downloader

Documentation

Overview

Package downloader contains downloading files helpers.

Index

• Variables
• type Builder
  • func (b *Builder) Parallel(ctx context.Context, output io.WriterAt) (tg.StorageFileTypeClass, error)
  • func (b *Builder) Stream(ctx context.Context, output io.Writer) (tg.StorageFileTypeClass, error)
  • func (b *Builder) ToPath(ctx context.Context, path string) (_ tg.StorageFileTypeClass, err error)
  • func (b *Builder) WithThreads(threads int) *Builder
  • func (b *Builder) WithVerify(verify bool) *Builder
• type CDN
• type Client
• type Downloader
  • func NewDownloader() *Downloader
  • func (d *Downloader) CDN(rpc Client, cdnRPC CDN, redirect *tg.UploadFileCDNRedirect) *Builder
  • func (d *Downloader) Download(rpc Client, location tg.InputFileLocationClass) *Builder
  • func (d *Downloader) DownloadDirect(rpc Client, location tg.InputFileLocationClass) *Builder
  • func (d *Downloader) Web(rpc Client, location tg.InputWebFileLocationClass) *Builder
  • func (d *Downloader) WithPartSize(partSize int) *Downloader
• type ExpiredTokenError
  • func (r *ExpiredTokenError) Error() string
• type RedirectError
  • func (r *RedirectError) Error() string

Variables

var ErrHashMismatch = errors.New("file hash mismatch")

ErrHashMismatch means that download hash verification was failed.

Types

type Builder

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

Builder is a download builder.

func (*Builder) Parallel

func (b *Builder) Parallel(ctx context.Context, output io.WriterAt) (tg.StorageFileTypeClass, error)

Parallel downloads file to given io.WriterAt.

func (*Builder) Stream

func (b *Builder) Stream(ctx context.Context, output io.Writer) (tg.StorageFileTypeClass, error)

Stream downloads file to given io.Writer. NB: in this mode download can't be parallel.

func (*Builder) ToPath

func (b *Builder) ToPath(ctx context.Context, path string) (_ tg.StorageFileTypeClass, err error)

ToPath downloads file to given path.

func (*Builder) WithThreads

func (b *Builder) WithThreads(threads int) *Builder

WithThreads sets downloading goroutines limit.

func (*Builder) WithVerify

func (b *Builder) WithVerify(verify bool) *Builder

WithVerify sets verify parameter. If verify is true, file hashes will be checked Verify is true by default for CDN downloads.

type CDN

type CDN interface {
	UploadGetCDNFile(ctx context.Context, request *tg.UploadGetCDNFileRequest) (tg.UploadCDNFileClass, error)
}

CDN represents Telegram RPC client to CDN server.

type Client

type Client interface {
	UploadGetFile(ctx context.Context, request *tg.UploadGetFileRequest) (tg.UploadFileClass, error)
	UploadGetFileHashes(ctx context.Context, request *tg.UploadGetFileHashesRequest) ([]tg.FileHash, error)

	UploadReuploadCDNFile(ctx context.Context, request *tg.UploadReuploadCDNFileRequest) ([]tg.FileHash, error)
	UploadGetCDNFileHashes(ctx context.Context, request *tg.UploadGetCDNFileHashesRequest) ([]tg.FileHash, error)

	UploadGetWebFile(ctx context.Context, request *tg.UploadGetWebFileRequest) (*tg.UploadWebFile, error)
}

Client represents Telegram RPC client.

type Downloader

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

Downloader is Telegram file downloader.

func NewDownloader

func NewDownloader() *Downloader

NewDownloader creates new Downloader.

func (*Downloader) CDN

func (d *Downloader) CDN(rpc Client, cdnRPC CDN, redirect *tg.UploadFileCDNRedirect) *Builder

CDN creates Builder for CDN downloads.

func (*Downloader) Download

func (d *Downloader) Download(rpc Client, location tg.InputFileLocationClass) *Builder

Download creates Builder for plain downloads.

Method sets CDNSupported field for upload.getFile. Use DownloadDirect for direct downloads without CDN support.

See https://core.telegram.org/cdn.

func (*Downloader) DownloadDirect

func (d *Downloader) DownloadDirect(rpc Client, location tg.InputFileLocationClass) *Builder

DownloadDirect creates Builder for plain downloads with disabled CDN redirect handling.

func (*Downloader) Web

func (d *Downloader) Web(rpc Client, location tg.InputWebFileLocationClass) *Builder

Web creates Builder for web files downloads.

func (*Downloader) WithPartSize

func (d *Downloader) WithPartSize(partSize int) *Downloader

WithPartSize sets chunk size. Must be divisible by 4KB.

See https://core.telegram.org/api/files#downloading-files.

type ExpiredTokenError

type ExpiredTokenError struct {
	*tg.UploadCDNFileReuploadNeeded
}

ExpiredTokenError error is returned when Downloader get expired file token for CDN. See https://core.telegram.org/constructor/upload.fileCdnRedirect.

func (*ExpiredTokenError) Error

func (r *ExpiredTokenError) Error() string

Error implements error interface.

type RedirectError

type RedirectError struct {
	Redirect *tg.UploadFileCDNRedirect
}

RedirectError error is returned when Downloader get CDN redirect. See https://core.telegram.org/constructor/upload.fileCdnRedirect.

func (*RedirectError) Error

func (r *RedirectError) Error() string

Error implements error interface.