Function read_resp_hdr

plugins/slice/slice.cc:230–282

}

static int
read_resp_hdr(TSCont contp, TSEvent event, void *edata)
{
  TSHttpTxn   txnp = static_cast<TSHttpTxn>(edata);
  PluginInfo *info = static_cast<PluginInfo *>(TSContDataGet(contp));

  // This function does the following things:
  // 1. Parse the object size from Content-Length
  // 2. Cache the object size
  // 3. If the object will be sliced in subsequent requests, turn off the cache to avoid taking up space, and head-of-line blocking.

  int   urllen = 0;
  char *urlstr = TSHttpTxnEffectiveUrlStringGet(txnp, &urllen);
  if (urlstr != nullptr) {
    TxnHdrMgr                response;
    TxnHdrMgr::HeaderGetFunc func = event == TS_EVENT_HTTP_CACHE_LOOKUP_COMPLETE ? TSHttpTxnCachedRespGet : TSHttpTxnServerRespGet;
    response.populateFrom(txnp, func);
    HttpHeader const resp_header(response.m_buffer, response.m_lochdr);
    char             constr[1024];
    int              conlen = sizeof constr;
    bool const hasContentLength(resp_header.valueForKey(TS_MIME_FIELD_CONTENT_LENGTH, TS_MIME_LEN_CONTENT_LENGTH, constr, &conlen));
    if (hasContentLength) {
      uint64_t content_length;

      [[maybe_unused]] auto [ptr, ec] = std::from_chars(constr, constr + conlen, content_length);
      if (ec == std::errc()) {
        if (content_length >= info->config.m_min_size_to_slice) {
          // Remember that this object is big
          info->config.sizeCacheAdd({urlstr, static_cast<size_t>(urllen)}, content_length);
          // This object will be sliced in future requests.  Don't cache it for now.
          TSHttpTxnServerRespNoStoreSet(txnp, 1);
          TSStatIntIncrement(info->config.stat_FN, 1);
        } else {
          TSStatIntIncrement(info->config.stat_TN, 1);
        }
      } else {
        ERROR_LOG("Could not parse content-length: %.*s", conlen, constr);
        TSStatIntIncrement(info->config.stat_bad_cl, 1);
      }
    } else {
      DEBUG_LOG("Could not get a content length for updating object size");
      TSStatIntIncrement(info->config.stat_no_cl, 1);
    }
    TSfree(urlstr);
  } else {
    ERROR_LOG("Could not get URL for obj size.");
    TSStatIntIncrement(info->config.stat_no_url, 1);
  }

  // Reenable and continue with the state machine.
  TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE);
  return 0;
}

int
global_read_request_hook(TSCont // contp