rag_code.py

from qdrant_client import models
from qdrant_client import QdrantClient
from llama_index.embeddings.huggingface import HuggingFaceEmbedding
from llama_index.llms.sambanovasystems import SambaNovaCloud

from llama_index.core.base.llms.types import (
    ChatMessage,
    MessageRole,
)

def batch_iterate(lst, batch_size):
    """Yield successive n-sized chunks from lst."""
    for i in range(0, len(lst), batch_size):
        yield lst[i : i + batch_size]

class EmbedData:

    def __init__(self, embed_model_name="BAAI/bge-large-en-v1.5", batch_size = 32):
        self.embed_model_name = embed_model_name
        self.embed_model = self._load_embed_model()
        self.batch_size = batch_size
        self.embeddings = []
        
    def _load_embed_model(self):
        embed_model = HuggingFaceEmbedding(model_name=self.embed_model_name, trust_remote_code=True, cache_folder='./hf_cache')
        return embed_model

    def generate_embedding(self, context):
        return self.embed_model.get_text_embedding_batch(context)
        
    def embed(self, contexts):
        
        self.contexts = contexts
        
        for batch_context in batch_iterate(contexts, self.batch_size):
            batch_embeddings = self.generate_embedding(batch_context)
            self.embeddings.extend(batch_embeddings)

class QdrantVDB_QB:

    def __init__(self, collection_name, vector_dim = 768, batch_size=512):
        self.collection_name = collection_name
        self.batch_size = batch_size
        self.vector_dim = vector_dim
        
    def define_client(self):
        
        self.client = QdrantClient(url="http://localhost:6333", prefer_grpc=True)
        
    def create_collection(self):
        
        if not self.client.collection_exists(collection_name=self.collection_name):

            self.client.create_collection(collection_name=f"{self.collection_name}",
                                          
                                          vectors_config=models.VectorParams(size=self.vector_dim,
                                                                             distance=models.Distance.DOT,
                                                                             on_disk=True),
                                          
                                          optimizers_config=models.OptimizersConfigDiff(default_segment_number=5,
                                                                                        indexing_threshold=0),
                                          
                                          quantization_config=models.BinaryQuantization(
                                                        binary=models.BinaryQuantizationConfig(always_ram=True)),
                                         )
            
    def ingest_data(self, embeddata):
    
        for batch_context, batch_embeddings in zip(batch_iterate(embeddata.contexts, self.batch_size), 
                                                    batch_iterate(embeddata.embeddings, self.batch_size)):
    
            self.client.upload_collection(collection_name=self.collection_name,
                                          vectors=batch_embeddings,
                                          payload=[{"context": context} for context in batch_context])

        self.client.update_collection(collection_name=self.collection_name,
                                      optimizer_config=models.OptimizersConfigDiff(indexing_threshold=20000)
                                     )
        
class Retriever:

    def __init__(self, vector_db, embeddata):
        
        self.vector_db = vector_db
        self.embeddata = embeddata

    def search(self, query):
        query_embedding = self.embeddata.embed_model.get_query_embedding(query)
        
        
        result = self.vector_db.client.search(
            collection_name=self.vector_db.collection_name,
            
            query_vector=query_embedding,
            
            search_params=models.SearchParams(
                quantization=models.QuantizationSearchParams(
                    ignore=False,
                    rescore=True,
                    oversampling=2.0,
                )
            ),
            
            timeout=1000,
        )

        return result
    
class RAG:

    def __init__(self,
                 retriever,
                 llm_name = "llama3.2:1b"
                 ):
        
        system_msg = ChatMessage(
            role=MessageRole.SYSTEM,
            content="You are a helpful assistant that answers questions about the user's document.",
        )
        self.messages = [system_msg, ]
        self.llm_name = llm_name
        self.llm = self._setup_llm()
        self.retriever = retriever
        self.qa_prompt_tmpl_str = ("Context information is below.\n"
                                   "---------------------\n"
                                   "{context}\n"
                                   "---------------------\n"
                                   "Given the context information above I want you to think step by step to answer the query in a crisp manner, incase case you don't know the answer say 'I don't know!'.\n"
                                   "Query: {query}\n"
                                   "Answer: "
                                   )

    def _setup_llm(self):
        return SambaNovaCloud(
                        model=self.llm_name,
                        temperature=0.7,
                        context_window=100000,
                    )

    def generate_context(self, query):

        result = self.retriever.search(query)
        context = [dict(data) for data in result]
        combined_prompt = []

        for entry in context[:2]:
            context = entry["payload"]["context"]

            combined_prompt.append(context)

        return "\n\n---\n\n".join(combined_prompt)

    def query(self, query):
        context = self.generate_context(query=query)
        
        prompt = self.qa_prompt_tmpl_str.format(context=context, query=query)

        user_msg = ChatMessage(role=MessageRole.USER, content=prompt)

        # self.messages.append(ChatMessage(role=MessageRole.USER, content=prompt))
                
        streaming_response = self.llm.stream_complete(user_msg.content)
        
        return streaming_response
    
    # def append_ai_response(self, message):

    #     self.messages.append(ChatMessage(role=MessageRole.ASSISTANT, content=message))