651 lines
21 KiB
Python
651 lines
21 KiB
Python
|
import asyncio
|
||
|
import sys
|
||
|
import threading
|
||
|
from asyncio import QueueEmpty as AsyncQueueEmpty
|
||
|
from asyncio import QueueFull as AsyncQueueFull
|
||
|
from collections import deque
|
||
|
from heapq import heappop, heappush
|
||
|
from queue import Empty as SyncQueueEmpty
|
||
|
from queue import Full as SyncQueueFull
|
||
|
from typing import Any, Callable, Deque, Generic, List, Optional, Set, TypeVar
|
||
|
|
||
|
from typing_extensions import Protocol
|
||
|
|
||
|
|
||
|
__version__ = "1.0.0"
|
||
|
__all__ = (
|
||
|
"Queue",
|
||
|
"PriorityQueue",
|
||
|
"LifoQueue",
|
||
|
"SyncQueue",
|
||
|
"AsyncQueue",
|
||
|
"BaseQueue",
|
||
|
)
|
||
|
|
||
|
|
||
|
T = TypeVar("T")
|
||
|
OptFloat = Optional[float]
|
||
|
|
||
|
|
||
|
class BaseQueue(Protocol[T]):
|
||
|
@property
|
||
|
def maxsize(self) -> int:
|
||
|
...
|
||
|
|
||
|
@property
|
||
|
def closed(self) -> bool:
|
||
|
...
|
||
|
|
||
|
def task_done(self) -> None:
|
||
|
...
|
||
|
|
||
|
def qsize(self) -> int:
|
||
|
...
|
||
|
|
||
|
@property
|
||
|
def unfinished_tasks(self) -> int:
|
||
|
...
|
||
|
|
||
|
def empty(self) -> bool:
|
||
|
...
|
||
|
|
||
|
def full(self) -> bool:
|
||
|
...
|
||
|
|
||
|
def put_nowait(self, item: T) -> None:
|
||
|
...
|
||
|
|
||
|
def get_nowait(self) -> T:
|
||
|
...
|
||
|
|
||
|
|
||
|
class SyncQueue(BaseQueue[T], Protocol[T]):
|
||
|
@property
|
||
|
def maxsize(self) -> int:
|
||
|
...
|
||
|
|
||
|
@property
|
||
|
def closed(self) -> bool:
|
||
|
...
|
||
|
|
||
|
def task_done(self) -> None:
|
||
|
...
|
||
|
|
||
|
def qsize(self) -> int:
|
||
|
...
|
||
|
|
||
|
@property
|
||
|
def unfinished_tasks(self) -> int:
|
||
|
...
|
||
|
|
||
|
def empty(self) -> bool:
|
||
|
...
|
||
|
|
||
|
def full(self) -> bool:
|
||
|
...
|
||
|
|
||
|
def put_nowait(self, item: T) -> None:
|
||
|
...
|
||
|
|
||
|
def get_nowait(self) -> T:
|
||
|
...
|
||
|
|
||
|
def put(self, item: T, block: bool = True, timeout: OptFloat = None) -> None:
|
||
|
...
|
||
|
|
||
|
def get(self, block: bool = True, timeout: OptFloat = None) -> T:
|
||
|
...
|
||
|
|
||
|
def join(self) -> None:
|
||
|
...
|
||
|
|
||
|
|
||
|
class AsyncQueue(BaseQueue[T], Protocol[T]):
|
||
|
async def put(self, item: T) -> None:
|
||
|
...
|
||
|
|
||
|
async def get(self) -> T:
|
||
|
...
|
||
|
|
||
|
async def join(self) -> None:
|
||
|
...
