Move role middleware and cache logic into a manager

middleware/roles.go

@@ -1,66 +0,0 @@
-package middleware
-
-import (
-	"context"
-	"encoding/json"
-	"net/http"
-
-	"github.com/micro/go-micro/v2/metadata"
-	"github.com/owncloud/ocis-pkg/v2/log"
-	"github.com/owncloud/ocis-pkg/v2/roles"
-	settings "github.com/owncloud/ocis-settings/pkg/proto/v0"
-)
-
-// Roles manages a roles.Cache by fetching and inserting roles unknown by the cache.
-// Relevant roleIDs are extracted from the metadata context, i.e. the roleIDs of the authenticated user.
-func Roles(log log.Logger, rs settings.RoleService, cache *roles.Cache) func(next http.Handler) http.Handler {
-	return func(next http.Handler) http.Handler {
-		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			// get roleIDs from context
-			roleIDs, ok := ReadRoleIDsFromContext(r.Context())
-			if !ok {
-				log.Debug().Msg("failed to read roleIDs from context")
-				next.ServeHTTP(w, r)
-				return
-			}
-
-			// check which roles are not cached, yet
-			lookup := make([]string, 0)
-			for _, roleID := range roleIDs {
-				if hit := cache.Get(roleID); hit == nil {
-					lookup = append(lookup, roleID)
-				}
-			}
-
-			// fetch roles
-			if len(lookup) > 0 {
-				request := &settings.ListBundlesRequest{
-					BundleIds: lookup,
-				}
-				res, err := rs.ListRoles(r.Context(), request)
-				if err != nil {
-					log.Debug().Err(err).Msg("failed to fetch roles by roleIDs")
-					next.ServeHTTP(w, r)
-					return
-				}
-				for _, role := range res.Bundles {
-					cache.Set(role.Id, role)
-				}
-			}
-			next.ServeHTTP(w, r)
-		})
-	}
-}
-
-// ReadRoleIDsFromContext extracts roleIDs from the metadata context and returns them as []string
-func ReadRoleIDsFromContext(ctx context.Context) (roleIDs []string, ok bool) {
-	roleIDsJSON, ok := metadata.Get(ctx, RoleIDs)
-	if !ok {
-		return nil, false
-	}
-	err := json.Unmarshal([]byte(roleIDsJSON), &roleIDs)
-	if err != nil {
-		return nil, false
-	}
-	return roleIDs, true
-}

roles/cache.go

@@ -13,27 +13,25 @@ type entry struct {
 	inserted time.Time
 }
 
-// Cache is a cache implementation for roles, keyed by roleIDs.
-type Cache struct {
+// cache is a cache implementation for roles, keyed by roleIDs.
+type cache struct {
 	entries map[string]entry
 	size    int
 	ttl     time.Duration
 	m       sync.Mutex
 }
 
-// NewCache returns a new instance of Cache.
-func NewCache(o ...Option) Cache {
-	opts := newOptions(o...)
-
-	return Cache{
-		size:    opts.size,
-		ttl:	 opts.ttl,
+// newCache returns a new instance of Cache.
+func newCache(size int, ttl time.Duration) cache {
+	return cache{
+		size:    size,
+		ttl:     ttl,
 		entries: map[string]entry{},
 	}
 }
 
-// Get gets a role-bundle by a given `roleID`.
-func (c *Cache) Get(roleID string) *settings.Bundle {
+// get gets a role-bundle by a given `roleID`.
+func (c *cache) get(roleID string) *settings.Bundle {
 	c.m.Lock()
 	defer c.m.Unlock()
 
@@ -43,23 +41,8 @@ func (c *Cache) Get(roleID string) *settings.Bundle {
 	return nil
 }
 
-// FindPermissionByID searches for a permission-setting by the permissionID, but limited to the given roleIDs
-func (c *Cache) FindPermissionByID(roleIDs []string, permissionID string) *settings.Setting {
-	for _, roleID := range roleIDs {
-		role := c.Get(roleID)
-		if role != nil {
-			for _, setting := range role.Settings {
-				if setting.Id == permissionID {
-					return setting
-				}
-			}
-		}
-	}
-	return nil
-}
-
-// Set sets a roleID / role-bundle.
-func (c *Cache) Set(roleID string, value *settings.Bundle) {
+// set sets a roleID / role-bundle.
+func (c *cache) set(roleID string, value *settings.Bundle) {
 	c.m.Lock()
 	defer c.m.Unlock()
 
@@ -73,8 +56,8 @@ func (c *Cache) Set(roleID string, value *settings.Bundle) {
 	}
 }
 
-// Evict frees memory from the cache by removing entries that exceeded the cache TTL.
-func (c *Cache) evict() {
+// evict frees memory from the cache by removing entries that exceeded the cache TTL.
+func (c *cache) evict() {
 	for i := range c.entries {
 		if c.entries[i].inserted.Add(c.ttl).Before(time.Now()) {
 			delete(c.entries, i)
@@ -82,12 +65,7 @@ func (c *Cache) evict() {
 	}
 }
 
