Files
UnrealEngineUWP/Engine/Source/Developer/DerivedDataCache/Private/FileSystemDerivedDataBackend.cpp
Daniel Broder 9f50173ccf Merging using UE4-Fortnite-To-UE4 from CL 2236347
Unshelved this merge from Stephan and then completed the merge with additional fixes and testing.

Hand fixed some WorldExp compile issues due to changes to OnPaint() signature.

#Integration

[CL 2245992 by Daniel Broder in Main branch]
2014-08-06 16:12:41 -04:00

292 lines
11 KiB
C++

// Copyright 1998-2014 Epic Games, Inc. All Rights Reserved.
#include "Core.h"
#include "DerivedDataBackendInterface.h"
#include "DDCCleanup.h"
#define MAX_BACKEND_KEY_LENGTH (120)
#define MAX_BACKEND_NUMBERED_SUBFOLDER_LENGTH (9)
#define MAX_CACHE_DIR_LEN (119)
#define MAX_CACHE_EXTENTION_LEN (4)
/**
* Cache server that uses the OS filesystem
* The entire API should be callable from any thread (except the singleton can be assumed to be called at least once before concurrent access).
**/
class FFileSystemDerivedDataBackend : public FDerivedDataBackendInterface
{
public:
/**
* Constructor that should only be called once by the singleton, grabs the cache path from the ini
* @param InCacheDirectory directory to store the cache in
* @param bForceReadOnly if true, do not attempt to write to this cache
*/
FFileSystemDerivedDataBackend(const TCHAR* InCacheDirectory, bool bForceReadOnly, bool bTouchFiles, bool bPurgeTransientData, bool bDeleteOldFiles, int32 InDaysToDeleteUnusedFiles, int32 InMaxNumFoldersToCheck, int32 InMaxContinuousFileChecks)
: CachePath(InCacheDirectory)
, bReadOnly(bForceReadOnly)
, bFailed(true)
, bTouch(bTouchFiles)
, bPurgeTransient(bPurgeTransientData)
, DaysToDeleteUnusedFiles(InDaysToDeleteUnusedFiles)
{
// If we find a platform that has more stingent limits, this needs to be rethought.
static_assert(MAX_BACKEND_KEY_LENGTH + MAX_CACHE_DIR_LEN + MAX_BACKEND_NUMBERED_SUBFOLDER_LENGTH + MAX_CACHE_EXTENTION_LEN < PLATFORM_MAX_FILEPATH_LENGTH,
"Not enough room left for cache keys in max path.");
const double SlowInitDuration = 10.0;
double AccessDuration = 0.0;
check(CachePath.Len());
FPaths::NormalizeFilename(CachePath);
const FString AbsoluteCachePath = IFileManager::Get().ConvertToAbsolutePathForExternalAppForRead(*CachePath);
if (AbsoluteCachePath.Len() > MAX_CACHE_DIR_LEN)
{
const FText ErrorMessage = FText::Format( NSLOCTEXT("DerivedDataCache", "PathTooLong", "Cache path {0} is longer than {1} characters...please adjust [DerivedDataBackendGraph] paths to be shorter (this leaves more room for cache keys)."), FText::FromString( AbsoluteCachePath ), FText::AsNumber( MAX_CACHE_DIR_LEN ) );
FMessageDialog::Open(EAppMsgType::Ok, ErrorMessage);
UE_LOG(LogDerivedDataCache, Fatal, TEXT("%s"), *ErrorMessage.ToString());
}
if (!bReadOnly)
{
double TestStart = FPlatformTime::Seconds();
FString TempFilename = CachePath / FGuid::NewGuid().ToString() + ".tmp";
FFileHelper::SaveStringToFile(FString("TEST"),*TempFilename);
int32 TestFileSize = IFileManager::Get().FileSize(*TempFilename);
if (TestFileSize < 4)
{
UE_LOG(LogDerivedDataCache, Warning, TEXT("Fail to write to %s, derived data cache to this directory will be read only."),*CachePath);
}
else
{
bFailed = false;
}
if (TestFileSize >= 0)
{
IFileManager::Get().Delete(*TempFilename, false, false, true);
}
AccessDuration = FPlatformTime::Seconds() - TestStart;
}
if (bFailed)
{
double StartTime = FPlatformTime::Seconds();
TArray<FString> FilesAndDirectories;
IFileManager::Get().FindFiles(FilesAndDirectories,*(CachePath / TEXT("*.*")), true, true);
AccessDuration = FPlatformTime::Seconds() - StartTime;
if (FilesAndDirectories.Num() > 0)
