use an in memory store for containers

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

oci/memory_store.go

@@ -0,0 +1,92 @@
+package oci
+
+import "sync"
+
+// memoryStore implements a Store in memory.
+type memoryStore struct {
+	s map[string]*Container
+	sync.RWMutex
+}
+
+// NewMemoryStore initializes a new memory store.
+func NewMemoryStore() Store {
+	return &memoryStore{
+		s: make(map[string]*Container),
+	}
+}
+
+// Add appends a new container to the memory store.
+// It overrides the id if it existed before.
+func (c *memoryStore) Add(id string, cont *Container) {
+	c.Lock()
+	c.s[id] = cont
+	c.Unlock()
+}
+
+// Get returns a container from the store by id.
+func (c *memoryStore) Get(id string) *Container {
+	c.RLock()
+	res := c.s[id]
+	c.RUnlock()
+	return res
+}
+
+// Delete removes a container from the store by id.
+func (c *memoryStore) Delete(id string) {
+	c.Lock()
+	delete(c.s, id)
+	c.Unlock()
+}
+
+// List returns a sorted list of containers from the store.
+// The containers are ordered by creation date.
+func (c *memoryStore) List() []*Container {
+	containers := History(c.all())
+	containers.sort()
+	return containers
+}
+
+// Size returns the number of containers in the store.
+func (c *memoryStore) Size() int {
+	c.RLock()
+	defer c.RUnlock()
+	return len(c.s)
+}
+
+// First returns the first container found in the store by a given filter.
+func (c *memoryStore) First(filter StoreFilter) *Container {
+	for _, cont := range c.all() {
+		if filter(cont) {
+			return cont
+		}
+	}
+	return nil
+}
+
+// ApplyAll calls the reducer function with every container in the store.
+// This operation is asyncronous in the memory store.
+// NOTE: Modifications to the store MUST NOT be done by the StoreReducer.
+func (c *memoryStore) ApplyAll(apply StoreReducer) {
+	wg := new(sync.WaitGroup)
+	for _, cont := range c.all() {
+		wg.Add(1)
+		go func(container *Container) {
+			apply(container)
+			wg.Done()
+		}(cont)
+	}
+
+	wg.Wait()
+}
+
+func (c *memoryStore) all() []*Container {
+	c.RLock()
+	containers := make([]*Container, 0, len(c.s))
+	for _, cont := range c.s {
+		containers = append(containers, cont)
+	}
+	c.RUnlock()
+	return containers
+}
+
+var _ Store = &memoryStore{}