X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FProfileData%2FInstrProfReader.cpp;h=6f201243736d09baecce19d27c1fa7478a70add8;hb=7b81b822ba8418a27225056bff9229b2d6c7dca9;hp=c563355599f103814c16e4530f5173df9186cdc6;hpb=ddfcb21b3f728fd569e106f43c1bcaed356223e4;p=oota-llvm.git

diff --git a/lib/ProfileData/InstrProfReader.cpp b/lib/ProfileData/InstrProfReader.cpp
index c563355599f..6f201243736 100644
--- a/lib/ProfileData/InstrProfReader.cpp
+++ b/lib/ProfileData/InstrProfReader.cpp
@@ -13,48 +13,85 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ProfileData/InstrProfReader.h"
-#include "llvm/ProfileData/InstrProf.h"
-
+#include "llvm/ADT/STLExtras.h"
 #include <cassert>
 
 using namespace llvm;
 
-static uint64_t getRawMagic() {
-  return
-    uint64_t('l') << 56 |
-    uint64_t('p') << 48 |
-    uint64_t('r') << 40 |
-    uint64_t('o') << 32 |
-    uint64_t('f') << 24 |
-    uint64_t('r') << 16 |
-    uint64_t('a') <<  8 |
-    uint64_t('w');
-}
-
-error_code InstrProfReader::create(std::string Path,
-                                   std::unique_ptr<InstrProfReader> &Result) {
-  std::unique_ptr<MemoryBuffer> Buffer;
-  if (error_code EC = MemoryBuffer::getFileOrSTDIN(Path, Buffer))
+static ErrorOr<std::unique_ptr<MemoryBuffer>>
+setupMemoryBuffer(std::string Path) {
+  ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
+      MemoryBuffer::getFileOrSTDIN(Path);
+  if (std::error_code EC = BufferOrErr.getError())
+    return EC;
+  return std::move(BufferOrErr.get());
+}
+
+static std::error_code initializeReader(InstrProfReader &Reader) {
+  return Reader.readHeader();
+}
+
+ErrorOr<std::unique_ptr<InstrProfReader>>
+InstrProfReader::create(std::string Path) {
+  // Set up the buffer to read.
+  auto BufferOrError = setupMemoryBuffer(Path);
+  if (std::error_code EC = BufferOrError.getError())
     return EC;
+  return InstrProfReader::create(std::move(BufferOrError.get()));
+}
 
-  // Sanity check the file.
+ErrorOr<std::unique_ptr<InstrProfReader>>
+InstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
+  // Sanity check the buffer.
   if (Buffer->getBufferSize() > std::numeric_limits<unsigned>::max())
     return instrprof_error::too_large;
 
-  if (Buffer->getBufferSize() < sizeof(uint64_t)) {
-    Result.reset(new TextInstrProfReader(Buffer));
-    Result->readHeader();
-    return instrprof_error::success;
-  }
-
-  uint64_t Magic = *(uint64_t *)Buffer->getBufferStart();
-  uint64_t SwappedMagic = sys::SwapByteOrder(Magic);
-  if (Magic == getRawMagic() || SwappedMagic == getRawMagic())
-    Result.reset(new RawInstrProfReader(Buffer));
+  std::unique_ptr<InstrProfReader> Result;
+  // Create the reader.
+  if (IndexedInstrProfReader::hasFormat(*Buffer))
+    Result.reset(new IndexedInstrProfReader(std::move(Buffer)));
+  else if (RawInstrProfReader64::hasFormat(*Buffer))
+    Result.reset(new RawInstrProfReader64(std::move(Buffer)));
+  else if (RawInstrProfReader32::hasFormat(*Buffer))
+    Result.reset(new RawInstrProfReader32(std::move(Buffer)));
+  else if (TextInstrProfReader::hasFormat(*Buffer))
+    Result.reset(new TextInstrProfReader(std::move(Buffer)));
   else
-    Result.reset(new TextInstrProfReader(Buffer));
-  Result->readHeader();
-  return instrprof_error::success;
+    return instrprof_error::unrecognized_format;
+
+  // Initialize the reader and return the result.
+  if (std::error_code EC = initializeReader(*Result))
+    return EC;
+
+  return std::move(Result);
+}
+
+ErrorOr<std::unique_ptr<IndexedInstrProfReader>>
+IndexedInstrProfReader::create(std::string Path) {
+  // Set up the buffer to read.
+  auto BufferOrError = setupMemoryBuffer(Path);
+  if (std::error_code EC = BufferOrError.getError())
+    return EC;
+  return IndexedInstrProfReader::create(std::move(BufferOrError.get()));
+}
+
+
+ErrorOr<std::unique_ptr<IndexedInstrProfReader>>
+IndexedInstrProfReader::create(std::unique_ptr<MemoryBuffer> Buffer) {
+  // Sanity check the buffer.
+  if (Buffer->getBufferSize() > std::numeric_limits<unsigned>::max())
+    return instrprof_error::too_large;
+
+  // Create the reader.
+  if (!IndexedInstrProfReader::hasFormat(*Buffer))
+    return instrprof_error::bad_magic;
+  auto Result = llvm::make_unique<IndexedInstrProfReader>(std::move(Buffer));
+
+  // Initialize the reader and return the result.
+  if (std::error_code EC = initializeReader(*Result))
+    return EC;
+
+  return std::move(Result);
 }
 
