Method openWriteOverwrite

src/iocore/cache/CacheWrite.cc:620–663

begin overwrite

// begin overwrite
int
CacheVC::openWriteOverwrite(int event, Event *e)
{
  cancel_trigger();
  if (event != AIO_EVENT_DONE) {
    if (event == EVENT_IMMEDIATE) {
      last_collision = nullptr;
    }
  } else {
    Doc *doc = nullptr;
    set_io_not_in_progress();
    if (_action.cancelled) {
      return openWriteCloseDir(event, e);
    }
    if (!io.ok()) {
      goto Ldone;
    }
    doc = reinterpret_cast<Doc *>(buf->data());
    if (!(doc->first_key == first_key)) {
      goto Lcollision;
    }
    od->first_dir = dir;
    first_buf     = buf;
    goto Ldone;
  }
Lcollision: {
  CACHE_TRY_LOCK(lock, stripe->mutex, this_ethread());
  if (!lock.is_locked()) {
    VC_LOCK_RETRY_EVENT();
  }
  int res = dir_probe(&first_key, stripe, &dir, &last_collision);
  if (res > 0) {
    if ((res = do_read_call(&first_key)) == EVENT_RETURN) {
      goto Lcallreturn;
    }
    return res;
  }
}
Ldone:
  SET_HANDLER(&CacheVC::openWriteMain);
  return callcont(CACHE_EVENT_OPEN_WRITE);
Lcallreturn:
  return handleEvent(AIO_EVENT_DONE, nullptr); // hopefully a tail call
}

// openWriteStartDone handles vector read (addition of alternates)
// and lock misses