+// Remove all expired session cache entries, then remove more entries
+// until approximate remaining size <= maxsize/2
+func (c *cache) pruneSessions() {
+ now := time.Now()
+ var size int64
+ keys := c.sessions.Keys()
+ for _, token := range keys {
+ ent, ok := c.sessions.Peek(token)
+ if !ok {
+ continue
+ }
+ s := ent.(*cachedSession)
+ if s.expire.Before(now) {
+ c.sessions.Remove(token)
+ continue
+ }
+ if fs, ok := s.fs.Load().(arvados.CustomFileSystem); ok {
+ size += fs.MemorySize()
+ }
+ }
+ // Remove tokens until reaching size limit, starting with the
+ // least frequently used entries (which Keys() returns last).
+ for i := len(keys) - 1; i >= 0; i-- {
+ token := keys[i]
+ if size <= c.cluster.Collections.WebDAVCache.MaxCollectionBytes/2 {
+ break
+ }
+ ent, ok := c.sessions.Peek(token)
+ if !ok {
+ continue
+ }
+ s := ent.(*cachedSession)
+ fs, _ := s.fs.Load().(arvados.CustomFileSystem)
+ if fs == nil {
+ continue
+ }
+ c.sessions.Remove(token)
+ size -= fs.MemorySize()
+ }
+}
+
+func (c *cache) Get(arv *arvadosclient.ArvadosClient, targetID string, forceReload bool) (*arvados.Collection, error) {
+ c.setupOnce.Do(c.setup)
+ c.metrics.requests.Inc()
+
+ var pdhRefresh bool