Files
MoviePilot/app/agent/middleware/usage.py
2026-08-06 23:34:29 +08:00

384 lines
12 KiB
Python

from collections.abc import Awaitable, Callable
from typing import Any
from langchain.agents.middleware.types import (
AgentMiddleware,
ContextT,
ModelRequest,
ModelResponse,
ResponseT,
)
from langchain_core.messages import AIMessage
from app.log import logger
class UsageMiddleware(AgentMiddleware):
"""记录模型调用 usage 信息并回传给外部会话。"""
def __init__(
self,
*,
on_usage: Callable[[dict[str, Any]], None] | None = None,
) -> None:
self.on_usage = on_usage
@staticmethod
def _coerce_int(value: Any) -> int | None:
if value is None:
return None
try:
return int(value)
except (TypeError, ValueError):
return None
@classmethod
def _lookup_int(cls, container: Any, *keys: str) -> int | None:
if not container:
return None
getter = getattr(container, "get", None)
if callable(getter):
for key in keys:
value = getter(key)
if value is not None:
return cls._coerce_int(value)
for key in keys:
value = getattr(container, key, None)
if value is not None:
return cls._coerce_int(value)
return None
@classmethod
def _first_int(
cls,
candidates: tuple[tuple[Any, tuple[str, ...]], ...],
) -> int | None:
"""按优先级返回首个可用的 usage 整数值。"""
for container, keys in candidates:
value = cls._lookup_int(container, *keys)
if value is not None:
return value
return None
@classmethod
def _extract_model_name(cls, model: Any) -> str | None:
return (
getattr(model, "model", None)
or getattr(model, "model_name", None)
or getattr(model, "model_id", None)
)
@classmethod
def _extract_context_window_tokens(cls, model: Any) -> int | None:
profile = getattr(model, "profile", None)
if not profile:
return None
return cls._lookup_int(profile, "max_input_tokens", "input_token_limit")
@classmethod
def _extract_usage(cls, ai_message: AIMessage) -> dict[str, Any]:
usage_metadata = getattr(ai_message, "usage_metadata", None)
input_tokens = cls._lookup_int(usage_metadata, "input_tokens")
output_tokens = cls._lookup_int(usage_metadata, "output_tokens")
total_tokens = cls._lookup_int(usage_metadata, "total_tokens")
response_metadata = getattr(ai_message, "response_metadata", None) or {}
token_usage = (
response_metadata.get("token_usage")
or response_metadata.get("usage")
or response_metadata.get("usage_metadata")
or {}
)
input_token_details = None
if usage_metadata:
getter = getattr(usage_metadata, "get", None)
input_token_details = (
getter("input_token_details")
if callable(getter)
else getattr(usage_metadata, "input_token_details", None)
)
cache_read_tokens = cls._first_int(
(
(
input_token_details,
(
"cache_read",
"cached_tokens",
"cache_read_input_tokens",
"cacheReadInputTokens",
),
),
(
token_usage,
(
"prompt_cache_hit_tokens",
"cache_read_input_tokens",
"cacheReadInputTokens",
),
),
(
response_metadata,
(
"prompt_cache_hit_tokens",
"cache_read_input_tokens",
"cacheReadInputTokens",
"cached_tokens",
),
),
)
)
if cache_read_tokens is None:
cache_read_tokens = cls._first_int(
(
(
token_usage.get("prompt_tokens_details", {}),
("cached_tokens", "cache_read"),
),
(
token_usage.get("input_tokens_details", {}),
("cached_tokens", "cache_read"),
),
)
)
cache_write_tokens = cls._first_int(
(
(
input_token_details,
(
"cache_creation",
"cache_write",
"cache_write_tokens",
"cache_write_input_tokens",
"cacheWriteInputTokens",
),
),
(
token_usage,
(
"cache_creation_input_tokens",
"cache_write_tokens",
"cache_write_input_tokens",
"cacheWriteInputTokens",
),
),
(
response_metadata,
(
"cache_creation_input_tokens",
"cache_write_tokens",
"cache_write_input_tokens",
"cacheWriteInputTokens",
),
),
)
)
if cache_write_tokens is None:
cache_write_tokens = cls._first_int(
(
(
token_usage.get("prompt_tokens_details", {}),
("cache_write_tokens", "cache_creation"),
),
(
token_usage.get("input_tokens_details", {}),
("cache_write_tokens", "cache_creation"),
),
)
)
