morm

type Counter struct {
	ID    []byte `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
	Count int64  `protobuf:"varint,2,opt,name=count,proto3" json:"count,omitempty"`
}

type Model interface {
	weave.Persistent
	Validate() error
	Copy() orm.CloneableData
	GetID() []byte
	SetID([]byte) error
}

type ModelBucket interface {
	// One query the database for a single model instance. Lookup is done
	// by the primary index key. Result is loaded into given destination
	// model.
	// This method returns ErrNotFound if the entity does not exist in the
	// database.
	// If given model type cannot be used to contain stored entity, ErrType
	// is returned.
	One(db weave.ReadOnlyKVStore, key []byte, dest Model) error

	// PrefixScan will scan for all models with a primary key (ID)
	// that begins with the given prefix.
	// The function returns a (possibly empty) iterator, which can
	// load each model as it arrives.
	// If reverse is true, iterates in descending order (highest value first),
	// otherwise, it iterates in
	PrefixScan(db weave.ReadOnlyKVStore, prefix []byte, reverse bool) (ModelIterator, error)

	// ByIndex returns all objects that secondary index with given name and
	// given key. Main index is always unique but secondary indexes can
	// return more than one value for the same key.
	// All matching entities are appended to given destination slice. If no
	// result was found, no error is returned and destination slice is not
	// modified.
	ByIndex(db weave.ReadOnlyKVStore, indexName string, key []byte, dest ModelSlicePtr) error

	// IndexScan does a PrefixScan, but on the named index. This would let us eg. load all counters
	// in order of their count. Or easily find the lowest or highest count.
	IndexScan(db weave.ReadOnlyKVStore, indexName string, prefix []byte, reverse bool) (ModelIterator, error)

	// Put saves given model in the database. Before inserting into
	// database, model is validated using its Validate method.
	// If the key is nil or zero length then a sequence generator is used
	// to create a unique key value.
	// Using a key that already exists in the database cause the value to
	// be overwritten.
	Put(db weave.KVStore, m Model) error

	// Delete removes an entity with given primary key from the database.
	// It returns ErrNotFound if an entity with given key does not exist.
	Delete(db weave.KVStore, key []byte) error

	// Has returns nil if an entity with given primary key value exists. It
	// returns ErrNotFound if no entity can be found.
	// Has is a cheap operation that that does not read the data and only
	// checks the existence of it.
	Has(db weave.KVStore, key []byte) error

	// Register registers this buckets content to be accessible via query
	// requests under the given name.
	Register(name string, r weave.QueryRouter)
}

type ModelBucketOption func(mb *modelBucket)

type ModelIterator interface {
	// LoadNext moves the iterator to the next sequntial key in the database and
	// loads the current value at the given key into the passed destination.
	LoadNext(dest Model) error

	// Release releases the Iterator.
	Release()
}

type ModelSlicePtr interface{}