Remove in-memory state implementation

We originally added this in the *very early* days of Podman,
before a proper persistent state was written, so we had something
to test with. It was retained after the original SQLite state
(and current BoltDB state) were written so it could be used for
testing Libpod in unit tests with no requirement for on-disk
storage. Well, such unit tests never materialized, and if we were
to write some now the requirement to have a temporary directory
for storing data on disk is not that bad. I can basically
guarantee there are no users of this in the wild because, even if
you managed to figure out how to configure it when we don't
document it, it's completely unusable with Podman since all your
containers and pods will disappear every time Podman exits.

Given all this, and since it's an ongoing maintenance burden I no
longer wish to deal with, let's just remove it.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 0 insertions, 127 deletions

diff --git a/pkg/registrar/registrar.go b/pkg/registrar/registrar.go
deleted file mode 100644
index 1e75ee995..000000000
--- a/pkg/registrar/registrar.go
+++ /dev/null
@@ -1,127 +0,0 @@
-// Package registrar provides name registration. It reserves a name to a given key.
-package registrar
-
-import (
-	"errors"
-	"sync"
-)
-
-var (
-	// ErrNameReserved is an error which is returned when a name is requested to be reserved that already is reserved
-	ErrNameReserved = errors.New("name is reserved")
-	// ErrNameNotReserved is an error which is returned when trying to find a name that is not reserved
-	ErrNameNotReserved = errors.New("name is not reserved")
-	// ErrNoSuchKey is returned when trying to find the names for a key which is not known
-	ErrNoSuchKey = errors.New("provided key does not exist")
-)
-
-// Registrar stores indexes a list of keys and their registered names as well as indexes names and the key that they are registered to
-// Names must be unique.
-// Registrar is safe for concurrent access.
-type Registrar struct {
-	idx   map[string][]string
-	names map[string]string
-	mu    sync.Mutex
-}
-
-// NewRegistrar creates a new Registrar with the an empty index
-func NewRegistrar() *Registrar {
-	return &Registrar{
-		idx:   make(map[string][]string),
-		names: make(map[string]string),
-	}
-}
-
-// Reserve registers a key to a name
-// Reserve is idempotent
-// Attempting to reserve a key to a name that already exists results in an `ErrNameReserved`
-// A name reservation is globally unique
-func (r *Registrar) Reserve(name, key string) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	if k, exists := r.names[name]; exists {
-		if k != key {
-			return ErrNameReserved
-		}
-		return nil
-	}
-
-	r.idx[key] = append(r.idx[key], name)
-	r.names[name] = key
-	return nil
-}
-
-// Release releases the reserved name
-// Once released, a name can be reserved again
-func (r *Registrar) Release(name string) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	key, exists := r.names[name]
-	if !exists {
-		return
-	}
-
-	for i, n := range r.idx[key] {
-		if n != name {
-			continue
-		}
-		r.idx[key] = append(r.idx[key][:i], r.idx[key][i+1:]...)
-		break
-	}
-
-	delete(r.names, name)
-
-	if len(r.idx[key]) == 0 {
-		delete(r.idx, key)
-	}
-}
-
-// Delete removes all reservations for the passed in key.
-// All names reserved to this key are released.
-func (r *Registrar) Delete(key string) {
-	r.mu.Lock()
-	for _, name := range r.idx[key] {
-		delete(r.names, name)
-	}
-	delete(r.idx, key)
-	r.mu.Unlock()
-}
-
-// GetNames lists all the reserved names for the given key
-func (r *Registrar) GetNames(key string) ([]string, error) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-
-	names, exists := r.idx[key]
-	if !exists {
-		return nil, ErrNoSuchKey
-	}
-	return names, nil
-}
-
-// Get returns the key that the passed in name is reserved to
-func (r *Registrar) Get(name string) (string, error) {
-	r.mu.Lock()
-	key, exists := r.names[name]
-	r.mu.Unlock()
-
-	if !exists {
-		return "", ErrNameNotReserved
-	}
-	return key, nil
-}
-
-// GetAll returns all registered names
-func (r *Registrar) GetAll() map[string][]string {
-	out := make(map[string][]string)
-
-	r.mu.Lock()
-	// copy index into out
-	for id, names := range r.idx {
-		out[id] = names
-	}
-	r.mu.Unlock()
-	return out
-}