public static IWeightTensor BuildTensorForSourceTokenGroupAt(IComputeGraph computeGraph, ISntPairBatch sntPairBatch, ShuffleEnums shuffleType, IEncoder encoder, IModel modelMetaData, IWeightTensor srcEmbedding, IWeightTensor posEmbedding, IWeightTensor segmentEmbedding, int groupId)
{
var contextTokens = InsertCLSToken(sntPairBatch.GetSrcTokens(groupId));
var originalSrcContextLength = BuildInTokens.PadSentences(contextTokens);
var contextTokenIds = modelMetaData.SrcVocab.GetWordIndex(contextTokens);
IWeightTensor encContextOutput = InnerRunner(computeGraph, contextTokenIds, originalSrcContextLength, shuffleType, encoder, modelMetaData, srcEmbedding, posEmbedding, segmentEmbedding);
int contextPaddedLen = contextTokens[0].Count;
float[] contextCLSIdxs = new float[sntPairBatch.BatchSize];
for (int j = 0; j < sntPairBatch.BatchSize; j++)
{
contextCLSIdxs[j] = j * contextPaddedLen;
}
IWeightTensor contextCLSOutput = computeGraph.IndexSelect(encContextOutput, contextCLSIdxs);
return(contextCLSOutput);
}
/// <summary>
/// Run forward part on given single device
/// </summary>
/// <param name="computeGraph">The computing graph for current device. It gets created and passed by the framework</param>
/// <param name="srcSnts">A batch of input tokenized sentences in source side</param>
/// <param name="tgtSnts">A batch of output tokenized sentences in target side</param>
/// <param name="deviceIdIdx">The index of current device</param>
/// <returns>The cost of forward part</returns>
public override List <NetworkResult> RunForwardOnSingleDevice(IComputeGraph computeGraph, ISntPairBatch sntPairBatch, int deviceIdIdx, bool isTraining, DecodingOptions decodingOptions)
{
List <NetworkResult> nrs = new List <NetworkResult>();
(IEncoder encoder, IWeightTensor srcEmbedding, List <IFeedForwardLayer> encoderFFLayer, IWeightTensor posEmbedding, IWeightTensor segmentEmbedding) = GetNetworksOnDeviceAt(deviceIdIdx);
var srcSnts = sntPairBatch.GetSrcTokens(0);
var originalSrcLengths = BuildInTokens.PadSentences(srcSnts);
var srcTokensList = m_modelMetaData.SrcVocab.GetWordIndex(srcSnts);
IWeightTensor encOutput = Encoder.Run(computeGraph, sntPairBatch, encoder, m_modelMetaData, m_shuffleType, srcEmbedding, posEmbedding, segmentEmbedding, srcTokensList, originalSrcLengths);
int srcSeqPaddedLen = srcSnts[0].Count;
int batchSize = srcSnts.Count;
float[] clsIdxs = new float[batchSize];
for (int i = 0; i < batchSize; i++)
{
for (int j = 0; j < srcSnts[i].Count; j++)
{
if (srcSnts[i][j] == BuildInTokens.CLS)
{
clsIdxs[i] = i * srcSeqPaddedLen + j;
break;
}
}
}
IWeightTensor clsWeightTensor = computeGraph.IndexSelect(encOutput, clsIdxs);
for (int i = 0; i < m_encoderFFLayer.Length; i++)
{
float cost = 0.0f;
NetworkResult nr = new NetworkResult
{
Output = new List <List <List <string> > >()
};
IWeightTensor ffLayer = encoderFFLayer[i].Process(clsWeightTensor, batchSize, computeGraph);
using (IWeightTensor probs = computeGraph.Softmax(ffLayer, runGradients: false, inPlace: true))
