xenadmin/XenAdmin/Diagnostics/Hotfixing/SingleHotfix.cs

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using System.IO;
using System.Linq;
using System.Threading;
using XenAdmin.Core;
using XenAPI;

namespace XenAdmin.Diagnostics.Hotfixing
{

    internal class SingleHotfix : Hotfix
    {
        public override string UUID { get; set; }
        public override string Filename { get; set; }

        public sealed override void Apply(Host host, Session session)
        {
            Pool_patch patch = host.Connection.Cache.Find_By_Uuid<Pool_patch>(UUID);
            if (patch == null)
            {
                var master = Helpers.GetMaster(host.Connection);
                var action = new Actions.UploadPatchAction(master.Connection, Path.Combine(Program.AssemblyDir, Filename));
                action.RunExternal(session);
                patch = action.PatchRefs[master];
            }
            Pool_patch.apply(session, patch.opaque_ref, host.opaque_ref);

            int numberRetries = 0;
            do
            {
                Thread.Sleep(500);
                patch = host.Connection.Cache.Find_By_Uuid<Pool_patch>(UUID);
                numberRetries++;

            } while (patch == null && numberRetries < 10);
        }

        public override bool ShouldBeAppliedTo(Host host)
        {
            var patches = host.Connection.ResolveAll(host.patches);
            var poolPatches = patches.Select(hostPatch => hostPatch.Connection.Resolve(hostPatch.pool_patch));
            return !poolPatches.Any( patch => UUID.Contains(patch.uuid));
        }
    }

}