cache_write_ttl_tokens = sum(
cls._lookup_int(
input_token_details,
ttl_key,
)
or 0
for ttl_key in (
"ephemeral_5m_input_tokens",
"ephemeral_1h_input_tokens",
)
)
if cache_write_ttl_tokens:
cache_write_tokens = cache_write_ttl_tokens
cache_miss_tokens = cls._first_int(
(
(
token_usage,
("prompt_cache_miss_tokens", "cache_miss_input_tokens"),
),
(
response_metadata,
("prompt_cache_miss_tokens", "cache_miss_input_tokens"),
),
)
)
if input_tokens is None:
input_tokens = cls._lookup_int(
token_usage,
"prompt_tokens",
"input_tokens",
)
if input_tokens is None:
input_tokens = cls._lookup_int(
response_metadata,
"prompt_token_count",
"input_tokens",
)
if input_tokens is None:
bedrock_input_tokens = cls._lookup_int(token_usage, "inputTokens")
if bedrock_input_tokens is not None:
input_tokens = (
bedrock_input_tokens
+ (cache_read_tokens or 0)
+ (cache_write_tokens or 0)
)
if input_tokens is None and any(
value is not None
for value in (
cache_read_tokens,
cache_write_tokens,
cache_miss_tokens,
)
):
input_tokens = (
(cache_read_tokens or 0)
+ (cache_write_tokens or 0)
+ (cache_miss_tokens or 0)
)
if output_tokens is None:
output_tokens = cls._lookup_int(
token_usage,
"completion_tokens",
"output_tokens",
)
if output_tokens is None:
output_tokens = cls._lookup_int(
response_metadata,
"candidates_token_count",
"output_tokens",
)
if total_tokens is None:
total_tokens = cls._lookup_int(token_usage, "total_tokens")
if total_tokens is None:
total_tokens = cls._lookup_int(response_metadata, "total_token_count")
has_cache_usage = any(
value is not None
for value in (
cache_read_tokens,
cache_write_tokens,
cache_miss_tokens,
)
)
has_usage = any(
value is not None
for value in (
input_tokens,
output_tokens,
total_tokens,
cache_read_tokens,
cache_write_tokens,
cache_miss_tokens,
)
)
resolved_input = input_tokens or 0
resolved_output = output_tokens or 0
resolved_total = (
total_tokens
if total_tokens is not None
else resolved_input + resolved_output
)
resolved_cache_read = cache_read_tokens or 0
resolved_cache_write = cache_write_tokens or 0
uncached_input_tokens = (
cache_miss_tokens
if cache_miss_tokens is not None
else max(
resolved_input - resolved_cache_read - resolved_cache_write,
0,
)
)
cache_hit_ratio = (
resolved_cache_read / resolved_input
if has_cache_usage and resolved_input
else None
)
return {
"has_usage": has_usage,
"cache_usage_available": has_cache_usage,
"input_tokens": resolved_input,
"output_tokens": resolved_output,
"total_tokens": resolved_total,
"cache_read_input_tokens": resolved_cache_read,
"cache_write_input_tokens": resolved_cache_write,
"uncached_input_tokens": uncached_input_tokens,
"cache_hit_ratio": cache_hit_ratio,
}
async def awrap_model_call(
self,
request: ModelRequest[ContextT],
handler: Callable[
[ModelRequest[ContextT]], Awaitable[ModelResponse[ResponseT]]
],
) -> ModelResponse[ResponseT]:
response = await handler(request)
if not callable(self.on_usage):
return response
try:
ai_message = next(
(
message
for message in reversed(response.result)
if isinstance(message, AIMessage)
),
None,
)
usage = (
self._extract_usage(ai_message)
if ai_message
else {
"has_usage": False,
"cache_usage_available": False,
"input_tokens": 0,
"output_tokens": 0,
"total_tokens": 0,
"cache_read_input_tokens": 0,
"cache_write_input_tokens": 0,
"uncached_input_tokens": 0,
"cache_hit_ratio": None,
}
)
context_window_tokens = self._extract_context_window_tokens(request.model)
context_usage_ratio = None
if context_window_tokens and usage["has_usage"]:
context_usage_ratio = usage["input_tokens"] / context_window_tokens
self.on_usage(
{
"model": self._extract_model_name(request.model),
"context_window_tokens": context_window_tokens,
"context_usage_ratio": context_usage_ratio,
**usage,
}
)
except Exception as e:
logger.debug("记录模型 usage 失败: %s", e)
return response
__all__ = ["UsageMiddleware"]