MBLayoutPtr SequencePacker::CreateMBLayout(const StreamBatch& batch)
{
vector<MBLayout::SequenceInfo> infos;
for (size_t index = 0; index < batch.size(); ++index)
{
MBLayout::SequenceInfo info;
info.seqId = index;
info.tBegin = 0;
info.tEnd = batch[index]->m_numberOfSamples;
infos.push_back(info);
}
vector<pair<size_t, size_t>> placement;
vector<size_t> rowAllocations;
// Creating the minibatch layout.
MBLayoutPtr pMBLayout = make_shared<MBLayout>();
pMBLayout->InitAsPackedSequences(infos, placement, rowAllocations);
return pMBLayout;
}
StreamMinibatchPtr SequencePacker::PackStreamMinibatch(const std::vector<SequenceDataPtr>& sequences, size_t streamId)
{
// Create sequence info for each sequences that we have got from the transformer.
std::vector<MBLayout::SequenceInfo> inputSequences;
for (size_t index = 0; index < sequences.size(); ++index)
{
MBLayout::SequenceInfo info;
// In each minibatch sequence ids should be unique.
// They have to match between different input streams in the same minibatch.
// We are using sequence index in the set of received sequences.
// TODO: should we use m_key as sequence id and pass it with data?
info.seqId = index;
info.tBegin = 0;
info.tEnd = sequences[index]->m_numberOfSamples;
inputSequences.push_back(info);
}
std::vector<std::pair<size_t, size_t>> placement;
std::vector<size_t> rowAllocations;
// Creating the minibatch layout.
MBLayoutPtr layout = std::make_shared<MBLayout>();
layout->InitAsPackedSequences(inputSequences, placement, rowAllocations);
// Allocating necessary data buffer for the stream.
size_t sampleSize = GetSampleSize(m_inputStreams[streamId]);
size_t totalNumberOfSamplesInBytes = layout->GetNumCols() * sampleSize;
if (m_streamBufferSizes[streamId] < totalNumberOfSamplesInBytes)
{
m_streamBuffers[streamId] = AllocateBuffer(layout->GetNumCols(), sampleSize);
m_streamBufferSizes[streamId] = totalNumberOfSamplesInBytes;
}
// Packing the actual data.
StorageType storageType = m_inputStreams[streamId]->m_storageType;
size_t elementSize = GetSizeByType(m_inputStreams[streamId]->m_elementType);
const auto& packedSequences = layout->GetAllSequences();
char* streamBuffer = m_streamBuffers[streamId].get();
for (const auto& sequence : packedSequences)
{
if (sequence.seqId == GAP_SEQUENCE_ID)
continue;
const auto& data = sequences[sequence.seqId];
// Packing the sequence
for (size_t sampleIndex = 0; sampleIndex < sequence.GetNumTimeSteps(); ++sampleIndex)
{
char* destination = streamBuffer + layout->GetColumnIndex(sequence, sampleIndex) * sampleSize;
if (storageType == StorageType::dense)
{
PackDenseSample(destination, data, sampleIndex, elementSize, sampleSize);
}
else // sparse
{
assert(storageType == StorageType::sparse_csc);
PackSparseSample(destination, data, sampleIndex, elementSize, sampleSize);
}
}
}
// Ok, minibatch is ready, give it out.
StreamMinibatchPtr result = std::make_shared<StreamMinibatch>();
result->m_data = m_streamBuffers[streamId].get();
result->m_layout = layout;
return result;
}