 void InstrProfIterator::Increment() {
@@ -62,9 +99,18 @@ void InstrProfIterator::Increment() {
     *this = InstrProfIterator();
 }
 
-error_code TextInstrProfReader::readNextRecord(InstrProfRecord &Record) {
-  // Skip empty lines.
-  while (!Line.is_at_end() && Line->empty())
+bool TextInstrProfReader::hasFormat(const MemoryBuffer &Buffer) {
+  // Verify that this really looks like plain ASCII text by checking a
+  // 'reasonable' number of characters (up to profile magic size).
+  size_t count = std::min(Buffer.getBufferSize(), sizeof(uint64_t));
+  StringRef buffer = Buffer.getBufferStart();
+  return count == 0 || std::all_of(buffer.begin(), buffer.begin() + count,
+    [](char c) { return ::isprint(c) || ::isspace(c); });
+}
+
+std::error_code TextInstrProfReader::readNextRecord(InstrProfRecord &Record) {
+  // Skip empty lines and comments.
+  while (!Line.is_at_end() && (Line->empty() || Line->startswith("#")))
     ++Line;
   // If we hit EOF while looking for a name, we're done.
   if (Line.is_at_end())
@@ -76,7 +122,7 @@ error_code TextInstrProfReader::readNextRecord(InstrProfRecord &Record) {
   // Read the function hash.
   if (Line.is_at_end())
     return error(instrprof_error::truncated);
-  if ((Line++)->getAsInteger(10, Record.Hash))
+  if ((Line++)->getAsInteger(0, Record.Hash))
     return error(instrprof_error::malformed);
 
   // Read the number of counters.
@@ -85,49 +131,77 @@ error_code TextInstrProfReader::readNextRecord(InstrProfRecord &Record) {
     return error(instrprof_error::truncated);
   if ((Line++)->getAsInteger(10, NumCounters))
     return error(instrprof_error::malformed);
+  if (NumCounters == 0)
+    return error(instrprof_error::malformed);
 
   // Read each counter and fill our internal storage with the values.
-  Counts.clear();
-  Counts.reserve(NumCounters);
+  Record.Counts.clear();
+  Record.Counts.reserve(NumCounters);
   for (uint64_t I = 0; I < NumCounters; ++I) {
     if (Line.is_at_end())
       return error(instrprof_error::truncated);
     uint64_t Count;
     if ((Line++)->getAsInteger(10, Count))
       return error(instrprof_error::malformed);
-    Counts.push_back(Count);
+    Record.Counts.push_back(Count);
   }
-  // Give the record a reference to our internal counter storage.
-  Record.Counts = Counts;
 
