Method openWriteStartDone

src/iocore/cache/CacheWrite.cc:667–775

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

// openWriteStartDone handles vector read (addition of alternates)
// and lock misses
int
CacheVC::openWriteStartDone(int event, Event *e)
{
  intptr_t err = ECACHE_NO_DOC;
  cancel_trigger();
  if (is_io_in_progress()) {
    if (event != AIO_EVENT_DONE) {
      return EVENT_CONT;
    }
    set_io_not_in_progress();
  }
  {
    CACHE_TRY_LOCK(lock, stripe->mutex, mutex->thread_holding);
    if (!lock.is_locked()) {
      VC_LOCK_RETRY_EVENT();
    }

    if (_action.cancelled && (!od || !od->has_multiple_writers())) {
      goto Lcancel;
    }

    if (event == AIO_EVENT_DONE) { // vector read done
      Doc *doc = reinterpret_cast<Doc *>(buf->data());
      if (!io.ok()) {
        err = ECACHE_READ_FAIL;
        goto Lfailure;
      }

      /* INKqa07123.
         A directory entry which is no longer valid may have been overwritten.
         We need to start afresh from the beginning by setting last_collision
         to nullptr.
       */
      if (!stripe->dir_valid(&dir)) {
        DDbg(dbg_ctl_cache_write, "OpenReadStartDone: Dir not valid: Write Head: %" PRId64 ", Dir: %" PRId64,
             (int64_t)stripe->offset_to_vol_offset(stripe->directory.header->write_pos), dir_offset(&dir));
        last_collision = nullptr;
        goto Lcollision;
      }
      if (!(doc->first_key == first_key)) {
        goto Lcollision;
      }

      if (doc->magic != DOC_MAGIC || !doc->hlen || this->load_http_info(write_vector, doc, buf.object()) != doc->hlen) {
        err = ECACHE_BAD_META_DATA;
        goto Lfailure;
      }
      ink_assert(write_vector->count() > 0);
      od->first_dir = dir;
      first_dir     = dir;
      if (doc->single_fragment()) {
        // fragment is tied to the vector
        od->move_resident_alt = true;
        od->single_doc_key    = doc->key;
        dir_assign(&od->single_doc_dir, &dir);
        dir_set_tag(&od->single_doc_dir, od->single_doc_key.slice32(2));
      }
      first_buf = buf;