Slight refactor; add creds cache worker

* Split the main function into a couple of more functions
* Add credentials, entity, pool and scaleset cache
* add credentials worker that updates the cache

Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>

cache/entity_cache.go

@@ -0,0 +1,189 @@
+package cache
+
+import (
+	"sync"
+
+	"github.com/cloudbase/garm/params"
+)
+
+var entityCache *EntityCache
+
+func init() {
+	ghEntityCache := &EntityCache{
+		entities: make(map[string]EntityItem),
+	}
+	entityCache = ghEntityCache
+}
+
+type EntityItem struct {
+	Entity    params.GithubEntity
+	Pools     map[string]params.Pool
+	ScaleSets map[uint]params.ScaleSet
+}
+
+type EntityCache struct {
+	mux sync.Mutex
+	// entity IDs are UUID4s. It is highly unlikely they will collide (🤞).
+	entities map[string]EntityItem
+}
+
+func (e *EntityCache) GetEntity(entity params.GithubEntity) (EntityItem, bool) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entity.ID]; ok {
+		// Updating specific credential details will not update entity cache which
+		// uses those credentials.
+		// Entity credentials in the cache are only updated if you swap the creds
+		// on the entity. We get the updated credentials from the credentials cache.
+		creds, ok := GetGithubCredentials(cache.Entity.Credentials.ID)
+		if ok {
+			cache.Entity.Credentials = creds
+		}
+		return cache, true
+	}
+	return EntityItem{}, false
+}
+
+func (e *EntityCache) SetEntity(entity params.GithubEntity) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	e.entities[entity.ID] = EntityItem{
+		Entity: entity,
+	}
+}
+
+func (e *EntityCache) ReplaceEntityPools(entityID string, pools map[string]params.Pool) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		cache.Pools = pools
+		e.entities[entityID] = cache
+	}
+}
+
+func (e *EntityCache) ReplaceEntityScaleSets(entityID string, scaleSets map[uint]params.ScaleSet) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		cache.ScaleSets = scaleSets
+		e.entities[entityID] = cache
+	}
+}
+
+func (e *EntityCache) DeleteEntity(entityID string) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+	delete(e.entities, entityID)
+}
+
+func (e *EntityCache) SetEntityPool(entityID string, pool params.Pool) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		cache.Pools[pool.ID] = pool
+		e.entities[entityID] = cache
+	}
+}
+
+func (e *EntityCache) SetEntityScaleSet(entityID string, scaleSet params.ScaleSet) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		cache.ScaleSets[scaleSet.ID] = scaleSet
+		e.entities[entityID] = cache
+	}
+}
+
+func (e *EntityCache) DeleteEntityPool(entityID string, poolID string) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		delete(cache.Pools, poolID)
+		e.entities[entityID] = cache
+	}
+}
+
+func (e *EntityCache) DeleteEntityScaleSet(entityID string, scaleSetID uint) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		delete(cache.ScaleSets, scaleSetID)
+		e.entities[entityID] = cache
+	}
+}
+
+func (e *EntityCache) GetEntityPool(entityID string, poolID string) (params.Pool, bool) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		if pool, ok := cache.Pools[poolID]; ok {
+			return pool, true
+		}
+	}
+	return params.Pool{}, false
+}
+
+func (e *EntityCache) GetEntityScaleSet(entityID string, scaleSetID uint) (params.ScaleSet, bool) {
+	e.mux.Lock()
+	defer e.mux.Unlock()
+
+	if cache, ok := e.entities[entityID]; ok {
+		if scaleSet, ok := cache.ScaleSets[scaleSetID]; ok {
+			return scaleSet, true
+		}
+	}
+	return params.ScaleSet{}, false
+}
+
+func GetEntity(entity params.GithubEntity) (EntityItem, bool) {
+	return entityCache.GetEntity(entity)
+}
+
+func SetEntity(entity params.GithubEntity) {
+	entityCache.SetEntity(entity)
+}
+
+func ReplaceEntityPools(entityID string, pools map[string]params.Pool) {
+	entityCache.ReplaceEntityPools(entityID, pools)
+}
+
+func ReplaceEntityScaleSets(entityID string, scaleSets map[uint]params.ScaleSet) {
+	entityCache.ReplaceEntityScaleSets(entityID, scaleSets)
+}
+
+func DeleteEntity(entityID string) {
+	entityCache.DeleteEntity(entityID)
+}
+
+func SetEntityPool(entityID string, pool params.Pool) {
+	entityCache.SetEntityPool(entityID, pool)
+}
+
+func SetEntityScaleSet(entityID string, scaleSet params.ScaleSet) {
+	entityCache.SetEntityScaleSet(entityID, scaleSet)
+}
+
+func DeleteEntityPool(entityID string, poolID string) {
+	entityCache.DeleteEntityPool(entityID, poolID)
+}
+
+func DeleteEntityScaleSet(entityID string, scaleSetID uint) {
+	entityCache.DeleteEntityScaleSet(entityID, scaleSetID)
+}
+
+func GetEntityPool(entityID string, poolID string) (params.Pool, bool) {
+	return entityCache.GetEntityPool(entityID, poolID)
+}
+
+func GetEntityScaleSet(entityID string, scaleSetID uint) (params.ScaleSet, bool) {
+	return entityCache.GetEntityScaleSet(entityID, scaleSetID)
+}