Class ProgressSpeedSampler

Namespace

Archiver.Core.Services

Assembly

Archiver.Core.dll

EMA-smoothed transfer-speed sampler shared between Archiver.App's status line and Archiver.Shell's progress dialog (T-F142) — extracted from what was private, untested arithmetic inline in Archiver.App's MainViewModel.UpdateOperationStatus. Public (not internal), matching Archiver.Core.IO.Crc32's own precedent for a dependency-free algorithm needed by multiple frontends. Sampling only: byte/speed string formatting (localization-adjacent in the App, plain text in the Shell dialog) and ETA (derived from Percent, not bytes — works already, isn't shared) both stay separate per frontend, not folded in here. Callers gate on TotalBytes > 0 themselves before calling Sample(long, DateTime) — a report with no real byte total carries no speed signal at all, and deciding to skip it is the caller's job, not this sampler's, so it stays a pure function of (bytes, time). Construct a fresh instance per operation (Archive/Extract) rather than reusing one across operations — there is no Reset() by design, so a stale carried-over speed from reusing an instance across two operations is not possible.

public sealed class ProgressSpeedSampler

Inheritance

object

ProgressSpeedSampler

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Constructors

ProgressSpeedSampler(DateTime?)

Starts a fresh sampler — construct one per operation (see class remarks).

public ProgressSpeedSampler(DateTime? startTimeUtc = null)

Parameters

startTimeUtc DateTime?

Methods

Sample(long, DateTime)

Updates the running EMA from a new (bytesTransferred, nowUtc) sample and returns the current smoothed bytes/sec (0 until the first valid sample). A sample is only folded in once at least Archiver.Core.Services.ProgressSpeedSampler.MinSampleIntervalSeconds has elapsed since the last one AND bytesTransferred has actually advanced — this also means a non-increasing or repeated bytesTransferred (an out-of-order report, or the same report delivered twice) is tolerated by construction: it is simply ignored, never treated as a negative delta or a spike, and the last known smoothed value is returned unchanged.

public double Sample(long bytesTransferred, DateTime nowUtc)

Parameters

bytesTransferred long

nowUtc DateTime

Returns

double