gotosocial/internal/processing/processor.go

/*
   GoToSocial
   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU Affero General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

package processing

import (
	"context"
	"net/http"
	"net/url"
	"time"

	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
	"github.com/superseriousbusiness/gotosocial/internal/concurrency"
	"github.com/superseriousbusiness/gotosocial/internal/db"
	"github.com/superseriousbusiness/gotosocial/internal/email"
	"github.com/superseriousbusiness/gotosocial/internal/federation"
	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
	"github.com/superseriousbusiness/gotosocial/internal/media"
	"github.com/superseriousbusiness/gotosocial/internal/messages"
	"github.com/superseriousbusiness/gotosocial/internal/oauth"
	"github.com/superseriousbusiness/gotosocial/internal/processing/account"
	"github.com/superseriousbusiness/gotosocial/internal/processing/admin"
	federationProcessor "github.com/superseriousbusiness/gotosocial/internal/processing/federation"
	mediaProcessor "github.com/superseriousbusiness/gotosocial/internal/processing/media"
	"github.com/superseriousbusiness/gotosocial/internal/processing/status"
	"github.com/superseriousbusiness/gotosocial/internal/processing/streaming"
	"github.com/superseriousbusiness/gotosocial/internal/processing/user"
	"github.com/superseriousbusiness/gotosocial/internal/storage"
	"github.com/superseriousbusiness/gotosocial/internal/stream"
	"github.com/superseriousbusiness/gotosocial/internal/timeline"
	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
	"github.com/superseriousbusiness/gotosocial/internal/visibility"
)

// Processor should be passed to api modules (see internal/apimodule/...). It is used for
// passing messages back and forth from the client API and the federating interface, via channels.
// It also contains logic for filtering which messages should end up where.
// It is designed to be used asynchronously: the client API and the federating API should just be able to
// fire messages into the processor and not wait for a reply before proceeding with other work. This allows
// for clean distribution of messages without slowing down the client API and harming the user experience.
type Processor interface {
	// Start starts the Processor, reading from its channels and passing messages back and forth.
	Start() error
	// Stop stops the processor cleanly, finishing handling any remaining messages before closing down.
	Stop() error
	// ProcessFromClientAPI processes one message coming from the clientAPI channel, and triggers appropriate side effects.
	ProcessFromClientAPI(ctx context.Context, clientMsg messages.FromClientAPI) error
	// ProcessFromFederator processes one message coming from the federator channel, and triggers appropriate side effects.
	ProcessFromFederator(ctx context.Context, federatorMsg messages.FromFederator) error

	/*
		CLIENT API-FACING PROCESSING FUNCTIONS
		These functions are intended to be called when the API client needs an immediate (ie., synchronous) reply
		to an HTTP request. As such, they will only do the bare-minimum of work necessary to give a properly
		formed reply. For more intensive (and time-consuming) calls, where you don't require an immediate
		response, pass work to the processor using a channel instead.
	*/

