53 lines
2.0 KiB
Go
53 lines
2.0 KiB
Go
// Mgmt
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// Copyright (C) 2013-2018+ James Shubin and the project contributors
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// Written by James Shubin <james@shubin.ca> and the project contributors
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//
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// This program is free software: you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program. If not, see <http://www.gnu.org/licenses/>.
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// Package funcs provides a framework for functions that change over time.
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package funcs
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import (
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"fmt"
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"github.com/purpleidea/mgmt/lang/interfaces"
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)
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// registeredFuncs is a global map of all possible funcs which can be used. You
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// should never touch this map directly. Use methods like Register instead. It
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// includes implementations which also satisfy PolyFunc as well.
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var registeredFuncs = make(map[string]func() interfaces.Func) // must initialize
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// Register takes a func and its name and makes it available for use. It is
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// commonly called in the init() method of the func at program startup. There is
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// no matching Unregister function. You may also register functions which
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// satisfy the PolyFunc interface.
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func Register(name string, fn func() interfaces.Func) {
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if _, exists := registeredFuncs[name]; exists {
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panic(fmt.Sprintf("a func named %s is already registered", name))
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}
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//gob.Register(fn())
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registeredFuncs[name] = fn
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}
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// Lookup returns a pointer to the function's struct. It may be convertible to a
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// PolyFunc if the particular function implements those additional methods.
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func Lookup(name string) (interfaces.Func, error) {
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f, exists := registeredFuncs[name]
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if !exists {
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return nil, fmt.Errorf("not found")
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}
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return f(), nil
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}
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