add command line options for compact block threshold and gc verbose (#557)

- Feature: Added new options to zenserver for GC V2
  - `--gc-compactblock-threshold` GCV2 - how much of a compact block should be used to skip compacting the block, default is 90%
  - `--gc-verbose` GCV2 - enable more verbose output when running a GC pass
- Feature: Added new options to `zen gc` command for GC V2
  - `--compactblockthreshold` GCV2 - how much of a compact block should be used to skip compacting the block, default is 90%
  - `--verbose` GCV2 - enable more verbose output when running a GC pass
- Feature: Added new parameters for endpoint `admin/gc` (PUT)
  - `compactblockthreshold` GCV2 - how much of a compact block should be used to skip compacting the block, default is 90%
  - `verbose` GCV2 - enable more verbose output when running a GC pass

1 files changed, 17 insertions, 1 deletions

diff --git a/src/zenserver/projectstore/projectstore.cpp b/src/zenserver/projectstore/projectstore.cpp
index 617104ddc..21aa6b44a 100644
--- a/src/zenserver/projectstore/projectstore.cpp
+++ b/src/zenserver/projectstore/projectstore.cpp
@@ -3341,8 +3341,24 @@ public:
 		}
 	}
 
-	virtual void RemoveUsedReferencesFromSet(GcCtx&, HashSet& IoCids) override
+	virtual void RemoveUsedReferencesFromSet(GcCtx& Ctx, HashSet& IoCids) override
 	{
+		ZEN_ASSERT(m_OplogLock);
+
+		size_t	   InitialCount = IoCids.size();
+		Stopwatch  Timer;
+		const auto _ = MakeGuard([&] {
+			if (!Ctx.Settings.Verbose)
+			{
+				return;
+			}
+			ZEN_INFO("GCV2: projectstore [FILTER REFERENCES] '{}': filtered out {} used references out of {} in {}",
+					 m_Oplog.m_BasePath,
+					 InitialCount - IoCids.size(),
+					 InitialCount,
+					 NiceTimeSpanMs(Timer.GetElapsedTimeMs()));
+		});
+
 		for (const IoHash& ReferenceHash : m_References)
 		{
 			IoCids.erase(ReferenceHash);