	// AccountCreate processes the given form for creating a new account, returning an oauth token for that account if successful.
	AccountCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.AccountCreateRequest) (*apimodel.Token, gtserror.WithCode)
	// AccountDeleteLocal processes the delete of a LOCAL account using the given form.
	AccountDeleteLocal(ctx context.Context, authed *oauth.Auth, form *apimodel.AccountDeleteRequest) gtserror.WithCode
	// AccountGet processes the given request for account information.
	AccountGet(ctx context.Context, authed *oauth.Auth, targetAccountID string) (*apimodel.Account, gtserror.WithCode)
	// AccountGet processes the given request for account information.
	AccountGetLocalByUsername(ctx context.Context, authed *oauth.Auth, username string) (*apimodel.Account, gtserror.WithCode)
	AccountGetCustomCSSForUsername(ctx context.Context, username string) (string, gtserror.WithCode)
	// AccountGetRSSFeedForUsername returns a function to get the RSS feed of latest posts for given local account username.
	// This function should only be called if necessary: the given lastModified time can be used to check this.
	// Will return 404 if an rss feed for that user is not available, or a different error if something else goes wrong.
	AccountGetRSSFeedForUsername(ctx context.Context, username string) (func() (string, gtserror.WithCode), time.Time, gtserror.WithCode)
	// AccountUpdate processes the update of an account with the given form
	AccountUpdate(ctx context.Context, authed *oauth.Auth, form *apimodel.UpdateCredentialsRequest) (*apimodel.Account, gtserror.WithCode)
	// AccountStatusesGet fetches a number of statuses (in time descending order) from the given account, filtered by visibility for
	// the account given in authed.
	AccountStatusesGet(ctx context.Context, authed *oauth.Auth, targetAccountID string, limit int, excludeReplies bool, excludeReblogs bool, maxID string, minID string, pinned bool, mediaOnly bool, publicOnly bool) (*apimodel.PageableResponse, gtserror.WithCode)
	// AccountWebStatusesGet fetches a number of statuses (in descending order) from the given account. It selects only
	// statuses which are suitable for showing on the public web profile of an account.
	AccountWebStatusesGet(ctx context.Context, targetAccountID string, maxID string) (*apimodel.PageableResponse, gtserror.WithCode)
	// AccountFollowersGet fetches a list of the target account's followers.
	AccountFollowersGet(ctx context.Context, authed *oauth.Auth, targetAccountID string) ([]apimodel.Account, gtserror.WithCode)
	// AccountFollowingGet fetches a list of the accounts that target account is following.
	AccountFollowingGet(ctx context.Context, authed *oauth.Auth, targetAccountID string) ([]apimodel.Account, gtserror.WithCode)
	// AccountRelationshipGet returns a relationship model describing the relationship of the targetAccount to the Authed account.
	AccountRelationshipGet(ctx context.Context, authed *oauth.Auth, targetAccountID string) (*apimodel.Relationship, gtserror.WithCode)
	// AccountFollowCreate handles a follow request to an account, either remote or local.
	AccountFollowCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.AccountFollowRequest) (*apimodel.Relationship, gtserror.WithCode)
	// AccountFollowRemove handles the removal of a follow/follow request to an account, either remote or local.
	AccountFollowRemove(ctx context.Context, authed *oauth.Auth, targetAccountID string) (*apimodel.Relationship, gtserror.WithCode)
	// AccountBlockCreate handles the creation of a block from authed account to target account, either remote or local.
	AccountBlockCreate(ctx context.Context, authed *oauth.Auth, targetAccountID string) (*apimodel.Relationship, gtserror.WithCode)
	// AccountBlockRemove handles the removal of a block from authed account to target account, either remote or local.
	AccountBlockRemove(ctx context.Context, authed *oauth.Auth, targetAccountID string) (*apimodel.Relationship, gtserror.WithCode)

