ftruncate in larger blocks

#include <sys/mman.h>

#include <unistd.h>

#include "pagemanager.h"

#include <fnordmetric/environment.h>

#include <fnordmetric/io/file.h>

#include <fnordmetric/io/fileutil.h>

  mmap_mutex_.lock();

  if (last_byte > file_size_) {

    // FIXPAUL truncate in larger blocks

    FileUtil::truncate(filename_, last_byte);

    file_size_ = last_byte;

    auto new_size =

        ((last_byte / kMmapSizeMultiplier) + 1) * kMmapSizeMultiplier;

    if (fnordmetric::env()->verbose()) {

      fnordmetric::env()->logger()->printf(

          "DEBUG",

          "Truncating file %s to %lu bytes",

          filename_.c_str(),

          (long unsigned) new_size);

    }

    FileUtil::truncate(filename_, new_size);

    file_size_ = new_size;

  }

  auto page_ref = new MmappedPageRef(page, getMmappedFile(last_byte));

   */

  MmappedFile* getMmappedFile(uint64_t last_byte);

  const std::string& filename_;

  const std::string filename_;

  size_t file_size_;

  MmappedFile* current_mapping_;

  std::mutex mmap_mutex_;