59 lines
1.5 KiB
Go
59 lines
1.5 KiB
Go
// Copyright (c) 2023 Joshua Rich <joshua.rich@gmail.com>
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//
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// This software is released under the MIT License.
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// https://opensource.org/licenses/MIT
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package config
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import (
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"context"
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"errors"
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)
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type Config interface {
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Get(string) (interface{}, error)
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Set(string, interface{}) error
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Validate() error
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Refresh() error
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}
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// key is an unexported type for keys defined in this package.
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// This prevents collisions with keys defined in other packages.
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type key int
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// configKey is the key for agent.AppConfig values in Contexts. It is
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// unexported; clients use config.NewContext and config.FromContext
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// instead of using this key directly.
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var configKey key
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// StoreInContext returns a new Context that stores the Config, c.
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func StoreInContext(ctx context.Context, c Config) context.Context {
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return context.WithValue(ctx, configKey, c)
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}
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// FetchFromContext returns the Config value stored in ctx, if any.
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func FetchFromContext(ctx context.Context) (Config, error) {
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if c, ok := ctx.Value(configKey).(Config); !ok {
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return nil, errors.New("no API in context")
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} else {
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return c, nil
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}
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}
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// FetchPropertyFromContext is a helper function to retrieve a specific config
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// property from the Config store in ctx, rather than retrieving the entire
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// Config object.
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func FetchPropertyFromContext(ctx context.Context, property string) (interface{}, error) {
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config, err := FetchFromContext(ctx)
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if err != nil {
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return nil, err
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} else {
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value, err := config.Get(property)
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if err != nil {
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return nil, err
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} else {
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return value, nil
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}
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}
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}
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