fix oplog state check and wiping (#154)

fix oplog state check
fix wipe of oplog storage + meta only on invalid oplog
handle vanishing oplog during gc

2 files changed, 18 insertions, 2 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b7d66427b..959b1b5bc 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 - Improvement: zen `oplog-mirror` command now has new filter options to control which files are realized to disk: `--key` for op key, `--file` for file path matching and `--chunk` for chunk id matching
 - Improvement: Validate oplog log file and wipe state if it is corrupt before attempting to open
 - Improvement: `project-drop` command defaults to `--dry-run=true` and will only delete the target if `--dry-run=false` is added to the command line to avoid accidental delete
+- Improvement: Gracefully handle oplog being deleted during early phase of GC
 
 ## 5.5.6
 - Bugfix: Make sure `noexcept` functions does not leak exceptions via ASSERT statements which causes crash via abort
diff --git a/src/zenserver/projectstore/projectstore.cpp b/src/zenserver/projectstore/projectstore.cpp
index b0d2554d6..a34f2f4d5 100644
--- a/src/zenserver/projectstore/projectstore.cpp
+++ b/src/zenserver/projectstore/projectstore.cpp
@@ -352,7 +352,16 @@ struct ProjectStore::OplogStorage : public RefCounted
 		return std::filesystem::exists(GetLogPath(BasePath)) && std::filesystem::exists(GetBlobsPath(BasePath));
 	}
 	[[nodiscard]] bool		  IsValid() const { return IsValid(m_OplogStoragePath); }
-	[[nodiscard]] static bool IsValid(const std::filesystem::path& BasePath) { return TCasLogFile<OplogEntry>::IsValid(BasePath); }
+	[[nodiscard]] static bool IsValid(const std::filesystem::path& BasePath)
+	{
+		return TCasLogFile<OplogEntry>::IsValid(GetLogPath(BasePath));
+	}
+	void WipeState() const
+	{
+		std::error_code Ec;
+		std::filesystem::remove(GetLogPath(), Ec);
+		std::filesystem::remove(GetBlobsPath(), Ec);
+	}
 
 	static bool Delete(const std::filesystem::path& BasePath) { return DeleteDirectories(BasePath); }
 
@@ -950,7 +959,9 @@ ProjectStore::Oplog::Oplog(std::string_view				Id,
 		if (!m_Storage->IsValid())
 		{
 			ZEN_WARN("Invalid oplog found at '{}'. Wiping state for oplog.", m_BasePath);
-			StoreExists = false;
+			m_Storage->WipeState();
+			std::error_code DummyEc;
+			std::filesystem::remove(m_MetaPath, DummyEc);
 		}
 	}
 	m_Storage->Open(/* IsCreate */ !StoreExists);
@@ -5502,6 +5513,10 @@ public:
 			Oplog = new ProjectStore::Oplog(m_OplogId, m_Project.Get(), m_Project->m_CidStore, m_OplogBasePath, std::filesystem::path{});
 			Oplog->Read();
 		}
+		else
+		{
+			return;
+		}
 
 		RwLock::SharedLockScope ____(Oplog->m_OplogLock);
 		if (Ctx.IsCancelledFlag)