optimize filecas write file (#613)

* try to move file into place before trying speculative remove of target file

1 files changed, 10 insertions, 16 deletions

diff --git a/src/zenstore/cache/cachedisklayer.cpp b/src/zenstore/cache/cachedisklayer.cpp
index c2e811003..67f587a7c 100644
--- a/src/zenstore/cache/cachedisklayer.cpp
+++ b/src/zenstore/cache/cachedisklayer.cpp
@@ -2724,14 +2724,19 @@ ZenCacheDiskLayer::CacheBucket::PutStandaloneCacheValue(const IoHash& HashKey, c
 
 	RwLock::ExclusiveLockScope ValueLock(LockForHash(HashKey));
 
-	// We do a speculative remove of the file instead of probing with a exists call and check the error code instead
-	RemoveFile(FsPath, Ec);
+	// Assume parent directory exists
+	DataFile.MoveTemporaryIntoPlace(FsPath, Ec);
 	if (Ec)
 	{
-		if (Ec.value() != ENOENT)
+		CreateDirectories(FsPath.parent_path());
+
+		// Try again after we or someone else created the directory
+		Ec.clear();
+		DataFile.MoveTemporaryIntoPlace(FsPath, Ec);
+
+		if (Ec)
 		{
-			ZEN_WARN("Failed to remove file '{}' for put in '{}', reason: '{}', retrying.", FsPath, m_BucketDir, Ec.message());
-			Sleep(100);
+			// We do a speculative remove of the file instead of probing with a exists call and check the error code instead
 			Ec.clear();
 			RemoveFile(FsPath, Ec);
 			if (Ec && Ec.value() != ENOENT)
@@ -2739,17 +2744,6 @@ ZenCacheDiskLayer::CacheBucket::PutStandaloneCacheValue(const IoHash& HashKey, c
 				throw std::system_error(Ec, fmt::format("Failed to remove file '{}' for put in '{}'", FsPath, m_BucketDir));
 			}
 		}
-	}
-
-	// Assume parent directory exists
-	DataFile.MoveTemporaryIntoPlace(FsPath, Ec);
-	if (Ec)
-	{
-		CreateDirectories(FsPath.parent_path());
-
-		// Try again after we or someone else created the directory
-		Ec.clear();
-		DataFile.MoveTemporaryIntoPlace(FsPath, Ec);
 
 		// Retry if we still fail to handle contention to file system
 		uint32_t RetriesLeft = 3;