|
||
|
|
||
|
|
||
|
class Queue(Generic[T]):
|
||
|
def __init__(self, maxsize: int = 0) -> None:
|
||
|
self._loop = asyncio.get_running_loop()
|
||
|
self._maxsize = maxsize
|
||
|
|
||
|
self._init(maxsize)
|
||
|
|
||
|
self._unfinished_tasks = 0
|
||
|
|
||
|
self._sync_mutex = threading.Lock()
|
||
|
self._sync_not_empty = threading.Condition(self._sync_mutex)
|
||
|
self._sync_not_full = threading.Condition(self._sync_mutex)
|
||
|
self._all_tasks_done = threading.Condition(self._sync_mutex)
|
||
|
|
||
|
self._async_mutex = asyncio.Lock()
|
||
|
if sys.version_info[:3] == (3, 10, 0):
|
||
|
# Workaround for Python 3.10 bug, see #358:
|
||
|
getattr(self._async_mutex, "_get_loop", lambda: None)()
|
||
|
self._async_not_empty = asyncio.Condition(self._async_mutex)
|
||
|
self._async_not_full = asyncio.Condition(self._async_mutex)
|
||
|
self._finished = asyncio.Event()
|
||
|
self._finished.set()
|
||
|
|
||
|
self._closing = False
|
||
|
self._pending = set() # type: Set[asyncio.Future[Any]]
|
||
|
|
||
|
def checked_call_soon_threadsafe(
|
||
|
callback: Callable[..., None], *args: Any
|
||
|
) -> None:
|
||
|
try:
|
||
|
self._loop.call_soon_threadsafe(callback, *args)
|
||
|
except RuntimeError:
|
||
|
# swallowing agreed in #2
|
||
|
pass
|
||
|
|
||
|
self._call_soon_threadsafe = checked_call_soon_threadsafe
|
||
|
|
||
|
def checked_call_soon(callback: Callable[..., None], *args: Any) -> None:
|
||
|
if not self._loop.is_closed():
|
||
|
self._loop.call_soon(callback, *args)
|
||
|
|
||
|
self._call_soon = checked_call_soon
|
||
|
|
||
|
self._sync_queue = _SyncQueueProxy(self)
|
||
|
self._async_queue = _AsyncQueueProxy(self)
|
||
|
|
||
|
def close(self) -> None:
|
||
|
with self._sync_mutex:
|
||
|
self._closing = True
|
||
|
for fut in self._pending:
|
||
|
fut.cancel()
|
||
|
self._finished.set() # unblocks all async_q.join()
|
||
|
self._all_tasks_done.notify_all() # unblocks all sync_q.join()
|
||
|
|
||
|
async def wait_closed(self) -> None:
|
||
|
# should be called from loop after close().
|
||
|
# Nobody should put/get at this point,
|
||
|
# so lock acquiring is not required
|
||
|
if not self._closing:
|
||
|
raise RuntimeError("Waiting for non-closed queue")
|
||
|
# give execution chances for the task-done callbacks
|
||
|
# of async tasks created inside
|
||
|
# _notify_async_not_empty, _notify_async_not_full
|
||
|
# methods.
|
||
|
await asyncio.sleep(0)
|
||
|
if not self._pending:
|
||
|
return
|
||
|
await asyncio.wait(self._pending)
|
||
|
|
||
|
@property
|
||
|
def closed(self) -> bool:
|
||
|
return self._closing and not self._pending
|
||
|
|
||
|
@property
|
||
|
def maxsize(self) -> int:
|
||
|
return self._maxsize
|
||
|
|
||
|
@property
|
||
|
def sync_q(self) -> "_SyncQueueProxy[T]":
|
||
|
return self._sync_queue
|
||
|
|
||
|
@property
|
||
|
def async_q(self) -> "_AsyncQueueProxy[T]":
