d30ff6cfae
Instead of constantly making these updates, let's just remove the year since things are stored in git anyways, and this is not an actual modern legal risk anymore.
119 lines
3.6 KiB
Go
119 lines
3.6 KiB
Go
// Mgmt
|
|
// Copyright (C) James Shubin and the project contributors
|
|
// Written by James Shubin <james@shubin.ca> and the project contributors
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
//
|
|
// Additional permission under GNU GPL version 3 section 7
|
|
//
|
|
// If you modify this program, or any covered work, by linking or combining it
|
|
// with embedded mcl code and modules (and that the embedded mcl code and
|
|
// modules which link with this program, contain a copy of their source code in
|
|
// the authoritative form) containing parts covered by the terms of any other
|
|
// license, the licensors of this program grant you additional permission to
|
|
// convey the resulting work. Furthermore, the licensors of this program grant
|
|
// the original author, James Shubin, additional permission to update this
|
|
// additional permission if he deems it necessary to achieve the goals of this
|
|
// additional permission.
|
|
|
|
package structs
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
|
|
"github.com/purpleidea/mgmt/lang/interfaces"
|
|
"github.com/purpleidea/mgmt/lang/types"
|
|
)
|
|
|
|
const (
|
|
// ConstFuncName is the unique name identifier for this function.
|
|
ConstFuncName = "const"
|
|
)
|
|
|
|
// ConstFunc is a function that returns the constant value passed to Value.
|
|
type ConstFunc struct {
|
|
Value types.Value
|
|
NameHint string
|
|
|
|
init *interfaces.Init
|
|
}
|
|
|
|
// String returns a simple name for this function. This is needed so this struct
|
|
// can satisfy the pgraph.Vertex interface.
|
|
func (obj *ConstFunc) String() string {
|
|
if obj.NameHint != "" {
|
|
return obj.NameHint
|
|
}
|
|
if obj.Value != nil && obj.Value.Type() != nil {
|
|
return fmt.Sprintf("%s: %s(%s)", ConstFuncName, obj.Value.Type().String(), obj.Value.String())
|
|
}
|
|
return ConstFuncName
|
|
}
|
|
|
|
// Validate makes sure we've built our struct properly.
|
|
func (obj *ConstFunc) Validate() error {
|
|
if obj.Value == nil {
|
|
return fmt.Errorf("must specify `Value` input")
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Info returns some static info about itself.
|
|
func (obj *ConstFunc) Info() *interfaces.Info {
|
|
var typ *types.Type
|
|
if obj.Value != nil { // don't panic if called speculatively
|
|
if t := obj.Value.Type(); t != nil {
|
|
typ = types.NewType(fmt.Sprintf("func() %s", t.String()))
|
|
}
|
|
}
|
|
return &interfaces.Info{
|
|
Pure: true,
|
|
Memo: false, // TODO: ???
|
|
Sig: typ,
|
|
Err: obj.Validate(), // XXX: implement this and check .Err in engine!
|
|
}
|
|
}
|
|
|
|
// Init runs some startup code for this const.
|
|
func (obj *ConstFunc) Init(init *interfaces.Init) error {
|
|
obj.init = init
|
|
return nil
|
|
}
|
|
|
|
// Stream returns the single value that this const has, and then closes.
|
|
func (obj *ConstFunc) Stream(ctx context.Context) error {
|
|
value, err := obj.Call(ctx, nil)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
select {
|
|
case obj.init.Output <- value:
|
|
// pass
|
|
case <-ctx.Done():
|
|
return nil
|
|
}
|
|
close(obj.init.Output) // signal that we're done sending
|
|
return nil
|
|
}
|
|
|
|
// Call this function with the input args and return the value if it is possible
|
|
// to do so at this time.
|
|
func (obj *ConstFunc) Call(ctx context.Context, args []types.Value) (types.Value, error) {
|
|
if obj.Value == nil {
|
|
return nil, fmt.Errorf("no value available from const")
|
|
}
|
|
return obj.Value, nil
|
|
}
|