{
if (isTraining)
{
var tgtSnts = sntPairBatch.GetTgtTokens(i);
for (int k = 0; k < batchSize; k++)
{
int ix_targets_k_j = m_modelMetaData.ClsVocabs[i].GetWordIndex(tgtSnts[k][0]);
float score_k = probs.GetWeightAt(new long[] { k, ix_targets_k_j });
cost += (float)-Math.Log(score_k);
probs.SetWeightAt(score_k - 1, new long[] { k, ix_targets_k_j });
}
ffLayer.CopyWeightsToGradients(probs);
nr.Cost = cost / batchSize;
}
else
{
// Output "i"th target word
using var targetIdxTensor = computeGraph.Argmax(probs, 1);
float[] targetIdx = targetIdxTensor.ToWeightArray();
List <string> targetWords = m_modelMetaData.ClsVocabs[i].ConvertIdsToString(targetIdx.ToList());
nr.Output.Add(new List <List <string> >());
for (int k = 0; k < batchSize; k++)
{
nr.Output[0].Add(new List <string>());
nr.Output[0][k].Add(targetWords[k]);
}
}
}
nrs.Add(nr);
}
return(nrs);
}
/// <summary>
/// Create input embedding from token embeddings, segment embeddings
/// </summary>
/// <param name="seqs"></param>
/// <param name="g"></param>
/// <param name="embeddingsTensor"></param>
/// <param name="seqOriginalLengths"></param>
/// <param name="segmentEmbedding"></param>
/// <param name="vocab"></param>
/// <returns>The embedding tensor. shape: (batchsize * seqLen, embedding_dim) </returns>
public static IWeightTensor CreateTokensEmbeddings(List <List <int> > seqs, IComputeGraph g, IWeightTensor embeddingsTensor,
IWeightTensor segmentEmbedding, Vocab vocab, float scaleFactor = 1.0f, bool enableTagEmbedding = false)
{
int batchSize = seqs.Count;
int seqLen = seqs[0].Count;
float[] idxs = new float[batchSize * seqLen];
float[] segIdxs = new float[batchSize * seqLen];
List <float[]> tagIdxsList = new List <float[]>();
//float[] tagIdxs = new float[batchSize * seqLen];
for (int i = 0; i < batchSize; i++)
{
int segIdx = 0;
List <int> currTagIdxs = new List <int>();
int currTagLevel = 0;
for (int j = 0; j < seqLen; j++)
{
idxs[i * seqLen + j] = seqs[i][j];
segIdxs[i * seqLen + j] = segIdx;
string token = vocab.GetString(seqs[i][j]);
if (token == BuildInTokens.SEP)
{
//A new segment
segIdx++;
}
if (enableTagEmbedding)
{
if (token.StartsWith("<") && token.EndsWith(">") && BuildInTokens.IsPreDefinedToken(token) == false)
{
if (token[1] == '/')
{
currTagLevel--;
currTagIdxs[currTagLevel] = -1;
}
else
{
//A new opening tag
while (tagIdxsList.Count <= currTagLevel)
{
float[] tagIdxs = new float[batchSize * seqLen];
Array.Fill(tagIdxs, -1.0f);
tagIdxsList.Add(tagIdxs);
}
while (currTagIdxs.Count <= currTagLevel)
{
currTagIdxs.Add(-1);
}
currTagIdxs[currTagLevel] = seqs[i][j];
currTagLevel++;
}
}
else
{
for (int k = 0; k < currTagLevel; k++)
{
tagIdxsList[k][i * seqLen + j] = currTagIdxs[k];
//Logger.WriteLine($"Add tag embeddings: '{currTagIdxs[k]}'");
}
}
}
}
}
IWeightTensor tagEmbeddings = null;
if (enableTagEmbedding)
{
for (int k = 0; k < tagIdxsList.Count; k++)
{
var tagEmbeddings_k = g.IndexSelect(embeddingsTensor, tagIdxsList[k], clearWeights: true);