-// Length returns the amount of entries.
-func (c *Cache) Length() int {
-	return len(c.entries)
-}
-
-// fits returns whether the cache is at full capacity.
-func (c *Cache) fits() bool {
+// fits returns whether the cache fits more entries.
+func (c *cache) fits() bool {
 	return c.size > len(c.entries)
 }

roles/manager.go

@@ -0,0 +1,67 @@
+package roles
+
+import (
+	"context"
+
+	"github.com/owncloud/ocis-pkg/v2/log"
+	settings "github.com/owncloud/ocis-settings/pkg/proto/v0"
+)
+
+type Manager struct {
+	logger      log.Logger
+	cache       cache
+	roleService settings.RoleService
+}
+
+func NewManager(o ...Option) Manager {
+	opts := newOptions(o...)
+
+	return Manager{
+		cache:       newCache(opts.size, opts.ttl),
+		roleService: opts.roleService,
+	}
+}
+
+// List returns all roles that match the given roleIDs.
+func (m *Manager) List(ctx context.Context, roleIDs []string) []*settings.Bundle {
+	// get from cache
+	result := make([]*settings.Bundle, 0)
+	lookup := make([]string, 0)
+	for _, roleID := range roleIDs {
+		if hit := m.cache.get(roleID); hit == nil {
+			lookup = append(lookup, roleID)
+		} else {
+			result = append(result, hit)
+		}
+	}
+
+	// if there are roles missing, fetch them from the RoleService
+	if len(lookup) > 0 {
+		request := &settings.ListBundlesRequest{
+			BundleIds: lookup,
+		}
+		res, err := m.roleService.ListRoles(ctx, request)
+		if err != nil {
+			m.logger.Debug().Err(err).Msg("failed to fetch roles by roleIDs")
+		}
+		for _, role := range res.Bundles {
+			m.cache.set(role.Id, role)
+			result = append(result, role)
+		}
+	}
+
+	return result
+}
+
+// FindPermissionByID searches for a permission-setting by the permissionID, but limited to the given roleIDs
+func (m *Manager) FindPermissionByID(ctx context.Context, roleIDs []string, permissionID string) *settings.Setting {
+	for _, role := range m.List(ctx, roleIDs) {
+		for _, setting := range role.Settings {
+			if setting.Id == permissionID {
+				return setting
+			}
+		}
+	}
+	return nil
+}
+

roles/option.go

@@ -2,31 +2,50 @@ package roles
 
 import (
 	"time"
+
+	"github.com/owncloud/ocis-pkg/v2/log"
+	settings "github.com/owncloud/ocis-settings/pkg/proto/v0"
 )
 
 // Options are all the possible options.
 type Options struct {
-	size int
-	ttl  time.Duration
+	size        int
+	ttl         time.Duration
+	logger      log.Logger
+	roleService settings.RoleService
 }
 
 // Option mutates option
 type Option func(*Options)
 
-// Size configures the size of the cache in items.
-func Size(s int) Option {
+// CacheSize configures the size of the cache in items.
+func CacheSize(s int) Option {
 	return func(o *Options) {
 		o.size = s
 	}
 }
 
-// TTL rebuilds the cache after the configured duration.
-func TTL(ttl time.Duration) Option {
+// CacheTTL rebuilds the cache after the configured duration.
+func CacheTTL(ttl time.Duration) Option {
 	return func(o *Options) {
 		o.ttl = ttl
 	}
 }
 
+// Logger sets a preconfigured logger
+func Logger(logger log.Logger) Option {
+	return func(o *Options) {
+		o.logger = logger
+	}
+}
+
+// RoleService provides endpoints for fetching roles.
+func RoleService(rs settings.RoleService) Option {
+	return func(o *Options) {
+		o.roleService = rs
+	}
+}
+
 func newOptions(opts ...Option) Options {
 	o := Options{}
 

roles/util.go

@@ -0,0 +1,22 @@
+package roles
+
+import (
+	"context"
+	"encoding/json"
+
+	"github.com/micro/go-micro/v2/metadata"
+	"github.com/owncloud/ocis-pkg/v2/middleware"
+)
+
+// ReadRoleIDsFromContext extracts roleIDs from the metadata context and returns them as []string
+func ReadRoleIDsFromContext(ctx context.Context) (roleIDs []string, ok bool) {
+	roleIDsJSON, ok := metadata.Get(ctx, middleware.RoleIDs)
+	if !ok {
+		return nil, false
+	}
+	err := json.Unmarshal([]byte(roleIDsJSON), &roleIDs)
+	if err != nil {
+		return nil, false
+	}
+	return roleIDs, true
+}