</configuration>";
 }
 
+template <typename T, typename U>
+void damagedConfigStreamProperty(std::stringstream& out, T key, U value) {
+  out << "<propertyy>"
+      << "<name>" << key << "</name>"
+      << "<value>" << value << "</value>"
+      << "</property>";
+}
+
+template <typename T, typename U, typename... Args>
+void damagedConfigStreamProperty(std::stringstream& out, T key, U value,
+                                Args... args) {
+  damagedConfigStreamProperty(out, key, value);
+  damagedConfigStreamProperty(out, args...);
+}
+
+template <typename... Args>
+void damagedConfigStream(std::stringstream& out, Args... args) {
+  out << "<configuration>";
+  damagedConfigStreamProperty(out, args...);
+  out << "</configuration>";
+}
+
 template <typename... Args>
 optional<Configuration> simpleConfig(Args... args) {
   std::stringstream stream;
@@ -72,6 +95,16 @@ void writeSimpleConfig(const std::string& filename, Args... args) {
   out << stream.rdbuf();
 }
 
+template <typename... Args>
+void writeDamagedConfig(const std::string& filename, Args... args) {
+  std::stringstream stream;
+  damagedConfigStream(stream, args...);
+
+  std::ofstream out;
+  out.open(filename);
+  out << stream.rdbuf();
+}
+
 // TempDir: is deleted on destruction
 class TempFile {
 public:

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

@@ -19,6 +19,7 @@
 #include "common/hdfs_configuration.h"
 #include "configuration_test.h"
 #include <gmock/gmock.h>
+#include <iostream>
 
 using ::testing::_;
 
@@ -111,6 +112,53 @@ TEST(HdfsConfigurationTest, TestDefaultConfigs) {
     EXPECT_TRUE(config && "Parse streams");
     EXPECT_EQ("value2", config->GetWithDefault("key2", ""));
   }
+
+
+}
+
+TEST(HdfsConfigurationTest, TestConfigParserAPI) {
+  // Config parser API
+  {
+    TempDir tempDir;
+    TempFile coreSite(tempDir.path + "/core-site.xml");
+    writeSimpleConfig(coreSite.filename, "key1", "value1");
+    TempFile hdfsSite(tempDir.path + "/hdfs-site.xml");
+    writeSimpleConfig(hdfsSite.filename, "key2", "value2");
+
+    ConfigParser parser(tempDir.path);
+
+    EXPECT_EQ("value1", parser.get_string_or("key1", ""));
+    EXPECT_EQ("value2", parser.get_string_or("key2", ""));
+
+    auto stats = parser.ValidateResources();
+
+    EXPECT_EQ("core-site.xml", stats[0].first);
+    EXPECT_EQ("OK", stats[0].second.ToString());
+
+    EXPECT_EQ("hdfs-site.xml", stats[1].first);
+    EXPECT_EQ("OK", stats[1].second.ToString());
+  }
+
+  {
+    TempDir tempDir;
+    TempFile coreSite(tempDir.path + "/core-site.xml");
+    writeSimpleConfig(coreSite.filename, "key1", "value1");
+    TempFile hdfsSite(tempDir.path + "/hdfs-site.xml");
+    writeDamagedConfig(hdfsSite.filename, "key2", "value2");
+
+    ConfigParser parser(tempDir.path);
+
+    EXPECT_EQ("value1", parser.get_string_or("key1", ""));
+    EXPECT_EQ("", parser.get_string_or("key2", ""));
+
+    auto stats = parser.ValidateResources();
+
+    EXPECT_EQ("core-site.xml", stats[0].first);
+    EXPECT_EQ("OK", stats[0].second.ToString());
+
+    EXPECT_EQ("hdfs-site.xml", stats[1].first);
+    EXPECT_EQ("Exception:The configuration file has invalid xml around character 74", stats[1].second.ToString());
+  }
 }
 
 int main(int argc, char *argv[])

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

@@ -22,15 +22,29 @@
 namespace hdfs {
 
   std::shared_ptr<hdfs::FileSystem> doConnect(hdfs::URI & uri, bool max_timeout) {
+
+    //This sets the config path to the default: "$HADOOP_CONF_DIR" or "/etc/hadoop/conf"
+    //and loads default config files core-site.xml and hdfs-site.xml from the config path
+    hdfs::ConfigParser parser;
+    if(!parser.LoadDefaultResources()){
+      std::cerr << "Could not load default resources. " << std::endl;
+      exit(EXIT_FAILURE);
+    }
+    auto stats = parser.ValidateResources();
+    //validating core-site.xml
+    if(!stats[0].second.ok()){
+      std::cerr << stats[0].first << " is invalid: " << stats[0].second.ToString() << std::endl;
+      exit(EXIT_FAILURE);
+    }
+    //validating hdfs-site.xml
+    if(!stats[1].second.ok()){
+      std::cerr << stats[1].first << " is invalid: " << stats[1].second.ToString() << std::endl;
+      exit(EXIT_FAILURE);
+    }
     hdfs::Options options;
-    //Setting the config path to the default: "$HADOOP_CONF_DIR" or "/etc/hadoop/conf"
+    if(!parser.get_options(options)){
-    hdfs::ConfigurationLoader loader;
+      std::cerr << "Could not load Options object. " << std::endl;
-    //Loading default config files core-site.xml and hdfs-site.xml from the config path
+      exit(EXIT_FAILURE);
-    hdfs::optional<HdfsConfiguration> config = loader.LoadDefaultResources<HdfsConfiguration>();
-    //TODO: HDFS-9539 - after this is resolved, valid config will always be returned.
-    if(config){
-      //Loading options from the config
-      options = config->GetOptions();
     }
     if(max_timeout){
       //TODO: HDFS-9539 - until then we increase the time-out to allow all recursive async calls to finish

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

@@ -21,9 +21,6 @@
 #define TOOLS_COMMON_H_
 
 #include "hdfspp/hdfspp.h"
-#include "hdfspp/uri.h"
-#include "common/hdfs_configuration.h"
-#include "common/configuration_loader.h"
 #include <mutex>
 
 namespace hdfs {