if (tagEmbeddings == null)
{
tagEmbeddings = tagEmbeddings_k;
}
else
{
tagEmbeddings = g.Add(tagEmbeddings, tagEmbeddings_k);
}
}
}
IWeightTensor embeddingRst = g.IndexSelect(embeddingsTensor, idxs);
if (scaleFactor != 1.0f)
{
embeddingRst = g.Mul(embeddingRst, scaleFactor, inPlace: true);
}
// Apply segment embeddings to the input sequence embeddings
if (segmentEmbedding != null)
{
embeddingRst = g.Add(embeddingRst, g.IndexSelect(segmentEmbedding, segIdxs));
}
if (tagEmbeddings != null)
{
embeddingRst = g.Add(embeddingRst, tagEmbeddings);
}
return(embeddingRst);
}
/// <summary>
/// Run forward part on given single device
/// </summary>
/// <param name="computeGraph">The computing graph for current device. It gets created and passed by the framework</param>
/// <param name="srcSnts">A batch of input tokenized sentences in source side</param>
/// <param name="tgtSnts">A batch of output tokenized sentences in target side</param>
/// <param name="deviceIdIdx">The index of current device</param>
/// <returns>The cost of forward part</returns>
public override List <NetworkResult> RunForwardOnSingleDevice(IComputeGraph computeGraph, ISntPairBatch sntPairBatch, int deviceIdIdx, bool isTraining, DecodingOptions decodingOptions)
{
(IEncoder encoder, IDecoder decoder, IFeedForwardLayer encoderFFLayer, IFeedForwardLayer decoderFFLayer, IWeightTensor srcEmbedding, IWeightTensor tgtEmbedding, IWeightTensor posEmbedding, IWeightTensor segmentEmbedding) = GetNetworksOnDeviceAt(deviceIdIdx);
var srcSnts = sntPairBatch.GetSrcTokens(0);
var originalSrcLengths = BuildInTokens.PadSentences(srcSnts);
var srcTokensList = m_modelMetaData.SrcVocab.GetWordIndex(srcSnts);
IWeightTensor encOutput = Encoder.Run(computeGraph, sntPairBatch, encoder, m_modelMetaData, m_shuffleType, srcEmbedding, posEmbedding, segmentEmbedding, srcTokensList, originalSrcLengths);
List <NetworkResult> nrs = new List <NetworkResult>();
int srcSeqPaddedLen = srcSnts[0].Count;
int batchSize = srcSnts.Count;
float[] clsIdxs = new float[batchSize];
for (int i = 0; i < batchSize; i++)
{
for (int j = 0; j < srcSnts[i].Count; j++)
{
if (srcSnts[i][j] == BuildInTokens.CLS)
{
clsIdxs[i] = i * srcSeqPaddedLen + j;
break;
}
}
}
IWeightTensor clsWeightTensor = computeGraph.IndexSelect(encOutput, clsIdxs);
float cost = 0.0f;
NetworkResult nrCLS = new NetworkResult
{
Output = new List <List <List <string> > >()
};
IWeightTensor ffLayer = encoderFFLayer.Process(clsWeightTensor, batchSize, computeGraph);
using (IWeightTensor probs = computeGraph.Softmax(ffLayer, runGradients: false, inPlace: true))
{
if (isTraining)
{
var clsSnts = sntPairBatch.GetTgtTokens(0);
for (int k = 0; k < batchSize; k++)
{
int ix_targets_k_j = m_modelMetaData.ClsVocab.GetWordIndex(clsSnts[k][0]);
float score_k = probs.GetWeightAt(new long[] { k, ix_targets_k_j });
cost += (float)-Math.Log(score_k);
probs.SetWeightAt(score_k - 1, new long[] { k, ix_targets_k_j });
}
ffLayer.CopyWeightsToGradients(probs);
nrCLS.Cost = cost / batchSize;
