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f5628ad | 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 | from langchain_classic.memory import ConversationBufferWindowMemory
from server.utils import load_config, setup_logger
logger = setup_logger(__name__)
def create_memory(memory_key: str = "chat_history", max_token_limit: int = 2000) -> ConversationBufferWindowMemory:
"""
Create LangChain ConversationBufferWindowMemory.
memory_key = "chat_history"
return_messages = True
k = number of recent conversation turns to keep
"""
config = load_config()
max_token_limit = config.get("memory", {}).get("max_token_limit", max_token_limit)
# Use window memory with k turns (approximate: ~200 tokens per turn)
k_turns = max(1, max_token_limit // 200)
memory = ConversationBufferWindowMemory(
memory_key=memory_key,
return_messages=True,
output_key="answer",
k=k_turns,
)
logger.info(f"Created conversation memory (k={k_turns} turns)")
return memory
def get_memory_as_string(memory: ConversationBufferWindowMemory) -> str:
"""Return conversation history as formatted string for display in UI."""
messages = memory.chat_memory.messages
lines = []
for msg in messages:
role = "User" if msg.type == "human" else "Assistant"
lines.append(f"{role}: {msg.content}")
return "\n".join(lines)
def clear_memory(memory: ConversationBufferWindowMemory) -> None:
"""Clear all messages. Called on 'New Conversation' button."""
memory.clear()
logger.info("Conversation memory cleared")
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