|
||
|
return self._async_queue
|
||
|
|
||
|
# Override these methods to implement other queue organizations
|
||
|
# (e.g. stack or priority queue).
|
||
|
# These will only be called with appropriate locks held
|
||
|
|
||
|
def _init(self, maxsize: int) -> None:
|
||
|
self._queue = deque() # type: Deque[T]
|
||
|
|
||
|
def _qsize(self) -> int:
|
||
|
return len(self._queue)
|
||
|
|
||
|
# Put a new item in the queue
|
||
|
def _put(self, item: T) -> None:
|
||
|
self._queue.append(item)
|
||
|
|
||
|
# Get an item from the queue
|
||
|
def _get(self) -> T:
|
||
|
return self._queue.popleft()
|
||
|
|
||
|
def _put_internal(self, item: T) -> None:
|
||
|
self._put(item)
|
||
|
self._unfinished_tasks += 1
|
||
|
self._finished.clear()
|
||
|
|
||
|
def _notify_sync_not_empty(self) -> None:
|
||
|
def f() -> None:
|
||
|
with self._sync_mutex:
|
||
|
self._sync_not_empty.notify()
|
||
|
|
||
|
self._loop.run_in_executor(None, f)
|
||
|
|
||
|
def _notify_sync_not_full(self) -> None:
|
||
|
def f() -> None:
|
||
|
with self._sync_mutex:
|
||
|
self._sync_not_full.notify()
|
||
|
|
||
|
fut = asyncio.ensure_future(self._loop.run_in_executor(None, f))
|
||
|
fut.add_done_callback(self._pending.discard)
|
||
|
self._pending.add(fut)
|
||
|
|
||
|
def _notify_async_not_empty(self, *, threadsafe: bool) -> None:
|
||
|
async def f() -> None:
|
||
|
async with self._async_mutex:
|
||
|
self._async_not_empty.notify()
|
||
|
|
||
|
def task_maker() -> None:
|
||
|
task = self._loop.create_task(f())
|
||
|
task.add_done_callback(self._pending.discard)
|
||
|
self._pending.add(task)
|
||
|
|
||
|
if threadsafe:
|
||
|
self._call_soon_threadsafe(task_maker)
|
||
|
else:
|
||
|
self._call_soon(task_maker)
|
||
|
|
||
|
def _notify_async_not_full(self, *, threadsafe: bool) -> None:
|
||
|
async def f() -> None:
|
||
|
async with self._async_mutex:
|
||
|
self._async_not_full.notify()
|
||
|
|
||
|
def task_maker() -> None:
|
||
|
task = self._loop.create_task(f())
|
||
|
task.add_done_callback(self._pending.discard)
|
||
|
self._pending.add(task)
|
||
|
|
||
|
if threadsafe:
|
||
|
self._call_soon_threadsafe(task_maker)
|
||
|
else:
|
||
|
self._call_soon(task_maker)
|
||
|
|
||
|
def _check_closing(self) -> None:
|
||
|
if self._closing:
|
||
|
raise RuntimeError("Operation on the closed queue is forbidden")
|
||
|
|
||
|
|
||
|
class _SyncQueueProxy(SyncQueue[T]):
|
||
|
"""Create a queue object with a given maximum size.
|
||
|
|
||
|
If maxsize is <= 0, the queue size is infinite.
|
||
|
"""
|
||
|
|
||
|
def __init__(self, parent: Queue[T]):
|
||
|
self._parent = parent
|
||
|
|
||
|
@property
|
||
|
def maxsize(self) -> int:
|
||
|
return self._parent._maxsize
|
||
|
|
||
|
@property
|
||
|
def closed(self) -> bool:
|
||
|
return self._parent.closed
|
||
|
|
||
|
def task_done(self) -> None:
|
||
|
"""Indicate that a formerly enqueued task is complete.
|
||
|
|
||
|
Used by Queue consumer threads. For each get() used to fetch a task,
|
||
|
a subsequent call to task_done() tells the queue that the processing
|
||
|
on the task is complete.
|
||
|
|
||
|
If a join() is currently blocking, it will resume when all items
|
||
|
have been processed (meaning that a task_done() call was received
|
||
|
for every item that had been put() into the queue).
|
||
|
|
||
|
Raises a ValueError if called more times than there were items
|
||
|
placed in the queue.
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
with self._parent._all_tasks_done:
|
||
|
unfinished = self._parent._unfinished_tasks - 1
|
||
|
if unfinished <= 0:
|
||
|
if unfinished < 0:
|
||
|
raise ValueError("task_done() called too many times")
|
||
|
self._parent._all_tasks_done.notify_all()
|
||
|
self._parent._loop.call_soon_threadsafe(self._parent._finished.set)
|
||
|
self._parent._unfinished_tasks = unfinished
|
||
|
|
||
|
def join(self) -> None:
|
||
|
"""Blocks until all items in the Queue have been gotten and processed.
|
||
|
|
||
|
The count of unfinished tasks goes up whenever an item is added to the
|
||
|
queue. The count goes down whenever a consumer thread calls task_done()
|
||
|
to indicate the item was retrieved and all work on it is complete.
|
||
|
|
||
|
When the count of unfinished tasks drops to zero, join() unblocks.
