e653d63bc1
OSS restructuring for open-core model: - Rename package from agentserver/ to xml_pipeline/ - Update all imports (44 Python files, 31 docs/configs) - Update pyproject.toml for OSS distribution (v0.3.0) - Move prompt_toolkit from core to optional [console] extra - Remove auth/server/lsp from core optional deps (-> Nextra) New console example in examples/console/: - Self-contained demo with handlers and config - Uses prompt_toolkit (optional, falls back to input()) - No password auth, no TUI, no LSP — just the basics - Shows how to use xml-pipeline as a library Import changes: - from agentserver.* -> from xml_pipeline.* - CLI entry points updated: xml_pipeline.cli:main Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
300 lines
9.1 KiB
Python
300 lines
9.1 KiB
Python
"""
|
|
context_buffer.py — Virtual memory manager for AI agents.
|
|
|
|
Provides thread-scoped, append-only storage for validated message payloads.
|
|
Handlers receive immutable references to buffer slots, never copies.
|
|
|
|
Design principles:
|
|
- Append-only: Messages cannot be modified after insertion
|
|
- Thread isolation: Handlers only see their thread's context
|
|
- Immutable references: Handlers get read-only views
|
|
- Complete audit trail: All messages preserved in order
|
|
|
|
Analogous to OS virtual memory:
|
|
- Thread ID = virtual address space
|
|
- Buffer slot = memory page
|
|
- Thread registry = page table
|
|
- Immutable reference = read-only mapping
|
|
|
|
Usage:
|
|
buffer = get_context_buffer()
|
|
|
|
# Append validated payload (returns slot reference)
|
|
ref = buffer.append(thread_id, payload, metadata)
|
|
|
|
# Handler receives reference
|
|
handler(ref.payload, ref.metadata)
|
|
|
|
# Get thread history
|
|
history = buffer.get_thread(thread_id)
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
from dataclasses import dataclass, field
|
|
from typing import Any, Dict, List, Optional, Iterator
|
|
from datetime import datetime, timezone
|
|
import threading
|
|
import uuid
|
|
|
|
|
|
@dataclass(frozen=True)
|
|
class SlotMetadata:
|
|
"""Immutable metadata for a buffer slot."""
|
|
thread_id: str
|
|
from_id: str
|
|
to_id: str
|
|
slot_index: int
|
|
timestamp: str
|
|
payload_type: str
|
|
|
|
# Handler-facing metadata (subset exposed to handlers)
|
|
own_name: Optional[str] = None
|
|
is_self_call: bool = False
|
|
usage_instructions: str = ""
|
|
todo_nudge: str = ""
|
|
|
|
|
|
@dataclass(frozen=True)
|
|
class BufferSlot:
|
|
"""
|
|
Immutable slot in the context buffer.
|
|
|
|
frozen=True ensures the slot cannot be modified after creation.
|
|
Handlers receive this directly - they cannot mutate it.
|
|
"""
|
|
payload: Any # The validated @xmlify dataclass (immutable reference)
|
|
metadata: SlotMetadata # Immutable slot metadata
|
|
|
|
@property
|
|
def thread_id(self) -> str:
|
|
return self.metadata.thread_id
|
|
|
|
@property
|
|
def from_id(self) -> str:
|
|
return self.metadata.from_id
|
|
|
|
@property
|
|
def to_id(self) -> str:
|
|
return self.metadata.to_id
|
|
|
|
@property
|
|
def index(self) -> int:
|
|
return self.metadata.slot_index
|
|
|
|
|
|
class ThreadContext:
|
|
"""
|
|
Append-only context buffer for a single thread.
|
|
|
|
All slots are immutable once appended.
|
|
"""
|
|
|
|
def __init__(self, thread_id: str):
|
|
self.thread_id = thread_id
|
|
self._slots: List[BufferSlot] = []
|
|
self._lock = threading.Lock()
|
|
self._created_at = datetime.now(timezone.utc)
|
|
|
|
def append(
|
|
self,
|
|
payload: Any,
|
|
from_id: str,
|
|
to_id: str,
|
|
own_name: Optional[str] = None,
|
|
is_self_call: bool = False,
|
|
usage_instructions: str = "",
|
|
todo_nudge: str = "",
|
|
) -> BufferSlot:
|
|
"""
|
|
Append a validated payload to this thread's context.
|
|
|
|
Returns the immutable slot reference.
|
|
"""
|
|
with self._lock:
|
|
slot_index = len(self._slots)
|
|
|
|
metadata = SlotMetadata(
|
|
thread_id=self.thread_id,
|
|
from_id=from_id,
|
|
to_id=to_id,
|
|
slot_index=slot_index,
|
|
timestamp=datetime.now(timezone.utc).isoformat(),
|
|
payload_type=type(payload).__name__,
|
|
own_name=own_name,
|
|
is_self_call=is_self_call,
|
|
usage_instructions=usage_instructions,
|
|
todo_nudge=todo_nudge,
|
|
)
|
|
|
|
slot = BufferSlot(payload=payload, metadata=metadata)
|
|
self._slots.append(slot)
|
|
|
|
return slot
|
|
|
|
def __len__(self) -> int:
|
|
with self._lock:
|
|
return len(self._slots)
|
|
|
|
def __getitem__(self, index: int) -> BufferSlot:
|
|
with self._lock:
|
|
return self._slots[index]
|
|
|
|
def __iter__(self) -> Iterator[BufferSlot]:
|
|
# Return a copy of the list to avoid mutation during iteration
|
|
with self._lock:
|
|
return iter(list(self._slots))
|
|
|
|
def get_slice(self, start: int = 0, end: Optional[int] = None) -> List[BufferSlot]:
|
|
"""Get a slice of the context (for paging/windowing)."""
