ai-agent-book 精选快照（<2MB 代码与文档，来自 github.com/bojieli/ai-agent-book）

chapter9/browser-use-rpa/browser-use/browser_use/agent/message_manager/views.py

@@ -0,0 +1,98 @@
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+from pydantic import BaseModel, ConfigDict, Field
+
+from browser_use.llm.messages import (
+	BaseMessage,
+)
+
+if TYPE_CHECKING:
+	pass
+
+
+class HistoryItem(BaseModel):
+	"""Represents a single agent history item with its data and string representation"""
+
+	step_number: int | None = None
+	evaluation_previous_goal: str | None = None
+	memory: str | None = None
+	next_goal: str | None = None
+	action_results: str | None = None
+	error: str | None = None
+	system_message: str | None = None
+
+	model_config = ConfigDict(arbitrary_types_allowed=True)
+
+	def model_post_init(self, __context) -> None:
+		"""Validate that error and system_message are not both provided"""
+		if self.error is not None and self.system_message is not None:
+			raise ValueError('Cannot have both error and system_message at the same time')
+
+	def to_string(self) -> str:
+		"""Get string representation of the history item"""
+		step_str = 'step' if self.step_number is not None else 'step_unknown'
+
+		if self.error:
+			return f"""<{step_str}>
+{self.error}
+</{step_str}>"""
+		elif self.system_message:
+			return self.system_message
+		else:
+			content_parts = []
+
+			# Only include evaluation_previous_goal if it's not None/empty
+			if self.evaluation_previous_goal:
+				content_parts.append(f'{self.evaluation_previous_goal}')
+
+			# Always include memory
+			if self.memory:
+				content_parts.append(f'{self.memory}')
+
+			# Only include next_goal if it's not None/empty
+			if self.next_goal:
+				content_parts.append(f'{self.next_goal}')
+
+			if self.action_results:
+				content_parts.append(self.action_results)
+
+			content = '\n'.join(content_parts)
+
+			return f"""<{step_str}>
+{content}
+</{step_str}>"""
+
+
+class MessageHistory(BaseModel):
+	"""History of messages"""
+
+	system_message: BaseMessage | None = None
+	state_message: BaseMessage | None = None
+	context_messages: list[BaseMessage] = Field(default_factory=list)
+	model_config = ConfigDict(arbitrary_types_allowed=True)
+
+	def get_messages(self) -> list[BaseMessage]:
+		"""Get all messages in the correct order: system -> state -> contextual"""
+		messages = []
+		if self.system_message:
+			messages.append(self.system_message)
+		if self.state_message:
+			messages.append(self.state_message)
+		messages.extend(self.context_messages)
+
+		return messages
+
+
+class MessageManagerState(BaseModel):
+	"""Holds the state for MessageManager"""
+
+	history: MessageHistory = Field(default_factory=MessageHistory)
+	tool_id: int = 1
+	agent_history_items: list[HistoryItem] = Field(
+		default_factory=lambda: [HistoryItem(step_number=0, system_message='Agent initialized')]
+	)
+	read_state_description: str = ''
+
+	model_config = ConfigDict(arbitrary_types_allowed=True)