events: remove memory eventer

This type is unsused, undocumented and basically broken. If this would
be used anywhere it will just deadlock after writing 100+ events without
reading as the channel will just be full.

It was added in commit 8da5f3f733 but never used there nor is there any
justification why this was added in the commit message or PR comments.

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

libpod/events/config.go

@@ -16,8 +16,6 @@ const (
 	Journald EventerType = iota
 	// Null is a no-op events logger. It does not read or write events.
 	Null EventerType = iota
-	// Memory indicates the event logger will hold events in memory
-	Memory EventerType = iota
 )
 
 // Event describes the attributes of a libpod event

libpod/events/events.go

@@ -20,8 +20,6 @@ func (et EventerType) String() string {
 		return "file"
 	case Journald:
 		return "journald"
-	case Memory:
-		return "memory"
 	case Null:
 		return "none"
 	default:
@@ -36,8 +34,6 @@ func IsValidEventer(eventer string) bool {
 		return true
 	case Journald.String():
 		return true
-	case Memory.String():
-		return true
 	case Null.String():
 		return true
 	default:

libpod/events/events_freebsd.go

@@ -15,8 +15,6 @@ func NewEventer(options EventerOptions) (Eventer, error) {
 		return EventLogFile{options}, nil
 	case strings.ToUpper(Null.String()):
 		return newNullEventer(), nil
-	case strings.ToUpper(Memory.String()):
-		return NewMemoryEventer(), nil
 	default:
 		return nil, fmt.Errorf("unknown event logger type: %s", strings.ToUpper(options.EventerType))
 	}

libpod/events/events_linux.go

@@ -21,8 +21,6 @@ func NewEventer(options EventerOptions) (Eventer, error) {
 		return newLogFileEventer(options)
 	case strings.ToUpper(Null.String()):
 		return newNullEventer(), nil
-	case strings.ToUpper(Memory.String()):
-		return NewMemoryEventer(), nil
 	default:
 		return nil, fmt.Errorf("unknown event logger type: %s", strings.ToUpper(options.EventerType))
 	}

libpod/events/memory.go

@@ -1,49 +0,0 @@
-package events
-
-import (
-	"context"
-)
-
-// EventMemory is the structure for event writing to a channel. It contains the eventer
-// options and the event itself.  Methods for reading and writing are also defined from it.
-type EventMemory struct {
-	options  EventerOptions
-	elements chan *Event
-}
-
-// Write event to memory queue
-func (e EventMemory) Write(event Event) (err error) {
-	e.elements <- &event
-	return
-}
-
-// Read event(s) from memory queue
-func (e EventMemory) Read(ctx context.Context, options ReadOptions) (err error) {
-	select {
-	case <-ctx.Done():
-		return
-	default:
-	}
-
-	select {
-	case event := <-e.elements:
-		options.EventChannel <- event
-	default:
-	}
-	return nil
-}
-
-// String returns eventer type
-func (e EventMemory) String() string {
-	return e.options.EventerType
-}
-
-// NewMemoryEventer returns configured MemoryEventer
-func NewMemoryEventer() Eventer {
-	return EventMemory{
-		options: EventerOptions{
-			EventerType: Memory.String(),
-		},
-		elements: make(chan *Event, 100),
-	}
-}