Class LibraryDownloads

Namespace

EncDotNet.S100.Collections.Library

Assembly

EncDotNet.S100.Collections.dll

Downloads online library items (NOAA and USACE ENCs, community packages, S-100 feeds and the NOAA S-102/S-104/S-111 forecast catalogues; issues #655, #670, #680, #685) into managed folders, a few at a time, and resolves their downloaded copies so they behave as local items. UI-free: the viewer adds its progress notification on top, and a headless host (#792) reads Progress and StatusOf(CollectionItem) directly.

public sealed class LibraryDownloads : ILibraryLocalCopies

Inheritance

object

LibraryDownloads

Implements

ILibraryLocalCopies

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

Thread-safe. Events are raised on whichever thread did the work.

Constructors

LibraryDownloads(EncCellDownloader)

Creates downloads that save every item with downloader.

public LibraryDownloads(EncCellDownloader downloader)

Parameters

downloader EncCellDownloader

The downloader (and so the managed folder) for every item.

LibraryDownloads(Func<RemoteItemLocation, EncCellDownloader?>)

Creates downloads that pick a downloader (and so a managed folder) per download location, e.g. one per provider or per DownloadFolder.

public LibraryDownloads(Func<RemoteItemLocation, EncCellDownloader?> downloaderFor)

Parameters

downloaderFor Func<RemoteItemLocation, EncCellDownloader>

The downloader for a location; null means the location is not downloadable. See ManagedFolders(HttpClient, string, HttpClient?, SecomRevocation?, SecomServerTrust?, Func<SecomTrustAnchors>?) for the hosts' layout.

Fields

MaxConcurrentDownloads

How many downloads run at once.

public const int MaxConcurrentDownloads = 3

Field Value

int

ProgressInterval

How often, at most, ProgressChanged is raised.

public static readonly TimeSpan ProgressInterval

Field Value

TimeSpan

Properties

Logger

Where download batches and failed downloads are logged, or null for no logging. Items are logged by name only, never by location, since a location can carry credentials.

public ILogger? Logger { get; init; }

Property Value

ILogger

Progress

The running bulk download, or null when none is running.

public LibraryDownloadProgress? Progress { get; }

Property Value

LibraryDownloadProgress

Methods

CanDownload(CollectionItem)

True when item can be downloaded (online, not cancelled, and a downloader takes it).

public bool CanDownload(CollectionItem item)

Parameters

item CollectionItem

The library item.

Returns

bool

Cancel(CollectionItem)

Cancels item's download (queued or running); the rest of the batch carries on.

public void Cancel(CollectionItem item)

Parameters

item CollectionItem

The library item.

CancelAll()

Cancels the running bulk download.

public void CancelAll()

Delete(RemoteItemLocation, string)

Deletes the downloaded copy named name from the managed folder that location downloads to, and forgets it, so its items are online again.

public bool Delete(RemoteItemLocation location, string name)

Parameters

location RemoteItemLocation

Any download location of that folder.

name string

The cell or package name (as DownloadedNames(RemoteItemLocation) lists it).

Returns

bool

True when a copy was deleted.

DownloadAsync(IReadOnlyList<CollectionItem>, IProgress<LibraryDownloadProgress>?, CancellationToken)

Downloads the downloadable items among items, at most MaxConcurrentDownloads at a time. A package downloads once however many of its datasets are asked for. Never throws for a failed or cancelled download: the result counts them.

public Task<LibraryDownloadResult> DownloadAsync(IReadOnlyList<CollectionItem> items, IProgress<LibraryDownloadProgress>? progress = null, CancellationToken cancellationToken = default)

Parameters

items IReadOnlyList<CollectionItem>

The items to download; others are ignored.

progress IProgress<LibraryDownloadProgress>

Told the batch's progress when it starts and each time an item finishes (reported on the finishing thread, not posted), or null.

cancellationToken CancellationToken

Cancels the whole batch.

Returns

Task<LibraryDownloadResult>

How many downloaded and failed, and whether the batch was cancelled.