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
with self._parent._all_tasks_done:
|
||
|
while self._parent._unfinished_tasks:
|
||
|
self._parent._all_tasks_done.wait()
|
||
|
self._parent._check_closing()
|
||
|
|
||
|
def qsize(self) -> int:
|
||
|
"""Return the approximate size of the queue (not reliable!)."""
|
||
|
return self._parent._qsize()
|
||
|
|
||
|
@property
|
||
|
def unfinished_tasks(self) -> int:
|
||
|
"""Return the number of unfinished tasks."""
|
||
|
return self._parent._unfinished_tasks
|
||
|
|
||
|
def empty(self) -> bool:
|
||
|
"""Return True if the queue is empty, False otherwise (not reliable!).
|
||
|
|
||
|
This method is likely to be removed at some point. Use qsize() == 0
|
||
|
as a direct substitute, but be aware that either approach risks a race
|
||
|
condition where a queue can grow before the result of empty() or
|
||
|
qsize() can be used.
|
||
|
|
||
|
To create code that needs to wait for all queued tasks to be
|
||
|
completed, the preferred technique is to use the join() method.
|
||
|
"""
|
||
|
return not self._parent._qsize()
|
||
|
|
||
|
def full(self) -> bool:
|
||
|
"""Return True if the queue is full, False otherwise (not reliable!).
|
||
|
|
||
|
This method is likely to be removed at some point. Use qsize() >= n
|
||
|
as a direct substitute, but be aware that either approach risks a race
|
||
|
condition where a queue can shrink before the result of full() or
|
||
|
qsize() can be used.
|
||
|
"""
|
||
|
return 0 < self._parent._maxsize <= self._parent._qsize()
|
||
|
|
||
|
def put(self, item: T, block: bool = True, timeout: OptFloat = None) -> None:
|
||
|
"""Put an item into the queue.
|
||
|
|
||
|
If optional args 'block' is true and 'timeout' is None (the default),
|
||
|
block if necessary until a free slot is available. If 'timeout' is
|
||
|
a non-negative number, it blocks at most 'timeout' seconds and raises
|
||
|
the Full exception if no free slot was available within that time.
|
||
|
Otherwise ('block' is false), put an item on the queue if a free slot
|
||
|
is immediately available, else raise the Full exception ('timeout'
|
||
|
is ignored in that case).
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
with self._parent._sync_not_full:
|
||
|
if self._parent._maxsize > 0:
|
||
|
if not block:
|
||
|
if self._parent._qsize() >= self._parent._maxsize:
|
||
|
raise SyncQueueFull
|
||
|
elif timeout is None:
|
||
|
while self._parent._qsize() >= self._parent._maxsize:
|
||
|
self._parent._sync_not_full.wait()
|
||
|
elif timeout < 0:
|
||
|
raise ValueError("'timeout' must be a non-negative number")
|
||
|
else:
|
||
|
time = self._parent._loop.time
|
||
|
endtime = time() + timeout
|
||
|
while self._parent._qsize() >= self._parent._maxsize:
|
||
|
remaining = endtime - time()
|
||
|
if remaining <= 0.0:
|
||
|
raise SyncQueueFull
|
||
|
self._parent._sync_not_full.wait(remaining)
|
||
|
self._parent._put_internal(item)
|
||
|
self._parent._sync_not_empty.notify()
|
||
|
self._parent._notify_async_not_empty(threadsafe=True)
|
||
|
|
||
|
def get(self, block: bool = True, timeout: OptFloat = None) -> T:
|
||
|
"""Remove and return an item from the queue.
|
||
|
|
||
|
If optional args 'block' is true and 'timeout' is None (the default),
|
||
|
block if necessary until an item is available. If 'timeout' is
|
||
|
a non-negative number, it blocks at most 'timeout' seconds and raises
|
||
|
the Empty exception if no item was available within that time.
|
||
|
Otherwise ('block' is false), return an item if one is immediately
|
||
|
available, else raise the Empty exception ('timeout' is ignored
|
||
|
in that case).
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
with self._parent._sync_not_empty:
|
||
|
if not block:
|
||
|
if not self._parent._qsize():
|
||
|
raise SyncQueueEmpty
|
||
|
elif timeout is None:
|
||
|
while not self._parent._qsize():
|
||
|
self._parent._sync_not_empty.wait()
|
||
|
elif timeout < 0:
|
||
|
raise ValueError("'timeout' must be a non-negative number")
|
||
|
else:
|
||
|
time = self._parent._loop.time
|
||
|
endtime = time() + timeout
|
||
|
while not self._parent._qsize():
|
||
|
remaining = endtime - time()
|
||
|
if remaining <= 0.0:
|
||
|
raise SyncQueueEmpty
|
||
|
self._parent._sync_not_empty.wait(remaining)
|
||
|
item = self._parent._get()
|
||
|
self._parent._sync_not_full.notify()
|
||
|
self._parent._notify_async_not_full(threadsafe=True)
|
||
|
return item
|
||
|
|
||
|
def put_nowait(self, item: T) -> None:
|
||
|
"""Put an item into the queue without blocking.
