dp-zp-agent/tools/rag/embedding_utils.py

285 lines
7.1 KiB
Python

from __future__ import annotations
import os
import hashlib
import json
from functools import lru_cache
from typing import Any
import numpy as np
from tools.retrieval.text_budget import split_to_fit
from tools.runtime.runtime_assets import local_model
DEFAULT_EMBEDDING_MODEL = "intfloat/multilingual-e5-small"
DEFAULT_BATCH_SIZE = 32
def embedding_model_name() -> str:
return (
os.getenv(
"EMBEDDING_MODEL",
DEFAULT_EMBEDDING_MODEL,
).strip()
or DEFAULT_EMBEDDING_MODEL
)
def embedding_batch_size() -> int:
raw_value = os.getenv(
"EMBEDDING_BATCH_SIZE",
str(DEFAULT_BATCH_SIZE),
).strip()
try:
value = int(raw_value)
except ValueError:
return DEFAULT_BATCH_SIZE
return max(
1,
value,
)
def get_embedding_model(
model_name: str,
):
return _load_embedding_model(model_name, os.getenv("EMBEDDING_REVISION") or None)
@lru_cache(maxsize=2)
def _load_embedding_model(model_name: str, revision: str | None):
from sentence_transformers import (
SentenceTransformer,
)
bundled = local_model(model_name, revision)
return SentenceTransformer(
bundled or model_name,
revision=None if bundled else revision,
local_files_only=bool(bundled) or os.getenv("HF_HUB_OFFLINE") == "1",
)
def model_profile(model_name: str) -> dict:
"""Fingerprint the loaded weights, tokenizer and pooling, not a mutable alias."""
return _model_profile(model_name, get_embedding_model(model_name))
@lru_cache(maxsize=2)
def _model_profile(model_name, model):
import torch
weights = hashlib.sha256()
for name, tensor in sorted(model.state_dict().items()):
weights.update(name.encode())
weights.update(str((tuple(tensor.shape), tensor.dtype)).encode())
weights.update(tensor.detach().cpu().contiguous().view(torch.uint8).numpy().tobytes())
tokenizer_config = json.loads(model.tokenizer.backend_tokenizer.to_str())
# Fast tokenizers store the last call's padding/truncation in the backend.
# These mutable execution settings must not change the vocabulary fingerprint.
tokenizer_config.pop("padding", None)
tokenizer_config.pop("truncation", None)
tokenizer = json.dumps(
tokenizer_config, sort_keys=True, separators=(",", ":"), ensure_ascii=False
)
modules = {
name: module.get_config_dict()
for name, module in model._modules.items()
if hasattr(module, "get_config_dict")
}
profile = {
"model": model_name,
"weights_sha256": weights.hexdigest(),
"tokenizer_sha256": hashlib.sha256(tokenizer.encode()).hexdigest(),
"max_seq_length": int(model.max_seq_length),
"modules": modules,
"passage_prefix": "passage: ",
"query_prefix": "query: ",
"normalize_embeddings": True,
"dtype": "float32",
"segment_policy": "lossless-v1",
}
profile["fingerprint"] = hashlib.sha256(
json.dumps(profile, sort_keys=True).encode()
).hexdigest()
return profile
def passage_token_count(text: str, *, model_name: str | None = None) -> int:
model = get_embedding_model(model_name or embedding_model_name())
return len(
model.tokenizer(
"passage: " + text, truncation=False, add_special_tokens=True, verbose=False
)["input_ids"]
)
def split_passage(text: str, *, model_name: str | None = None) -> list[str]:
selected = model_name or embedding_model_name()
limit = int(get_embedding_model(selected).max_seq_length)
return split_to_fit(
text, lambda value: passage_token_count(value, model_name=selected) <= limit
)
def build_embedding_text(
chunk: dict[str, Any],
) -> str:
parts: list[str] = []
title = str(chunk.get("title") or "").strip()
author = str(chunk.get("author") or "").strip()
tags = [str(value).strip() for value in (chunk.get("tags") or []) if str(value).strip()]
categories = [
str(value).strip() for value in (chunk.get("categories") or []) if str(value).strip()
]
text = str(chunk.get("text") or "").strip()
if title:
parts.append(f"Názov: {title}")
if author:
parts.append(f"Autor: {author}")
if tags:
parts.append("Tagy: " + ", ".join(tags))
if categories:
parts.append("Kategórie: " + ", ".join(categories))
if text:
parts.append(text)
return "\n".join(parts)
def embed_passages(
texts: list[str],
*,
model_name: str | None = None,
) -> np.ndarray:
if not texts:
return np.empty(
(
0,
0,
),
dtype=np.float32,
)
selected_model = model_name or embedding_model_name()
model = get_embedding_model(selected_model)
prepared = ["passage: " + text for text in texts]
if any(
passage_token_count(text, model_name=selected_model) > model.max_seq_length
for text in texts
):
raise ValueError("Embedding input exceeds model limit; split it before encoding.")
vectors = model.encode(
prepared,
batch_size=(embedding_batch_size()),
show_progress_bar=False,
convert_to_numpy=True,
normalize_embeddings=True,
)
return np.asarray(
vectors,
dtype=np.float32,
)
def embed_query(
query: str,
*,
model_name: str | None = None,
) -> np.ndarray:
clean_query = query.strip()
if not clean_query:
raise ValueError("Query nesmie byť prázdny")
selected_model = model_name or embedding_model_name()
model = get_embedding_model(selected_model)
length = len(
model.tokenizer(
"query: " + clean_query, truncation=False, add_special_tokens=True, verbose=False
)["input_ids"]
)
if length > model.max_seq_length:
raise ValueError("Query prekračuje tokenový limit embeddingového modelu")
vector = model.encode(
["query: " + clean_query],
batch_size=1,
show_progress_bar=False,
convert_to_numpy=True,
normalize_embeddings=True,
)[0]
return np.asarray(
vector,
dtype=np.float32,
)
def vector_to_blob(
vector: np.ndarray,
) -> bytes:
normalized = np.asarray(
vector,
dtype=np.float32,
)
return normalized.tobytes()
def blob_to_vector(
blob: bytes,
dimensions: int,
) -> np.ndarray:
vector = np.frombuffer(
blob,
dtype=np.float32,
)
if vector.shape[0] != dimensions:
raise RuntimeError("Neplatný rozmer " "uloženého embeddingu")
return vector
def cosine_similarity(
first: np.ndarray,
second: np.ndarray,
) -> float:
if first.shape != second.shape:
raise ValueError("Embeddingy majú " "rozdielny rozmer")
first_norm = float(np.linalg.norm(first))
second_norm = float(np.linalg.norm(second))
if first_norm == 0.0 or second_norm == 0.0:
return 0.0
return float(
np.dot(
first,
second,
)
/ (first_norm * second_norm)
)