text: // 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 ARROW_UTIL_IO_UTIL_H
  #define ARROW_UTIL_IO_UTIL_H
  
  #include <iostream>
  #include <memory>
  
  #include "arrow/buffer.h"
  #include "arrow/io/interfaces.h"
  #include "arrow/status.h"
  
  namespace arrow {
  namespace io {
  
  // Output stream that just writes to stdout.
  class StdoutStream : public OutputStream {
   public:
    StdoutStream() : pos_(0) { set_mode(FileMode::WRITE); }
    virtual ~StdoutStream() {}
  
    Status Close() override { return Status::OK(); }
  
    Status Tell(int64_t* position) const override {
      *position = pos_;
      return Status::OK();
    }
  
    Status Write(const void* data, int64_t nbytes) override {
      pos_ += nbytes;
      std::cout.write(reinterpret_cast<const char*>(data), nbytes);
      return Status::OK();
    }
  
   private:
    int64_t pos_;
  };
  
  // Input stream that just reads from stdin.
  class StdinStream : public InputStream {
   public:
    StdinStream() : pos_(0) { set_mode(FileMode::READ); }
    virtual ~StdinStream() {}
  
    Status Close() override { return Status::OK(); }
  
    Status Tell(int64_t* position) const override {
      *position = pos_;
      return Status::OK();
    }
  
    Status Read(int64_t nbytes, int64_t* bytes_read, void* out) override {
      std::cin.read(reinterpret_cast<char*>(out), nbytes);
      if (std::cin) {
        *bytes_read = nbytes;
        pos_ += nbytes;
      } else {
        *bytes_read = 0;
      }
      return Status::OK();
    }
  
    Status Read(int64_t nbytes, std::shared_ptr<Buffer>* out) override {
      auto buffer = std::make_shared<PoolBuffer>(NULLPTR);
      RETURN_NOT_OK(buffer->Resize(nbytes));
      int64_t bytes_read;
      RETURN_NOT_OK(Read(nbytes, &bytes_read, buffer->mutable_data()));
      RETURN_NOT_OK(buffer->Resize(bytes_read, false));
      *out = buffer;
      return Status::OK();
    }
  
   private:
    int64_t pos_;
  };
  
  }  // namespace io
  }  // namespace arrow
  
  #endif  // ARROW_UTIL_IO_UTIL_H
  