Merge pull request #6472 from MetRonnie/cylc-remove

Implement `cylc remove` proposal

changes.d/6472.feat.md

@@ -0,0 +1,5 @@
+`cylc remove` improvements:
+- It can now remove tasks that are no longer active, making it look like they never ran.
+- Removing a submitted/running task will kill it.
+- Added the `--flow` option.
+- Removed tasks are now demoted to `flow=none` but retained in the workflow database for provenance.

cylc/flow/command_validation.py

@@ -24,19 +24,34 @@
 )
 
 from cylc.flow.exceptions import InputError
-from cylc.flow.id import IDTokens, Tokens
+from cylc.flow.flow_mgr import (
+    FLOW_ALL,
+    FLOW_NEW,
+    FLOW_NONE,
+)
+from cylc.flow.id import (
+    IDTokens,
+    Tokens,
+)
 from cylc.flow.task_outputs import TASK_OUTPUT_SUCCEEDED
-from cylc.flow.flow_mgr import FLOW_ALL, FLOW_NEW, FLOW_NONE
 
 
-ERR_OPT_FLOW_VAL = "Flow values must be an integer, or 'all', 'new', or 'none'"
+ERR_OPT_FLOW_VAL = (
+    f"Flow values must be integers, or '{FLOW_ALL}', '{FLOW_NEW}', "
+    f"or '{FLOW_NONE}'"
+)
+ERR_OPT_FLOW_VAL_2 = f"Flow values must be integers, or '{FLOW_ALL}'"
 ERR_OPT_FLOW_COMBINE = "Cannot combine --flow={0} with other flow values"
 ERR_OPT_FLOW_WAIT = (
     f"--wait is not compatible with --flow={FLOW_NEW} or --flow={FLOW_NONE}"
 )
 
 
-def flow_opts(flows: List[str], flow_wait: bool) -> None:
+def flow_opts(
+    flows: List[str],
+    flow_wait: bool,
+    allow_new_or_none: bool = True
+) -> None:
     """Check validity of flow-related CLI options.
 
     Note the schema defaults flows to [].
@@ -63,16 +78,23 @@ def flow_opts(flows: List[str], flow_wait: bool) -> None:
         cylc.flow.exceptions.InputError: --wait is not compatible with
         --flow=new or --flow=none
 
+        >>> flow_opts(["new"], False, allow_new_or_none=False)
+        Traceback (most recent call last):
+        cylc.flow.exceptions.InputError: ... must be integers, or 'all'
+
     """
     if not flows:
         return
 
     flows = [val.strip() for val in flows]
 
     for val in flows:
+        val = val.strip()
         if val in {FLOW_NONE, FLOW_NEW, FLOW_ALL}:
             if len(flows) != 1:
                 raise InputError(ERR_OPT_FLOW_COMBINE.format(val))
+            if not allow_new_or_none and val in {FLOW_NEW, FLOW_NONE}:
+                raise InputError(ERR_OPT_FLOW_VAL_2)
         else:
             try:
                 int(val)

cylc/flow/commands.py

@@ -53,18 +53,24 @@
 """
 
 from contextlib import suppress
-from time import sleep, time
+from time import (
+    sleep,
+    time,
+)
 from typing import (
+    TYPE_CHECKING,
     AsyncGenerator,
     Callable,
     Dict,
     Iterable,
     List,
     Optional,
-    TYPE_CHECKING,
+    TypeVar,
     Union,
 )
 
+from metomi.isodatetime.parsers import TimePointParser
+
 from cylc.flow import LOG
 import cylc.flow.command_validation as validate
 from cylc.flow.exceptions import (
@@ -73,38 +79,40 @@
     CylcConfigError,
 )
 import cylc.flow.flags
+from cylc.flow.flow_mgr import get_flow_nums_set
 from cylc.flow.log_level import log_level_to_verbosity
 from cylc.flow.network.schema import WorkflowStopMode
 from cylc.flow.parsec.exceptions import ParsecError
 from cylc.flow.task_id import TaskID
-from cylc.flow.workflow_status import RunMode, StopMode
+from cylc.flow.workflow_status import (
+    RunMode,
+    StopMode,
+)
 
-from metomi.isodatetime.parsers import TimePointParser
 
 if TYPE_CHECKING:
     from cylc.flow.scheduler import Scheduler
 
     # define a type for command implementations
-    Command = Callable[
-        ...,
-        AsyncGenerator,
-    ]
+    Command = Callable[..., AsyncGenerator]
+    # define a generic type needed for the @_command decorator
+    _TCommand = TypeVar('_TCommand', bound=Command)
 
