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- from flask import Flask, request, jsonify
- from sentence_transformers import SentenceTransformer
- from sklearn.metrics.pairwise import cosine_similarity
- import json
- app = Flask(__name__)
- # 创建一个全局的模型缓存字典
- model_cache = {}
- # 分割文本块
- def split_text(text, block_size, overlap_chars, delimiter):
- chunks = text.split(delimiter)
- text_blocks = []
- current_block = ""
- for chunk in chunks:
- if len(current_block) + len(chunk) + 1 <= block_size:
- if current_block:
- current_block += " " + chunk
- else:
- current_block = chunk
- else:
- text_blocks.append(current_block)
- current_block = chunk
- if current_block:
- text_blocks.append(current_block)
- overlap_blocks = []
- for i in range(len(text_blocks)):
- if i > 0:
- overlap_block = text_blocks[i - 1][-overlap_chars:] + text_blocks[i]
- overlap_blocks.append(overlap_block)
- overlap_blocks.append(text_blocks[i])
- return overlap_blocks
- # 文本向量化
- def vectorize_text_blocks(text_blocks, model):
- return model.encode(text_blocks)
- # 文本检索
- def retrieve_top_k(query, knowledge_base, k, block_size, overlap_chars, delimiter, model):
- # 将知识库拆分为文本块
- text_blocks = split_text(knowledge_base, block_size, overlap_chars, delimiter)
- # 向量化文本块
- knowledge_vectors = vectorize_text_blocks(text_blocks, model)
- # 向量化查询文本
- query_vector = model.encode([query]).reshape(1, -1)
- # 计算相似度
- similarities = cosine_similarity(query_vector, knowledge_vectors)
- # 获取相似度最高的 k 个文本块的索引
- top_k_indices = similarities[0].argsort()[-k:][::-1]
- # 返回文本块和它们的向量
- top_k_texts = [text_blocks[i] for i in top_k_indices]
- top_k_embeddings = [knowledge_vectors[i] for i in top_k_indices]
- return top_k_texts, top_k_embeddings
- @app.route('/vectorize', methods=['POST'])
- def vectorize_text():
- # 从请求中获取 JSON 数据
- data = request.json
- print(f"Received request data: {data}") # 调试输出请求数据
- text_list = data.get("text", [])
- model_name = data.get("model_name", "msmarco-distilbert-base-tas-b") # 默认模型
- delimiter = data.get("delimiter", "\n") # 默认分隔符
- k = int(data.get("k", 3)) # 默认检索条数
- block_size = int(data.get("block_size", 500)) # 默认文本块大小
- overlap_chars = int(data.get("overlap_chars", 50)) # 默认重叠字符数
- if not text_list:
- return jsonify({"error": "Text is required."}), 400
- # 检查模型是否已经加载
- if model_name not in model_cache:
- try:
- model = SentenceTransformer(model_name)
- model_cache[model_name] = model # 缓存模型
- except Exception as e:
- return jsonify({"error": f"Failed to load model: {e}"}), 500
- model = model_cache[model_name]
- top_k_texts_all = []
- top_k_embeddings_all = []
- # 如果只有一个查询文本
- if len(text_list) == 1:
- top_k_texts, top_k_embeddings = retrieve_top_k(text_list[0], text_list[0], k, block_size, overlap_chars, delimiter, model)
- top_k_texts_all.append(top_k_texts)
- top_k_embeddings_all.append(top_k_embeddings)
- elif len(text_list) > 1:
- # 如果多个查询文本,依次处理
- for query in text_list:
- top_k_texts, top_k_embeddings = retrieve_top_k(query, text_list[0], k, block_size, overlap_chars, delimiter, model)
- top_k_texts_all.append(top_k_texts)
- top_k_embeddings_all.append(top_k_embeddings)
- # 将嵌入向量(ndarray)转换为可序列化的列表
- top_k_embeddings_all = [[embedding.tolist() for embedding in embeddings] for embeddings in top_k_embeddings_all]
- print(f"Top K texts: {top_k_texts_all}") # 打印检索到的文本
- print(f"Top K embeddings: {top_k_embeddings_all}") # 打印检索到的向量
- # 返回 JSON 格式的数据
- return jsonify({
- "topKEmbeddings": top_k_embeddings_all # 返回嵌入向量
- })
- if __name__ == '__main__':
- app.run(host="0.0.0.0", port=5000, debug=True)
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