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// Copyright Epic Games, Inc. All Rights Reserved.
#include <zenstore/cas.h>
#include "CompactCas.h"
#include <zencore/except.h>
#include <zencore/memory.h>
#include <zencore/string.h>
#include <zencore/thread.h>
#include <zencore/uid.h>
#include <filesystem>
#include <functional>
#include <gsl/gsl-lite.hpp>
//////////////////////////////////////////////////////////////////////////
namespace zen {
void
CasContainerStrategy::Initialize(const std::string_view ContainerBaseName, uint64_t Alignment, bool IsNewStore)
{
ZEN_ASSERT(IsPow2(Alignment));
ZEN_ASSERT(!m_IsInitialized);
m_PayloadAlignment = Alignment;
std::string BaseName(ContainerBaseName);
std::filesystem::path SobsPath = m_Config.RootDirectory / (BaseName + ".ucas");
std::filesystem::path SidxPath = m_Config.RootDirectory / (BaseName + ".uidx");
std::filesystem::path SlogPath = m_Config.RootDirectory / (BaseName + ".ulog");
m_SmallObjectFile.Open(SobsPath, IsNewStore);
m_SmallObjectIndex.Open(SidxPath, IsNewStore);
m_CasLog.Open(SlogPath, IsNewStore);
// TODO: should validate integrity of container files here
uint64_t MaxFileOffset = 0;
{
// This is not technically necessary (nobody should be accessing us from
// another thread at this stage) but may help static analysis
zen::RwLock::ExclusiveLockScope _(m_LocationMapLock);
m_CasLog.Replay([&](const CasDiskIndexEntry& Record) {
m_LocationMap[Record.Key] = Record.Location;
MaxFileOffset = std::max<uint64_t>(MaxFileOffset, Record.Location.Offset + Record.Location.Size);
});
}
m_CurrentInsertOffset = (MaxFileOffset + m_PayloadAlignment - 1) & ~(m_PayloadAlignment - 1);
m_CurrentIndexOffset = m_SmallObjectIndex.FileSize();
m_IsInitialized = true;
}
CasStore::InsertResult
CasContainerStrategy::InsertChunk(const void* ChunkData, size_t ChunkSize, const IoHash& ChunkHash)
{
{
RwLock::SharedLockScope _(m_LocationMapLock);
auto KeyIt = m_LocationMap.find(ChunkHash);
if (KeyIt != m_LocationMap.end())
{
return CasStore::InsertResult{.New = false};
}
}
// New entry
RwLock::ExclusiveLockScope _(m_InsertLock);
const uint64_t InsertOffset = m_CurrentInsertOffset;
m_SmallObjectFile.Write(ChunkData, ChunkSize, InsertOffset);
m_CurrentInsertOffset = (m_CurrentInsertOffset + ChunkSize + m_PayloadAlignment - 1) & ~(m_PayloadAlignment - 1);
RwLock::ExclusiveLockScope __(m_LocationMapLock);
CasDiskLocation Location{.Offset = InsertOffset, .Size = /* TODO FIX */ uint32_t(ChunkSize)};
m_LocationMap[ChunkHash] = Location;
CasDiskIndexEntry IndexEntry{.Key = ChunkHash, .Location = Location};
m_CasLog.Append(IndexEntry);
return CasStore::InsertResult{.New = true};
}
CasStore::InsertResult
CasContainerStrategy::InsertChunk(IoBuffer Chunk, const IoHash& ChunkHash)
{
return InsertChunk(Chunk.Data(), Chunk.Size(), ChunkHash);
}
IoBuffer
CasContainerStrategy::FindChunk(const IoHash& ChunkHash)
{
RwLock::SharedLockScope _(m_LocationMapLock);
auto KeyIt = m_LocationMap.find(ChunkHash);
if (KeyIt != m_LocationMap.end())
{
const CasDiskLocation& Location = KeyIt->second;
return zen::IoBufferBuilder::MakeFromFileHandle(m_SmallObjectFile.Handle(), Location.Offset, Location.Size);
}
// Not found
return IoBuffer();
}
bool
CasContainerStrategy::HaveChunk(const IoHash& ChunkHash)
{
RwLock::SharedLockScope _(m_LocationMapLock);
auto KeyIt = m_LocationMap.find(ChunkHash);
if (KeyIt != m_LocationMap.end())
{
return true;
}
return false;
}
void
CasContainerStrategy::FilterChunks(CasChunkSet& InOutChunks)
{
// This implementation is good enough for relatively small
// chunk sets (in terms of chunk identifiers), but would
// benefit from a better implementation which removes
// items incrementally for large sets, especially when
// we're likely to already have a large proportion of the
// chunks in the set
std::unordered_set<IoHash> HaveSet;
for (const IoHash& Hash : InOutChunks.GetChunkSet())
{
if (HaveChunk(Hash))
{
HaveSet.insert(Hash);
}
}
for (const IoHash& Hash : HaveSet)
{
InOutChunks.RemoveIfPresent(Hash);
}
}
void
CasContainerStrategy::Flush()
{
m_CasLog.Flush();
m_SmallObjectIndex.Flush();
m_SmallObjectFile.Flush();
}
void
CasContainerStrategy::Scrub()
{
RwLock::SharedLockScope _(m_LocationMapLock);
}
void
CasContainerStrategy::MakeSnapshot()
{
RwLock::SharedLockScope _(m_LocationMapLock);
std::vector<CasDiskIndexEntry> Entries{m_LocationMap.size()};
uint64_t EntryIndex = 0;
for (auto& Entry : m_LocationMap)
{
CasDiskIndexEntry& IndexEntry = Entries[EntryIndex++];
IndexEntry.Key = Entry.first;
IndexEntry.Location = Entry.second;
}
m_SmallObjectIndex.Write(Entries.data(), Entries.size() * sizeof(CasDiskIndexEntry), 0);
}
} // namespace zen
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