librarian

type Addr ¶

type Addr string

Addr is an address (or key) in the index. TODO maybe not use a string but a Stringer or interface{ Addr() string }?

type Index ¶

type Index interface {
	// Get returns the an observable of the value stored at the address.
	// Getting an unset value retuns a valid Observable with a value
	// of type Unset and a nil error.
	Get(context.Context, Addr) (luigi.Observable, error)
}

Index provides an index table keyed by Addr. Often also implements Setter.

type SeqSetterIndex ¶

type SeqSetterIndex interface {
	SetterIndex

	SetSeq(margaret.Seq) error
	GetSeq() (margaret.Seq, error)

	io.Closer
}

type Setter ¶

type Setter interface {
	// Set sets a value in the index
	Set(context.Context, Addr, interface{}) error

	// Delete deletes a value from the index
	Delete(context.Context, Addr) error
}

type SetterIndex ¶

type SetterIndex interface {
	Index
	Setter

	Flush() error
}

SetterIndex is an index that can be updated using calls to Set and Delete.

type SinkIndex ¶

type SinkIndex interface {
	luigi.Sink

	QuerySpec() margaret.QuerySpec
}

SinkIndex is an index that is updated by processing a stream.

func NewSinkIndex(f StreamProcFunc, idx SeqSetterIndex) SinkIndex

type StreamProcFunc ¶

type StreamProcFunc func(context.Context, margaret.Seq, interface{}, SetterIndex) error

type UnsetValue ¶

type UnsetValue struct {
	Addr Addr
}

UnsetValue is the value of observable returned by idx.Get() when the requested address has not been set yet.