	// AdminAccountAction handles the creation/execution of an action on an account.
	AdminAccountAction(ctx context.Context, authed *oauth.Auth, form *apimodel.AdminAccountActionRequest) gtserror.WithCode
	// AdminEmojiCreate handles the creation of a new instance emoji by an admin, using the given form.
	AdminEmojiCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.EmojiCreateRequest) (*apimodel.Emoji, gtserror.WithCode)
	// AdminEmojisGet allows admins to view emojis based on various filters.
	AdminEmojisGet(ctx context.Context, authed *oauth.Auth, domain string, includeDisabled bool, includeEnabled bool, shortcode string, maxShortcodeDomain string, minShortcodeDomain string, limit int) (*apimodel.PageableResponse, gtserror.WithCode)
	// AdminEmojiGet returns the admin view of an emoji with the given ID
	AdminEmojiGet(ctx context.Context, authed *oauth.Auth, id string) (*apimodel.AdminEmoji, gtserror.WithCode)
	// AdminEmojiDelete deletes one *local* emoji with the given key. Remote emojis will not be deleted this way.
	// Only admin users in good standing should be allowed to access this function -- check this before calling it.
	AdminEmojiDelete(ctx context.Context, authed *oauth.Auth, id string) (*apimodel.AdminEmoji, gtserror.WithCode)
	// AdminEmojiCategoriesGet gets a list of all existing emoji categories.
	AdminEmojiCategoriesGet(ctx context.Context) ([]*apimodel.EmojiCategory, gtserror.WithCode)
	// AdminDomainBlockCreate handles the creation of a new domain block by an admin, using the given form.
	AdminDomainBlockCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.DomainBlockCreateRequest) (*apimodel.DomainBlock, gtserror.WithCode)
	// AdminDomainBlocksImport handles the import of multiple domain blocks by an admin, using the given form.
	AdminDomainBlocksImport(ctx context.Context, authed *oauth.Auth, form *apimodel.DomainBlockCreateRequest) ([]*apimodel.DomainBlock, gtserror.WithCode)
	// AdminDomainBlocksGet returns a list of currently blocked domains.
	AdminDomainBlocksGet(ctx context.Context, authed *oauth.Auth, export bool) ([]*apimodel.DomainBlock, gtserror.WithCode)
	// AdminDomainBlockGet returns one domain block, specified by ID.
	AdminDomainBlockGet(ctx context.Context, authed *oauth.Auth, id string, export bool) (*apimodel.DomainBlock, gtserror.WithCode)
	// AdminDomainBlockDelete deletes one domain block, specified by ID, returning the deleted domain block.
	AdminDomainBlockDelete(ctx context.Context, authed *oauth.Auth, id string) (*apimodel.DomainBlock, gtserror.WithCode)
	// AdminMediaRemotePrune triggers a prune of remote media according to the given number of mediaRemoteCacheDays
	AdminMediaPrune(ctx context.Context, mediaRemoteCacheDays int) gtserror.WithCode

	// AppCreate processes the creation of a new API application
	AppCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.ApplicationCreateRequest) (*apimodel.Application, gtserror.WithCode)

	// BlocksGet returns a list of accounts blocked by the requesting account.
	BlocksGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, limit int) (*apimodel.BlocksResponse, gtserror.WithCode)

	// CustomEmojisGet returns an array of info about the custom emojis on this server
	CustomEmojisGet(ctx context.Context) ([]*apimodel.Emoji, gtserror.WithCode)

	// FileGet handles the fetching of a media attachment file via the fileserver.
	FileGet(ctx context.Context, authed *oauth.Auth, form *apimodel.GetContentRequestForm) (*apimodel.Content, gtserror.WithCode)

	// FollowRequestsGet handles the getting of the authed account's incoming follow requests
	FollowRequestsGet(ctx context.Context, auth *oauth.Auth) ([]apimodel.Account, gtserror.WithCode)
	// FollowRequestAccept handles the acceptance of a follow request from the given account ID.
	FollowRequestAccept(ctx context.Context, auth *oauth.Auth, accountID string) (*apimodel.Relationship, gtserror.WithCode)
	// FollowRequestReject handles the rejection of a follow request from the given account ID.
	FollowRequestReject(ctx context.Context, auth *oauth.Auth, accountID string) (*apimodel.Relationship, gtserror.WithCode)

	// InstanceGet retrieves instance information for serving at api/v1/instance
	InstanceGet(ctx context.Context, domain string) (*apimodel.Instance, gtserror.WithCode)
	InstancePeersGet(ctx context.Context, authed *oauth.Auth, includeSuspended bool, includeOpen bool, flat bool) (interface{}, gtserror.WithCode)
	// InstancePatch updates this instance according to the given form.
	//
	// It should already be ascertained that the requesting account is authenticated and an admin.
	InstancePatch(ctx context.Context, form *apimodel.InstanceSettingsUpdateRequest) (*apimodel.Instance, gtserror.WithCode)

