fix oplog index path reading error (#246)

* when reading paths for oplog index, make sure we don't point our string view to potentially stale memory

1 files changed, 41 insertions, 30 deletions

diff --git a/src/zenserver/projectstore/projectstore.cpp b/src/zenserver/projectstore/projectstore.cpp
index 6f669f68e..89fbff06c 100644
--- a/src/zenserver/projectstore/projectstore.cpp
+++ b/src/zenserver/projectstore/projectstore.cpp
@@ -1776,7 +1776,7 @@ ProjectStore::Oplog::ReadIndexSnapshot()
 						Offset = RoundUp(Offset, OplogIndexHeader::DataAlignment);
 
 						BasicFileBuffer IndexFile(ObjectIndexFile, 65536);
-						auto			ReadString([&IndexFile, &Offset](uint32_t Length) -> std::string_view {
+						auto			ReadString([&IndexFile, &Offset](uint32_t Length) -> std::string {
 							   MemoryView StringData = IndexFile.MakeView(Length, Offset);
 							   if (StringData.GetSize() != Length)
 							   {
@@ -1785,15 +1785,15 @@ ProjectStore::Oplog::ReadIndexSnapshot()
 																		uint32_t(StringData.GetSize())));
 							   }
 							   Offset += Length;
-							   return std::string_view((const char*)StringData.GetData(), Length);
+							   return std::string((const char*)StringData.GetData(), Length);
 						   });
 						for (uint64_t FileLengthOffset = 0; FileLengthOffset < FilePathLengths.size();)
 						{
-							std::string_view ServerPath = ReadString(FilePathLengths[FileLengthOffset++]);
-							std::string_view ClientPath = ReadString(FilePathLengths[FileLengthOffset++]);
+							std::string ServerPath = ReadString(FilePathLengths[FileLengthOffset++]);
+							std::string ClientPath = ReadString(FilePathLengths[FileLengthOffset++]);
 							m_FileMap.insert_or_assign(
 								Keys[KeyOffset++],
-								FileMapEntry{.ServerPath = std::string(ServerPath), .ClientPath = std::string(ClientPath)});
+								FileMapEntry{.ServerPath = std::move(ServerPath), .ClientPath = std::move(ClientPath)});
 						}
 					}
 					m_LogFlushPosition = Header.LogPosition;
@@ -1978,32 +1978,38 @@ ProjectStore::Oplog::IterateChunks(std::span<Oid>													 ChunkIds,
 				break;
 			}
 			WorkLatch.AddCount(1);
-			OptionalWorkerPool->ScheduleWork([this, &WorkLatch, ChunkIndex, &FileChunkIndexes, &FileChunkPaths, &AsyncCallback, &Result]() {
-				auto _ = MakeGuard([&WorkLatch]() { WorkLatch.CountDown(); });
-				if (Result.load() == false)
-				{
-					return;
-				}
-				size_t						 FileChunkIndex = FileChunkIndexes[ChunkIndex];
-				const std::filesystem::path& FilePath		= FileChunkPaths[ChunkIndex];
-				try
-				{
-					IoBuffer Payload = IoBufferBuilder::MakeFromFile(FilePath);
-					if (!AsyncCallback(FileChunkIndex, Payload))
+			OptionalWorkerPool->ScheduleWork(
+				[this, &WorkLatch, &ChunkIds, ChunkIndex, &FileChunkIndexes, &FileChunkPaths, &AsyncCallback, &Result]() {
+					auto _ = MakeGuard([&WorkLatch]() { WorkLatch.CountDown(); });
+					if (Result.load() == false)
 					{
-						Result.store(false);
+						return;
 					}
-				}
-				catch (const std::exception& Ex)
-				{
-					ZEN_WARN("oplog '{}/{}': exception caught when iterating file chunk {}, path '{}'. Reason: '{}'",
-							 m_OuterProject->Identifier,
-							 m_OplogId,
-							 FileChunkIndex,
-							 FilePath,
-							 Ex.what());
-				}
-			});
+					size_t						 FileChunkIndex = FileChunkIndexes[ChunkIndex];
+					const std::filesystem::path& FilePath		= FileChunkPaths[ChunkIndex];
+					try
+					{
+						IoBuffer Payload = IoBufferBuilder::MakeFromFile(FilePath);
+						if (!Payload)
+						{
+							ZEN_WARN("Trying to fetch chunk {} using file path {} failed", ChunkIds[ChunkIndex], FilePath);
+						}
+
+						if (!AsyncCallback(FileChunkIndex, Payload))
+						{
+							Result.store(false);
+						}
+					}
+					catch (const std::exception& Ex)
+					{
+						ZEN_WARN("oplog '{}/{}': exception caught when iterating file chunk {}, path '{}'. Reason: '{}'",
+								 m_OuterProject->Identifier,
+								 m_OplogId,
+								 FileChunkIndex,
+								 FilePath,
+								 Ex.what());
+					}
+				});
 		}
 
 		WorkLatch.CountDown();
@@ -2054,7 +2060,12 @@ ProjectStore::Oplog::FindChunk(const Oid& ChunkId)
 
 		OplogLock.ReleaseNow();
 
-		return IoBufferBuilder::MakeFromFile(FilePath);
+		IoBuffer Result = IoBufferBuilder::MakeFromFile(FilePath);
+		if (!Result)
+		{
+			ZEN_WARN("Trying to fetch chunk {} using file path {} failed", ChunkId, FilePath);
+		}
+		return Result;
 	}
 
 	if (auto MetaIt = m_MetaMap.find(ChunkId); MetaIt != m_MetaMap.end())