updates

Documentation

Overview

Package updates provides a Telegram's internalState synchronization manager.

It guarantees that all internalState-sensitive updates will be performed in correct order.

Limitations:

1. Manager cannot verify stateless types of updates (tg.UpdatesClass without Seq, or tg.UpdateClass without Pts or Qts).

2. Due to the fact that updates.getDifference and updates.getChannelDifference do not return event sequences, manager cannot guarantee the correctness of these operations. We rely on the server here.

3. Manager cannot recover the channel gap if there is a ChannelDifferenceTooLong error. Restoring the internalState in such situation is not the prerogative of this manager. See: https://core.telegram.org/constructor/updates.channelDifferenceTooLong

TODO: Write implementation details.

Index

• type API
• type AuthOptions
• type ChannelAccessHasher
• type Config
• type Manager
  • func New(cfg Config) *Manager
  • func (m *Manager) Handle(ctx context.Context, u tg.UpdatesClass) error
  • func (m *Manager) Reset()
  • func (m *Manager) Run(ctx context.Context, api API, userID int64, opt AuthOptions) error
• type State
• type StateStorage

Types

type API

type API interface {
	UpdatesGetState(ctx context.Context) (*tg.UpdatesState, error)
	UpdatesGetDifference(ctx context.Context, request *tg.UpdatesGetDifferenceRequest) (tg.UpdatesDifferenceClass, error)
	UpdatesGetChannelDifference(ctx context.Context, request *tg.UpdatesGetChannelDifferenceRequest) (tg.UpdatesChannelDifferenceClass, error)
}

API is the interface which contains Telegram RPC methods used by manager for internalState synchronization.

type AuthOptions

type AuthOptions struct {
	IsBot   bool
	Forget  bool
	OnStart func(ctx context.Context)
}

type ChannelAccessHasher

type ChannelAccessHasher interface {
	SetChannelAccessHash(ctx context.Context, userID, channelID, accessHash int64) error
	GetChannelAccessHash(ctx context.Context, userID, channelID int64) (accessHash int64, found bool, err error)
}

ChannelAccessHasher stores users channel access hashes.

type Config

type Config struct {
	// Handler where updates will be passed.
	Handler telegram.UpdateHandler
	// Callback called if manager cannot
	// recover channel gap (optional).
	OnChannelTooLong func(channelID int64)
	// State storage.
	// In-mem used if not provided.
	Storage StateStorage
	// Channel access hash storage.
	// In-mem used if not provided.
	AccessHasher ChannelAccessHasher
	// Logger (optional).
	Logger *zap.Logger
	// TracerProvider (optional).
	TracerProvider trace.TracerProvider
}

Config of the manager.

type Manager

type Manager struct {
	// contains filtered or unexported fields
}

Manager deals with gaps.

Important: Updates produced by this manager may contain negative Pts/Qts/Seq values in tg.UpdateClass/tg.UpdatesClass (does not affects to the tg.MessageClass).

This is because telegram server does not return these sequences for getDifference/getChannelDifference results. You SHOULD NOT use them in update handlers at all.

func New

func New(cfg Config) *Manager

New creates new manager.

func (*Manager) Handle

func (m *Manager) Handle(ctx context.Context, u tg.UpdatesClass) error

Handle handles updates.

Important: If Run method not called, all updates will be passed to the provided handler as-is without any order verification or short updates transformation.

func (*Manager) Reset

func (m *Manager) Reset()

Reset notifies manager about user logout.

func (*Manager) Run

func (m *Manager) Run(ctx context.Context, api API, userID int64, opt AuthOptions) error

Run notifies manager about user authentication on the telegram server.

If forget is true, local internalState (if exist) will be overwritten with remote internalState.

type State

type State struct {
	Pts, Qts, Date, Seq int
}

State is the user internalState.

type StateStorage

type StateStorage interface {
	GetState(ctx context.Context, userID int64) (state State, found bool, err error)
	SetState(ctx context.Context, userID int64, state State) error
	SetPts(ctx context.Context, userID int64, pts int) error
	SetQts(ctx context.Context, userID int64, qts int) error
	SetDate(ctx context.Context, userID int64, date int) error
	SetSeq(ctx context.Context, userID int64, seq int) error
	SetDateSeq(ctx context.Context, userID int64, date, seq int) error
	GetChannelPts(ctx context.Context, userID, channelID int64) (pts int, found bool, err error)
	SetChannelPts(ctx context.Context, userID, channelID int64, pts int) error
	ForEachChannels(ctx context.Context, userID int64, f func(ctx context.Context, channelID int64, pts int) error) error
}

StateStorage is the users internalState storage.

Note: SetPts, SetQts, SetDate, SetSeq, SetDateSeq should return error if user internalState does not exist.