   return success();
 }
 
-static uint64_t getRawVersion() {
-  return 1;
+template <class IntPtrT>
+bool RawInstrProfReader<IntPtrT>::hasFormat(const MemoryBuffer &DataBuffer) {
+  if (DataBuffer.getBufferSize() < sizeof(uint64_t))
+    return false;
+  uint64_t Magic =
+    *reinterpret_cast<const uint64_t *>(DataBuffer.getBufferStart());
+  return RawInstrProf::getMagic<IntPtrT>() == Magic ||
+         sys::getSwappedBytes(RawInstrProf::getMagic<IntPtrT>()) == Magic;
 }
-namespace {
+
+template <class IntPtrT>
+std::error_code RawInstrProfReader<IntPtrT>::readHeader() {
+  if (!hasFormat(*DataBuffer))
+    return error(instrprof_error::bad_magic);
+  if (DataBuffer->getBufferSize() < sizeof(RawInstrProf::Header))
+    return error(instrprof_error::bad_header);
+  auto *Header = reinterpret_cast<const RawInstrProf::Header *>(
+      DataBuffer->getBufferStart());
+  ShouldSwapBytes = Header->Magic != RawInstrProf::getMagic<IntPtrT>();
+  return readHeader(*Header);
 }
-RawInstrProfReader::RawInstrProfReader(std::unique_ptr<MemoryBuffer> &DataBuffer)
-    : DataBuffer(DataBuffer.release()) { }
 
-error_code RawInstrProfReader::readHeader() {
-  if (DataBuffer->getBufferSize() < sizeof(RawHeader))
-    return error(instrprof_error::malformed);
-  const RawHeader *Header = (RawHeader *)DataBuffer->getBufferStart();
-  if (Header->Magic == getRawMagic())
-    ShouldSwapBytes = false;
-  else {
-    if (sys::SwapByteOrder(Header->Magic) != getRawMagic())
-      return error(instrprof_error::malformed);
+template <class IntPtrT>
+std::error_code
+RawInstrProfReader<IntPtrT>::readNextHeader(const char *CurrentPos) {
+  const char *End = DataBuffer->getBufferEnd();
+  // Skip zero padding between profiles.
+  while (CurrentPos != End && *CurrentPos == 0)
+    ++CurrentPos;
+  // If there's nothing left, we're done.
+  if (CurrentPos == End)
+    return instrprof_error::eof;
+  // If there isn't enough space for another header, this is probably just
+  // garbage at the end of the file.
+  if (CurrentPos + sizeof(RawInstrProf::Header) > End)
+    return instrprof_error::malformed;
+  // The writer ensures each profile is padded to start at an aligned address.
+  if (reinterpret_cast<size_t>(CurrentPos) % alignOf<uint64_t>())
+    return instrprof_error::malformed;
+  // The magic should have the same byte order as in the previous header.
+  uint64_t Magic = *reinterpret_cast<const uint64_t *>(CurrentPos);
+  if (Magic != swap(RawInstrProf::getMagic<IntPtrT>()))
+    return instrprof_error::bad_magic;
 
-    ShouldSwapBytes = true;
-  }
+  // There's another profile to read, so we need to process the header.
+  auto *Header = reinterpret_cast<const RawInstrProf::Header *>(CurrentPos);
   return readHeader(*Header);
 }
 
-error_code RawInstrProfReader::readHeader(const RawHeader &Header) {
-  if (swap(Header.Version) != getRawVersion())
+template <class IntPtrT>
+std::error_code RawInstrProfReader<IntPtrT>::readHeader(
+    const RawInstrProf::Header &Header) {
+  if (swap(Header.Version) != RawInstrProf::Version)
     return error(instrprof_error::unsupported_version);
 
   CountersDelta = swap(Header.CountersDelta);
@@ -136,51 +210,305 @@ error_code RawInstrProfReader::readHeader(const RawHeader &Header) {
   auto CountersSize = swap(Header.CountersSize);
   auto NamesSize = swap(Header.NamesSize);
 
-  ptrdiff_t DataOffset = sizeof(RawHeader);
-  ptrdiff_t CountersOffset = DataOffset + sizeof(ProfileData) * DataSize;
+  ptrdiff_t DataOffset = sizeof(RawInstrProf::Header);
+  ptrdiff_t CountersOffset =
+      DataOffset + sizeof(RawInstrProf::ProfileData<IntPtrT>) * DataSize;
   ptrdiff_t NamesOffset = CountersOffset + sizeof(uint64_t) * CountersSize;
-  size_t FileSize = NamesOffset + sizeof(char) * NamesSize;
+  size_t ProfileSize = NamesOffset + sizeof(char) * NamesSize;
 
