Method chunk_file

src/client/SyntheticClient.cc:3339–3396

}

int SyntheticClient::chunk_file(string &filename)
{
  UserPerm perms = client->pick_my_perms();
  int fd = client->open(filename.c_str(), O_RDONLY, perms);
  if (fd < 0)
    return fd;

  struct stat st;
  int ret = client->fstat(fd, &st, perms);
  if (ret < 0) {
    client->close(fd);
    return ret;
  }
  uint64_t size = st.st_size;
  dout(0) << "file " << filename << " size is " << size << dendl;

  inode_t inode{};
  inode.ino = st.st_ino;
  ret = client->fdescribe_layout(fd, &inode.layout);
  ceph_assert(ret == 0); // otherwise fstat did a bad thing

  uint64_t pos = 0;
  bufferlist from_before;
  while (pos < size) {
    int get = std::min<int>(size - pos, 1048576);

    ceph::mutex flock = ceph::make_mutex("synclient chunk_file lock");
    ceph::condition_variable cond;
    bool done;
    bufferlist bl;
    {
      std::unique_lock locker{flock};
      Context *onfinish = new C_SafeCond(flock, cond, &done);
      client->filer->read(inode.ino, &inode.layout, CEPH_NOSNAP, pos, get, &bl, 0,
			  onfinish);
      cond.wait(locker, [&done] { return done; });
    }
    dout(0) << "got " << bl.length() << " bytes at " << pos << dendl;
    
    if (from_before.length()) {
      dout(0) << " including bit from previous block" << dendl;
      pos -= from_before.length();
      from_before.claim_append(bl);
      bl.swap(from_before);
    }      

    // ....

    // keep last 32 bytes around
    from_before.clear();
    from_before.substr_of(bl, bl.length()-32, 32);

    pos += bl.length();
  }

  client->close(fd);
  return 0;
}