 # a directory of registered commands (populated on module import)
 COMMANDS: 'Dict[str, Command]' = {}
 
 
 def _command(name: str):
     """Decorator to register a command."""
-    def _command(fcn: 'Command'):
+    def _command(fcn: '_TCommand') -> '_TCommand':
         nonlocal name
         COMMANDS[name] = fcn
-        fcn.command_name = name  # type: ignore
+        fcn.command_name = name  # type: ignore[attr-defined]
         return fcn
     return _command
 
 
-async def run_cmd(fcn, *args, **kwargs):
+async def run_cmd(bound_fcn: AsyncGenerator):
     """Run a command outside of the scheduler's main loop.
 
     Normally commands are run via the Scheduler's command_queue (which is
@@ -119,10 +127,9 @@ async def run_cmd(fcn, *args, **kwargs):
     For these purposes use "run_cmd", otherwise, queue commands via the
     scheduler as normal.
     """
-    cmd = fcn(*args, **kwargs)
-    await cmd.__anext__()  # validate
+    await bound_fcn.__anext__()  # validate
     with suppress(StopAsyncIteration):
-        return await cmd.__anext__()  # run
+        return await bound_fcn.__anext__()  # run
 
 
 @_command('set')
@@ -310,11 +317,15 @@ async def set_verbosity(schd: 'Scheduler', level: Union[int, str]):
 
 
 @_command('remove_tasks')
-async def remove_tasks(schd: 'Scheduler', tasks: Iterable[str]):
+async def remove_tasks(
+    schd: 'Scheduler', tasks: Iterable[str], flow: List[str]
+):
     """Remove tasks."""
     validate.is_tasks(tasks)
+    validate.flow_opts(flow, flow_wait=False, allow_new_or_none=False)
     yield
-    yield schd.pool.remove_tasks(tasks)
+    flow_nums = get_flow_nums_set(flow)
+    schd.remove_tasks(tasks, flow_nums)
 
 
 @_command('reload_workflow')

cylc/flow/data_store_mgr.py

@@ -2356,22 +2356,42 @@ def delta_task_held(
         self.updates_pending = True
 
     def delta_task_flow_nums(self, itask: TaskProxy) -> None:
-        """Create delta for change in task proxy flow_nums.
+        """Create delta for change in task proxy flow numbers.
 
         Args:
-            itask (cylc.flow.task_proxy.TaskProxy):
-                Update task-node from corresponding task proxy
-                objects from the workflow task pool.
-
+            itask: TaskProxy with updated flow numbers.
         """
         tproxy: Optional[PbTaskProxy]
         tp_id, tproxy = self.store_node_fetcher(itask.tokens)
         if not tproxy:
             return
-        tp_delta = self.updated[TASK_PROXIES].setdefault(
-            tp_id, PbTaskProxy(id=tp_id))
+        self._delta_task_flow_nums(tp_id, itask.flow_nums)
+
+    def delta_remove_task_flow_nums(
+        self, task: str, removed: 'FlowNums'
+    ) -> None:
+        """Create delta for removal of flow numbers from a task proxy.
+
+        Args:
+            task: Relative ID of task.
+            removed: Flow numbers to remove from the task proxy in the
+                data store.
+        """
+        tproxy: Optional[PbTaskProxy]
+        tp_id, tproxy = self.store_node_fetcher(
+            Tokens(task, relative=True).duplicate(**self.id_)
+        )
+        if not tproxy:
+            return
+        new_flow_nums = deserialise_set(tproxy.flow_nums).difference(removed)
+        self._delta_task_flow_nums(tp_id, new_flow_nums)
+
+    def _delta_task_flow_nums(self, tp_id: str, flow_nums: 'FlowNums') -> None:
+        tp_delta: PbTaskProxy = self.updated[TASK_PROXIES].setdefault(
+            tp_id, PbTaskProxy(id=tp_id)
+        )
         tp_delta.stamp = f'{tp_id}@{time()}'
-        tp_delta.flow_nums = serialise_set(itask.flow_nums)
+        tp_delta.flow_nums = serialise_set(flow_nums)
         self.updates_pending = True
 
