| // 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. |
| |
| #ifndef __MESOS_MODULE_HPP__ |
| #define __MESOS_MODULE_HPP__ |
| |
| // Mesos Module API (MESOS-1384). |
| // |
| // A Mesos module is an instance of a module 'kind' known to Mesos, |
| // implemented in a dynamically loaded library. A module library can |
| // hold multiple modules. When a Mesos master or slave is started, it |
| // takes a list of libraries with contained modules as command line |
| // argument (in JSON format or a path to a JSON file). |
| // |
| // JSON := {"libraries": [library, ...]} |
| // library := {"file": <library path>, |
| // "modules": [<module name>, ...]} |
| // |
| // How to write a module library: |
| // 1. Define a create() function that returns a pointer to an object |
| // of 'kind' type. |
| // 2. If you want to indicate backwards compatibility for a module, |
| // create: |
| // 'bool compatible() { return true; } |
| // (You can replace compatible with any other name). |
| // If you want custom compatibility checks, replace the return |
| // statement above with them. |
| // 3. Define a variable of Module<KIND> struct type and populate the |
| // fields (including pointers to 'create' and 'compatible'). The |
| // variable name thus becomes the module name. |
| |
| #include <mesos/version.hpp> |
| |
| #define MESOS_MODULE_API_VERSION "2" |
| |
| namespace mesos { |
| namespace modules { |
| |
| // Internal utilities, not part of the module API: |
| |
| // Declare a loadable module library. |
| // This also provides handshakes with Mesos for version checking. |
| struct ModuleBase |
| { |
| ModuleBase( |
| const char* _moduleApiVersion, |
| const char* _mesosVersion, |
| const char* _kind, |
| const char* _authorName, |
| const char* _authorEmail, |
| const char* _description, |
| bool (*_compatible)()) |
| : moduleApiVersion(_moduleApiVersion), |
| mesosVersion(_mesosVersion), |
| kind(_kind), |
| authorName(_authorName), |
| authorEmail(_authorEmail), |
| description(_description), |
| compatible(_compatible) {} |
| |
| const char* moduleApiVersion; |
| const char* mesosVersion; |
| |
| // String representation of module 'kind' returned from 'create'. |
| const char* kind; |
| const char* authorName; |
| const char* authorEmail; |
| const char* description; |
| |
| // Callback invoked to check version compatibility. If this field |
| // is `nullptr`, backwards compatibility is disabled and the module |
| // version must match the Mesos release version exactly. If the |
| // macro is used, Mesos first checks backwards compatibility against |
| // its own internal table maintained by Mesos developers, then your |
| // implementation that follows the macro gets a say. If you return |
| // true, the module is admitted. |
| bool (*compatible)(); |
| }; |
| |
| |
| // These declarations are neeed only for later specializations. |
| |
| template <typename T> |
| struct Module; |
| |
| template <typename T> |
| const char* kind(); |
| |
| } // namespace modules { |
| } // namespace mesos { |
| |
| #endif // __MESOS_MODULE_HPP__ |