PinContext.pseudo.go

// PinStore implements storage abstractions for user pinned content.
type PinningStore struct {
  s Store // Store can also implement MetaStore. In boltdb this is possible through using alternate buckets
  m MetaStore
}

type Store interface {
  Get(swarm.Address) swarm.Chunk
  Put(swarm.Chunk)
  Iterate(IterFn) error
  Delete(swarm.Address)
  Count() int
}

type MetaStore interface {
  Get(k []byte) []byte
  Put(k []byte, v []byte)
  Iterate(IterFn)
  Delete(k []byte)
}

// PinStore implements an ubiquitous Get method that
// can blindly check all buckets for a chunk address.
// This allows the PinStore to act as an aggregate for
// chunk lookups.
func (p PinStore) Get(swarm.Address) swarm.Chunk {
  buckets :=  p.m.Get(bucketsKey) //buckets store the pin bucket name for all pins
  for _,b := range buckets{
    if ch := u.s.Get(addr); ch != nil {
      return ch
    }
  }
  return nil
}


// NewContext returns a new pinning context.
func (p PinStore) NewContext() (GetterPutter,string) {
  buckets :=  p.m.Get(bucketsKey) //buckets store the pin bucket name for all pins
  bucket := p.newContext()
  buckets = append(buckets, bucket))

  return p.s.PrefixStore(bucket),bucket // boltdb simple store needs to support writes which are prefixed by a bucket name
}

// Context returns a GetterPutter that can write chunks
// into a bucket. It requires that pinId exists as a
// pinning context.
func (p PinStore) Context(pinId string) GetterPutter {
  buckets :=  p.m.Get(bucketsKey) //buckets store the pin bucket name for all pins
  return p.s.PrefixStore(buckets[pinId]) // boltdb simple store needs to support writes which are prefixed by a bucket name
}

func (p PinStore) Unpin(pinId string) {
  buckets :=  p.m.Get(bucketsKey) //buckets store the pin bucket name for all pins
  p.destroy(buckets[pinId])
}

func (p PinStore) destroy(key string) {
  return p.s.DeleteBucket(key)
}