Files
UnrealEngineUWP/Engine/Source/Developer/DerivedDataCache/Private/DerivedDataCache.cpp
nick darnell 7fb5ae96d7 Changing the DDC interface to use TArrayView instead of TArray for placing data into the DDC.
Updating the ArrayView with new comparison operators to have greater replacement for what TArray provides.

#rb Marc.Audy, Steve.Robb


#ROBOMERGE-OWNER: nick.darnell
#ROBOMERGE-AUTHOR: nick.darnell
#ROBOMERGE-SOURCE: CL 11843381 via CL 11843463 via CL 11843492
#ROBOMERGE-BOT: (v656-11643781)

[CL 11879995 by nick darnell in Main branch]
2020-03-03 14:33:45 -05:00

548 lines
19 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "CoreMinimal.h"
#include "Misc/CommandLine.h"
#include "HAL/ThreadSafeCounter.h"
#include "Misc/ScopeLock.h"
#include "Stats/StatsMisc.h"
#include "Stats/Stats.h"
#include "Async/AsyncWork.h"
#include "Async/TaskGraphInterfaces.h"
#include "Serialization/MemoryReader.h"
#include "Serialization/MemoryWriter.h"
#include "Modules/ModuleManager.h"
#include "DerivedDataCacheInterface.h"
#include "DerivedDataBackendInterface.h"
#include "DerivedDataPluginInterface.h"
#include "DDCCleanup.h"
#include "ProfilingDebugging/CookStats.h"
DEFINE_STAT(STAT_DDC_NumGets);
DEFINE_STAT(STAT_DDC_NumPuts);
DEFINE_STAT(STAT_DDC_NumBuilds);
DEFINE_STAT(STAT_DDC_NumExist);
DEFINE_STAT(STAT_DDC_SyncGetTime);
DEFINE_STAT(STAT_DDC_ASyncWaitTime);
DEFINE_STAT(STAT_DDC_PutTime);
DEFINE_STAT(STAT_DDC_SyncBuildTime);
DEFINE_STAT(STAT_DDC_ExistTime);
//#define DDC_SCOPE_CYCLE_COUNTER(x) QUICK_SCOPE_CYCLE_COUNTER(STAT_ ## x)
#define DDC_SCOPE_CYCLE_COUNTER(x) TRACE_CPUPROFILER_EVENT_SCOPE(x);
#if ENABLE_COOK_STATS
#include "DerivedDataCacheUsageStats.h"
namespace DerivedDataCacheCookStats
{
// Use to prevent potential divide by zero issues
inline double SafeDivide(const int64 Numerator, const int64 Denominator)
{
return Denominator != 0 ? (double)Numerator / (double)Denominator : 0.0;
}
// AddCookStats cannot be a lambda because of false positives in static analysis.
// See https://developercommunity.visualstudio.com/content/problem/576913/c6244-regression-in-new-lambda-processorpermissive.html
static void AddCookStats(FCookStatsManager::AddStatFuncRef AddStat)
{
TMap<FString, FDerivedDataCacheUsageStats> DDCStats;
GetDerivedDataCacheRef().GatherUsageStats(DDCStats);
{
const FString StatName(TEXT("DDC.Usage"));
for (const auto& UsageStatPair : DDCStats)
{
UsageStatPair.Value.LogStats(AddStat, StatName, UsageStatPair.Key);
}
}
// Now lets add some summary data to that applies some crazy knowledge of how we set up our DDC. The goal
// is to print out the global hit rate, and the hit rate of the local and shared DDC.
// This is done by adding up the total get/miss calls the root node receives.
// Then we find the FileSystem nodes that correspond to the local and shared cache using some hacky logic to detect a "network drive".
// If the DDC graph ever contains more than one local or remote filesystem, this will only find one of them.
{
TArray<FString, TInlineAllocator<20>> Keys;
DDCStats.GenerateKeyArray(Keys);
FString* RootKey = Keys.FindByPredicate([](const FString& Key) {return Key.StartsWith(TEXT(" 0:")); });
// look for a Filesystem DDC that doesn't have a UNC path. Ugly, yeah, but we only cook on PC at the moment.