	// MediaCreate handles the creation of a media attachment, using the given form.
	MediaCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.AttachmentRequest) (*apimodel.Attachment, gtserror.WithCode)
	// MediaGet handles the GET of a media attachment with the given ID
	MediaGet(ctx context.Context, authed *oauth.Auth, attachmentID string) (*apimodel.Attachment, gtserror.WithCode)
	// MediaUpdate handles the PUT of a media attachment with the given ID and form
	MediaUpdate(ctx context.Context, authed *oauth.Auth, attachmentID string, form *apimodel.AttachmentUpdateRequest) (*apimodel.Attachment, gtserror.WithCode)

	// NotificationsGet
	NotificationsGet(ctx context.Context, authed *oauth.Auth, excludeTypes []string, limit int, maxID string, sinceID string) (*apimodel.PageableResponse, gtserror.WithCode)
	// NotificationsClear
	NotificationsClear(ctx context.Context, authed *oauth.Auth) gtserror.WithCode

	OAuthHandleTokenRequest(r *http.Request) (map[string]interface{}, gtserror.WithCode)
	OAuthHandleAuthorizeRequest(w http.ResponseWriter, r *http.Request) gtserror.WithCode

	// SearchGet performs a search with the given params, resolving/dereferencing remotely as desired
	SearchGet(ctx context.Context, authed *oauth.Auth, searchQuery *apimodel.SearchQuery) (*apimodel.SearchResult, gtserror.WithCode)

	// StatusCreate processes the given form to create a new status, returning the api model representation of that status if it's OK.
	StatusCreate(ctx context.Context, authed *oauth.Auth, form *apimodel.AdvancedStatusCreateForm) (*apimodel.Status, gtserror.WithCode)
	// StatusDelete processes the delete of a given status, returning the deleted status if the delete goes through.
	StatusDelete(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Status, gtserror.WithCode)
	// StatusFave processes the faving of a given status, returning the updated status if the fave goes through.
	StatusFave(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Status, gtserror.WithCode)
	// StatusBoost processes the boost/reblog of a given status, returning the newly-created boost if all is well.
	StatusBoost(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Status, gtserror.WithCode)
	// StatusUnboost processes the unboost/unreblog of a given status, returning the status if all is well.
	StatusUnboost(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Status, gtserror.WithCode)
	// StatusBoostedBy returns a slice of accounts that have boosted the given status, filtered according to privacy settings.
	StatusBoostedBy(ctx context.Context, authed *oauth.Auth, targetStatusID string) ([]*apimodel.Account, gtserror.WithCode)
	// StatusFavedBy returns a slice of accounts that have liked the given status, filtered according to privacy settings.
	StatusFavedBy(ctx context.Context, authed *oauth.Auth, targetStatusID string) ([]*apimodel.Account, gtserror.WithCode)
	// StatusGet gets the given status, taking account of privacy settings and blocks etc.
	StatusGet(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Status, gtserror.WithCode)
	// StatusUnfave processes the unfaving of a given status, returning the updated status if the fave goes through.
	StatusUnfave(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Status, gtserror.WithCode)
	// StatusGetContext returns the context (previous and following posts) from the given status ID
	StatusGetContext(ctx context.Context, authed *oauth.Auth, targetStatusID string) (*apimodel.Context, gtserror.WithCode)

	// HomeTimelineGet returns statuses from the home timeline, with the given filters/parameters.
	HomeTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.PageableResponse, gtserror.WithCode)
	// PublicTimelineGet returns statuses from the public/local timeline, with the given filters/parameters.
	PublicTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, sinceID string, minID string, limit int, local bool) (*apimodel.PageableResponse, gtserror.WithCode)
	// FavedTimelineGet returns faved statuses, with the given filters/parameters.
	FavedTimelineGet(ctx context.Context, authed *oauth.Auth, maxID string, minID string, limit int) (*apimodel.PageableResponse, gtserror.WithCode)

	// AuthorizeStreamingRequest returns a gotosocial account in exchange for an access token, or an error if the given token is not valid.
	AuthorizeStreamingRequest(ctx context.Context, accessToken string) (*gtsmodel.Account, gtserror.WithCode)
	// OpenStreamForAccount opens a new stream for the given account, with the given stream type.
	OpenStreamForAccount(ctx context.Context, account *gtsmodel.Account, streamType string) (*stream.Stream, gtserror.WithCode)

