download

Documentation

Index

• func DeleteDownload(downloadID string) error
• type Download
  • func GetDownload(downloadID string) (*Download, error)
  • func ListDownloads() ([]*Download, error)
  • func NewDownload(downloadURL string, totalWorkers uint16) (*Download, error)
  • func (d *Download) Execute(ctx context.Context) error
  • func (d *Download) FilePath() string
  • func (d *Download) FolderPath() string
  • func (d *Download) OutputFilePath() string
  • func (d *Download) String() string
  • func (d *Download) Writer() (io.WriteCloser, error)
• type Worker
  • func NewWorker(workerIndex uint16, totalWorkers uint16, downloadId string, downloadURL string, ...) *Worker
  • func (w *Worker) CurrentSize() uint64
  • func (w *Worker) DownloadSize() uint64
  • func (w *Worker) Execute(ctx context.Context, bar *pb.ProgressBar) error
  • func (w *Worker) FilePath() string
  • func (w *Worker) Reader() (io.ReadCloser, error)
  • func (w *Worker) Writer() (io.WriteCloser, error)

Functions

func DeleteDownload

func DeleteDownload(downloadID string) error

DeleteDownload removes the download folder.

Types

type Download

type Download struct {
	// ID is the task unique identifier.
	// It is used to allow the download of many files with the same name from different sources.
	// This field will be initialized on runtime.
	ID string `toml:"-"`

	// URL represents the url from which the manager will download the file.
	URL string `toml:"url"`

	// Name is the original filename.
	Name string `toml:"name"`

	// Size is the total file size in bytes.
	Size uint64 `toml:"size"`

	// IsResumable flags a download as resumable.
	// If false, the download will be automatically removed on cancellation.
	// This field will be initialized on runtime.
	IsResumable bool `toml:"-"`

	// Workers is the number of parallel connections configured for the manager.
	// Initially it is set by the user, but falls to 1 if the server does not accept range or does not provide a
	// content length.
	Workers []*Worker `toml:"workers"`
}

Download stores the information relative to a download, including the workers.

func GetDownload

func GetDownload(downloadID string) (*Download, error)

GetDownload gets a download by his id.

func ListDownloads

func ListDownloads() ([]*Download, error)

ListDownloads lists all the saved downloads.

func NewDownload

func NewDownload(downloadURL string, totalWorkers uint16) (*Download, error)

NewDownload fetches the download url, obtains all the information required to start a download and finally returns the download struct.

func (*Download) Execute

func (d *Download) Execute(ctx context.Context) error

Execute downloads the specified file. This operation blocks the execution until it finishes or is cancelled by the context.

func (*Download) FilePath

func (d *Download) FilePath() string

FilePath gets the path to the download TOML file.

func (*Download) FolderPath

func (d *Download) FolderPath() string

FolderPath gets the path to the download folder.

func (*Download) OutputFilePath

func (d *Download) OutputFilePath() string

OutputFilePath returns the path of the download output.

func (*Download) String

func (d *Download) String() string

String returns a pretty string with the download's information.

func (*Download) Writer

func (d *Download) Writer() (io.WriteCloser, error)

Writer opens the output file in write-only mode.

type Worker

type Worker struct {
	// Index is the index of the worker.
	// During the merge process, the worker downloads will be concatenated using this index.
	Index uint16 `toml:"index"`

	// DownloadID stores the id of the download.
	DownloadID string `toml:"download_id"`

	// DownloadURL stores the url of the download.
	DownloadURL string `toml:"download_url"`

	// RangeFrom is the start point of the worker download.
	RangeFrom uint64 `toml:"range_from"`

	// RangeTo is the end position of the worker download.
	RangeTo uint64 `toml:"range_to"`
}

Worker represents a goroutine in charge of downloading a file part/segment.

func NewWorker

func NewWorker(workerIndex uint16, totalWorkers uint16, downloadId string, downloadURL string, downloadSize uint64) *Worker

NewWorker computes the start & end point of the worker download and returns a new worker.

func (*Worker) CurrentSize

func (w *Worker) CurrentSize() uint64

CurrentSize returns the size of the worker file.

func (*Worker) DownloadSize

func (w *Worker) DownloadSize() uint64

DownloadSize calculates the difference between the maximum and minimum range.

func (*Worker) Execute

func (w *Worker) Execute(ctx context.Context, bar *pb.ProgressBar) error

Execute starts the download of the file slice. This operation is blocking and must be called inside a goroutine.

func (*Worker) FilePath

func (w *Worker) FilePath() string

FilePath returns the worker file path.

func (*Worker) Reader

func (w *Worker) Reader() (io.ReadCloser, error)

Reader opens the worker file in read-only mode.

func (*Worker) Writer

func (w *Worker) Writer() (io.WriteCloser, error)

Writer opens the worker file in append-write-only mode.