Umbraco-CMS/src/Umbraco.Infrastructure/Suspendable.cs

using Microsoft.Extensions.Logging;
using Umbraco.Cms.Core;
using Umbraco.Cms.Core.Cache;
using Umbraco.Cms.Infrastructure.Examine;

namespace Umbraco.Cms.Infrastructure
{
    public static class Suspendable
    {
        public static class PageCacheRefresher
        {
            private static bool s_tried, s_suspended;

            public static bool CanRefreshDocumentCacheFromDatabase
            {
                get
                {
                    // trying a full refresh
                    if (s_suspended == false)
                    {
                        return true;
                    }

                    s_tried = true; // remember we tried
                    return false;
                }
            }

            // trying a partial update
            // ok if not suspended, or if we haven't done a full already
            public static bool CanUpdateDocumentCache => s_suspended == false || s_tried == false;

            public static void SuspendDocumentCache()
            {
                StaticApplicationLogging.Logger.LogInformation("Suspend document cache.");
                s_suspended = true;
            }

            public static void ResumeDocumentCache(CacheRefresherCollection cacheRefresherCollection)
            {
                s_suspended = false;

                StaticApplicationLogging.Logger.LogInformation("Resume document cache (reload:{Tried}).", s_tried);

                if (s_tried == false)
                {
                    return;
                }

                s_tried = false;

                ICacheRefresher pageRefresher = cacheRefresherCollection[ContentCacheRefresher.UniqueId];
                pageRefresher.RefreshAll();
            }
        }

        //This is really needed at all since the only place this is used is in ExamineComponent and that already maintains a flag of whether it suspsended or not
        // AHH... but Deploy probably uses this?
        public static class ExamineEvents
        {
            private static bool s_tried, s_suspended;

            public static bool CanIndex
            {
                get
                {
                    if (s_suspended == false)
                    {
                        return true;
                    }

                    s_tried = true; // remember we tried
                    return false;
                }
            }

            public static void SuspendIndexers(ILogger logger)
            {
                logger.LogInformation("Suspend indexers.");
                s_suspended = true;
            }

            public static void ResumeIndexers(ExamineIndexRebuilder backgroundIndexRebuilder)
            {
                s_suspended = false;

                StaticApplicationLogging.Logger.LogInformation("Resume indexers (rebuild:{Tried}).", s_tried);

                if (s_tried == false)
                {
                    return;
                }

                s_tried = false;

                backgroundIndexRebuilder.RebuildIndexes(false);
            }
        }

        public static class ScheduledPublishing
        {
            private static bool s_suspended;

            public static bool CanRun => s_suspended == false;

            public static void Suspend()
            {
                StaticApplicationLogging.Logger.LogInformation("Suspend scheduled publishing.");
                s_suspended = true;
            }

            public static void Resume()
            {
                StaticApplicationLogging.Logger.LogInformation("Resume scheduled publishing.");
                s_suspended = false;
            }
        }
    }
}