-  if (FileSize != DataBuffer->getBufferSize())
-    return error(instrprof_error::malformed);
+  auto *Start = reinterpret_cast<const char *>(&Header);
+  if (Start + ProfileSize > DataBuffer->getBufferEnd())
+    return error(instrprof_error::bad_header);
 
-  Data = (ProfileData *)(DataBuffer->getBufferStart() + DataOffset);
+  Data = reinterpret_cast<const RawInstrProf::ProfileData<IntPtrT> *>(
+      Start + DataOffset);
   DataEnd = Data + DataSize;
-  CountersStart = (uint64_t *)(DataBuffer->getBufferStart() + CountersOffset);
-  NamesStart = DataBuffer->getBufferStart() + NamesOffset;
+  CountersStart = reinterpret_cast<const uint64_t *>(Start + CountersOffset);
+  NamesStart = Start + NamesOffset;
+  ProfileEnd = Start + ProfileSize;
 
   return success();
 }
 
-error_code RawInstrProfReader::readNextRecord(InstrProfRecord &Record) {
-  if (Data == DataEnd)
-    return error(instrprof_error::eof);
+template <class IntPtrT>
+std::error_code RawInstrProfReader<IntPtrT>::readName(InstrProfRecord &Record) {
+  Record.Name = StringRef(getName(Data->NamePtr), swap(Data->NameSize));
+  if (Record.Name.data() < NamesStart ||
+      Record.Name.data() + Record.Name.size() > DataBuffer->getBufferEnd())
+    return error(instrprof_error::malformed);
 
-  // Get the raw data.
-  StringRef RawName(getName(Data->NamePtr), swap(Data->NameSize));
-  auto RawCounts = makeArrayRef(getCounter(Data->CounterPtr),
-                                swap(Data->NumCounters));
+  return success();
+}
+
+template <class IntPtrT>
+std::error_code RawInstrProfReader<IntPtrT>::readFuncHash(
+    InstrProfRecord &Record) {
+  Record.Hash = swap(Data->FuncHash);
+  return success();
+}
+
+template <class IntPtrT>
+std::error_code RawInstrProfReader<IntPtrT>::readRawCounts(
+    InstrProfRecord &Record) {
+  uint32_t NumCounters = swap(Data->NumCounters);
+  IntPtrT CounterPtr = Data->CounterPtr;
+  if (NumCounters == 0)
+    return error(instrprof_error::malformed);
+
+  auto RawCounts = makeArrayRef(getCounter(CounterPtr), NumCounters);
+  auto *NamesStartAsCounter = reinterpret_cast<const uint64_t *>(NamesStart);
 
   // Check bounds.
-  if (RawName.data() < NamesStart ||
-      RawName.data() + RawName.size() > DataBuffer->getBufferEnd() ||
-      RawCounts.data() < CountersStart ||
-      RawCounts.data() + RawCounts.size() > (uint64_t *)NamesStart)
+  if (RawCounts.data() < CountersStart ||
+      RawCounts.data() + RawCounts.size() > NamesStartAsCounter)
     return error(instrprof_error::malformed);
 
-  // Store the data in Record, byte-swapping as necessary.
-  Record.Hash = swap(Data->FuncHash);
-  Record.Name = RawName;
   if (ShouldSwapBytes) {
-    Counts.clear();
-    Counts.reserve(RawCounts.size());
+    Record.Counts.clear();
+    Record.Counts.reserve(RawCounts.size());
     for (uint64_t Count : RawCounts)
-      Counts.push_back(swap(Count));
-    Record.Counts = Counts;
+      Record.Counts.push_back(swap(Count));
   } else
     Record.Counts = RawCounts;
 
