Files
hunjing/backend/app/ai_provider/embedding/openai_format.py
T
2026-08-21 16:00:13 +08:00

170 lines
5.5 KiB
Python

"""OpenAI 兼容格式的 Embedding 适配器 — ``POST /v1/embeddings``。
覆盖 OpenAI、DeepSeek、以及任何兼容 OpenAI 嵌入端点的提供商。
请求::
POST {base_url}/v1/embeddings
Authorization: Bearer {api_key}
Content-Type: application/json
{
"model": "text-embedding-3-small",
"input": ["要嵌入的文本"],
"encoding_format": "float"
}
响应::
{
"object": "list",
"data": [
{"object": "embedding", "index": 0, "embedding": [0.xxx, ...]}
],
"model": "text-embedding-3-small",
"usage": {"prompt_tokens": 5, "total_tokens": 5}
}
"""
from __future__ import annotations
from typing import Any
import httpx
from app.ai_provider.embedding.base import (
EmbeddingAdapterBase,
EmbeddingProtocol,
EmbeddingRequest,
EmbeddingResponse,
EmbeddingResult,
EmbeddingServiceError,
)
from app.core.logging import logger
class OpenAIFormatEmbeddingAdapter(EmbeddingAdapterBase, EmbeddingProtocol):
"""OpenAI 兼容嵌入适配器,覆盖 95%+ 的嵌入服务提供商。"""
_adapter_type = "embedding"
_default_timeout = 60
def __init__(
self,
*,
base_url: str,
api_key: str,
model: str = "text-embedding-3-small",
request_timeout_seconds: int = 60,
) -> None:
self._base_url = base_url.rstrip("/")
self._api_key = api_key
self._model = model
self._timeout = request_timeout_seconds
self._client: httpx.AsyncClient | None = None
# ── 客户端 ───────────────────────────────────────────────────────────
@property
def _http(self) -> httpx.AsyncClient:
if self._client is None or self._client.is_closed:
self._client = httpx.AsyncClient(timeout=httpx.Timeout(self._timeout))
return self._client
async def close(self) -> None:
if self._client is not None and not self._client.is_closed:
await self._client.aclose()
# ── EmbeddingProtocol ────────────────────────────────────────────────
async def embed(self, request: EmbeddingRequest) -> EmbeddingResponse:
"""通过 ``POST /v1/embeddings`` 将文本转换为向量。"""
url = f"{self._base_url}/v1/embeddings"
payload: dict[str, Any] = {
"model": request.model or self._model,
"input": request.input,
"encoding_format": request.encoding_format,
}
if request.dimensions is not None:
payload["dimensions"] = request.dimensions
if request.user is not None:
payload["user"] = request.user
headers = {
"Content-Type": "application/json",
}
if self._api_key:
headers["Authorization"] = f"Bearer {self._api_key}"
logger.info(
"embedding.request",
model=payload["model"],
input_count=len(request.input) if isinstance(request.input, list) else 1,
dimensions=request.dimensions,
url=url,
)
try:
response = await self._http.post(url, json=payload, headers=headers)
except httpx.TimeoutException as exc:
raise EmbeddingServiceError(
status_code=504,
code="embedding_timeout",
message="Embedding request timed out.",
) from exc
except httpx.RequestError as exc:
raise EmbeddingServiceError(
status_code=503,
code="embedding_connection_error",
message=f"Embedding connection error: {exc}",
) from exc
if response.status_code != 200:
body = response.text[:500]
raise EmbeddingServiceError(
status_code=response.status_code,
code="embedding_api_error",
message=f"Embedding API returned {response.status_code}: {body}",
)
result = self._parse_response(response.json())
logger.info(
"embedding.success",
model=payload["model"],
total_vectors=len(result.data),
usage=result.usage,
)
return result
# ── 辅助方法 ──────────────────────────────────────────────────────────
@staticmethod
def _parse_response(body: dict) -> EmbeddingResponse:
"""从 OpenAI 格式的嵌入响应中提取结果。"""
try:
raw_data = body.get("data", [])
results = []
for item in raw_data:
results.append(
EmbeddingResult(
embedding=item.get("embedding", []),
index=item.get("index", 0),
)
)
# 按 index 排序确保顺序
results.sort(key=lambda r: r.index)
return EmbeddingResponse(
data=results,
model=body.get("model", ""),
usage=body.get("usage"),
)
except Exception as exc:
raise EmbeddingServiceError(
status_code=500,
code="embedding_response_parse_error",
message=f"Failed to parse embedding response: {exc}",
) from exc