|
||
|
|
||
|
Only enqueue the item if a free slot is immediately available.
|
||
|
Otherwise raise the Full exception.
|
||
|
"""
|
||
|
return self.put(item, block=False)
|
||
|
|
||
|
def get_nowait(self) -> T:
|
||
|
"""Remove and return an item from the queue without blocking.
|
||
|
|
||
|
Only get an item if one is immediately available. Otherwise
|
||
|
raise the Empty exception.
|
||
|
"""
|
||
|
return self.get(block=False)
|
||
|
|
||
|
|
||
|
class _AsyncQueueProxy(AsyncQueue[T]):
|
||
|
"""Create a queue object with a given maximum size.
|
||
|
|
||
|
If maxsize is <= 0, the queue size is infinite.
|
||
|
"""
|
||
|
|
||
|
def __init__(self, parent: Queue[T]):
|
||
|
self._parent = parent
|
||
|
|
||
|
@property
|
||
|
def closed(self) -> bool:
|
||
|
return self._parent.closed
|
||
|
|
||
|
def qsize(self) -> int:
|
||
|
"""Number of items in the queue."""
|
||
|
return self._parent._qsize()
|
||
|
|
||
|
@property
|
||
|
def unfinished_tasks(self) -> int:
|
||
|
"""Return the number of unfinished tasks."""
|
||
|
return self._parent._unfinished_tasks
|
||
|
|
||
|
@property
|
||
|
def maxsize(self) -> int:
|
||
|
"""Number of items allowed in the queue."""
|
||
|
return self._parent._maxsize
|
||
|
|
||
|
def empty(self) -> bool:
|
||
|
"""Return True if the queue is empty, False otherwise."""
|
||
|
return self.qsize() == 0
|
||
|
|
||
|
def full(self) -> bool:
|
||
|
"""Return True if there are maxsize items in the queue.
|
||
|
|
||
|
Note: if the Queue was initialized with maxsize=0 (the default),
|
||
|
then full() is never True.
|
||
|
"""
|
||
|
if self._parent._maxsize <= 0:
|
||
|
return False
|
||
|
else:
|
||
|
return self.qsize() >= self._parent._maxsize
|
||
|
|
||
|
async def put(self, item: T) -> None:
|
||
|
"""Put an item into the queue.
|
||
|
|
||
|
Put an item into the queue. If the queue is full, wait until a free
|
||
|
slot is available before adding item.
|
||
|
|
||
|
This method is a coroutine.
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
async with self._parent._async_not_full:
|
||
|
self._parent._sync_mutex.acquire()
|
||
|
locked = True
|
||
|
try:
|
||
|
if self._parent._maxsize > 0:
|
||
|
do_wait = True
|
||
|
while do_wait:
|
||
|
do_wait = self._parent._qsize() >= self._parent._maxsize
|
||
|
if do_wait:
|
||
|
locked = False
|
||
|
self._parent._sync_mutex.release()
|
||
|
await self._parent._async_not_full.wait()
|
||
|
self._parent._sync_mutex.acquire()
|
||
|
locked = True
|
||
|
|
||
|
self._parent._put_internal(item)
|
||
|
self._parent._async_not_empty.notify()
|
||
|
self._parent._notify_sync_not_empty()
|
||
|
finally:
|
||
|
if locked:
|
||
|
self._parent._sync_mutex.release()
|
||
|
|
||
|
def put_nowait(self, item: T) -> None:
|
||
|
"""Put an item into the queue without blocking.
|
||
|
|
||
|
If no free slot is immediately available, raise QueueFull.
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
with self._parent._sync_mutex:
|
||
|
if self._parent._maxsize > 0:
|
||
|
if self._parent._qsize() >= self._parent._maxsize:
|
||
|
raise AsyncQueueFull
|
||
|
|
||
|
self._parent._put_internal(item)
|
||
|
self._parent._notify_async_not_empty(threadsafe=False)
|
||
|
self._parent._notify_sync_not_empty()
|
||
|
|
||
|
async def get(self) -> T:
|
||
|
"""Remove and return an item from the queue.
|
||
|
|
||
|
If queue is empty, wait until an item is available.
|
||
|
|
||
|
This method is a coroutine.
