From 896df7f11b441a9b8dfa50820024a82884da58d0 Mon Sep 17 00:00:00 2001
From: BLUESKY477 <abcd15803148000@163.com>
Date: Fri, 22 May 2026 19:23:44 -0500
Subject: Add files via upload

---
 resulets/baselines/dense_retrieval.py | 143 ++++++++++++++++++++++++++++++++++
 1 file changed, 143 insertions(+)
 create mode 100644 resulets/baselines/dense_retrieval.py

(limited to 'resulets/baselines/dense_retrieval.py')

diff --git a/resulets/baselines/dense_retrieval.py b/resulets/baselines/dense_retrieval.py
new file mode 100644
index 0000000..a627319
--- /dev/null
+++ b/resulets/baselines/dense_retrieval.py
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+"""Dense Retrieval ICL baselines.
+
+Uses sentence-transformers for dense retrieval over the user support set,
+then places top-K retrieved items as in-context examples.
+"""
+
+from dataclasses import dataclass
+
+import torch
+
+
+@dataclass(frozen=True)
+class DenseRetrieverConfig:
+    method_name: str
+    model_name: str
+    text_mode: str = "input_output"
+    query_prefix: str = ""
+    passage_prefix: str = ""
+    normalize_embeddings: bool = True
+    citation_year: str = ""
+    description: str = ""
+
+
+DENSE_RETRIEVER_CONFIGS = {
+    "dense_minilm_top1": DenseRetrieverConfig(
+        method_name="dense_minilm_top1",
+        model_name="sentence-transformers/all-MiniLM-L6-v2",
+        citation_year="MiniLM 2020; Sentence-Transformers checkpoint circa 2021",
+        description="Lightweight SBERT/MiniLM dense retriever.",
+    ),
+    "dense_mpnet_top1": DenseRetrieverConfig(
+        method_name="dense_mpnet_top1",
+        model_name="sentence-transformers/all-mpnet-base-v2",
+        citation_year="MPNet 2020; Sentence-Transformers checkpoint circa 2021",
+        description="Stronger SBERT/MPNet dense retriever.",
+    ),
+    "dense_e5_top1": DenseRetrieverConfig(
+        method_name="dense_e5_top1",
+        model_name="intfloat/e5-base-v2",
+        query_prefix="query: ",
+        passage_prefix="passage: ",
+        citation_year="E5 2022",
+        description="E5 dense retriever with the model-card query/passage prefixes.",
+    ),
+    "dense_bge_top1": DenseRetrieverConfig(
+        method_name="dense_bge_top1",
+        model_name="BAAI/bge-base-en-v1.5",
+        query_prefix="Represent this sentence for searching relevant passages: ",
+        citation_year="BGE v1.5 2023",
+        description="BGE v1.5 dense retriever with the recommended query instruction.",
+    ),
+}
+
+
+def get_dense_retriever_config(method_name: str) -> DenseRetrieverConfig:
+    return DENSE_RETRIEVER_CONFIGS[method_name]
+
+
+class DenseRetriever:
+    """Dense retriever using sentence-transformers embeddings."""
+
+    def __init__(
+        self,
+        model_name='sentence-transformers/all-MiniLM-L6-v2',
+        device='cpu',
+        text_mode='input_output',
+        query_prefix='',
+        passage_prefix='',
+        normalize_embeddings=True,
+    ):
+        self.model_name = model_name
+        self.text_mode = text_mode
+        self.query_prefix = query_prefix
+        self.passage_prefix = passage_prefix
+        self.normalize_embeddings = normalize_embeddings
+        from sentence_transformers import SentenceTransformer
+        self.model = SentenceTransformer(model_name, device=device)
+
+    def _support_text(self, item: dict) -> str:
+        if self.text_mode == 'input':
+            return item['support_input']
+        if self.text_mode == 'output':
+            return item['support_output']
+        if self.text_mode == 'input_output':
+            return f"{item['support_input']}\n{item['support_output']}"
+        raise ValueError(f"Unknown dense retrieval text_mode: {self.text_mode}")
+
+    def retrieve_top_k(self, query: str, support_items: list, k: int = 1, return_metadata=False):
+        """Retrieve top-k support items most relevant to query.
+
+        Args:
+            query: query input text
+            support_items: list of dicts with 'support_input', 'support_output'
+            k: number of items to retrieve
+            return_metadata: whether to also return retrieval diagnostics
+
+        Returns:
+            List of top-k support items, optionally with metadata.
+        """
+        if len(support_items) <= k:
+            metadata = [
+                {
+                    'rank': rank + 1,
+                    'support_index': rank,
+                    'score': None,
+                    'model_name': self.model_name,
+                    'text_mode': self.text_mode,
+                }
+                for rank in range(len(support_items))
+            ]
+            return (support_items, metadata) if return_metadata else support_items
+
+        query_text = self.query_prefix + query
+        texts = [self.passage_prefix + self._support_text(item) for item in support_items]
+        embeddings = self.model.encode(
+            [query_text] + texts,
+            convert_to_tensor=True,
+            normalize_embeddings=self.normalize_embeddings,
+        )
+
+        query_emb = embeddings[0]
+        item_embs = embeddings[1:]
+
+        if self.normalize_embeddings:
+            similarities = item_embs @ query_emb
+        else:
+            similarities = torch.nn.functional.cosine_similarity(
+                query_emb.unsqueeze(0), item_embs, dim=1
+            )
+
+        top_indices = similarities.argsort(descending=True)[:k].tolist()
+        selected = [support_items[i] for i in top_indices]
+        metadata = [
+            {
+                'rank': rank + 1,
+                'support_index': idx,
+                'score': float(similarities[idx].detach().cpu()),
+                'model_name': self.model_name,
+                'text_mode': self.text_mode,
+            }
+            for rank, idx in enumerate(top_indices)
+        ]
+        return (selected, metadata) if return_metadata else selected
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