| /* |
| 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 <cstdio> |
| #include <cstring> |
| |
| #include "ts/ts.h" |
| #include "ts/remap.h" |
| |
| #include "policy_manager.h" |
| #include "configs.h" |
| |
| const char *PLUGIN_NAME = "cache_promote"; |
| |
| // This has to be a global here. I tried doing a classic singleton (with a getInstance()) in the PolicyManager, |
| // but then reloading the DSO does not work. What happens is that the old singleton is stil there, even though |
| // the rest of the plugin is reloaded. Very scary, and not what we need / want; if the plugin reloads, the |
| // PolicyManager has to reload (and start fresh) as well. |
| static PolicyManager gManager; |
| |
| ////////////////////////////////////////////////////////////////////////////////////////////// |
| // Main "plugin", a TXN hook in the TS_HTTP_READ_CACHE_HDR_HOOK. Unless the policy allows |
| // caching, we will turn off the cache from here on for the TXN. |
| // |
| // NOTE: This is not optimal, the goal was to handle this before we lock the URL in the |
| // cache. However, that does not work. Hence, for now, we also schedule the continuation |
| // for READ_RESPONSE_HDR such that we can turn off the actual cache write. |
| // |
| static int |
| cont_handle_policy(TSCont contp, TSEvent event, void *edata) |
| { |
| TSHttpTxn txnp = static_cast<TSHttpTxn>(edata); |
| PromotionConfig *config = static_cast<PromotionConfig *>(TSContDataGet(contp)); |
| |
| switch (event) { |
| // Main HOOK |
| case TS_EVENT_HTTP_CACHE_LOOKUP_COMPLETE: |
| if (!TSHttpTxnIsInternal(txnp)) { |
| int obj_status; |
| |
| if (TS_ERROR != TSHttpTxnCacheLookupStatusGet(txnp, &obj_status)) { |
| switch (obj_status) { |
| case TS_CACHE_LOOKUP_MISS: |
| case TS_CACHE_LOOKUP_SKIPPED: |
| if (config->getPolicy()->doSample() && config->getPolicy()->doPromote(txnp)) { |
| TSDebug(PLUGIN_NAME, "cache-status is %d, and leaving cache on (promoted)", obj_status); |
| } else { |
| TSDebug(PLUGIN_NAME, "cache-status is %d, and turning off the cache (not promoted)", obj_status); |
| TSHttpTxnServerRespNoStoreSet(txnp, 1); |
| } |
| break; |
| default: |
| // Do nothing, just let it handle the lookup. |
| TSDebug(PLUGIN_NAME, "cache-status is %d (hit), nothing to do", obj_status); |
| |
| if (config->getPolicy()->stats_enabled) { |
| TSStatIntIncrement(config->getPolicy()->cache_hits_id, 1); |
| } |
| break; |
| } |
| } |
| |
| if (config->getPolicy()->stats_enabled) { |
| TSStatIntIncrement(config->getPolicy()->total_requests_id, 1); |
| } |
| } else { |
| TSDebug(PLUGIN_NAME, "request is an internal (plugin) request, implicitly promoted"); |
| } |
| break; |
| |
| // Should not happen |
| default: |
| TSDebug(PLUGIN_NAME, "unhandled event %d", static_cast<int>(event)); |
| break; |
| } |
| |
| // Reenable and continue with the state machine. |
| TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE); |
| return 0; |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////////////////////// |
| // Initialize the plugin as a remap plugin. |
| // |
| TSReturnCode |
| TSRemapInit(TSRemapInterface *api_info, char *errbuf, int errbuf_size) |
| { |
| if (api_info->size < sizeof(TSRemapInterface)) { |
| strncpy(errbuf, "[tsremap_init] - Incorrect size of TSRemapInterface structure", errbuf_size - 1); |
| return TS_ERROR; |
| } |
| |
| if (api_info->tsremap_version < TSREMAP_VERSION) { |
| snprintf(errbuf, errbuf_size, "[tsremap_init] - Incorrect API version %ld.%ld", api_info->tsremap_version >> 16, |
| (api_info->tsremap_version & 0xffff)); |
| return TS_ERROR; |
| } |
| |
| TSDebug(PLUGIN_NAME, "remap plugin is successfully initialized"); |
| return TS_SUCCESS; /* success */ |
| } |
| |
| void |
| TSRemapDone() |
| { |
| TSDebug(PLUGIN_NAME, "called TSRemapDone()"); |
| gManager.clear(); |
| } |
| |
| TSReturnCode |
| TSRemapNewInstance(int argc, char *argv[], void **ih, char * /* errbuf */, int /* errbuf_size */) |
| { |
| PromotionConfig *config = new PromotionConfig(&gManager); |
| |
| --argc; |
| ++argv; |
| if (config->factory(argc, argv)) { |
| TSCont contp = TSContCreate(cont_handle_policy, nullptr); |
| |
| TSContDataSet(contp, static_cast<void *>(config)); |
| *ih = static_cast<void *>(contp); |
| |
| return TS_SUCCESS; |
| } else { |
| delete config; |
| return TS_ERROR; |
| } |
| } |
| |
| void |
| TSRemapDeleteInstance(void *ih) |
| { |
| TSCont contp = static_cast<TSCont>(ih); |
| PromotionConfig *config = static_cast<PromotionConfig *>(TSContDataGet(contp)); |
| |
| delete config; // This will return the PromotionPolicy to the PromotionManager as well |
| TSContDestroy(contp); |
| } |
| |
| ////////////////////////////////////////////////////////////////////////////////////////////// |
| // Schedule the cache-read continuation for this remap rule. |
| // |
| TSRemapStatus |
| TSRemapDoRemap(void *ih, TSHttpTxn rh, TSRemapRequestInfo * /* ATS_UNUSED rri */) |
| { |
| if (nullptr == ih) { |
| TSDebug(PLUGIN_NAME, "no promotion rules configured, this is probably a plugin bug"); |
| } else { |
| TSCont contp = static_cast<TSCont>(ih); |
| |
| TSDebug(PLUGIN_NAME, "scheduling a TS_HTTP_CACHE_LOOKUP_COMPLETE_HOOK hook"); |
| TSHttpTxnHookAdd(rh, TS_HTTP_CACHE_LOOKUP_COMPLETE_HOOK, contp); |
| } |
| |
| return TSREMAP_NO_REMAP; |
| } |