machine/go/machine/store/store.go

// Package store is for storing and retrieving machine.Descriptions.
package store

import (
	"context"

	"go.skia.org/infra/machine/go/machine"
)

// UpdateCallback is the callback that Store.Update() takes to update a single
// machine.Description. We use a callback because we want to compare the old
// state to decide the new state, along with other bits of info we can include
// in a closure, such as an incoming event. See also processor.Process.
type UpdateCallback func(machine.Description) machine.Description

// Store and retrieve machine.Descriptions.
type Store interface {
	// Update the machine with the given machineID using the given callback
	// function.
	//
	// updateCallback may be called more than once (e.g. transaction retries).
	Update(ctx context.Context, machineID string, updateCallback UpdateCallback) error

	// Get returns the Description for the given machine.
	Get(ctx context.Context, machineID string) (machine.Description, error)

	// ListPowerCycle returns a list of machine names that need powercycling.
	ListPowerCycle(ctx context.Context) ([]string, error)

	// List returns a slice containing all known machines.
	List(ctx context.Context) ([]machine.Description, error)

	// Delete removes a machine from the database.
	Delete(ctx context.Context, machineID string) error

	// Get a list of Kingsford machines that aren't running tasks.
	GetFreeMachines(ctx context.Context, pool string) ([]machine.Description, error)
}