ollama/model/models/nomicbert/model.go

245 lines
7.2 KiB
Go

package nomicbert
import (
"cmp"
"math"
"github.com/ollama/ollama/fs"
"github.com/ollama/ollama/ml"
"github.com/ollama/ollama/ml/nn"
"github.com/ollama/ollama/ml/nn/pooling"
"github.com/ollama/ollama/ml/nn/rope"
"github.com/ollama/ollama/model"
"github.com/ollama/ollama/model/input"
)
type Model struct {
model.Base
model.TextProcessor
TokenEmbedding *nn.Embedding `gguf:"token_embd"`
TypeEmbedding *nn.Embedding `gguf:"token_types"`
TokenEmbeddingNorm *nn.LayerNorm `gguf:"token_embd_norm"`
Layers []EncoderLayer `gguf:"blk"`
Options
}
type Options struct {
hiddenSize int
numHeads int
headDim int
eps float32
poolingType pooling.Type
normalize bool
ropeFreqBase float32
// MoE specific options (used by v2 / MoE models only)
numExperts int
numExpertsUsed int
moeEveryNLayers int
}
func (o Options) applyRotaryPositionEmbeddings(ctx ml.Context, states, positions ml.Tensor) ml.Tensor {
return nn.RoPE(ctx, states, positions, o.headDim, o.ropeFreqBase, 1.0, rope.WithTypeNeoX())
}
type EncoderLayer struct {
*Attention
AttentionNorm *nn.LayerNorm `gguf:"attn_output_norm"`
FeedForward FeedForward
MLPNorm *nn.LayerNorm `gguf:"layer_output_norm"`
}
type Attention struct {
QKV *nn.Linear `gguf:"attn_qkv"`
Output *nn.Linear `gguf:"attn_output"`
}
type FeedForward interface {
Forward(ml.Context, ml.Tensor, *Options) ml.Tensor
}
type dense struct {
Gate *nn.Linear `gguf:"ffn_gate"`
Up *nn.Linear `gguf:"ffn_up"`
Down *nn.Linear `gguf:"ffn_down"`
}
func (mlp *dense) Forward(ctx ml.Context, hiddenStates ml.Tensor, _ *Options) ml.Tensor {
hidden := mlp.Gate.Forward(ctx, hiddenStates).SILU(ctx, mlp.Up.Forward(ctx, hiddenStates))
return mlp.Down.Forward(ctx, hidden)
}
// denseGELU implements MLP with GELU activation for v2 MoE dense layers
type denseGELU struct {
Up *nn.Linear `gguf:"ffn_up"`
Down *nn.Linear `gguf:"ffn_down"`
}
func (mlp *denseGELU) Forward(ctx ml.Context, hiddenStates ml.Tensor, _ *Options) ml.Tensor {
return mlp.Down.Forward(ctx, mlp.Up.Forward(ctx, hiddenStates).GELU(ctx))
}
// sparse implements MoE with expert routing
type sparse struct {
Router *nn.Linear `gguf:"ffn_gate_inp"`
Up *nn.LinearBatch `gguf:"ffn_up_exps"`
Down *nn.LinearBatch `gguf:"ffn_down_exps"`
}
func (moe *sparse) Forward(ctx ml.Context, hiddenStates ml.Tensor, opts *Options) ml.Tensor {
hiddenDim, sequenceLength, batchSize := hiddenStates.Dim(0), hiddenStates.Dim(1), hiddenStates.Dim(2)
hiddenStates = hiddenStates.Reshape(ctx, hiddenDim, sequenceLength*batchSize)
routerLogits := moe.Router.Forward(ctx, hiddenStates)
routingWeights := routerLogits.Softmax(ctx)
selectedExperts := routingWeights.TopK(ctx, opts.numExpertsUsed)
routingWeights = routingWeights.Reshape(ctx, 1, opts.numExperts, hiddenStates.Dim(1)).Rows(ctx, selectedExperts)
hiddenStates = hiddenStates.Reshape(ctx, hiddenStates.Dim(0), 1, hiddenStates.Dim(1))
hiddenStates = moe.Up.Forward(ctx, hiddenStates, selectedExperts).GELU(ctx)
experts := moe.Down.Forward(ctx, hiddenStates, selectedExperts)
experts = experts.Mul(ctx, routingWeights)
nextStates := experts.View(ctx, 0, experts.Dim(0), experts.Stride(2), experts.Dim(2))
for i := 1; i < opts.numExpertsUsed; i++ {
nextStates = nextStates.Add(ctx, experts.View(ctx, i*experts.Stride(1), experts.Dim(0), experts.Stride(2), experts.Dim(2)))
}
return nextStates
}
func (m *Model) Forward(ctx ml.Context, batch input.Batch) (ml.Tensor, error) {
hiddenStates := m.TokenEmbedding.Forward(ctx, batch.Inputs)
