I'd propose adding new TS APIs that make overriding configuration variables more flexible.
``` TS_RECORDDATATYPE_VARIANT using TSConfigValue = std::variant<HttpStatusCodeList *>; TSReturnCode TSHttpTxnConfigParse(TSConfigValue &dst, TSOverridableConfigKey key, const char *value, size_t length); TSReturnCode TSHttpTxnConfigSet(TSHttpTxn txnp, TSOverridableConfigKey key, const TSConfigValue &src); ``` ## Current Limitations Today, we can override configs only in int, float, and string. ``` TSReturnCode TSHttpTxnConfigIntSet(TSHttpTxn txnp, TSOverridableConfigKey conf, TSMgmtInt value); TSReturnCode TSHttpTxnConfigFloatSet(TSHttpTxn txnp, TSOverridableConfigKey conf, TSMgmtFloat value); TSReturnCode TSHttpTxnConfigStringSet(TSHttpTxn txnp, TSOverridableConfigKey conf, const char *value, int length); ``` However, some configs like `negative_caching_list` are list. While it's technically possible to override these configs with `TSHttpTxnConfigStringSet` and `MgmtConverter`, every transaction needs to run the converter. ## New APIs With the new APIs, we can - Parse only once on (re)loading configs - Store the parsed structure in a `TSConfigValue` - Override the value on remap `TSConfigValue` is a `std::variant` for type safety and future extension. For now, it has only `HttpStatusCodeList *` for negative_caching_list and negative_revalidating_list, but whenever we want to override configs that has other types, we can add it in this variant. Please take a look at PR#12284 for implementations. https://github.com/apache/trafficserver/pull/12284 Thanks, Masaori
