Add e5-mistral modules [unreachable code] - step 1/3 (#983)

python/sglang/srt/layers/pooler.py

+# adapted from
+# https://github.com/vllm-project/vllm/blob/82a1b1a82b1fbb454c82a9ef95730b929c9b270c/vllm/model_executor/layers/pooler.py
+
+from dataclasses import dataclass
+from enum import IntEnum
+
+import torch
+import torch.nn as nn
+
+from sglang.srt.model_executor.model_runner import InputMetadata
+
+
+class PoolingType(IntEnum):
+    LAST = 0
+
+
+@dataclass
+class EmbeddingPoolerOutput:
+    embeddings: torch.Tensor
+
+
+class Pooler(nn.Module):
+    """A layer that pools specific information from hidden states.
+    This layer does the following:
+    1. Extracts specific tokens or aggregates data based on pooling method.
+    2. Normalizes output if specified.
+    3. Returns structured results as `PoolerOutput`.
+    Attributes:
+        pooling_type: The type of pooling to use (LAST, AVERAGE, MAX).
+        normalize: Whether to normalize the pooled data.
+    """
+
+    def __init__(self, pooling_type: PoolingType, normalize: bool):
+        super().__init__()
+        self.pooling_type = pooling_type
+        self.normalize = normalize
+
+    def forward(
+        self, hidden_states: torch.Tensor, input_metadata: InputMetadata
+    ) -> EmbeddingPoolerOutput:
+        if self.pooling_type == PoolingType.LAST:
+            last_token_indices = torch.cumsum(input_metadata.extend_seq_lens, dim=0) - 1
+            pooled_data = hidden_states[last_token_indices]
+        else:
+            raise ValueError(f"Invalid pooling type: {self.pooling_type}")
+
+        if self.normalize:
+            pooled_data = nn.functional.normalize(pooled_data, p=2, dim=1)
+
+        return EmbeddingPoolerOutput(embeddings=pooled_data)

python/sglang/srt/models/llama_embedding.py

+from typing import Iterable, Optional, Tuple
+
+import torch
+from torch import nn
+from transformers import LlamaConfig
+from vllm.model_executor.model_loader.weight_utils import default_weight_loader
+
+from sglang.srt.layers.pooler import EmbeddingPoolerOutput, Pooler, PoolingType
+from sglang.srt.model_executor.model_runner import InputMetadata
+from sglang.srt.models.llama2 import LlamaForCausalLM, LlamaModel
+
+
+class LlamaEmbeddingModel(nn.Module):
+    def __init__(
+        self,
+        config: LlamaConfig,
+        quant_config=None,
+        cache_config=None,
+        efficient_weight_load=False,
+    ) -> None:
+        super().__init__()
+        self.model = LlamaModel(config, quant_config=quant_config)
+        self.pooler = Pooler(pooling_type=PoolingType.LAST, normalize=True)
+
+    @torch.no_grad()
+    def forward(
+        self,
+        input_ids: torch.Tensor,
+        positions: torch.Tensor,
+        input_metadata: InputMetadata,
+        input_embeds: torch.Tensor = None,
+    ) -> EmbeddingPoolerOutput:
+        hidden_states = self.model(input_ids, positions, input_metadata, input_embeds)
+        return self.pooler(hidden_states, input_metadata)
+
+    def load_weights(
+        self, weights: Iterable[Tuple[str, torch.Tensor]], name=None, loaded_weight=None
+    ):
+        stacked_params_mapping = [
+            # (param_name, shard_name, shard_id)
+            ("qkv_proj", "q_proj", "q"),
+            ("qkv_proj", "k_proj", "k"),
+            ("qkv_proj", "v_proj", "v"),
+            ("gate_up_proj", "gate_proj", 0),
+            ("gate_up_proj", "up_proj", 1),
+        ]
+        params_dict = dict(self.model.named_parameters())
+
+        def load_weights_per_param(name, loaded_weight):
+            if "rotary_emb.inv_freq" in name or "projector" in name:
+                return
+            if "rotary_emb.cos_cached" in name or "rotary_emb.sin_cached" in name:
+                # Models trained using ColossalAI may include these tensors in
+                # the checkpoint. Skip them.
+                return
+            for param_name, weight_name, shard_id in stacked_params_mapping:
+                if weight_name not in name:
+                    continue
+                name = name.replace(weight_name, param_name)
+                # Skip loading extra bias for GPTQ models.
+                if name.endswith(".bias") and name not in params_dict:
+                    continue
+                if name.startswith("model.vision_tower") and name not in params_dict:
+                    continue
+                param = params_dict[name]
+                weight_loader = param.weight_loader
+                weight_loader(param, loaded_weight, shard_id)
+                break
+            else:
+                # Skip loading extra bias for GPTQ models.
+                if name.endswith(".bias") and name not in params_dict:
+                    return
+                if name.startswith("model.vision_tower") and name not in params_dict:
+                    return
+                param = params_dict[name]
+                weight_loader = getattr(param, "weight_loader", default_weight_loader)
+                weight_loader(param, loaded_weight)
+
+        if name is None or loaded_weight is None:
+            for name, loaded_weight in weights:
+                load_weights_per_param(name, loaded_weight)
+        else:
+            load_weights_per_param(name, loaded_weight)
+
+
+EntryClass = LlamaEmbeddingModel