budul.ProgressWatcher 2.1.0

ProgressWatcher

Lightweight, thread-safe progress coordination library for nested and parallel operations.

• PackageId: budul.ProgressWatcher
• Supported TFMs: netstandard2.0, netstandard2.1, net7.0, net8.0
• Repository: https://github.com/budul100/ProgressWatcher
• License: MIT

Overview

ProgressWatcher provides a small API to create progress packages (IPackage) and a top-level Watcher that aggregates progress and status information for UI or logging consumers. Packages support nested child packages, fractional progress reporters (IProgress<double>), and efficient thread-local batching for high-concurrency scenarios.

Installation

Install from NuGet:

dotnet add package budul.ProgressWatcher

Quick start (synchronous)

using ProgressWatcher;

var watcher = new Watcher(); 
var package = watcher.GetPackage(allSteps: 3, status: "Starting work...");

package.NextStep("Step 1 done"); 
package.NextStep("Step 2 done"); 
package.NextStep("Step 3 done");
package.Dispose(); // or package.Complete() 

// watcher.ProgressAll, watcher.ProgressTip and watcher.Status update via PropertyChanged

Parallel usage (hot loops)

For high-concurrency loops (e.g. Parallel.ForEach or many threads) use NextStepLocal() to avoid contention. After the loop finishes, call FlushCounterLocal() to ensure any thread-local counts are aggregated and reported.

using ProgressWatcher; 
using System.Threading.Tasks;

var items = Enumerable.Range(0, 1_000_000); 

var watcher = new Watcher(); 
var package = watcher.GetPackage(items, "Processing items");

Parallel.ForEach(items, item => { // work on item...
	// report work from current thread using thread-local batching
	package.NextStepLocal();
});

// ensure remaining local counts are flushed 
package.FlushCounterLocal(); 
package.Dispose();

Important notes:

• Always call FlushCounterLocal() after a parallel loop; otherwise some thread-local counts may remain unreported.
• NextStepLocal() is intended for hot/tight loops and batches updates on a per-thread basis to reduce synchronization costs.

Using progress reporters and weights

Get a fractional progress reporter when you need to report continuous progress from a subtask:

var parent = watcher.GetPackage(status: "Parent", steps: 1); 

using var reporter = parent.GetProgress(status: "Loading", steps: 10, weight: 0.5)
{
	reporter.NextStep(4);
}

parent.Dispose();

Weights:

• weight is a value in [0.0, 1.0] that assigns how much of the parent's remaining progress the child consumes.
• Passing 0 uses automatic weight calculation based on remaining steps.

Nesting and lifecycle

• Create nested work with GetPackage(...) or fractional reporters with GetProgress(...).
• Call Dispose() on a package to complete it and notify the parent. Complete() sets progress to 100% immediately.
• Top-level Watcher exposes events: ProgressStarted, ProgressCompleted, ChildStarted, ChildDisposed and properties ProgressAll, ProgressTip, Status, IsRunning (useful for UI binding).

Thread-safety and throttling

• Package is designed for concurrent reporting. Use NextStepLocal() in parallel scenarios and FlushCounterLocal() afterwards.
• Progress updates are internally throttled using a minimum delta and minimum interval before forwarding to the parent. This avoids flooding UI updates while remaining responsive.

Best practices

• Prefer NextStepLocal() inside parallel loops; call FlushCounterLocal() after the loop.
• Dispose or Complete() packages to ensure parents advance to completion.
• Use GetProgress(...) for long-running subtasks that report fractional progress.

API summary

• Watcher � top-level aggregator; use GetPackage(...) to start work and bind to ProgressAll, ProgressTip, Status.
• IPackage � use NextStep(), NextStepLocal(), GetPackage(...), GetProgress(...), FlushCounterLocal(), Complete(), Dispose().