replace copy file (#403)

Custom CopyFile in zen builds command increasing throughput by 50% on Windows and give better progress update

2 files changed, 35 insertions, 6 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a7a24c75..591bd4e81 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -34,6 +34,7 @@
 - Improvement: Skip command line arguments that are empty or just a single space for `zen` command line tool on Mac/Linux to handle "triple space" problem. UE-273411
 - Improvement: Extend log information when httpsys response sending fails
 - Improvement: Log warning when port remappng occurs due to desired port is already in use
+- Improvement: Custom CopyFile in `zen builds` command increasing throughput by 50% on Windows and give better progress update
 
 ## 5.6.7
 - Feature: Support for `--log-progress` to output UE style `@progress` log messages has been added to
diff --git a/src/zen/cmds/builds_cmd.cpp b/src/zen/cmds/builds_cmd.cpp
index 78d362fdb..1a570d6da 100644
--- a/src/zen/cmds/builds_cmd.cpp
+++ b/src/zen/cmds/builds_cmd.cpp
@@ -304,6 +304,26 @@ namespace {
 		}
 	}
 
+	void CopyFile(const std::filesystem::path& SourceFilePath,
+				  const std::filesystem::path& TargetFilePath,
+				  uint64_t					   RawSize,
+				  std::atomic<uint64_t>&	   WriteCount,
+				  std::atomic<uint64_t>&	   WriteByteCount)
+	{
+		BasicFile TargetFile(TargetFilePath, BasicFile::Mode::kTruncate);
+		PrepareFileForScatteredWrite(TargetFile.Handle(), RawSize);
+		uint64_t Offset = 0;
+		if (!ScanFile(SourceFilePath, 512u * 1024u, [&](const void* Data, size_t Size) {
+				TargetFile.Write(Data, Size, Offset);
+				Offset += Size;
+				WriteCount++;
+				WriteByteCount += Size;
+			}))
+		{
+			throw std::runtime_error(fmt::format("Failed to copy scavanged file '{}' to '{}'", SourceFilePath, TargetFilePath));
+		}
+	}
+
 	uint32_t SetNativeFileAttributes(const std::filesystem::path FilePath, SourcePlatform SourcePlatform, uint32_t Attributes)
 	{
 #if ZEN_PLATFORM_WINDOWS
@@ -6198,6 +6218,10 @@ namespace {
 					Work.ScheduleWork(WritePool, [&, ScavengeOpIndex](std::atomic<bool>&) mutable {
 						if (!AbortFlag)
 						{
+							ZEN_TRACE_CPU("UpdateFolder_WriteScavanged");
+
+							FilteredWrittenBytesPerSecond.Start();
+
 							const ScavengeCopyOperation& ScavengeOp		  = ScavengeCopyOperations[ScavengeOpIndex];
 							const ChunkedFolderContent&	 ScavengedContent = ScavengedContents[ScavengeOp.ScavengedContentIndex];
 							const std::filesystem::path	 ScavengedPath	  = ScavengedContent.Paths[ScavengeOp.ScavengedPathIndex];
@@ -6211,10 +6235,8 @@ namespace {
 							const std::filesystem::path TempFilePath =
 								GetTempChunkedSequenceFileName(CacheFolderPath, RemoteSequenceRawHash);
 
-							CopyFile(ScavengedFilePath, TempFilePath, {.EnableClone = false});
-
-							DiskStats.WriteCount++;
-							DiskStats.WriteByteCount += ScavengeOp.RawSize;
+							const uint64_t RawSize = ScavengedContent.RawSizes[ScavengeOp.ScavengedContentIndex];
+							CopyFile(ScavengedFilePath, TempFilePath, RawSize, DiskStats.WriteCount, DiskStats.WriteByteCount);
 
 							const std::filesystem::path CacheFilePath =
 								GetFinalChunkedSequenceFileName(CacheFolderPath, RemoteSequenceRawHash);
@@ -7527,7 +7549,10 @@ namespace {
 									ZEN_ASSERT_SLOW(IsFileWithRetry(SourceFilePath));
 
 									ZEN_DEBUG("Copying from '{}' -> '{}'", SourceFilePath, FirstTargetFilePath);
-									CopyFile(SourceFilePath, FirstTargetFilePath, {.EnableClone = false});
+									const uint64_t		  RawSize = LocalContent.RawSizes[LocalPathIndex];
+									std::atomic<uint64_t> WriteCount;
+									std::atomic<uint64_t> WriteByteCount;
+									CopyFile(SourceFilePath, FirstTargetFilePath, RawSize, WriteCount, WriteByteCount);
 									RebuildFolderStateStats.FinalizeTreeFilesCopiedCount++;
 								}
 								else
@@ -7581,7 +7606,10 @@ namespace {
 
 									ZEN_ASSERT_SLOW(IsFileWithRetry(FirstTargetFilePath));
 									ZEN_DEBUG("Copying from '{}' -> '{}'", FirstTargetFilePath, TargetFilePath);
-									CopyFile(FirstTargetFilePath, TargetFilePath, {.EnableClone = false});
+									const uint64_t		  RawSize = RemoteContent.RawSizes[RemotePathIndex];
+									std::atomic<uint64_t> WriteCount;
+									std::atomic<uint64_t> WriteByteCount;
+									CopyFile(FirstTargetFilePath, TargetFilePath, RawSize, WriteCount, WriteByteCount);
 									RebuildFolderStateStats.FinalizeTreeFilesCopiedCount++;
 								}