typeEmbed := m.TypeEmbedding.Weight.Slice(ctx, 1, 0, 1, 1)
hiddenStates = hiddenStates.Add(ctx, typeEmbed)
hiddenStates = m.TokenEmbeddingNorm.Forward(ctx, hiddenStates, m.eps)
positions := ctx.Input().FromInts(batch.Positions, len(batch.Positions))
for _, layer := range m.Layers {
hiddenStates = layer.Forward(ctx, hiddenStates, positions, &m.Options)
}
hiddenStates = m.poolingType.Forward(ctx, hiddenStates)
if m.normalize {
hiddenStates = hiddenStates.L2Norm(ctx, 1e-12)
}
return hiddenStates, nil
}
func (e *EncoderLayer) Forward(ctx ml.Context, hiddenStates ml.Tensor, positions ml.Tensor, opts *Options) ml.Tensor {
residual := hiddenStates
hiddenStates = e.Attention.Forward(ctx, hiddenStates, positions, opts)
hiddenStates = hiddenStates.Add(ctx, residual)
hiddenStates = e.AttentionNorm.Forward(ctx, hiddenStates, opts.eps)
residual = hiddenStates
hiddenStates = e.FeedForward.Forward(ctx, hiddenStates, opts)
hiddenStates = hiddenStates.Add(ctx, residual)
hiddenStates = e.MLPNorm.Forward(ctx, hiddenStates, opts.eps)
return hiddenStates
}
func (a *Attention) Forward(ctx ml.Context, hiddenStates ml.Tensor, positions ml.Tensor, opts *Options) ml.Tensor {
batchSize := hiddenStates.Dim(1)
qkv := a.QKV.Forward(ctx, hiddenStates)
qkv = qkv.Reshape(ctx, opts.headDim, opts.numHeads*3, batchSize)
chunks := qkv.Chunk(ctx, 1, opts.numHeads)
query, key, value := chunks[0], chunks[1], chunks[2]
query = opts.applyRotaryPositionEmbeddings(ctx, query, positions)
key = opts.applyRotaryPositionEmbeddings(ctx, key, positions)
attention := nn.Attention(ctx, query, key, value, 1.0/math.Sqrt(float64(opts.headDim)), nil)
attention = attention.Reshape(ctx, opts.hiddenSize, batchSize)
return a.Output.Forward(ctx, attention)
}
func New(c fs.Config) (model.Model, error) {
hiddenSize := int(c.Uint("embedding_length"))
numHeads := int(c.Uint("attention.head_count"))
headDim := hiddenSize / numHeads
processor := model.NewWordPiece(
&model.Vocabulary{
Values: c.Strings("tokenizer.ggml.tokens"),
Scores: c.Floats("tokenizer.ggml.scores"),
Types: c.Ints("tokenizer.ggml.token_type"),
AddBOS: c.Bool("tokenizer.ggml.add_bos_token", true),
BOS: []int32{
int32(cmp.Or(
c.Uint("tokenizer.ggml.cls_token_id"),
c.Uint("tokenizer.ggml.bos_token_id"),
)),
},
AddEOS: c.Bool("tokenizer.ggml.add_eos_token", true),
EOS: []int32{
int32(cmp.Or(
c.Uint("tokenizer.ggml.separator_token_id"),
c.Uint("tokenizer.ggml.eos_token_id"),
)),
},
},
false,
)
blockCount := int(c.Uint("block_count"))
moeEveryNLayers := int(c.Uint("moe_every_n_layers", 0))
layers := make([]EncoderLayer, blockCount)
for i := range layers {
if moeEveryNLayers > 0 {
// Layer uses MoE if (i+1) % moe_every_n_layers == 0
if (i+1)%moeEveryNLayers == 0 {
layers[i].FeedForward = &sparse{}
} else {
layers[i].FeedForward = &denseGELU{}
}
} else {
layers[i].FeedForward = &dense{}
}
}
return &Model{
TextProcessor: processor,
Layers: layers,
Options: Options{
hiddenSize: hiddenSize,
numHeads: numHeads,
headDim: headDim,
eps: c.Float("attention.layer_norm_epsilon"),
poolingType: pooling.Type(c.Uint("pooling_type")),
normalize: c.Bool("normalize_embeddings", false),
ropeFreqBase: c.Float("rope.freq_base", 1000.0),
numExperts: int(c.Uint("expert_count")),
numExpertsUsed: int(c.Uint("expert_used_count")),
moeEveryNLayers: moeEveryNLayers,
},
}, nil
}
func init() {
model.Register("nomic-bert", New)
model.Register("nomic-bert_embed", New)
model.Register("nomic-bert-moe", New)
model.Register("nomic-bert-moe_embed", New)
}