.. Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. .. include:: ../../../common.defs .. default-domain:: c TSCacheRead *********** Synopsis ======== .. code-block:: cpp #include .. function:: TSAction TSCacheRead(TSCont contp, TSCacheKey key) Description =========== Asks the Traffic Server cache if the object corresponding to :arg:`key` exists in the cache and can be read. If the object can be read, the Traffic Server cache calls the continuation :arg:`contp` back with the event :data:`TS_EVENT_CACHE_OPEN_READ`. In this case, the cache also passes :arg:`contp` a cache vconnection and :arg:`contp` can then initiate a read operation on that vconnection using :type:`TSVConnRead`. If the object cannot be read, the cache calls :arg:`contp` back with the event :data:`TS_EVENT_CACHE_OPEN_READ_FAILED`. The user (:arg:`contp`) has the option to cancel the action returned by :type:`TSCacheRead`. Note that reentrant calls are possible, i.e. the cache can call back the user (:arg:`contp`) in the same call.