individual gc stats (#506)

- Feature: New parameter for endpoint `admin/gc` (GET) `details=true` which gives details stats on GC operation when using GC V2
- Feature: New options for zen command `gc-status`
  - `--details` that enables the detailed output from the last GC operation when using GC V2

1 files changed, 124 insertions, 6 deletions

diff --git a/src/zenserver/admin/admin.cpp b/src/zenserver/admin/admin.cpp
index fb376f238..83f33d4ea 100644
--- a/src/zenserver/admin/admin.cpp
+++ b/src/zenserver/admin/admin.cpp
@@ -199,6 +199,14 @@ HttpAdminService::HttpAdminService(GcScheduler&	   Scheduler,
 		[this](HttpRouterRequest& Req) {
 			const GcSchedulerState State = m_GcScheduler.GetState();
 
+			const HttpServerRequest::QueryParams Params = Req.ServerRequest().GetQueryParams();
+
+			bool Details = false;
+			if (auto Param = Params.GetValue("details"); Param == "true")
+			{
+				Details = true;
+			}
+
 			auto SecondsToString = [](std::chrono::seconds Secs) {
 				return NiceTimeSpanMs(uint64_t(std::chrono::milliseconds(Secs).count()));
 			};
@@ -226,6 +234,101 @@ HttpAdminService::HttpAdminService(GcScheduler&	   Scheduler,
 			Response << "DiskUsed" << NiceBytes(State.DiskUsed);
 			Response << "DiskFree" << NiceBytes(State.DiskFree);
 