FString* LocalDDCKey = Keys.FindByPredicate([](const FString& Key) {return Key.Contains(TEXT(": FileSystem.")) && !Key.Contains(TEXT("//")); });
// look for a UNC path
FString* SharedDDCKey = Keys.FindByPredicate([](const FString& Key) {return Key.Contains(TEXT(": FileSystem.//")); });
if (RootKey)
{
const FDerivedDataCacheUsageStats& RootStats = DDCStats[*RootKey];
int64 TotalGetHits =
RootStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, true) +
RootStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, false);
int64 TotalGetMisses =
RootStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Miss, FCookStats::CallStats::EStatType::Counter, true) +
RootStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Miss, FCookStats::CallStats::EStatType::Counter, false);
int64 TotalGets = TotalGetHits + TotalGetMisses;
int64 LocalHits = 0;
if (LocalDDCKey)
{
const FDerivedDataCacheUsageStats& LocalDDCStats = DDCStats[*LocalDDCKey];
LocalHits =
LocalDDCStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, true) +
LocalDDCStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, false);
}
int64 SharedHits = 0;
if (SharedDDCKey)
{
// The shared DDC is only queried if the local one misses (or there isn't one). So it's hit rate is technically
const FDerivedDataCacheUsageStats& SharedDDCStats = DDCStats[*SharedDDCKey];
SharedHits =
SharedDDCStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, true) +
SharedDDCStats.GetStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, false);
}
int64 TotalPutHits =
RootStats.PutStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, true) +
RootStats.PutStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Hit, FCookStats::CallStats::EStatType::Counter, false);
int64 TotalPutMisses =
RootStats.PutStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Miss, FCookStats::CallStats::EStatType::Counter, true) +
RootStats.PutStats.GetAccumulatedValue(FCookStats::CallStats::EHitOrMiss::Miss, FCookStats::CallStats::EStatType::Counter, false);
int64 TotalPuts = TotalPutHits + TotalPutMisses;
AddStat(TEXT("DDC.Summary"), FCookStatsManager::CreateKeyValueArray(
TEXT("TotalGetHits"), TotalGetHits,
TEXT("TotalGets"), TotalGets,
TEXT("TotalGetHitPct"), SafeDivide(TotalGetHits, TotalGets),
TEXT("LocalGetHitPct"), SafeDivide(LocalHits, TotalGets),
TEXT("SharedGetHitPct"), SafeDivide(SharedHits, TotalGets),
TEXT("OtherGetHitPct"), SafeDivide((TotalGetHits - LocalHits - SharedHits), TotalGets),
TEXT("GetMissPct"), SafeDivide(TotalGetMisses, TotalGets),
TEXT("TotalPutHits"), TotalPutHits,
TEXT("TotalPuts"), TotalPuts,
TEXT("TotalPutHitPct"), SafeDivide(TotalPutHits, TotalPuts),
TEXT("PutMissPct"), SafeDivide(TotalPutMisses, TotalPuts)
));
}
}
}
FCookStatsManager::FAutoRegisterCallback RegisterCookStats(AddCookStats);
}
#endif
/** Whether we want to verify the DDC (pass in -VerifyDDC on the command line)*/
bool GVerifyDDC = false;
/**
* Implementation of the derived data cache
* This API is fully threadsafe
**/
class FDerivedDataCache : public FDerivedDataCacheInterface
{
/**
* Async worker that checks the cache backend and if that fails, calls the deriver to build the data and then puts the results to the cache
**/
friend class FBuildAsyncWorker;
class FBuildAsyncWorker : public FNonAbandonableTask
{
public:
/**
* Constructor for async task
* @param InDataDeriver plugin to produce cache key and in the event of a miss, return the data.
* @param InCacheKey Complete cache key for this data.
