Building 1kk string of 10 chars each in arrow-cpp

build_str.cpp

#include "arrow/builder.h"
#include "arrow/array.h"
#include <vector>
#include <cstdlib>
#include <iostream>
#include <chrono>
#include <cmath>
#include <memory>

using namespace std;
using namespace arrow;

char random_char() {
   auto rnd = ('z' - 'a') * ((double)rand() / RAND_MAX);
   return 'a' + rnd;
}

void gen_rand(vector<char>& arr) {
   for (auto& el : arr) {
      el = random_char();
   }
}

int main() {
   constexpr int64_t N = 10'000'000;
   vector<char> arr;
   arr.resize(N);
   gen_rand(arr);
   StringBuilder builder;
   if (!builder.Reserve(N / 10).ok()) {
      throw;
   }
   auto start = chrono::high_resolution_clock::now();
   for (auto i = arr.begin(), end = arr.end(); i < end; i += 10) {
      Status s = builder.Append(&*i, 10);
      if (!s.ok()) {
         throw;
      }
   }

   shared_ptr<Array> output;
   Status s = builder.Finish(&output);
      if (!s.ok()) {
      throw;
   }
   auto end = chrono::high_resolution_clock::now();
   chrono::duration<double, milli> duration = end - start;

   cout << "Built array with " << output->length() << " elements."
      << "\n Took " << duration.count() << "ms" << endl;
   return 0;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.10)

LIST(APPEND CMAKE_MODULE_PATH "${CMAKE_SOURCE_DIR}/arrow/cpp/cmake_modules")

find_package(Arrow)

include_directories(${ARROW_INCLUDE_DIR})

MESSAGE( STATUS ${ARROW_INCLUDE_DIR})

add_executable(build_str build_str.cpp)
target_link_libraries(build_str ${ARROW_SHARED_LIB})