	// UserChangePassword changes the password for the given user, with the given form.
	UserChangePassword(ctx context.Context, authed *oauth.Auth, form *apimodel.PasswordChangeRequest) gtserror.WithCode
	// UserConfirmEmail confirms an email address using the given token.
	// The user belonging to the confirmed email is also returned.
	UserConfirmEmail(ctx context.Context, token string) (*gtsmodel.User, gtserror.WithCode)

	/*
		FEDERATION API-FACING PROCESSING FUNCTIONS
		These functions are intended to be called when the federating client needs an immediate (ie., synchronous) reply
		to an HTTP request. As such, they will only do the bare-minimum of work necessary to give a properly
		formed reply. For more intensive (and time-consuming) calls, where you don't require an immediate
		response, pass work to the processor using a channel instead.
	*/

	// GetFediUser handles the getting of a fedi/activitypub representation of a user/account, performing appropriate authentication
	// before returning a JSON serializable interface to the caller.
	GetFediUser(ctx context.Context, requestedUsername string, requestURL *url.URL) (interface{}, gtserror.WithCode)
	// GetFediFollowers handles the getting of a fedi/activitypub representation of a user/account's followers, performing appropriate
	// authentication before returning a JSON serializable interface to the caller.
	GetFediFollowers(ctx context.Context, requestedUsername string, requestURL *url.URL) (interface{}, gtserror.WithCode)
	// GetFediFollowing handles the getting of a fedi/activitypub representation of a user/account's following, performing appropriate
	// authentication before returning a JSON serializable interface to the caller.
	GetFediFollowing(ctx context.Context, requestedUsername string, requestURL *url.URL) (interface{}, gtserror.WithCode)
	// GetFediStatus handles the getting of a fedi/activitypub representation of a particular status, performing appropriate
	// authentication before returning a JSON serializable interface to the caller.
	GetFediStatus(ctx context.Context, requestedUsername string, requestedStatusID string, requestURL *url.URL) (interface{}, gtserror.WithCode)
	// GetFediStatus handles the getting of a fedi/activitypub representation of replies to a status, performing appropriate
	// authentication before returning a JSON serializable interface to the caller.
	GetFediStatusReplies(ctx context.Context, requestedUsername string, requestedStatusID string, page bool, onlyOtherAccounts bool, minID string, requestURL *url.URL) (interface{}, gtserror.WithCode)
	// GetFediOutbox returns the public outbox of the requested user, with the given parameters.
	GetFediOutbox(ctx context.Context, requestedUsername string, page bool, maxID string, minID string, requestURL *url.URL) (interface{}, gtserror.WithCode)
	// GetFediEmoji returns the AP representation of an emoji on this instance.
	GetFediEmoji(ctx context.Context, requestedEmojiID string, requestURL *url.URL) (interface{}, gtserror.WithCode)
	// GetWebfingerAccount handles the GET for a webfinger resource. Most commonly, it will be used for returning account lookups.
	GetWebfingerAccount(ctx context.Context, requestedUsername string) (*apimodel.WellKnownResponse, gtserror.WithCode)
	// GetNodeInfoRel returns a well known response giving the path to node info.
	GetNodeInfoRel(ctx context.Context, request *http.Request) (*apimodel.WellKnownResponse, gtserror.WithCode)
	// GetNodeInfo returns a node info struct in response to a node info request.
	GetNodeInfo(ctx context.Context, request *http.Request) (*apimodel.Nodeinfo, gtserror.WithCode)
	// InboxPost handles POST requests to a user's inbox for new activitypub messages.
	//
	// InboxPost returns true if the request was handled as an ActivityPub POST to an actor's inbox.
	// If false, the request was not an ActivityPub request and may still be handled by the caller in another way, such as serving a web page.
	//
	// If the error is nil, then the ResponseWriter's headers and response has already been written. If a non-nil error is returned, then no response has been written.
	//
	// If the Actor was constructed with the Federated Protocol enabled, side effects will occur.
	//
	// If the Federated Protocol is not enabled, writes the http.StatusMethodNotAllowed status code in the response. No side effects occur.
	InboxPost(ctx context.Context, w http.ResponseWriter, r *http.Request) (bool, error)
}

