86969739ae
- App-scoped typed Publish/Lookup with duplicate-provider errors - Set plugin IDs before Register so HasPlugin sees the full set - Greeter uses pact.OptionalMessage without importing optional
61 lines
1.2 KiB
Go
61 lines
1.2 KiB
Go
package backpack
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import (
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"fmt"
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"reflect"
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"sync"
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)
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// Registry is an app-scoped typed service catalog. It has no process-global state.
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type Registry struct {
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mu sync.RWMutex
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m map[reflect.Type]any
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}
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// NewRegistry returns an empty service registry.
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func NewRegistry() *Registry {
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return &Registry{m: make(map[reflect.Type]any)}
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}
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// Publish stores value under the concrete type argument T. Publishing the
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// same T twice is an error.
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func (r *Registry) Publish[T any](value T) error {
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if r == nil {
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return fmt.Errorf("backpack: registry is nil")
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}
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if any(value) == nil {
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return fmt.Errorf("backpack: publish nil service")
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}
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key := reflect.TypeFor[T]()
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r.mu.Lock()
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defer r.mu.Unlock()
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if r.m == nil {
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r.m = make(map[reflect.Type]any)
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}
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if _, exists := r.m[key]; exists {
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return fmt.Errorf("backpack: duplicate provider for %s", key)
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}
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r.m[key] = value
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return nil
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}
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// Lookup returns the service published under T, or (zero, false).
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func (r *Registry) Lookup[T any]() (T, bool) {
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var zero T
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if r == nil {
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return zero, false
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}
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key := reflect.TypeFor[T]()
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r.mu.RLock()
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defer r.mu.RUnlock()
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v, ok := r.m[key]
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if !ok {
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return zero, false
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}
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got, ok := v.(T)
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if !ok {
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return zero, false
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}
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return got, true
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}
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