}
else
{
// Output "i"th target word
using var targetIdxTensor = computeGraph.Argmax(probs, 1);
float[] targetIdx = targetIdxTensor.ToWeightArray();
List <string> targetWords = m_modelMetaData.ClsVocab.ConvertIdsToString(targetIdx.ToList());
nrCLS.Output.Add(new List <List <string> >());
for (int k = 0; k < batchSize; k++)
{
nrCLS.Output[0].Add(new List <string>());
nrCLS.Output[0][k].Add(targetWords[k]);
}
}
}
// Reset networks
decoder.Reset(computeGraph.GetWeightFactory(), srcSnts.Count);
// Generate output decoder sentences
var tgtSnts = sntPairBatch.GetTgtTokens(1);
var tgtTokensList = m_modelMetaData.TgtVocab.GetWordIndex(tgtSnts);
NetworkResult nr = new NetworkResult();
if (decoder is AttentionDecoder)
{
nr.Cost = Decoder.DecodeAttentionLSTM(tgtTokensList, computeGraph, encOutput, decoder as AttentionDecoder, decoderFFLayer, tgtEmbedding, m_modelMetaData.TgtVocab, srcSnts.Count, isTraining);
nr.Output = new List <List <List <string> > >
{
m_modelMetaData.TgtVocab.ConvertIdsToString(tgtTokensList)
};
}
else
{
if (isTraining)
{
(var c, _) = Decoder.DecodeTransformer(tgtTokensList, computeGraph, encOutput, decoder as TransformerDecoder, decoderFFLayer, tgtEmbedding, posEmbedding, originalSrcLengths, m_modelMetaData.TgtVocab, m_shuffleType, m_options.DropoutRatio, null, isTraining);
nr.Cost = c;
nr.Output = null;
}
else
{
List <List <BeamSearchStatus> > beam2batchStatus = Decoder.InitBeamSearchStatusListList(batchSize, tgtTokensList);
for (int i = 0; i < decodingOptions.MaxTgtSentLength; i++)
{
List <List <BeamSearchStatus> > batch2beam2seq = null; //(batch_size, beam_search_size)
try
{
foreach (var batchStatus in beam2batchStatus)
{
var batch2tgtTokens = Decoder.ExtractBatchTokens(batchStatus);
using var g = computeGraph.CreateSubGraph($"TransformerDecoder_Step_{i}");
(var cost2, var bssSeqList) = Decoder.DecodeTransformer(batch2tgtTokens, g, encOutput, decoder as TransformerDecoder, decoderFFLayer, tgtEmbedding, posEmbedding,
originalSrcLengths, m_modelMetaData.TgtVocab, m_shuffleType, 0.0f, decodingOptions, isTraining,
outputSentScore: decodingOptions.BeamSearchSize > 1, previousBeamSearchResults: batchStatus);
bssSeqList = Decoder.SwapBeamAndBatch(bssSeqList);
batch2beam2seq = Decoder.CombineBeamSearchResults(batch2beam2seq, bssSeqList);
}
}
catch (OutOfMemoryException)
{
GC.Collect();
Logger.WriteLine(Logger.Level.warn, $"We have out of memory while generating '{i}th' tokens, so terminate decoding for current sequences.");
break;
}
if (decodingOptions.BeamSearchSize > 1)
{
// Keep top N result and drop all others
for (int k = 0; k < batchSize; k++)
{
batch2beam2seq[k] = BeamSearch.GetTopNBSS(batch2beam2seq[k], decodingOptions.BeamSearchSize);
}
}
beam2batchStatus = Decoder.SwapBeamAndBatch(batch2beam2seq);
if (Decoder.AreAllSentsCompleted(beam2batchStatus))
{
break;
}
}
nr.Cost = 0.0f;
nr.Output = m_modelMetaData.TgtVocab.ExtractTokens(beam2batchStatus);
}
}
nr.RemoveDuplicatedEOS();
nrs.Add(nrCLS);
nrs.Add(nr);
return(nrs);
}