downloader

package
v0.42.0-alpha.1 Latest Latest
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 Go to latest Published: May 23, 2021 License: MIT Imports: 19 Imported by: 24

Documentation

Overview

Package downloader contains downloading files helpers.

Index

Examples

Constants

This section is empty.

Variables

View Source 
var ErrHashMismatch = xerrors.New("file hash mismatch")

ErrHashMismatch means that download hash verification was failed.

Functions

func ExpandThumbnail added in v0.41.0 

func ExpandThumbnail(data, to []byte) ([]byte, error)

ExpandThumbnail creates a JPG payload from stripped thumbnail bytes.

See https://core.telegram.org/api/files#stripped-thumbnails for reference.

Based on tdesktop implementation. See https://github.com/telegramdesktop/tdesktop/blob/v2.7.5/Telegram/SourceFiles/ui/image/image.cpp#L43.

Example 
package main

import (
	"bytes"
	"encoding/base64"
	"fmt"
	"image/jpeg"
	"image/png"

	"github.com/gotd/td/telegram/downloader"
	"github.com/gotd/td/tg"
)

func main() {
	userPhoto := tg.UserProfilePhoto{
		StrippedThumb: []uint8{
			0x01, 0x28, 0x28, 0x29, 0x40, 0x1d, 0xff, 0x00, 0x2a, 0x41, 0x8e, 0xe3, 0x22, 0xac, 0x42, 0x51,
			0xa0, 0x28, 0x03, 0x19, 0x1b, 0x9e, 0x07, 0x3f, 0xad, 0x69, 0x51, 0xbd, 0x91, 0xcf, 0x42, 0x29,
			0xea, 0xc8, 0x9a, 0x36, 0x0a, 0x1b, 0x6e, 0x01, 0xe0, 0x73, 0xd6, 0x99, 0xdf, 0xbf, 0xe2, 0x2a,
			0xdc, 0x71, 0xc8, 0xca, 0x11, 0x9d, 0x0e, 0xc3, 0xd7, 0x6f, 0x4f, 0xa5, 0x47, 0x2d, 0xb3, 0x2c,
			0x84, 0x20, 0x38, 0xec, 0x71, 0xd6, 0xa6, 0x12, 0xb3, 0xd4, 0xd2, 0xac, 0x14, 0x96, 0x8b, 0x52,
			0x0a, 0x2a, 0xc4, 0xb6, 0xa6, 0x38, 0x8b, 0x97, 0x04, 0x8e, 0xd8, 0xa2, 0xb6, 0x4d, 0x33, 0x95,
			0xc5, 0xad, 0x1a, 0x1b, 0x04, 0xcb, 0x11, 0xf9, 0xd0, 0x11, 0xeb, 0x8e, 0x45, 0x58, 0x8e, 0x68,
			0x93, 0x73, 0x96, 0x03, 0x79, 0xce, 0xd1, 0x55, 0x63, 0x50, 0x54, 0xb3, 0x64, 0xe3, 0xf0, 0x1f,
			0x89, 0xa4, 0x75, 0x20, 0xee, 0xe3, 0x6f, 0x6e, 0xd9, 0xa9, 0x71, 0x4d, 0x9a, 0x46, 0x72, 0x8a,
			0x2e, 0x79, 0xf2, 0x4a, 0x71, 0x02, 0x60, 0x7f, 0x79, 0xaa, 0x54, 0x46, 0x51, 0x97, 0x72, 0xcc,
			0x7f, 0x2a, 0x20, 0x74, 0x78, 0xc1, 0x40, 0x00, 0xf4, 0xf4, 0xa7, 0xb3, 0x05, 0x52, 0xc7, 0xa0,
			0xac, 0x9f, 0x63, 0x78, 0xae, 0xad, 0x94, 0xaf, 0xa4, 0xcb, 0x08, 0xc7, 0x41, 0xc9, 0xa2, 0xab,
			0xc8, 0xe6, 0x47, 0x66, 0x3d, 0xcd, 0x15, 0xbc, 0x55, 0x91, 0xc9, 0x39, 0x73, 0x3b, 0x88, 0x09,
			0x18, 0xf6, 0xe7, 0x14, 0x8c, 0xc5, 0x8e, 0x58, 0xe4, 0xd1, 0x45, 0x32, 0x6e, 0x3e, 0x19, 0x5a,
			0x27, 0xdc, 0x3a, 0x77, 0x1e, 0xb5, 0x62, 0xe2, 0xe5, 0x1e, 0x1d, 0xa9, 0xd4, 0xf5, 0xe3, 0xa5,
			0x14, 0x52, 0x71, 0x4d, 0xdc, 0xa5, 0x36, 0x95, 0x8a, 0x74, 0x51, 0x45, 0x32, 0x4f,
		},
	}

	result, err := downloader.ExpandThumbnail(userPhoto.StrippedThumb, nil)
	if err != nil {
		panic(err)
	}

	img, err := jpeg.Decode(bytes.NewReader(result))
	if err != nil {
		panic(err)
	}

	var buf bytes.Buffer
	if err := png.Encode(&buf, img); err != nil {
		panic(err)
	}
	fmt.Println("IMAGE:" + base64.StdEncoding.EncodeToString(buf.Bytes()))
}

Output:

Types

type Builder added in v0.24.0 

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

Builder is a download builder.

func (*Builder) Parallel added in v0.24.0 

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

Parallel downloads file to given io.WriterAt.

func (*Builder) Stream added in v0.24.0 

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 added in v0.24.0 

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

ToPath downloads file to given path.

func (*Builder) WithThreads added in v0.24.0 

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

WithThreads sets downloading goroutines limit.

func (*Builder) WithVerify added in v0.24.0 

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 added in v0.24.0 

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

CDN represents Telegram RPC client to CDN server.

type Client added in v0.24.0 

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 added in v0.24.0 

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 added in v0.24.0 

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

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

func (*Downloader) Web added in v0.24.0 

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 added in v0.24.0 

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 added in v0.24.0 

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.

Source Files

View all Source files

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