|
|
with self._lock:
|
|
return list(self._slots[start:end])
|
|
|
|
def get_by_type(self, payload_type: str) -> List[BufferSlot]:
|
|
"""Get all slots with a specific payload type."""
|
|
with self._lock:
|
|
return [s for s in self._slots if s.metadata.payload_type == payload_type]
|
|
|
|
def get_from(self, from_id: str) -> List[BufferSlot]:
|
|
"""Get all slots from a specific sender."""
|
|
with self._lock:
|
|
return [s for s in self._slots if s.from_id == from_id]
|
|
|
|
|
|
class ContextBuffer:
|
|
"""
|
|
Global context buffer managing all thread contexts.
|
|
|
|
Thread-safe. Singleton pattern via get_context_buffer().
|
|
"""
|
|
|
|
def __init__(self):
|
|
self._threads: Dict[str, ThreadContext] = {}
|
|
self._lock = threading.Lock()
|
|
|
|
# Limits (can be configured)
|
|
self.max_slots_per_thread: int = 10000
|
|
self.max_threads: int = 1000
|
|
|
|
def get_or_create_thread(self, thread_id: str) -> ThreadContext:
|
|
"""Get existing thread context or create new one."""
|
|
with self._lock:
|
|
if thread_id not in self._threads:
|
|
if len(self._threads) >= self.max_threads:
|
|
# GC: remove oldest thread (simple strategy)
|
|
oldest = min(self._threads.values(), key=lambda t: t._created_at)
|
|
del self._threads[oldest.thread_id]
|
|
|
|
self._threads[thread_id] = ThreadContext(thread_id)
|
|
|
|
return self._threads[thread_id]
|
|
|
|
def append(
|
|
self,
|
|
thread_id: str,
|
|
payload: Any,
|
|
from_id: str,
|
|
to_id: str,
|
|
own_name: Optional[str] = None,
|
|
is_self_call: bool = False,
|
|
usage_instructions: str = "",
|
|
todo_nudge: str = "",
|
|
) -> BufferSlot:
|
|
"""
|
|
Append a validated payload to a thread's context.
|
|
|
|
This is the main entry point for the pipeline.
|
|
Returns the immutable slot reference.
|
|
"""
|
|
thread = self.get_or_create_thread(thread_id)
|
|
|
|
# Enforce slot limit
|
|
if len(thread) >= self.max_slots_per_thread:
|
|
raise MemoryError(
|
|
f"Thread {thread_id} exceeded max slots ({self.max_slots_per_thread})"
|
|
)
|
|
|
|
return thread.append(
|
|
payload=payload,
|
|
from_id=from_id,
|
|
to_id=to_id,
|
|
own_name=own_name,
|
|
is_self_call=is_self_call,
|
|
usage_instructions=usage_instructions,
|
|
todo_nudge=todo_nudge,
|
|
)
|
|
|
|
def get_thread(self, thread_id: str) -> Optional[ThreadContext]:
|
|
"""Get a thread's context (None if not found)."""
|
|
with self._lock:
|
|
return self._threads.get(thread_id)
|
|
|
|
def thread_exists(self, thread_id: str) -> bool:
|
|
"""Check if a thread exists."""
|
|
with self._lock:
|
|
return thread_id in self._threads
|
|
|
|
def delete_thread(self, thread_id: str) -> bool:
|
|
"""Delete a thread's context (GC)."""
|
|
with self._lock:
|
|
if thread_id in self._threads:
|
|
del self._threads[thread_id]
|
|
return True
|
|
return False
|
|
|
|
def get_stats(self) -> Dict[str, Any]:
|
|
"""Get buffer statistics."""
|
|
with self._lock:
|
|
total_slots = sum(len(t) for t in self._threads.values())
|
|
return {
|
|
"thread_count": len(self._threads),
|
|
"total_slots": total_slots,
|
|
"max_threads": self.max_threads,
|
|
"max_slots_per_thread": self.max_slots_per_thread,
|
|
"threads": list(self._threads.keys()),
|
|
}
|
|
|
|
def clear(self):
|
|
"""Clear all contexts (for testing)."""
|
|
with self._lock:
|
|
self._threads.clear()
|
|
|
|
|
|
# ============================================================================
|
|
# Singleton
|
|
# ============================================================================
|
|
|
|
_buffer: Optional[ContextBuffer] = None
|
|
_buffer_lock = threading.Lock()
|
|
|
|
|
|
def get_context_buffer() -> ContextBuffer:
|
|
"""Get the global ContextBuffer singleton."""
|
|
global _buffer
|
|
if _buffer is None:
|
|
with _buffer_lock:
|
|
if _buffer is None:
|
|
_buffer = ContextBuffer()
|
|
return _buffer
|
|
|
|
|
|
# ============================================================================
|
|
# Handler-facing metadata adapter
|
|
# ============================================================================
|
|
|
|
def slot_to_handler_metadata(slot: BufferSlot) -> 'HandlerMetadata':
|
|
"""
|
|
Convert SlotMetadata to HandlerMetadata for backward compatibility.
|
|
|
|
Handlers still receive HandlerMetadata, but it's derived from the slot.
|
|
"""
|
|
from xml_pipeline.message_bus.message_state import HandlerMetadata
|
|
|
|
return HandlerMetadata(
|
|
thread_id=slot.metadata.thread_id,
|
|
from_id=slot.metadata.from_id,
|
|
own_name=slot.metadata.own_name,
|
|
is_self_call=slot.metadata.is_self_call,
|
|
usage_instructions=slot.metadata.usage_instructions,
|
|
todo_nudge=slot.metadata.todo_nudge,
|
|
)
|