// processor just implements the Processor interface
type processor struct {
	clientWorker *concurrency.WorkerPool[messages.FromClientAPI]
	fedWorker    *concurrency.WorkerPool[messages.FromFederator]

	federator       federation.Federator
	tc              typeutils.TypeConverter
	oauthServer     oauth.Server
	mediaManager    media.Manager
	storage         storage.Driver
	statusTimelines timeline.Manager
	db              db.DB
	filter          visibility.Filter

	/*
		SUB-PROCESSORS
	*/

	accountProcessor    account.Processor
	adminProcessor      admin.Processor
	statusProcessor     status.Processor
	streamingProcessor  streaming.Processor
	mediaProcessor      mediaProcessor.Processor
	userProcessor       user.Processor
	federationProcessor federationProcessor.Processor
}

// NewProcessor returns a new Processor.
func NewProcessor(
	tc typeutils.TypeConverter,
	federator federation.Federator,
	oauthServer oauth.Server,
	mediaManager media.Manager,
	storage storage.Driver,
	db db.DB,
	emailSender email.Sender,
	clientWorker *concurrency.WorkerPool[messages.FromClientAPI],
	fedWorker *concurrency.WorkerPool[messages.FromFederator],
) Processor {
	parseMentionFunc := GetParseMentionFunc(db, federator)

	statusProcessor := status.New(db, tc, clientWorker, parseMentionFunc)
	streamingProcessor := streaming.New(db, oauthServer)
	accountProcessor := account.New(db, tc, mediaManager, oauthServer, clientWorker, federator, parseMentionFunc)
	adminProcessor := admin.New(db, tc, mediaManager, clientWorker)
	mediaProcessor := mediaProcessor.New(db, tc, mediaManager, federator.TransportController(), storage)
	userProcessor := user.New(db, emailSender)
	federationProcessor := federationProcessor.New(db, tc, federator)
	filter := visibility.NewFilter(db)

	return &processor{
		clientWorker: clientWorker,
		fedWorker:    fedWorker,

		federator:       federator,
		tc:              tc,
		oauthServer:     oauthServer,
		mediaManager:    mediaManager,
		storage:         storage,
		statusTimelines: timeline.NewManager(StatusGrabFunction(db), StatusFilterFunction(db, filter), StatusPrepareFunction(db, tc), StatusSkipInsertFunction()),
		db:              db,
		filter:          visibility.NewFilter(db),

		accountProcessor:    accountProcessor,
		adminProcessor:      adminProcessor,
		statusProcessor:     statusProcessor,
		streamingProcessor:  streamingProcessor,
		mediaProcessor:      mediaProcessor,
		userProcessor:       userProcessor,
		federationProcessor: federationProcessor,
	}
}

// Start starts the Processor, reading from its channels and passing messages back and forth.
func (p *processor) Start() error {
	// Setup and start the client API worker pool
	p.clientWorker.SetProcessor(p.ProcessFromClientAPI)
	if err := p.clientWorker.Start(); err != nil {
		return err
	}

	// Setup and start the federator worker pool
	p.fedWorker.SetProcessor(p.ProcessFromFederator)
	if err := p.fedWorker.Start(); err != nil {
		return err
	}

	// Start status timelines
	if err := p.statusTimelines.Start(); err != nil {
		return err
	}

	return nil
}

// Stop stops the processor cleanly, finishing handling any remaining messages before closing down.
func (p *processor) Stop() error {
	if err := p.clientWorker.Stop(); err != nil {
		return err
	}

	if err := p.fedWorker.Stop(); err != nil {
		return err
	}

	if err := p.statusTimelines.Stop(); err != nil {
		return err
	}

	return nil
}