{
bReadOnly = true;
bFailed = false;
}
}
if (FString(FCommandLine::Get()).Contains(TEXT("DerivedDataCache")) )
{
bTouch = true; // we always touch files when running the DDC commandlet
}
// The command line (-ddctouch) enables touch on all filesystem backends if specified.
bTouch = bTouch || FParse::Param(FCommandLine::Get(), TEXT("DDCTOUCH"));
if (bReadOnly)
{
bTouch = false; // we won't touch read only paths
}
if (bTouch)
{
UE_LOG(LogDerivedDataCache, Display, TEXT("Files in %s will be touched."),*CachePath);
}
if (!bFailed && AccessDuration > SlowInitDuration)
{
UE_LOG(LogDerivedDataCache, Warning, TEXT("%s access is very slow (initialization took %.2lf seconds), consider disabling it."), *CachePath, AccessDuration);
}
if (!bReadOnly && !bFailed && bDeleteOldFiles && !FParse::Param(FCommandLine::Get(),TEXT("NODDCCLEANUP")) && FDDCCleanup::Get())
{
FDDCCleanup::Get()->AddFilesystem( CachePath, InDaysToDeleteUnusedFiles, InMaxNumFoldersToCheck, InMaxContinuousFileChecks );
}
}
/** return true if the cache is usable **/
bool IsUsable()
{
return !bFailed;
}
/** return true if this cache is writable **/
virtual bool IsWritable()
{
return !bReadOnly;
}
/**
* Synchronous test for the existence of a cache item
*
* @param CacheKey Alphanumeric+underscore key of this cache item
* @return true if the data probably will be found, this can't be guaranteed because of concurrency in the backends, corruption, etc
*/
virtual bool CachedDataProbablyExists(const TCHAR* CacheKey)
{
check(!bFailed);
FString Filename = BuildFilename(CacheKey);
FDateTime TimeStamp = IFileManager::Get().GetTimeStamp(*Filename);
bool bExists = TimeStamp > FDateTime::MinValue();
if (bExists)
{
// Update file timestamp to prevent it from being deleted by DDC Cleanup.
if (bTouch ||
(!bReadOnly && (FDateTime::UtcNow() - TimeStamp).GetDays() > (DaysToDeleteUnusedFiles / 4)))
{
IFileManager::Get().SetTimeStamp(*Filename, FDateTime::UtcNow());
}
}
return bExists;
}
/**
* Synchronous retrieve of a cache item
*
* @param CacheKey Alphanumeric+underscore key of this cache item
* @param OutData Buffer to receive the results, if any were found
* @return true if any data was found, and in this case OutData is non-empty
*/
virtual bool GetCachedData(const TCHAR* CacheKey,TArray<uint8>& Data)
{
check(!bFailed);
FString Filename = BuildFilename(CacheKey);
double StartTime = FPlatformTime::Seconds();
if (FFileHelper::LoadFileToArray(Data,*Filename,FILEREAD_Silent))
{
double ReadDuration = FPlatformTime::Seconds() - StartTime;
double ReadSpeed = ReadDuration > 5.0 ? (Data.Num() / ReadDuration) / (1024.0 * 1024.0) : 100.0;
// Slower than 0.5MB/s?
UE_CLOG(ReadSpeed < 0.5, LogDerivedDataCache, Warning, TEXT("%s access is very slow (%.2lfMB/s), consider disabling it."), *CachePath, ReadSpeed);
UE_LOG(LogDerivedDataCache, Verbose, TEXT("FileSystemDerivedDataBackend: Cache hit on %s"),*Filename);
return true;
}
UE_LOG(LogDerivedDataCache, Verbose, TEXT("FileSystemDerivedDataBackend: Cache miss on %s"),*Filename);
Data.Empty();
return false;
}
/**
* Asynchronous, fire-and-forget placement of a cache item
*
* @param CacheKey Alphanumeric+underscore key of this cache item
* @param OutData Buffer containing the data to cache, can be destroyed after the call returns, immediately
* @param bPutEvenIfExists If true, then do not attempt skip the put even if CachedDataProbablyExists returns true
*/
virtual void PutCachedData(const TCHAR* CacheKey, TArray<uint8>& Data, bool bPutEvenIfExists) override
{
check(!bFailed);
if (!bReadOnly)
{
if (bPutEvenIfExists || !CachedDataProbablyExists(CacheKey))
{
check(Data.Num());