DownloadedNames(RemoteItemLocation)

The names of the copies downloaded into the managed folder that location downloads to (cells or packages); empty when the location is not downloadable.

public IReadOnlyList<string> DownloadedNames(RemoteItemLocation location)

Parameters

location RemoteItemLocation

Any download location of that folder.

Returns

IReadOnlyList<string>

FolderOf(RemoteItemLocation)

The managed folder that location downloads to, or null when it is not downloadable.

public string? FolderOf(RemoteItemLocation location)

Parameters

location RemoteItemLocation

Any download location of that folder.

Returns

string

IsOutdated(CollectionItem)

True when the downloaded copy of item is an older edition or update.

public bool IsOutdated(CollectionItem item)

Parameters

item CollectionItem

Returns

bool

LocalEditionOf(CollectionItem)

The edition of item's downloaded copy, or null when not downloaded (or unknown).

public int? LocalEditionOf(CollectionItem item)

Parameters

item CollectionItem

Returns

int?

LocalPublishedAtOf(CollectionItem)

When item's downloaded copy was published (for a forecast, its run time), or null when not downloaded (or unknown).

public DateTimeOffset? LocalPublishedAtOf(CollectionItem item)

Parameters

item CollectionItem

Returns

DateTimeOffset?

Localize(CollectionItem)

Returns item with a local location when it is an online item that has been downloaded; otherwise the item itself.

public CollectionItem Localize(CollectionItem item)

Parameters

item CollectionItem

Returns

CollectionItem

ManagedFolders(HttpClient, string, HttpClient?, SecomRevocation?, SecomServerTrust?, Func<SecomTrustAnchors>?)

The managed download layout the viewer uses under its downloads root, so every host keeps downloads in the same place: an item that names its own folder (community lists, S-100 feeds and catalogues) gets that folder; otherwise USACE cells go to usace-ienc and everything else to noaa-enc.

public static Func<RemoteItemLocation, EncCellDownloader?> ManagedFolders(HttpClient http, string downloadsRoot, HttpClient? secomHttp = null, SecomRevocation? revocation = null, SecomServerTrust? secomTrust = null, Func<SecomTrustAnchors>? trustAnchors = null)

Parameters

http HttpClient

The client downloads use (with a generous timeout).

downloadsRoot string

The host's downloads root.

secomHttp HttpClient

The client SECOM objects are downloaded with (see SecomHttpClient); null uses http.

revocation SecomRevocation

Checks SECOM signers for revocation (see Revocation); null skips it.

secomTrust SecomServerTrust

Resolves each SECOM object's identity, presented and signed with (see SecomTrust); null downloads anonymously.

trustAnchors Func<SecomTrustAnchors>

Where SECOM signers' trust anchors come from (see TrustAnchorsSource); by default secomTrust's anchors, else BuiltIn.

Returns

Func<RemoteItemLocation, EncCellDownloader>

A downloader selector for LibraryDownloads(Func<RemoteItemLocation, EncCellDownloader?>).

Pin(CollectionItem)

Pins the downloaded run of a weather item (#1075): keeps a copy beside the latest, so the next run doesn't replace it. Its source lists the copy as a pinned item once it re-indexes.

public string? Pin(CollectionItem item)

Parameters

item CollectionItem

A weather item with a downloaded copy.

Returns

string

The pinned copy's name, or null when the item has no downloaded copy.

StatusOf(CollectionItem)

Where item stands in a download, or null when it is not queued, running or failed.

public LibraryDownloadItemStatus? StatusOf(CollectionItem item)

Parameters

item CollectionItem

The library item.

Returns

LibraryDownloadItemStatus

Unpin(CollectionItem)

Deletes a pinned weather run (an item IsPinned(CollectionItem) says is one, #1075).

public bool Unpin(CollectionItem pinned)

Parameters

pinned CollectionItem

The pinned item, as its source lists it.

Returns

bool

True when the copy was deleted.

Events

Changed

Raised when a download completes, fails or is cancelled (a copy appeared or changed), and when a batch starts or ends.

public event EventHandler? Changed

Event Type

EventHandler

ProgressChanged

Raised (throttled to ProgressInterval) as bytes arrive, so a host can show progress without re-resolving every item.

public event EventHandler? ProgressChanged

Event Type

EventHandler