**/
FBuildAsyncWorker(FDerivedDataPluginInterface* InDataDeriver, const TCHAR* InCacheKey, bool bInSynchronousForStats)
: bSuccess(false)
, bSynchronousForStats(bInSynchronousForStats)
, bDataWasBuilt(false)
, DataDeriver(InDataDeriver)
, CacheKey(InCacheKey)
{
}
/** Async worker that checks the cache backend and if that fails, calls the deriver to build the data and then puts the results to the cache **/
void DoWork()
{
TRACE_CPUPROFILER_EVENT_SCOPE(DDC_DoWork);
const int32 NumBeforeDDC = Data.Num();
bool bGetResult;
{
TRACE_CPUPROFILER_EVENT_SCOPE(DDC_Get);
INC_DWORD_STAT(STAT_DDC_NumGets);
STAT(double ThisTime = 0);
{
SCOPE_SECONDS_COUNTER(ThisTime);
bGetResult = FDerivedDataBackend::Get().GetRoot().GetCachedData(*CacheKey, Data);
}
INC_FLOAT_STAT_BY(STAT_DDC_SyncGetTime, bSynchronousForStats ? (float)ThisTime : 0.0f);
}
if (bGetResult)
{
if(GVerifyDDC && DataDeriver && DataDeriver->IsDeterministic())
{
TArray<uint8> CmpData;
DataDeriver->Build(CmpData);
const int32 NumInDDC = Data.Num() - NumBeforeDDC;
const int32 NumGenerated = CmpData.Num();
bool bMatchesInSize = NumGenerated == NumInDDC;
bool bDifferentMemory = true;
int32 DifferentOffset = 0;
if (bMatchesInSize)
{
bDifferentMemory = false;
for (int32 i = 0; i < NumGenerated; i++)
{
if (CmpData[i] != Data[i])
{
bDifferentMemory = true;
DifferentOffset = i;
break;
}
}
}
if(!bMatchesInSize || bDifferentMemory)
{
FString ErrMsg = FString::Printf(TEXT("There is a mismatch between the DDC data and the generated data for plugin (%s) for asset (%s). BytesInDDC:%d, BytesGenerated:%d, bDifferentMemory:%d, offset:%d"), DataDeriver->GetPluginName(), *DataDeriver->GetDebugContextString(), NumInDDC, NumGenerated, bDifferentMemory, DifferentOffset);
ensureMsgf(false, TEXT("%s"), *ErrMsg);
UE_LOG(LogDerivedDataCache, Error, TEXT("%s"), *ErrMsg );
}
}
check(Data.Num());
bSuccess = true;
delete DataDeriver;
DataDeriver = NULL;
}
else if (DataDeriver)
{
{
TRACE_CPUPROFILER_EVENT_SCOPE(DDC_Build);
INC_DWORD_STAT(STAT_DDC_NumBuilds);
STAT(double ThisTime = 0);
{
SCOPE_SECONDS_COUNTER(ThisTime);
bSuccess = DataDeriver->Build(Data);
bDataWasBuilt = true;
}
INC_FLOAT_STAT_BY(STAT_DDC_SyncBuildTime, bSynchronousForStats ? (float)ThisTime : 0.0f);
}
delete DataDeriver;
DataDeriver = NULL;
if (bSuccess)
{
check(Data.Num());
TRACE_CPUPROFILER_EVENT_SCOPE(DDC_Put);
INC_DWORD_STAT(STAT_DDC_NumPuts);
STAT(double ThisTime = 0);
{
SCOPE_SECONDS_COUNTER(ThisTime);
FDerivedDataBackend::Get().GetRoot().PutCachedData(*CacheKey, Data, true);
}
INC_FLOAT_STAT_BY(STAT_DDC_PutTime, bSynchronousForStats ? (float)ThisTime : 0.0f);
}
}
if (!bSuccess)
{
Data.Empty();
}
FDerivedDataBackend::Get().AddToAsyncCompletionCounter(-1);
}
FORCEINLINE TStatId GetStatId() const
{
RETURN_QUICK_DECLARE_CYCLE_STAT(FBuildAsyncWorker, STATGROUP_ThreadPoolAsyncTasks);
}
/** true in the case of a cache hit, otherwise the result of the deriver build call **/
bool bSuccess;
/** true if we should record the timing **/
bool bSynchronousForStats;
/** true if we had to build the data */
bool bDataWasBuilt;
/** Data dervier we are operating on **/
FDerivedDataPluginInterface* DataDeriver;
/** Cache key associated with this build **/
FString CacheKey;
/** Data to return to caller, later **/
TArray<uint8> Data;
};
public:
/** Constructor, called once to cereate a singleton **/
FDerivedDataCache()
: CurrentHandle(19248) // we will skip some potential handles to catch errors
{
FDerivedDataBackend::Get(); // we need to make sure this starts before we all us to start
GVerifyDDC = FParse::Param(FCommandLine::Get(), TEXT("VerifyDDC"));
}
/** Destructor, flushes all sync tasks **/
~FDerivedDataCache()
{
FScopeLock ScopeLock(&SynchronizationObject);
for (TMap<uint32,FAsyncTask<FBuildAsyncWorker>*>::TIterator It(PendingTasks); It; ++It)
{
It.Value()->EnsureCompletion();
