1-- 2-- SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3-- 4-- Copyright (c) 2018 Kyle Evans <kevans@FreeBSD.org> 5-- All rights reserved. 6-- 7-- Redistribution and use in source and binary forms, with or without 8-- modification, are permitted provided that the following conditions 9-- are met: 10-- 1. Redistributions of source code must retain the above copyright 11-- notice, this list of conditions and the following disclaimer. 12-- 2. Redistributions in binary form must reproduce the above copyright 13-- notice, this list of conditions and the following disclaimer in the 14-- documentation and/or other materials provided with the distribution. 15-- 16-- THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17-- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19-- ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20-- FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21-- DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22-- OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23-- HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24-- LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25-- OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26-- SUCH DAMAGE. 27-- 28-- $FreeBSD$ 29-- 30 31local hook = {} 32 33local registered_hooks = {} 34 35-- Module exports 36-- Register a hook type; these are the names that hooks may be registered for. 37-- It is expected that modules will register all of their hook types upon 38-- initial load. Other modules may then, at any time, register a hook for these 39-- types. 40-- 41-- Naming convention: hook types should be sensible named, preferably prefixed 42-- with the name of the module that registered them. They would also ideally 43-- describe an action that may or may not match a function name. 44-- e.g. config.reloaded which takes place after config has been reloaded, 45-- possibly from a different source. 46function hook.registerType(hooktype) 47 registered_hooks[hooktype] = {} 48end 49 50function hook.register(hooktype, hookfunc) 51 local selected_hooks = registered_hooks[hooktype] 52 if selected_hooks == nil then 53 print("Tried registering a hook for an unknown hook type: " .. 54 hooktype) 55 return 56 end 57 selected_hooks[#selected_hooks + 1] = hookfunc 58 registered_hooks[hooktype] = selected_hooks 59end 60 61-- Takes a hooktype and runs all functions associated with that specific hook 62-- type in the order that they were registered in. This ordering should likely 63-- not be relied upon. 64function hook.runAll(hooktype) 65 local selected_hooks = registered_hooks[hooktype] 66 if selected_hooks == nil then 67 -- This message, and the print() above, should only be seen by 68 -- developers. Hook type registration should have happened at 69 -- module load, so if this hasn't happened then we have messed 70 -- up the order in which we've loaded modules and we need to 71 -- catch that as soon as possible. 72 print("Tried to run hooks for an unknown hook type: " .. 73 hooktype) 74 return 0 75 end 76 if #selected_hooks > 0 then 77 for _, func in ipairs(selected_hooks) do 78 func() 79 end 80 end 81 return #selected_hooks 82end 83 84return hook 85