File size: 5,719 Bytes
6461f0c | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | """OpenAI-compatible HTTP client for a vLLM server.
The wire format uses the standard OpenAI ``/v1/chat/completions`` schema.
Frames are sent inline as base64 ``data:`` URLs.
"""
from __future__ import annotations
import json
import time
from typing import Any, Optional
import requests
class VLLMClient:
"""OpenAI-compatible client backed by a vLLM server."""
def __init__(
self,
base_url: str,
model_name: str,
api_key: str = "EMPTY",
max_tokens: int = 2048,
temperature: float = 0.0,
top_p: Optional[float] = None,
request_interval: float = 0.0,
max_retries: int = 3,
retry_base_delay: float = 2.0,
request_timeout: int = 300,
) -> None:
base_url = (base_url or "").rstrip("/")
if not base_url.endswith("/v1"):
base_url = f"{base_url}/v1"
self.base_url = base_url
self.model_name = model_name
self.max_tokens = int(max_tokens)
self.temperature = float(temperature)
self.top_p = top_p
self.request_interval = float(request_interval)
self.max_retries = int(max_retries)
self.retry_base_delay = float(retry_base_delay)
self.request_timeout = int(request_timeout)
self.headers = {
"Content-Type": "application/json",
"Authorization": f"Bearer {api_key or 'EMPTY'}",
}
# ------------------------------------------------------------------
# Public inference entry points
# ------------------------------------------------------------------
def infer_text_only(
self,
user_text: str,
system_text: Optional[str] = None,
) -> str:
messages = self._build_messages(
user_content=[{"type": "text", "text": user_text}],
system_text=system_text,
)
return self._infer(messages)
def infer_with_frames(
self,
user_text: str,
frame_b64_list: list[str],
system_text: Optional[str] = None,
) -> str:
content_parts: list[dict[str, Any]] = []
for frame_b64 in frame_b64_list:
content_parts.append(
{
"type": "image_url",
"image_url": {"url": f"data:image/jpeg;base64,{frame_b64}"},
}
)
content_parts.append({"type": "text", "text": user_text})
messages = self._build_messages(
user_content=content_parts, system_text=system_text
)
return self._infer(messages)
# ------------------------------------------------------------------
# Internal helpers
# ------------------------------------------------------------------
@staticmethod
def _build_messages(
user_content: list[dict[str, Any]],
system_text: Optional[str],
) -> list[dict[str, Any]]:
messages: list[dict[str, Any]] = []
if system_text and system_text.strip():
messages.append(
{
"role": "system",
"content": [{"type": "text", "text": system_text}],
}
)
messages.append({"role": "user", "content": user_content})
return messages
def _infer(self, messages: list[dict[str, Any]]) -> str:
url = f"{self.base_url}/chat/completions"
payload: dict[str, Any] = {
"model": self.model_name,
"messages": messages,
"max_tokens": self.max_tokens,
"temperature": self.temperature,
}
if self.top_p is not None:
payload["top_p"] = self.top_p
resp = self._post_with_retry(url, payload)
data = resp.json()
if data.get("error"):
raise RuntimeError(f"vLLM API error: {data['error']}")
choices = data.get("choices", [])
if not choices:
raise RuntimeError(
"vLLM API returned no choices: "
f"{json.dumps(data, ensure_ascii=False)[:500]}"
)
content = choices[0].get("message", {}).get("content", "")
if isinstance(content, str) and content.strip():
return content
if isinstance(content, list):
text_parts = [
part.get("text", "")
for part in content
if isinstance(part, dict)
]
text = "\n".join(p for p in text_parts if p)
if text.strip():
return text
raise RuntimeError(
"No text found in vLLM response: "
f"{json.dumps(data, ensure_ascii=False)[:500]}"
)
def _post_with_retry(
self, url: str, payload: dict[str, Any]
) -> requests.Response:
last_exc: Optional[Exception] = None
for attempt in range(self.max_retries):
try:
resp = requests.post(
url,
headers=self.headers,
json=payload,
timeout=self.request_timeout,
)
resp.raise_for_status()
return resp
except Exception as exc: # noqa: BLE001
last_exc = exc
if attempt < self.max_retries - 1:
delay = self.retry_base_delay * (2 ** attempt)
print(
f" [vllm retry] attempt {attempt + 1}/"
f"{self.max_retries} failed: {exc}; sleep {delay:.1f}s"
)
time.sleep(delay)
raise RuntimeError(
f"vLLM request failed after {self.max_retries} attempts: {last_exc}"
)
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