delete It.Value();
}
PendingTasks.Empty();
}
virtual bool GetSynchronous(FDerivedDataPluginInterface* DataDeriver, TArray<uint8>& OutData, bool* bDataWasBuilt = nullptr) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_GetSynchronous);
check(DataDeriver);
FString CacheKey = FDerivedDataCache::BuildCacheKey(DataDeriver);
UE_LOG(LogDerivedDataCache, Verbose, TEXT("GetSynchronous %s from '%s'"), *CacheKey, *DataDeriver->GetDebugContextString());
FAsyncTask<FBuildAsyncWorker> PendingTask(DataDeriver, *CacheKey, true);
AddToAsyncCompletionCounter(1);
PendingTask.StartSynchronousTask();
OutData = PendingTask.GetTask().Data;
if (bDataWasBuilt)
{
*bDataWasBuilt = PendingTask.GetTask().bDataWasBuilt;
}
return PendingTask.GetTask().bSuccess;
}
virtual uint32 GetAsynchronous(FDerivedDataPluginInterface* DataDeriver) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_GetAsynchronous);
FScopeLock ScopeLock(&SynchronizationObject);
const uint32 Handle = NextHandle();
FString CacheKey = FDerivedDataCache::BuildCacheKey(DataDeriver);
UE_LOG(LogDerivedDataCache, Verbose, TEXT("GetAsynchronous %s from '%s'"), *CacheKey, *DataDeriver->GetDebugContextString());
const bool bSync = !DataDeriver->IsBuildThreadsafe();
FAsyncTask<FBuildAsyncWorker>* AsyncTask = new FAsyncTask<FBuildAsyncWorker>(DataDeriver, *CacheKey, bSync);
check(!PendingTasks.Contains(Handle));
PendingTasks.Add(Handle,AsyncTask);
AddToAsyncCompletionCounter(1);
if (!bSync)
{
AsyncTask->StartBackgroundTask();
}
else
{
AsyncTask->StartSynchronousTask();
}
// Must return a valid handle
check(Handle != 0);
return Handle;
}
virtual bool PollAsynchronousCompletion(uint32 Handle) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_PollAsynchronousCompletion);
FAsyncTask<FBuildAsyncWorker>* AsyncTask = NULL;
{
FScopeLock ScopeLock(&SynchronizationObject);
AsyncTask = PendingTasks.FindRef(Handle);
}
check(AsyncTask);
return AsyncTask->IsDone();
}
virtual void WaitAsynchronousCompletion(uint32 Handle) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_WaitAsynchronousCompletion);
STAT(double ThisTime = 0);
{
SCOPE_SECONDS_COUNTER(ThisTime);
FAsyncTask<FBuildAsyncWorker>* AsyncTask = NULL;
{
FScopeLock ScopeLock(&SynchronizationObject);
AsyncTask = PendingTasks.FindRef(Handle);
}
check(AsyncTask);
AsyncTask->EnsureCompletion();
}
INC_FLOAT_STAT_BY(STAT_DDC_ASyncWaitTime,(float)ThisTime);
}
virtual bool GetAsynchronousResults(uint32 Handle, TArray<uint8>& OutData, bool* bDataWasBuilt = nullptr) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_GetAsynchronousResults);
FAsyncTask<FBuildAsyncWorker>* AsyncTask = NULL;
{
FScopeLock ScopeLock(&SynchronizationObject);
PendingTasks.RemoveAndCopyValue(Handle,AsyncTask);
}
check(AsyncTask);
if (bDataWasBuilt)
{
*bDataWasBuilt = AsyncTask->GetTask().bDataWasBuilt;
}
if (!AsyncTask->GetTask().bSuccess)
{
delete AsyncTask;
return false;
}
OutData = MoveTemp(AsyncTask->GetTask().Data);
delete AsyncTask;
check(OutData.Num());
return true;
}
virtual bool GetSynchronous(const TCHAR* CacheKey, TArray<uint8>& OutData, const FStringView& DataContext) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_GetSynchronous_Data);
UE_LOG(LogDerivedDataCache, Verbose, TEXT("GetSynchronous %s from '%.*s'"), CacheKey, DataContext.Len(), DataContext.GetData());
FAsyncTask<FBuildAsyncWorker> PendingTask((FDerivedDataPluginInterface*)NULL, CacheKey, true);
AddToAsyncCompletionCounter(1);
PendingTask.StartSynchronousTask();
OutData = PendingTask.GetTask().Data;
return PendingTask.GetTask().bSuccess;
}
virtual uint32 GetAsynchronous(const TCHAR* CacheKey, const FStringView& DataContext) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_GetAsynchronous_Handle);
FScopeLock ScopeLock(&SynchronizationObject);
UE_LOG(LogDerivedDataCache, Verbose, TEXT("GetAsynchronous %s from '%.*s'"), CacheKey, DataContext.Len(), DataContext.GetData());
