|
| 1 | +"""Summarizing conversation history management with configurable options.""" |
| 2 | + |
| 3 | +import logging |
| 4 | +from typing import List, Optional, cast |
| 5 | + |
| 6 | +from ...types.content import ContentBlock, Message, Messages |
| 7 | +from ...types.exceptions import ContextWindowOverflowException |
| 8 | +from ...types.models.model import Model |
| 9 | +from ...types.tools import ToolResult |
| 10 | +from .sliding_window_conversation_manager import SlidingWindowConversationManager |
| 11 | + |
| 12 | +logger = logging.getLogger(__name__) |
| 13 | + |
| 14 | + |
| 15 | +class SummarizingConversationManager(SlidingWindowConversationManager): |
| 16 | + """Extends sliding window manager with optional summarization of older messages. |
| 17 | +
|
| 18 | + This manager provides a configurable option to summarize older context instead of |
| 19 | + simply trimming it, helping preserve important information while staying within |
| 20 | + context limits. |
| 21 | + """ |
| 22 | + |
| 23 | + def __init__( |
| 24 | + self, |
| 25 | + window_size: int = 40, |
| 26 | + enable_summarization: bool = False, |
| 27 | + summarization_model: Optional[Model] = None, |
| 28 | + summary_ratio: float = 0.3, |
| 29 | + preserve_recent_messages: int = 10, |
| 30 | + ): |
| 31 | + """Initialize the summarizing conversation manager. |
| 32 | +
|
| 33 | + Args: |
| 34 | + window_size: Maximum number of messages to keep in history. |
| 35 | + Defaults to 40 messages. |
| 36 | + enable_summarization: Whether to enable summarization of older context. |
| 37 | + Defaults to False (falls back to sliding window behavior). |
| 38 | + summarization_model: Model to use for generating summaries. |
| 39 | + Required if enable_summarization is True. |
| 40 | + summary_ratio: Ratio of messages to summarize vs keep when window is exceeded. |
| 41 | + Value between 0.1 and 0.8. Defaults to 0.3 (summarize 30% of oldest messages). |
| 42 | + preserve_recent_messages: Minimum number of recent messages to always keep. |
| 43 | + Defaults to 10 messages. |
| 44 | + """ |
| 45 | + super().__init__(window_size) |
| 46 | + self.enable_summarization = enable_summarization |
| 47 | + self.summarization_model = summarization_model |
| 48 | + self.summary_ratio = max(0.1, min(0.8, summary_ratio)) |
| 49 | + self.preserve_recent_messages = preserve_recent_messages |
| 50 | + |
| 51 | + if enable_summarization and summarization_model is None: |
| 52 | + raise ValueError("summarization_model is required when enable_summarization is True") |
| 53 | + |
| 54 | + def reduce_context(self, messages: Messages, e: Optional[Exception] = None) -> None: |
| 55 | + """Reduce context using summarization if enabled, otherwise fall back to sliding window. |
| 56 | +
|
| 57 | + Args: |
| 58 | + messages: The messages to reduce. |
| 59 | + This list is modified in-place. |
| 60 | + e: The exception that triggered the context reduction, if any. |
| 61 | +
|
| 62 | + Raises: |
| 63 | + ContextWindowOverflowException: If the context cannot be reduced further. |
| 64 | + """ |
| 65 | + if not self.enable_summarization or self.summarization_model is None: |
| 66 | + # Fall back to standard sliding window behavior |
| 67 | + super().reduce_context(messages, e) |
| 68 | + return |
| 69 | + |
| 70 | + try: |
| 71 | + self._reduce_context_with_summarization(messages, e) |
| 72 | + except Exception as summarization_error: |
| 73 | + logger.warning("Summarization failed, falling back to sliding window: %s", summarization_error) |
| 74 | + # Fall back to sliding window if summarization fails |
| 75 | + super().reduce_context(messages, e) |
| 76 | + |
| 77 | + def _reduce_context_with_summarization(self, messages: Messages, e: Optional[Exception] = None) -> None: |
| 78 | + """Reduce context by summarizing older messages. |
| 79 | +
|
| 80 | + Args: |
| 81 | + messages: The messages to reduce. |
| 82 | + This list is modified in-place. |
| 83 | + e: The exception that triggered the context reduction, if any. |
| 84 | +
|
| 85 | + Raises: |
| 86 | + ContextWindowOverflowException: If the context cannot be reduced further. |
| 87 | + """ |
| 88 | + if len(messages) <= self.preserve_recent_messages: |
| 89 | + raise ContextWindowOverflowException("Cannot summarize: too few messages to preserve context") from e |
| 90 | + |
| 91 | + # Calculate how many messages to summarize |
| 92 | + messages_to_summarize_count = max(1, int(len(messages) * self.summary_ratio)) |
| 93 | + |
| 94 | + # Ensure we don't summarize recent messages |
