# Print Job Queue Implementation
#
# Copyright (C) 2021 Eric Callahan <arksine.code@gmail.com>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
from __future__ import annotations
import asyncio
import time
import logging
# Annotation imports
from typing import (
TYPE_CHECKING,
Any,
Optional,
Dict,
List,
Union,
)
if TYPE_CHECKING:
from confighelper import ConfigHelper
from websockets import WebRequest
from .klippy_apis import KlippyAPI
from .file_manager.file_manager import FileManager
class JobQueue:
def __init__(self, config: ConfigHelper) -> None:
self.server = config.get_server()
self.queued_jobs: Dict[str, QueuedJob] = {}
self.queue_state: str = "ready"
self.lock = asyncio.Lock()
self.load_on_start = config.getboolean("load_on_startup", False)
self.job_delay = config.getfloat("job_transition_delay", 0.01)
if self.job_delay <= 0.:
raise config.error(
"Value for option 'job_transition_delay' in section [job_queue]"
" must be above 0.0")
self.job_transition_gcode = config.get(
"job_transition_gcode", "").strip()
self.pop_queue_handle: Optional[asyncio.TimerHandle] = None
self.server.register_event_handler(
"server:klippy_ready", self._handle_ready)
self.server.register_event_handler(
"server:klippy_shutdown", self._handle_shutdown)
self.server.register_event_handler(
"job_state:complete", self._on_job_complete)
self.server.register_event_handler(
"job_state:error", self._on_job_abort)
self.server.register_event_handler(
"job_state:cancelled", self._on_job_abort)
self.server.register_endpoint(
"/server/job_queue/job", ['POST', 'DELETE'],
self._handle_job_request)
self.server.register_endpoint(
"/server/job_queue/pause", ['POST'], self._handle_pause_queue)
self.server.register_endpoint(
"/server/job_queue/resume", ['POST'], self._handle_resume_queue)
self.server.register_endpoint(
"/server/job_queue/status", ['GET'], self._handle_queue_status)
async def _handle_ready(self) -> None:
async with self.lock:
if not self.load_on_start or not self.queued_jobs:
return
# start a queued print
if self.queue_state in ['ready', 'paused']:
event_loop = self.server.get_event_loop()
self.queue_state = "loading"
self.pop_queue_handle = event_loop.delay_callback(
0.01, self._pop_job, False)
async def _handle_shutdown(self) -> None:
await self.pause_queue()
if not self.queued_jobs:
self.queue_state = "ready"
async def _on_job_complete(self,
prev_stats: Dict[str, Any],
new_stats: Dict[str, Any]
) -> None:
async with self.lock:
# Transition to the next job in the queue
if self.queue_state == "ready" and self.queued_jobs:
event_loop = self.server.get_event_loop()
self.queue_state = "loading"
self.pop_queue_handle = event_loop.delay_callback(
self.job_delay, self._pop_job)
async def _on_job_abort(self,
prev_stats: Dict[str, Any],
new_stats: Dict[str, Any]
) -> None:
async with self.lock:
if self.queued_jobs:
self.queue_state = "paused"
async def _pop_job(self, need_transition: bool = True) -> None:
self.pop_queue_handle = None
async with self.lock:
if self.queue_state == "paused":
return
if not self.queued_jobs:
self.queue_state = "ready"
return
kapis: KlippyAPI = self.server.lookup_component('klippy_apis')
uid, job = list(self.queued_jobs.items())[0]
filename = str(job)
can_print = await self._check_can_print()
if not can_print or self.queue_state != "loading":
self.queue_state = "paused"
return
try:
if self.job_transition_gcode and need_transition:
await kapis.run_gcode(self.job_transition_gcode)
# Check to see if the queue was paused while running
# the job transition gcode
if self.queue_state != "loading":
raise self.server.error(
"Queue State Changed during Transition Gcode")
self.queue_state = "starting"
await kapis.start_print(filename)
except self.server.error:
logging.exception(f"Error Loading print: {filename}")
self.queue_state = "paused"
else:
self.queued_jobs.pop(uid, None)
if self.queue_state == "starting":
# If the queue was not paused while starting the print,
# reset state to "ready"
self.queue_state = "ready"