FString Filename = BuildFilename(CacheKey);
FString TempFilename(TEXT("temp."));
TempFilename += FGuid::NewGuid().ToString();
TempFilename = FPaths::GetPath(Filename) / TempFilename;
bool bResult;
{
bResult = FFileHelper::SaveArrayToFile(Data, *TempFilename);
}
if (bResult)
{
if (IFileManager::Get().FileSize(*TempFilename) == Data.Num())
{
bool DoMove = !CachedDataProbablyExists(CacheKey);
if (bPutEvenIfExists && !DoMove)
{
DoMove = true;
RemoveCachedData(CacheKey, /*bTransient=*/ false);
}
if (DoMove)
{
if (!IFileManager::Get().Move(*Filename, *TempFilename, true, true, false, true))
{
UE_LOG(LogDerivedDataCache, Log, TEXT("FFileSystemDerivedDataBackend: Move collision, attempt at redundant update, OK %s."),*Filename);
}
else
{
UE_LOG(LogDerivedDataCache, Verbose, TEXT("FFileSystemDerivedDataBackend: Successful cache put to %s"),*Filename);
}
}
}
else
{
UE_LOG(LogDerivedDataCache, Warning, TEXT("FFileSystemDerivedDataBackend: Temp file is short %s!"),*TempFilename);
}
}
else
{
UE_LOG(LogDerivedDataCache, Warning, TEXT("FFileSystemDerivedDataBackend: Could not write temp file %s!"),*TempFilename);
}
// if everything worked, this is not necessary, but we will make every effort to avoid leaving junk in the cache
if (FPaths::FileExists(TempFilename))
{
IFileManager::Get().Delete(*TempFilename, false, false, true);
}
}
}
}
void RemoveCachedData(const TCHAR* CacheKey, bool bTransient) override
{
check(!bFailed);
if (!bReadOnly && (!bTransient || bPurgeTransient))
{
FString Filename = BuildFilename(CacheKey);
if (bTransient)
{
UE_LOG(LogDerivedDataCache,Verbose,TEXT("Deleting transient cached data. Key=%s Filename=%s"),CacheKey,*Filename);
}
IFileManager::Get().Delete(*Filename, false, false, true);
}
}
private:
/**
* Threadsafe method to compute the filename from the cachekey, currently just adds a path and an extension.
*
* @param CacheKey Alphanumeric+underscore key of this cache item
* @return filename built from the cache key
*/
FString BuildFilename(const TCHAR* CacheKey)
{
FString Key = FString(CacheKey).ToUpper();
for (int32 i = 0; i < Key.Len(); i++)
{
check(FChar::IsAlnum(Key[i]) || FChar::IsUnderscore(Key[i]) || Key[i] == L'$');
}
uint32 Hash = FCrc::StrCrc_DEPRECATED(*Key);
// this creates a tree of 1000 directories
FString HashPath = FString::Printf(TEXT("%1d/%1d/%1d/"),(Hash/100)%10,(Hash/10)%10,Hash%10);
return CachePath / HashPath / Key + TEXT(".udd");
}
/** Base path we are storing the cache files in. **/
FString CachePath;
/** If true, do not attempt to write to this cache **/
bool bReadOnly;
/** If true, we failed to write to this directory and it did not contain anything so we should not be used **/
bool bFailed;
/** If true, CachedDataProbablyExists will update the file timestamps. */
bool bTouch;
/** If true, allow transient data to be removed from the cache. */
bool bPurgeTransient;
/** Age of file when it should be deleted from DDC cache. */
int32 DaysToDeleteUnusedFiles;
};
FDerivedDataBackendInterface* CreateFileSystemDerivedDataBackend(const TCHAR* CacheDirectory, bool bForceReadOnly /*= false*/, bool bTouchFiles /*= false*/, bool bPurgeTransient /*= false*/, bool bDeleteOldFiles /*= false*/, int32 InDaysToDeleteUnusedFiles /*= 60*/, int32 InMaxNumFoldersToCheck /*= -1*/, int32 InMaxContinuousFileChecks /*= -1*/)
{
FFileSystemDerivedDataBackend* FileDDB = new FFileSystemDerivedDataBackend(CacheDirectory, bForceReadOnly, bTouchFiles, bPurgeTransient, bDeleteOldFiles, InDaysToDeleteUnusedFiles, InMaxNumFoldersToCheck, InMaxContinuousFileChecks);
if (!FileDDB->IsUsable())
{
delete FileDDB;
FileDDB = NULL;
}
return FileDDB;
}