Joseph Doherty
28 lines
1.3 KiB
C#
28 lines
1.3 KiB
C#
using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Transport;
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namespace ZB.MOM.WW.ScadaBridge.DeploymentManager;
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/// <summary>Recomputes deployment revisions from authoritative configuration on every probe.
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/// Process-local watermarks cannot prove freshness after another central changes the shared store,
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/// so nothing is memoised across calls.</summary>
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public sealed class StaleInstanceProbe : IStaleInstanceProbe
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{
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private readonly IFlatteningPipeline _flatteningPipeline;
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/// <summary>Initializes the authoritative probe.</summary>
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/// <param name="flatteningPipeline">The pipeline used to flatten instances for staleness comparison.</param>
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public StaleInstanceProbe(IFlatteningPipeline flatteningPipeline)
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{
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_flatteningPipeline = flatteningPipeline ?? throw new ArgumentNullException(nameof(flatteningPipeline));
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}
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/// <inheritdoc />
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public async Task<string?> GetCurrentRevisionHashAsync(int instanceId, CancellationToken cancellationToken = default)
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{
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// Hash only: staleness never reads the validation result.
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var result = await _flatteningPipeline.ComputeRevisionHashAsync(
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instanceId, _flatteningPipeline.CreateSession(), cancellationToken).ConfigureAwait(false);
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return result.IsSuccess ? result.Value : null;
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}
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}
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