async def _check_can_print(self) -> bool:
# Query the latest stats
kapis: KlippyAPI = self.server.lookup_component('klippy_apis')
try:
result = await kapis.query_objects({"print_stats": None})
except Exception:
# Klippy not connected
return False
if 'print_stats' not in result:
return False
state: str = result['print_stats']['state']
if state in ["printing", "paused"]:
return False
return True
async def queue_job(self, filename: str,
check_exists: bool = True
) -> bool:
async with self.lock:
# Make sure that the file exists
if check_exists:
self._check_job_file(filename)
can_print = await self._check_can_print()
if (
self.queue_state == "ready" and
not self.queued_jobs and
can_print
):
# Printer is ready to accept a print
kapis: KlippyAPI = self.server.lookup_component('klippy_apis')
try:
await kapis.start_print(filename)
except self.server.error:
# Attempt to start print failed, queue the print
pass
else:
return True
queued_job = QueuedJob(filename)
self.queued_jobs[queued_job.job_id] = queued_job
return False
async def pause_queue(self) -> None:
self.queue_state = "paused"
if self.pop_queue_handle is not None:
self.pop_queue_handle.cancel()
self.pop_queue_handle = None
# Acquire the lock to wait for any pending operations to
# complete
await self.lock.acquire()
self.lock.release()
def _job_map_to_list(self) -> List[Dict[str, Any]]:
cur_time = time.time()
return [job.as_dict(cur_time) for
job in self.queued_jobs.values()]
def _check_job_file(self, job_name: str) -> None:
fm: FileManager = self.server.lookup_component('file_manager')
if not fm.check_file_exists("gcodes", job_name):
raise self.server.error(
f"G-Code File {job_name} does not exist")
async def _handle_job_request(self,
web_request: WebRequest
) -> Dict[str, Any]:
action = web_request.get_action()
if action == "POST":
files: Union[List[str], str] = web_request.get('filenames')
if isinstance(files, str):
files = [f.strip() for f in files.split(',') if f.strip()]
# Validate that all files exist before queueing
for fname in files:
self._check_job_file(fname)
for fname in files:
await self.queue_job(fname, check_exists=False)
elif action == "DELETE":
if web_request.get_boolean("all", False):
async with self.lock:
self.queued_jobs.clear()
else:
job_ids: Union[List[str], str] = web_request.get('job_ids')
if isinstance(job_ids, str):
job_ids = [f.strip() for f in job_ids.split(',')
if f.strip()]
async with self.lock:
for uid in job_ids:
self.queued_jobs.pop(uid, None)
else:
raise self.server.error(f"Invalid action: {action}")
return {
'queued_jobs': self._job_map_to_list(),
'queue_state': self.queue_state
}
async def _handle_pause_queue(self,
web_request: WebRequest
) -> Dict[str, Any]:
await self.pause_queue()
return {
'queued_jobs': self._job_map_to_list(),
'queue_state': self.queue_state
}
async def _handle_resume_queue(self,
web_request: WebRequest
) -> Dict[str, Any]:
async with self.lock:
if self.queue_state == "paused":
self.queue_state = "ready"
if self.queued_jobs and self.pop_queue_handle is None:
self.queue_state = "loading"
event_loop = self.server.get_event_loop()
self.pop_queue_handle = event_loop.delay_callback(
0.01, self._pop_job)
return {
'queued_jobs': self._job_map_to_list(),
'queue_state': self.queue_state
}
async def _handle_queue_status(self,
web_request: WebRequest
) -> Dict[str, Any]:
return {
'queued_jobs': self._job_map_to_list(),
'queue_state': self.queue_state
}
async def close(self):
await self.pause_queue()
class QueuedJob:
def __init__(self, filename: str) -> None:
self.filename = filename
self.job_id = f"{id(self):016X}"
self.time_added = time.time()
def __str__(self) -> str:
return self.filename
def as_dict(self, cur_time: float) -> Dict[str, Any]:
return {
'filename': self.filename,
'job_id': self.job_id,
'time_added': self.time_added,
'time_in_queue': cur_time - self.time_added
}
def load_component(config: ConfigHelper) -> JobQueue:
return JobQueue(config)