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
async with self._parent._async_not_empty:
|
||
|
self._parent._sync_mutex.acquire()
|
||
|
locked = True
|
||
|
try:
|
||
|
do_wait = True
|
||
|
while do_wait:
|
||
|
do_wait = self._parent._qsize() == 0
|
||
|
|
||
|
if do_wait:
|
||
|
locked = False
|
||
|
self._parent._sync_mutex.release()
|
||
|
await self._parent._async_not_empty.wait()
|
||
|
self._parent._sync_mutex.acquire()
|
||
|
locked = True
|
||
|
|
||
|
item = self._parent._get()
|
||
|
self._parent._async_not_full.notify()
|
||
|
self._parent._notify_sync_not_full()
|
||
|
return item
|
||
|
finally:
|
||
|
if locked:
|
||
|
self._parent._sync_mutex.release()
|
||
|
|
||
|
def get_nowait(self) -> T:
|
||
|
"""Remove and return an item from the queue.
|
||
|
|
||
|
Return an item if one is immediately available, else raise QueueEmpty.
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
with self._parent._sync_mutex:
|
||
|
if self._parent._qsize() == 0:
|
||
|
raise AsyncQueueEmpty
|
||
|
|
||
|
item = self._parent._get()
|
||
|
self._parent._notify_async_not_full(threadsafe=False)
|
||
|
self._parent._notify_sync_not_full()
|
||
|
return item
|
||
|
|
||
|
def task_done(self) -> None:
|
||
|
"""Indicate that a formerly enqueued task is complete.
|
||
|
|
||
|
Used by queue consumers. For each get() used to fetch a task,
|
||
|
a subsequent call to task_done() tells the queue that the processing
|
||
|
on the task is complete.
|
||
|
|
||
|
If a join() is currently blocking, it will resume when all items have
|
||
|
been processed (meaning that a task_done() call was received for every
|
||
|
item that had been put() into the queue).
|
||
|
|
||
|
Raises ValueError if called more times than there were items placed in
|
||
|
the queue.
|
||
|
"""
|
||
|
self._parent._check_closing()
|
||
|
with self._parent._all_tasks_done:
|
||
|
if self._parent._unfinished_tasks <= 0:
|
||
|
raise ValueError("task_done() called too many times")
|
||
|
self._parent._unfinished_tasks -= 1
|
||
|
if self._parent._unfinished_tasks == 0:
|
||
|
self._parent._finished.set()
|
||
|
self._parent._all_tasks_done.notify_all()
|
||
|
|
||
|
async def join(self) -> None:
|
||
|
"""Block until all items in the queue have been gotten and processed.
|
||
|
|
||
|
The count of unfinished tasks goes up whenever an item is added to the
|
||
|
queue. The count goes down whenever a consumer calls task_done() to
|
||
|
indicate that the item was retrieved and all work on it is complete.
|
||
|
When the count of unfinished tasks drops to zero, join() unblocks.
|
||
|
"""
|
||
|
while True:
|
||
|
with self._parent._sync_mutex:
|
||
|
self._parent._check_closing()
|
||
|
if self._parent._unfinished_tasks == 0:
|
||
|
break
|
||
|
await self._parent._finished.wait()
|
||
|
|
||
|
|
||
|
class PriorityQueue(Queue[T]):
|
||
|
"""Variant of Queue that retrieves open entries in priority order
|
||
|
(lowest first).
|
||
|
|
||
|
Entries are typically tuples of the form: (priority number, data).
|
||
|
|
||
|
"""
|
||
|
|
||
|
def _init(self, maxsize: int) -> None:
|
||
|
self._heap_queue = [] # type: List[T]
|
||
|
|
||
|
def _qsize(self) -> int:
|
||
|
return len(self._heap_queue)
|
||
|
|
||
|
def _put(self, item: T) -> None:
|
||
|
heappush(self._heap_queue, item)
|
||
|
|
||
|
def _get(self) -> T:
|
||
|
return heappop(self._heap_queue)
|
||
|
|
||
|
|
||
|
class LifoQueue(Queue[T]):
|
||
|
"""Variant of Queue that retrieves most recently added entries first."""
|
||
|
|
||
|
def _qsize(self) -> int:
|
||
|
return len(self._queue)
|
||
|
|
||
|
def _put(self, item: T) -> None:
|
||
|
self._queue.append(item)
|
||
|
|
||
|
def _get(self) -> T:
|
||
|
return self._queue.pop()
|