     def delta_task_output(

cylc/flow/dbstatecheck.py

@@ -28,7 +28,7 @@
     IntegerPoint,
     IntegerInterval
 )
-from cylc.flow.flow_mgr import stringify_flow_nums
+from cylc.flow.flow_mgr import repr_flow_nums
 from cylc.flow.pathutil import expand_path
 from cylc.flow.rundb import CylcWorkflowDAO
 from cylc.flow.task_outputs import (
@@ -318,7 +318,7 @@ def workflow_state_query(
                 if flow_num is not None and flow_num not in flow_nums:
                     # skip result, wrong flow
                     continue
-                fstr = stringify_flow_nums(flow_nums)
+                fstr = repr_flow_nums(flow_nums)
                 if fstr:
                     res.append(fstr)
             db_res.append(res)

cylc/flow/flow_mgr.py

@@ -16,8 +16,15 @@
 
 """Manage flow counter and flow metadata."""
 
-from typing import Dict, Set, Optional, TYPE_CHECKING
 import datetime
+from typing import (
+    TYPE_CHECKING,
+    Dict,
+    Iterable,
+    List,
+    Optional,
+    Set,
+)
 
 from cylc.flow import LOG
 
@@ -55,36 +62,62 @@ def add_flow_opts(parser):
     )
 
 
-def stringify_flow_nums(flow_nums: Set[int], full: bool = False) -> str:
-    """Return a string representation of a set of flow numbers
+def get_flow_nums_set(flow: List[str]) -> FlowNums:
+    """Return set of integer flow numbers from list of strings.
 
-    Return:
-    - "none" for no flow
-    - "" for the original flow (flows only matter if there are several)
-    - otherwise e.g. "(flow=1,2,3)"
+    Returns an empty set if the input is empty or contains only "all".
+
+    >>> get_flow_nums_set(["1", "2", "3"])
+    {1, 2, 3}
+    >>> get_flow_nums_set([])
+    set()
+    >>> get_flow_nums_set(["all"])
+    set()
+    """
+    if flow == [FLOW_ALL]:
+        return set()
+    return {int(val.strip()) for val in flow}
+
+
+def stringify_flow_nums(flow_nums: Iterable[int]) -> str:
+    """Return the canonical string for a set of flow numbers.
 
     Examples:
+        >>> stringify_flow_nums({1})
+        '1'
+
+        >>> stringify_flow_nums({3, 1, 2})
+        '1,2,3'
+
         >>> stringify_flow_nums({})
+        ''
+
+    """
+    return ','.join(str(i) for i in sorted(flow_nums))
+
+
+def repr_flow_nums(flow_nums: FlowNums, full: bool = False) -> str:
+    """Return a representation of a set of flow numbers
+
+    If `full` is False, return an empty string for flows=1.
+
+    Examples:
+        >>> repr_flow_nums({})
         '(flows=none)'
 
-        >>> stringify_flow_nums({1})
+        >>> repr_flow_nums({1})
         ''
 
-        >>> stringify_flow_nums({1}, True)
+        >>> repr_flow_nums({1}, full=True)
         '(flows=1)'
 
-        >>> stringify_flow_nums({1,2,3})
+        >>> repr_flow_nums({1,2,3})
         '(flows=1,2,3)'
 
     """
     if not full and flow_nums == {1}:
         return ""
-    else:
-        return (
-            "(flows="
-            f"{','.join(str(i) for i in flow_nums) or 'none'}"
-            ")"
-        )
+    return f"(flows={stringify_flow_nums(flow_nums) or 'none'})"
 
 
 class FlowMgr:

cylc/flow/id.py

@@ -22,6 +22,7 @@
 from enum import Enum
 import re
 from typing import (
+    TYPE_CHECKING,
     Iterable,
     List,
     Optional,
@@ -33,6 +34,10 @@
 from cylc.flow import LOG
 
 
+if TYPE_CHECKING:
+    from cylc.flow.cycling import PointBase
+
+
 class IDTokens(Enum):
     """Cylc object identifier tokens."""
 
@@ -524,14 +529,14 @@ def duplicate(
 )
 
 
-def quick_relative_detokenise(cycle, task):
+def quick_relative_id(cycle: Union[str, int, 'PointBase'], task: str) -> str:
     """Generate a relative ID for a task.
 
     This is a more efficient solution to `Tokens` for cases where
     you only want the ID string and don't have any use for a Tokens object.
 
     Example:
-        >>> q = quick_relative_detokenise
+        >>> q = quick_relative_id
         >>> q('1', 'a') == Tokens(cycle='1', task='a').relative_id
         True