Github user xndai commented on a diff in the pull request:
https://github.com/apache/orc/pull/134#discussion_r138018152
--- Diff: c++/src/OrcHdfsFile.cc ---
@@ -0,0 +1,172 @@
+/**
+ * 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 "orc/OrcFile.hh"
+
+#include "Adaptor.hh"
+#include "Exceptions.hh"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "hdfspp/hdfspp.h"
+
+namespace orc {
+
+ class HdfsFileInputStream : public InputStream {
+ private:
+ std::string filename;
+ std::unique_ptr<hdfs::FileHandle> file;
+ std::unique_ptr<hdfs::FileSystem> file_system;
+ uint64_t totalLength;
+
+ public:
+ HdfsFileInputStream(std::string _filename) {
+ filename = _filename ;
+
+ //Building a URI object from the given uri_path
+ hdfs::URI uri;
+ try {
+ uri = hdfs::URI::parse_from_string(filename);
+ } catch (const hdfs::uri_parse_error&) {
+ throw ParseError("Malformed URI: " + filename);
+ }
+
+ //This sets conf path to default "$HADOOP_CONF_DIR" or
"/etc/hadoop/conf"
+ //and loads configs core-site.xml and hdfs-site.xml from the conf
path
+ hdfs::ConfigParser parser;
+ if(!parser.LoadDefaultResources()){
+ throw ParseError("Could not load default resources. ");
+ }
+ auto stats = parser.ValidateResources();
+ //validating core-site.xml
+ if(!stats[0].second.ok()){
+ throw ParseError(stats[0].first + " is invalid: " +
stats[0].second.ToString());
+ }
+ //validating hdfs-site.xml
+ if(!stats[1].second.ok()){
+ throw ParseError(stats[1].first + " is invalid: " +
stats[1].second.ToString());
+ }
+ hdfs::Options options;
+ if(!parser.get_options(options)){
+ throw ParseError("Could not load Options object. ");
+ }
+ hdfs::IoService * io_service = hdfs::IoService::New();
+ //Wrapping file_system into a unique pointer to guarantee deletion
+ file_system = std::unique_ptr<hdfs::FileSystem>(
+ hdfs::FileSystem::New(io_service, "", options));
+ if (file_system.get() == nullptr) {
+ throw ParseError("Can't create FileSystem object. ");
+ }
+ hdfs::Status status;
+ //Checking if the user supplied the host
+ if(!uri.get_host().empty()){
+ //Using port if supplied, otherwise using "" to look up port in
configs
+ std::string port = uri.has_port() ?
+ std::to_string(uri.get_port()) : "";
+ status = file_system->Connect(uri.get_host(), port);
+ if (!status.ok()) {
+ throw ParseError("Can't connect to " + uri.get_host()
+ + ":" + port + ". " + status.ToString());
+ }
+ } else {
+ status = file_system->ConnectToDefaultFs();
+ if (!status.ok()) {
+ if(!options.defaultFS.get_host().empty()){
+ throw ParseError("Error connecting to " +
+ options.defaultFS.str() + ". " + status.ToString());
+ } else {
+ throw ParseError(
+ "Error connecting to the cluster: defaultFS is empty. "
+ + status.ToString());
+ }
+ }
+ }
+
+ if (file_system.get() == nullptr) {
+ throw ParseError("Can't connect the file system. ");
+ }
+
+ hdfs::FileHandle *file_raw = nullptr;
+ status = file_system->Open(uri.get_path(), &file_raw);
--- End diff --
nit: you may want to cache "status" within the class.
---