+  return success();
+}
+
+template <class IntPtrT>
+std::error_code
+RawInstrProfReader<IntPtrT>::readNextRecord(InstrProfRecord &Record) {
+  if (atEnd())
+    if (std::error_code EC = readNextHeader(ProfileEnd))
+      return EC;
+
+  // Read name ad set it in Record.
+  if (std::error_code EC = readName(Record))
+    return EC;
+
+  // Read FuncHash and set it in Record.
+  if (std::error_code EC = readFuncHash(Record))
+    return EC;
+
+  // Read raw counts and set Record.
+  if (std::error_code EC = readRawCounts(Record))
+    return EC;
+
   // Iterate.
-  ++Data;
+  advanceData();
+  return success();
+}
+
+namespace llvm {
+template class RawInstrProfReader<uint32_t>;
+template class RawInstrProfReader<uint64_t>;
+}
+
+InstrProfLookupTrait::hash_value_type
+InstrProfLookupTrait::ComputeHash(StringRef K) {
+  return IndexedInstrProf::ComputeHash(HashType, K);
+}
+
+typedef InstrProfLookupTrait::data_type data_type;
+typedef InstrProfLookupTrait::offset_type offset_type;
+
+bool InstrProfLookupTrait::ReadValueProfilingData(
+    const unsigned char *&D, const unsigned char *const End) {
+  ErrorOr<std::unique_ptr<IndexedInstrProf::ValueProfData>> VDataPtrOrErr =
+      IndexedInstrProf::ValueProfData::getValueProfData(
+          D, End, ValueProfDataEndianness);
+
+  if (VDataPtrOrErr.getError())
+    return false;
+
+  VDataPtrOrErr.get()->deserializeTo(DataBuffer.back(), &HashKeys);
+  D += VDataPtrOrErr.get()->TotalSize;
+
+  return true;
+}
+
+data_type InstrProfLookupTrait::ReadData(StringRef K, const unsigned char *D,
+                                         offset_type N) {
+  // Check if the data is corrupt. If so, don't try to read it.
+  if (N % sizeof(uint64_t))
+    return data_type();
+
+  DataBuffer.clear();
+  std::vector<uint64_t> CounterBuffer;
+
+  using namespace support;
+  const unsigned char *End = D + N;
+  while (D < End) {
+    // Read hash.
+    if (D + sizeof(uint64_t) >= End)
+      return data_type();
+    uint64_t Hash = endian::readNext<uint64_t, little, unaligned>(D);
+
+    // Initialize number of counters for FormatVersion == 1.
+    uint64_t CountsSize = N / sizeof(uint64_t) - 1;
+    // If format version is different then read the number of counters.
+    if (FormatVersion != 1) {
+      if (D + sizeof(uint64_t) > End)
+        return data_type();
+      CountsSize = endian::readNext<uint64_t, little, unaligned>(D);
+    }
+    // Read counter values.
+    if (D + CountsSize * sizeof(uint64_t) > End)
+      return data_type();
+
+    CounterBuffer.clear();
+    CounterBuffer.reserve(CountsSize);
+    for (uint64_t J = 0; J < CountsSize; ++J)
+      CounterBuffer.push_back(endian::readNext<uint64_t, little, unaligned>(D));
+
+    DataBuffer.emplace_back(K, Hash, std::move(CounterBuffer));
+
+    // Read value profiling data.
+    if (FormatVersion > 2 && !ReadValueProfilingData(D, End)) {
+      DataBuffer.clear();
+      return data_type();
+    }
+  }
+  return DataBuffer;
+}
+
+std::error_code
+InstrProfReaderIndex::getRecords(StringRef FuncName,
+                                 ArrayRef<InstrProfRecord> &Data) {
+  auto Iter = Index->find(FuncName);
+  if (Iter == Index->end())
+    return instrprof_error::unknown_function;
+
+  Data = (*Iter);
+  if (Data.empty())
+    return instrprof_error::malformed;
+
+  return instrprof_error::success;
+}
+
+std::error_code InstrProfReaderIndex::getRecords(
+    ArrayRef<InstrProfRecord> &Data) {
+  if (atEnd()) return instrprof_error::eof;
+
+  Data = *RecordIterator;
+
+  if (Data.empty()) return instrprof_error::malformed;
+
+  return instrprof_error::success;
+}
+
+void InstrProfReaderIndex::Init(const unsigned char *Buckets,
+                                const unsigned char *const Payload,
+                                const unsigned char *const Base,
+                                IndexedInstrProf::HashT HashType,
+                                uint64_t Version) {
+  FormatVersion = Version;
+  Index.reset(IndexType::Create(Buckets, Payload, Base,