| 95 | + messages_to_summarize_count = min(messages_to_summarize_count, len(messages) - self.preserve_recent_messages) |
| 96 | + |
| 97 | + if messages_to_summarize_count <= 0: |
| 98 | + raise ContextWindowOverflowException("Cannot summarize: insufficient messages for summarization") from e |
| 99 | + |
| 100 | + # Extract messages to summarize |
| 101 | + messages_to_summarize = messages[:messages_to_summarize_count] |
| 102 | + remaining_messages = messages[messages_to_summarize_count:] |
| 103 | + |
| 104 | + # Generate summary |
| 105 | + summary_content = self._generate_summary(messages_to_summarize) |
| 106 | + |
| 107 | + # Create a summary message |
| 108 | + summary_message: Message = {"role": "assistant", "content": [ContentBlock(text=summary_content)]} |
| 109 | + |
| 110 | + # Replace the summarized messages with the summary |
| 111 | + messages[:] = [summary_message] + remaining_messages |
| 112 | + |
| 113 | + def _generate_summary(self, messages: List[Message]) -> str: |
| 114 | + """Generate a summary of the provided messages. |
| 115 | +
|
| 116 | + Args: |
| 117 | + messages: The messages to summarize. |
| 118 | +
|
| 119 | + Returns: |
| 120 | + A text summary of the conversation history. |
| 121 | +
|
| 122 | + Raises: |
| 123 | + Exception: If summary generation fails. |
| 124 | + """ |
| 125 | + if self.summarization_model is None: |
| 126 | + raise ValueError("Summarization model is required but not provided") |
| 127 | + |
| 128 | + # Convert messages to a readable format for summarization |
| 129 | + conversation_text = self._format_messages_for_summarization(messages) |
| 130 | + |
| 131 | + # Create system prompt for summarization task |
| 132 | + system_prompt = ( |
| 133 | + "You are a conversation summarizer. Provide a concise summary of the conversation history. " |
| 134 | + "Focus on key decisions, important context, and any ongoing tasks or topics. " |
| 135 | + "Keep the summary under 500 words and be factual and objective." |
| 136 | + ) |
| 137 | + |
| 138 | + # Create user message with conversation to summarize |
| 139 | + user_prompt = f"Please summarize this conversation:\n\n{conversation_text}" |
| 140 | + summary_messages: Messages = [{"role": "user", "content": [ContentBlock(text=user_prompt)]}] |
| 141 | + |
| 142 | + summary_response = "" |
| 143 | + for chunk in self.summarization_model.converse(summary_messages, system_prompt=system_prompt): |
| 144 | + # Extract text from streaming events |
| 145 | + if "contentBlockDelta" in chunk and "delta" in chunk["contentBlockDelta"]: |
| 146 | + delta = chunk["contentBlockDelta"]["delta"] |
| 147 | + if "text" in delta: |
| 148 | + summary_response += delta["text"] |
| 149 | + |
| 150 | + return f"[CONVERSATION SUMMARY]: {summary_response.strip()}" |
| 151 | + |
| 152 | + def _format_messages_for_summarization(self, messages: List[Message]) -> str: |
| 153 | + """Format messages into readable text for summarization. |
| 154 | +
|
| 155 | + Args: |
| 156 | + messages: The messages to format. |
| 157 | +
|
| 158 | + Returns: |
| 159 | + A formatted string representation of the messages. |
| 160 | + """ |
| 161 | + formatted_parts = [] |
| 162 | + |
| 163 | + for _, message in enumerate(messages): |
| 164 | + role = message["role"].capitalize() |
| 165 | + content_parts = [] |
| 166 | + |
| 167 | + for content in message["content"]: |
| 168 | + if "text" in content: |
| 169 | + content_parts.append(content["text"]) |
| 170 | + elif "toolUse" in content: |
| 171 | + tool_use = content["toolUse"] |
| 172 | + content_parts.append(f"[Used tool: {tool_use.get('name', 'unknown')}]") |
| 173 | + elif "toolResult" in content: |
| 174 | + tool_result = cast(ToolResult, content["toolResult"]) |
| 175 | + status = tool_result.get("status", "") |
| 176 | + if tool_result.get("content"): |
| 177 | + for tr_content in tool_result["content"]: |
| 178 | + if "text" in tr_content: |
| 179 | + content_parts.append(f"[Tool result: {tr_content['text'][:100]}...]") |
| 180 | + elif "json" in tr_content: |
| 181 | + content_parts.append("[Tool result: JSON data]") |
| 182 | + else: |
| 183 | + content_parts.append(f"[Tool result: {status}]") |
| 184 | + elif "image" in content: |
| 185 | + content_parts.append("[Image content]") |
| 186 | + elif "document" in content: |
| 187 | + content_parts.append("[Document content]") |
| 188 | + |
| 189 | + if content_parts: |
| 190 | + formatted_parts.append(f"{role}: {' '.join(content_parts)}") |
| 191 | + |
| 192 | + return "\n".join(formatted_parts) |
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