Mainflux.mainflux/things/things.go

102 lines
3.4 KiB
Go

// Copyright (c) Mainflux
// SPDX-License-Identifier: Apache-2.0
package things
import (
"context"
"github.com/mainflux/mainflux/pkg/errors"
)
var (
// ErrMalformedEntity indicates malformed entity specification (e.g.
// invalid username or password).
ErrMalformedEntity = errors.New("malformed entity specification")
// ErrNotFound indicates a non-existent entity request.
ErrNotFound = errors.New("non-existent entity")
// ErrConflict indicates that entity already exists.
ErrConflict = errors.New("entity already exists")
// ErrScanMetadata indicates problem with metadata in db
ErrScanMetadata = errors.New("failed to scan metadata in db")
// ErrSelectEntity indicates error while reading entity from database
ErrSelectEntity = errors.New("select entity from db error")
// ErrEntityConnected indicates error while checking connection in database
ErrEntityConnected = errors.New("check thing-channel connection in database error")
)
// Metadata to be used for mainflux thing or channel for customized
// describing of particular thing or channel.
type Metadata map[string]interface{}
// Thing represents a Mainflux thing. Each thing is owned by one user, and
// it is assigned with the unique identifier and (temporary) access key.
type Thing struct {
ID string
Owner string
Name string
Key string
Metadata Metadata
}
// Page contains page related metadata as well as list of things that
// belong to this page.
type Page struct {
PageMetadata
Things []Thing
}
// ThingRepository specifies a thing persistence API.
type ThingRepository interface {
// Save persists multiple things. Things are saved using a transaction. If one thing
// fails then none will be saved. Successful operation is indicated by non-nil
// error response.
Save(ctx context.Context, ths ...Thing) ([]Thing, error)
// Update performs an update to the existing thing. A non-nil error is
// returned to indicate operation failure.
Update(ctx context.Context, t Thing) error
// UpdateKey updates key value of the existing thing. A non-nil error is
// returned to indicate operation failure.
UpdateKey(ctx context.Context, owner, id, key string) error
// RetrieveByID retrieves the thing having the provided identifier, that is owned
// by the specified user.
RetrieveByID(ctx context.Context, owner, id string) (Thing, error)
// RetrieveByKey returns thing ID for given thing key.
RetrieveByKey(ctx context.Context, key string) (string, error)
// RetrieveAll retrieves the subset of things owned by the specified user
RetrieveAll(ctx context.Context, owner string, pm PageMetadata) (Page, error)
// RetrieveByIDs retrieves the subset of things specified by given thing ids.
RetrieveByIDs(ctx context.Context, thingIDs []string, pm PageMetadata) (Page, error)
// RetrieveByChannel retrieves the subset of things owned by the specified
// user and connected or not connected to specified channel.
RetrieveByChannel(ctx context.Context, owner, chID string, pm PageMetadata) (Page, error)
// Remove removes the thing having the provided identifier, that is owned
// by the specified user.
Remove(ctx context.Context, owner, id string) error
}
// ThingCache contains thing caching interface.
type ThingCache interface {
// Save stores pair thing key, thing id.
Save(context.Context, string, string) error
// ID returns thing ID for given key.
ID(context.Context, string) (string, error)
// Removes thing from cache.
Remove(context.Context, string) error
}