+                                InstrProfLookupTrait(HashType, Version)));
+  // Form the map of hash values to const char* keys in profiling data.
+  std::vector<std::pair<uint64_t, const char *>> HashKeys;
+  for (auto Key : Index->keys()) {
+    const char *KeyTableRef = StringTable.insertString(Key);
+    HashKeys.push_back(std::make_pair(ComputeHash(HashType, Key), KeyTableRef));
+  }
+  std::sort(HashKeys.begin(), HashKeys.end(), less_first());
+  HashKeys.erase(std::unique(HashKeys.begin(), HashKeys.end()), HashKeys.end());
+  // Set the hash key map for the InstrLookupTrait
+  Index->getInfoObj().setHashKeys(std::move(HashKeys));
+  RecordIterator = Index->data_begin();
+}
+
+bool IndexedInstrProfReader::hasFormat(const MemoryBuffer &DataBuffer) {
+  if (DataBuffer.getBufferSize() < 8)
+    return false;
+  using namespace support;
+  uint64_t Magic =
+      endian::read<uint64_t, little, aligned>(DataBuffer.getBufferStart());
+  // Verify that it's magical.
+  return Magic == IndexedInstrProf::Magic;
+}
+
+std::error_code IndexedInstrProfReader::readHeader() {
+  const unsigned char *Start =
+      (const unsigned char *)DataBuffer->getBufferStart();
+  const unsigned char *Cur = Start;
+  if ((const unsigned char *)DataBuffer->getBufferEnd() - Cur < 24)
+    return error(instrprof_error::truncated);
+
+  using namespace support;
+
+  auto *Header = reinterpret_cast<const IndexedInstrProf::Header *>(Cur);
+  Cur += sizeof(IndexedInstrProf::Header);
+
+  // Check the magic number.
+  uint64_t Magic = endian::byte_swap<uint64_t, little>(Header->Magic);
+  if (Magic != IndexedInstrProf::Magic)
+    return error(instrprof_error::bad_magic);
+
+  // Read the version.
+  uint64_t FormatVersion = endian::byte_swap<uint64_t, little>(Header->Version);
+  if (FormatVersion > IndexedInstrProf::Version)
+    return error(instrprof_error::unsupported_version);
+
+  // Read the maximal function count.
+  MaxFunctionCount =
+      endian::byte_swap<uint64_t, little>(Header->MaxFunctionCount);
+
+  // Read the hash type and start offset.
+  IndexedInstrProf::HashT HashType = static_cast<IndexedInstrProf::HashT>(
+      endian::byte_swap<uint64_t, little>(Header->HashType));
+  if (HashType > IndexedInstrProf::HashT::Last)
+    return error(instrprof_error::unsupported_hash_type);
+
+  uint64_t HashOffset = endian::byte_swap<uint64_t, little>(Header->HashOffset);
+
+  // The rest of the file is an on disk hash table.
+  Index.Init(Start + HashOffset, Cur, Start, HashType, FormatVersion);
+
+  return success();
+}
+
+ErrorOr<InstrProfRecord>
+IndexedInstrProfReader::getInstrProfRecord(StringRef FuncName,
+                                           uint64_t FuncHash) {
+  ArrayRef<InstrProfRecord> Data;
+  std::error_code EC = Index.getRecords(FuncName, Data);
+  if (EC != instrprof_error::success)
+    return EC;
+  // Found it. Look for counters with the right hash.
+  for (unsigned I = 0, E = Data.size(); I < E; ++I) {
+    // Check for a match and fill the vector if there is one.
+    if (Data[I].Hash == FuncHash) {
+      return std::move(Data[I]);
+    }
+  }
+  return error(instrprof_error::hash_mismatch);
+}
+
+std::error_code
+IndexedInstrProfReader::getFunctionCounts(StringRef FuncName, uint64_t FuncHash,
+                                          std::vector<uint64_t> &Counts) {
+  ErrorOr<InstrProfRecord> Record = getInstrProfRecord(FuncName, FuncHash);
+  if (std::error_code EC = Record.getError())
+    return EC;
+
+  Counts = Record.get().Counts;
+  return success();
+}
+
+std::error_code IndexedInstrProfReader::readNextRecord(
+    InstrProfRecord &Record) {
+  static unsigned RecordIndex = 0;
+
+  ArrayRef<InstrProfRecord> Data;
+
+  std::error_code EC = Index.getRecords(Data);
+  if (EC != instrprof_error::success)
+    return error(EC);
+
+  Record = Data[RecordIndex++];
+  if (RecordIndex >= Data.size()) {
+    Index.advanceToNextKey();
+    RecordIndex = 0;
+  }
   return success();
 }