| .. 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 |
| |
| .. _developer-cache-api-functions: |
| |
| API functions |
| ************* |
| |
| .. c:function:: void TSHttpTxnReqCacheableSet(TSHttpTxn txnp, int flag) |
| |
| Set a flag that marks a request as cacheable. This is a positive override |
| only, setting :arg:`flag` to ``0`` restores the default behavior, it does not |
| force the request to be uncacheable. |
| |
| .. c:function:: TSReturnCode TSCacheUrlSet(TSHttpTxn txnp, char const* url, int length) |
| |
| Set the cache key for the transaction :arg:`txnp` as the string pointed at by |
| :arg:`url` of :arg:`length` characters. It need not be NUL-terminated. This should |
| be called from ``TS_HTTP_READ_REQUEST_HDR_HOOK`` which is before cache lookup |
| but late enough that the HTTP request header is available. |
| |
| |
| The APIs that modify the cache key can be called as early as |
| ``TS_HTTP_READ_REQUEST_HDR_HOOK`` but no later than |
| ``TS_HTTP_POST_REMAP_HOOK``. The cache key is not only used for a cache lookup |
| before going to origin, but also to mark the intent to write to cache on an |
| origin response (if possible). |
| |
| Cache Internals |
| =============== |
| |
| .. cpp:function:: int DIR_SIZE_WITH_BLOCK(int big) |
| |
| A preprocessor macro which computes the maximum size of a fragment based on |
| the value of :arg:`big`. This is computed as if the argument where the value of |
| the :arg:`big` field in a struct :cpp:class:`Dir`. |
| |
| .. cpp:function:: int DIR_BLOCK_SIZE(int big) |
| |
| A preprocessor macro which computes the block size multiplier for a struct |
| :cpp:class:`Dir` where :arg:`big` is the :arg:`big` field value. |