Method HandleCacheOpenReadHit

src/proxy/http/HttpTransact.cc:2755–2986

////////////////////////////////////////////////////////////////////////// Name : HandleCacheOpenReadHit Description: handle result of a cache hit Details : Cache lookup succeeded and resulted in a cache hit. This means that the Accept* and Etags fields also matched. The cache lookup may have resulted in a vector of alternates (since lookup may be based on a url). A different function (

//
///////////////////////////////////////////////////////////////////////////////
void
HttpTransact::HandleCacheOpenReadHit(State *s)
{
  bool           needs_revalidate   = false;
  bool           needs_authenticate = false;
  bool           needs_cache_auth   = false;
  bool           server_up          = true;
  CacheHTTPInfo *obj;

  if (s->api_update_cached_object == HttpTransact::UPDATE_CACHED_OBJECT_CONTINUE) {
    obj = &s->cache_info.object_store;
    ink_assert(obj->valid());
  } else {
    obj = s->cache_info.object_read;
  }

  if (obj == nullptr || !obj->valid()) {
    HandleCacheOpenReadMiss(s);
    return;
  }

  // do we have to authenticate with the server before
  // sending back the cached response to the client?
  Authentication_t authentication_needed = AuthenticationNeeded(s->txn_conf, &s->hdr_info.client_request, obj->response_get());

  switch (authentication_needed) {
  case AUTHENTICATION_SUCCESS:
    TxnDbg(dbg_ctl_http_seq, "Authentication not needed");
    needs_authenticate = false;
    break;
  case AUTHENTICATION_MUST_REVALIDATE:
    SET_VIA_STRING(VIA_DETAIL_CACHE_LOOKUP, VIA_DETAIL_MISS_METHOD);
    TxnDbg(dbg_ctl_http_seq, "Authentication needed");
    needs_authenticate = true;
    break;
  case AUTHENTICATION_MUST_PROXY:
    TxnDbg(dbg_ctl_http_seq, "Authentication needed");
    HandleCacheOpenReadMiss(s);
    return;
  case AUTHENTICATION_CACHE_AUTH:
    TxnDbg(dbg_ctl_http_seq, "Authentication needed for cache_auth_content");
    needs_authenticate = false;
    needs_cache_auth   = true;
    break;
  default:
    ink_assert(!("AuthenticationNeeded has returned unsupported code."));
    break;
  }

  ink_assert(is_cache_hit(s->cache_lookup_result));

  // We'll request a revalidation under one of these conditions:
  //
  // 1. Cache lookup is a hit, but the response is stale
  // 2. The cached object has a "Cache-Control: no-cache" header
  //       *and*
  //    proxy.config.http.cache.ignore_server_no_cache is set to 0 (i.e don't ignore no cache -- the default setting)
  //