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125 lines
4.0 KiB
Python
125 lines
4.0 KiB
Python
"""Wrapper around llama.cpp embedding models."""
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from typing import Any, Dict, List, Optional
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from pydantic import BaseModel, Extra, Field, root_validator
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from langchain.embeddings.base import Embeddings
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class LlamaCppEmbeddings(BaseModel, Embeddings):
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"""Wrapper around llama.cpp embedding models.
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To use, you should have the llama-cpp-python library installed, and provide the
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path to the Llama model as a named parameter to the constructor.
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Check out: https://github.com/abetlen/llama-cpp-python
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Example:
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.. code-block:: python
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from langchain.embeddings import LlamaCppEmbeddings
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llama = LlamaCppEmbeddings(model_path="/path/to/model.bin")
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"""
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client: Any #: :meta private:
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model_path: str
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n_ctx: int = Field(512, alias="n_ctx")
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"""Token context window."""
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n_parts: int = Field(-1, alias="n_parts")
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"""Number of parts to split the model into.
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If -1, the number of parts is automatically determined."""
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seed: int = Field(-1, alias="seed")
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"""Seed. If -1, a random seed is used."""
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f16_kv: bool = Field(False, alias="f16_kv")
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"""Use half-precision for key/value cache."""
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logits_all: bool = Field(False, alias="logits_all")
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"""Return logits for all tokens, not just the last token."""
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vocab_only: bool = Field(False, alias="vocab_only")
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"""Only load the vocabulary, no weights."""
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use_mlock: bool = Field(False, alias="use_mlock")
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"""Force system to keep model in RAM."""
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n_threads: Optional[int] = Field(None, alias="n_threads")
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"""Number of threads to use. If None, the number
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of threads is automatically determined."""
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n_batch: Optional[int] = Field(8, alias="n_batch")
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"""Number of tokens to process in parallel.
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Should be a number between 1 and n_ctx."""
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n_gpu_layers: Optional[int] = Field(None, alias="n_gpu_layers")
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"""Number of layers to be loaded into gpu memory. Default None."""
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class Config:
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"""Configuration for this pydantic object."""
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extra = Extra.forbid
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@root_validator()
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def validate_environment(cls, values: Dict) -> Dict:
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"""Validate that llama-cpp-python library is installed."""
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model_path = values["model_path"]
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model_param_names = [
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"n_ctx",
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"n_parts",
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"seed",
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"f16_kv",
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"logits_all",
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"vocab_only",
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"use_mlock",
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"n_threads",
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"n_batch",
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]
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model_params = {k: values[k] for k in model_param_names}
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# For backwards compatibility, only include if non-null.
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if values["n_gpu_layers"] is not None:
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model_params["n_gpu_layers"] = values["n_gpu_layers"]
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try:
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from llama_cpp import Llama
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values["client"] = Llama(model_path, embedding=True, **model_params)
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except ImportError:
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raise ModuleNotFoundError(
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"Could not import llama-cpp-python library. "
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"Please install the llama-cpp-python library to "
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"use this embedding model: pip install llama-cpp-python"
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)
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except Exception as e:
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raise ValueError(
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f"Could not load Llama model from path: {model_path}. "
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f"Received error {e}"
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)
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return values
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def embed_documents(self, texts: List[str]) -> List[List[float]]:
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"""Embed a list of documents using the Llama model.
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Args:
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texts: The list of texts to embed.
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Returns:
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List of embeddings, one for each text.
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"""
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embeddings = [self.client.embed(text) for text in texts]
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return [list(map(float, e)) for e in embeddings]
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def embed_query(self, text: str) -> List[float]:
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"""Embed a query using the Llama model.
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Args:
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text: The text to embed.
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Returns:
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Embeddings for the text.
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"""
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embedding = self.client.embed(text)
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return list(map(float, embedding))
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