const uint32 Handle = NextHandle();
FAsyncTask<FBuildAsyncWorker>* AsyncTask = new FAsyncTask<FBuildAsyncWorker>((FDerivedDataPluginInterface*)NULL, CacheKey, false);
check(!PendingTasks.Contains(Handle));
PendingTasks.Add(Handle, AsyncTask);
AddToAsyncCompletionCounter(1);
AsyncTask->StartBackgroundTask();
return Handle;
}
virtual void Put(const TCHAR* CacheKey, TArrayView<const uint8> Data, const FStringView& DataContext, bool bPutEvenIfExists = false) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_Put);
UE_LOG(LogDerivedDataCache, Verbose, TEXT("Put %s from '%.*s'"), CacheKey, DataContext.Len(), DataContext.GetData());
STAT(double ThisTime = 0);
{
SCOPE_SECONDS_COUNTER(ThisTime);
FDerivedDataBackend::Get().GetRoot().PutCachedData(CacheKey, Data, bPutEvenIfExists);
}
INC_FLOAT_STAT_BY(STAT_DDC_PutTime,(float)ThisTime);
INC_DWORD_STAT(STAT_DDC_NumPuts);
}
virtual void MarkTransient(const TCHAR* CacheKey) override
{
FDerivedDataBackend::Get().GetRoot().RemoveCachedData(CacheKey, /*bTransient=*/ true);
}
virtual bool CachedDataProbablyExists(const TCHAR* CacheKey) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_CachedDataProbablyExists);
bool bResult;
INC_DWORD_STAT(STAT_DDC_NumExist);
STAT(double ThisTime = 0);
{
SCOPE_SECONDS_COUNTER(ThisTime);
bResult = FDerivedDataBackend::Get().GetRoot().CachedDataProbablyExists(CacheKey);
}
INC_FLOAT_STAT_BY(STAT_DDC_ExistTime, (float)ThisTime);
return bResult;
}
void NotifyBootComplete() override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_NotifyBootComplete);
FDerivedDataBackend::Get().NotifyBootComplete();
}
void AddToAsyncCompletionCounter(int32 Addend) override
{
FDerivedDataBackend::Get().AddToAsyncCompletionCounter(Addend);
}
void WaitForQuiescence(bool bShutdown) override
{
DDC_SCOPE_CYCLE_COUNTER(DDC_WaitForQuiescence);
FDerivedDataBackend::Get().WaitForQuiescence(bShutdown);
}
/** Get whether a Shared Data Cache is in use */
virtual bool GetUsingSharedDDC() const override
{
return FDerivedDataBackend::Get().GetUsingSharedDDC();
}
void GetDirectories(TArray<FString>& OutResults) override
{
FDerivedDataBackend::Get().GetDirectories(OutResults);
}
virtual void GatherUsageStats(TMap<FString, FDerivedDataCacheUsageStats>& UsageStatsMap) override
{
FDerivedDataBackend::Get().GatherUsageStats(UsageStatsMap);
}
/** Get event delegate for data cache notifications */
virtual FOnDDCNotification& GetDDCNotificationEvent()
{
return DDCNotificationEvent;
}
protected:
uint32 NextHandle()
{
return (uint32)CurrentHandle.Increment();
}
private:
/**
* Internal function to build a cache key out of the plugin name, versions and plugin specific info
* @param DataDeriver plugin to produce the elements of the cache key.
* @return Assembled cache key
**/
static FString BuildCacheKey(FDerivedDataPluginInterface* DataDeriver)
{
FString Result = FDerivedDataCacheInterface::BuildCacheKey(DataDeriver->GetPluginName(), DataDeriver->GetVersionString(), *DataDeriver->GetPluginSpecificCacheKeySuffix());
return Result;
}
/** Counter used to produce unique handles **/
FThreadSafeCounter CurrentHandle;
/** Object used for synchronization via a scoped lock **/
FCriticalSection SynchronizationObject;
/** Map of handle to pending task **/
TMap<uint32,FAsyncTask<FBuildAsyncWorker>*> PendingTasks;
/** Cache notification delegate */
FOnDDCNotification DDCNotificationEvent;
};
/**
* Module for the DDC
*/
class FDerivedDataCacheModule : public IDerivedDataCacheModule
{
public:
virtual FDerivedDataCacheInterface& GetDDC() override
{
static FDerivedDataCache SingletonInstance;
return SingletonInstance;
}
virtual void StartupModule() override
{
GetDDC();
}
virtual void ShutdownModule() override
{
FDDCCleanup::Shutdown();
}
};
IMPLEMENT_MODULE( FDerivedDataCacheModule, DerivedDataCache);