+			auto WriteReferencerStats = [&](CbObjectWriter& Response, const GcReferencerStats& Stats) {
+				if (Stats.Count == 0)
+				{
+					return;
+				}
+				Response << "Count" << Stats.Count;
+				Response << "Expired" << Stats.Expired;
+				Response << "Deleted" << Stats.Deleted;
+
+				Response << "RemovedDisk" << NiceBytes(Stats.RemovedDisk);
+				Response << "RemovedMemory" << NiceBytes(Stats.RemovedMemory);
+
+				Response << "RemoveExpiredData" << NiceTimeSpanMs(Stats.RemoveExpiredDataMS.count());
+				Response << "CreateReferenceCheckers" << NiceTimeSpanMs(Stats.CreateReferenceCheckersMS.count());
+				Response << "LockState" << NiceTimeSpanMs(Stats.LockStateMS.count());
+				Response << "Elapsed" << NiceTimeSpanMs(Stats.ElapsedMS.count());
+			};
+
+			auto WriteReferenceStoreStats = [&](CbObjectWriter& Response, const GcReferenceStoreStats& Stats) {
+				if (Stats.Count == 0)
+				{
+					return;
+				}
+				Response << "Count" << Stats.Count;
+				Response << "Pruned" << Stats.Pruned;
+				Response << "Compacted" << Stats.Compacted;
+
+				Response << "RemovedDisk" << NiceBytes(Stats.RemovedDisk);
+				Response << "RemovedMemory" << NiceBytes(Stats.RemovedMemory);
+
+				Response << "CreateReferencePruner" << NiceTimeSpanMs(Stats.CreateReferencePrunerMS.count());
+				Response << "RemoveUnreferencedData" << NiceTimeSpanMs(Stats.RemoveUnreferencedDataMS.count());
+				Response << "CompactReferenceStore" << NiceTimeSpanMs(Stats.CompactReferenceStoreMS.count());
+				Response << "Elapsed" << NiceTimeSpanMs(Stats.ElapsedMS.count());
+			};
+
+			auto WriteGCResult = [&](CbObjectWriter& Response, const GcResult& Result) {
+				Response << "RemovedDisk" << NiceBytes(Result.RemovedDisk);
+				Response << "RemovedMemory" << NiceBytes(Result.RemovedMemory);
+				Response << "WriteBlock" << NiceTimeSpanMs(Result.WriteBlockMS.count());
+				Response << "Elapsed" << NiceTimeSpanMs(Result.ElapsedMS.count());
+
+				if (!Details)
+				{
+					return;
+				}
+
+				Response << "RemoveExpiredData" << NiceTimeSpanMs(Result.RemoveExpiredDataMS.count());
+				Response << "CreateReferenceCheckers" << NiceTimeSpanMs(Result.CreateReferenceCheckersMS.count());
+				Response << "LockState" << NiceTimeSpanMs(Result.LockStateMS.count());
+
+				Response << "CreateReferencePruner" << NiceTimeSpanMs(Result.CreateReferencePrunerMS.count());
+				Response << "RemoveUnreferencedData" << NiceTimeSpanMs(Result.RemoveUnreferencedDataMS.count());
+				Response << "CompactReferenceStore" << NiceTimeSpanMs(Result.CompactReferenceStoreMS.count());
+
+				Response.BeginObject("ReferencerStats");
+				{
+					WriteReferencerStats(Response, Result.ReferencerStat);
+				}
+				Response.EndObject();
+
+				Response.BeginObject("ReferenceStoreStats");
+				{
+					WriteReferenceStoreStats(Response, Result.ReferenceStoreStat);
+				}
+				Response.EndObject();
+
+				if (!Result.ReferencerStats.empty())
+				{
+					Response.BeginArray("Referencers");
+					{
+						for (const std::pair<std::string, GcReferencerStats>& It : Result.ReferencerStats)
+						{
+							Response.BeginObject();
+							Response << "Name" << It.first;
+							WriteReferencerStats(Response, It.second);
+							Response.EndObject();
+						}
+					}
+					Response.EndArray();
+				}
+				if (!Result.ReferenceStoreStats.empty())
+				{
+					Response.BeginArray("ReferenceStores");
+					for (const std::pair<std::string, GcReferenceStoreStats>& It : Result.ReferenceStoreStats)
+					{
+						Response.BeginObject();
+						Response << "Name" << It.first;
+						WriteReferenceStoreStats(Response, It.second);
+						Response.EndObject();
+					}
+					Response.EndArray();
+				}
+			};
+
 			Response.BeginObject("FullGC");
 			{
 				Response << "LastTime" << fmt::format("{}", State.LastFullGcTime);
@@ -234,18 +337,33 @@ HttpAdminService::HttpAdminService(GcScheduler&	   Scheduler,
 				{
 					Response << "SpaceToNext" << NiceBytes(State.RemainingSpaceUntilFullGC);
 				}
-				Response << "LastDuration" << NiceTimeSpanMs(State.LastFullGcDuration.count());
-				Response << "LastDiskFreed" << NiceBytes(State.LastFullGCDiff.DiskSize);
-				Response << "LastMemoryFreed" << NiceBytes(State.LastFullGCDiff.MemorySize);
+				if (State.LastFullGCV2Result)
+				{
+					WriteGCResult(Response, State.LastFullGCV2Result.value());
+				}
+				else
+				{
+					Response << "LastDuration" << NiceTimeSpanMs(State.LastFullGcDuration.count());
+					Response << "LastDiskFreed" << NiceBytes(State.LastFullGCDiff.DiskSize);
+					Response << "LastMemoryFreed" << NiceBytes(State.LastFullGCDiff.MemorySize);
+				}
 			}
 			Response.EndObject();
 			Response.BeginObject("LightweightGC");
 			{
 				Response << "LastTime" << fmt::format("{}", State.LastLightweightGcTime);
 				Response << "TimeToNext" << SecondsToString(State.RemainingTimeUntilLightweightGc);
-				Response << "LastDuration" << NiceTimeSpanMs(State.LastLightweightGcDuration.count());
-				Response << "LastDiskFreed" << NiceBytes(State.LastLightweightGCDiff.DiskSize);
-				Response << "LastMemoryFreed" << NiceBytes(State.LastLightweightGCDiff.MemorySize);
+
+				if (State.LastLightweightGCV2Result)
+				{
+					WriteGCResult(Response, State.LastLightweightGCV2Result.value());
+				}
+				else
+				{
+					Response << "LastDuration" << NiceTimeSpanMs(State.LastLightweightGcDuration.count());
+					Response << "LastDiskFreed" << NiceBytes(State.LastLightweightGCDiff.DiskSize);
+					Response << "LastMemoryFreed" << NiceBytes(State.LastLightweightGCDiff.MemorySize);
+				}
 			}
 			Response.EndObject();
 			Req.ServerRequest().WriteResponse(HttpResponseCode::OK, Response.Save());