/
following_database.go
103 lines (74 loc) · 2.8 KB
/
following_database.go
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package activitypub
import (
"context"
"fmt"
"net/url"
"sort"
"strings"
"github.com/aaronland/go-roster"
)
type GetFollowingIdsCallbackFunc func(context.Context, int64) error
type GetFollowingCallbackFunc func(context.Context, string) error
type FollowingDatabase interface {
GetFollowingIdsForDateRange(context.Context, int64, int64, GetFollowingIdsCallbackFunc) error
GetFollowingForAccount(context.Context, int64, GetFollowingCallbackFunc) error
GetFollowing(context.Context, int64, string) (*Following, error)
AddFollowing(context.Context, *Following) error
RemoveFollowing(context.Context, *Following) error
Close(context.Context) error
}
var following_database_roster roster.Roster
// FollowingDatabaseInitializationFunc is a function defined by individual following_database package and used to create
// an instance of that following_database
type FollowingDatabaseInitializationFunc func(ctx context.Context, uri string) (FollowingDatabase, error)
// RegisterFollowingDatabase registers 'scheme' as a key pointing to 'init_func' in an internal lookup table
// used to create new `FollowingDatabase` instances by the `NewFollowingDatabase` method.
func RegisterFollowingDatabase(ctx context.Context, scheme string, init_func FollowingDatabaseInitializationFunc) error {
err := ensureFollowingDatabaseRoster()
if err != nil {
return err
}
return following_database_roster.Register(ctx, scheme, init_func)
}
func ensureFollowingDatabaseRoster() error {
if following_database_roster == nil {
r, err := roster.NewDefaultRoster()
if err != nil {
return err
}
following_database_roster = r
}
return nil
}
// NewFollowingDatabase returns a new `FollowingDatabase` instance configured by 'uri'. The value of 'uri' is parsed
// as a `url.URL` and its scheme is used as the key for a corresponding `FollowingDatabaseInitializationFunc`
// function used to instantiate the new `FollowingDatabase`. It is assumed that the scheme (and initialization
// function) have been registered by the `RegisterFollowingDatabase` method.
func NewFollowingDatabase(ctx context.Context, uri string) (FollowingDatabase, error) {
u, err := url.Parse(uri)
if err != nil {
return nil, err
}
scheme := u.Scheme
i, err := following_database_roster.Driver(ctx, scheme)
if err != nil {
return nil, err
}
init_func := i.(FollowingDatabaseInitializationFunc)
return init_func(ctx, uri)
}
// Schemes returns the list of schemes that have been registered.
func FollowingDatabaseSchemes() []string {
ctx := context.Background()
schemes := []string{}
err := ensureFollowingDatabaseRoster()
if err != nil {
return schemes
}
for _, dr := range following_database_roster.Drivers(ctx) {
scheme := fmt.Sprintf("%s://", strings.ToLower(dr))
schemes = append(schemes, scheme)
}
sort.Strings(schemes)
return schemes
}