X-Git-Url: https://plomlompom.com/repos/feed.xml?a=blobdiff_plain;ds=sidebyside;f=plomtask%2Fhttp.py;h=b7040f76fa9c3c1d58b0ceedc58fabf02752f616;hb=HEAD;hp=27066036b2c300e23f41f7d348e5090905c9f2f8;hpb=68d0abbe8563c6e778040b2d4f3f640858f5b968;p=plomtask diff --git a/plomtask/http.py b/plomtask/http.py index 2706603..b7040f7 100644 --- a/plomtask/http.py +++ b/plomtask/http.py @@ -3,6 +3,7 @@ from __future__ import annotations from dataclasses import dataclass from typing import Any, Callable from base64 import b64encode, b64decode +from binascii import Error as binascii_Exception from http.server import BaseHTTPRequestHandler from http.server import HTTPServer from urllib.parse import urlparse, parse_qs @@ -177,6 +178,38 @@ class TaskHandler(BaseHTTPRequestHandler): @staticmethod def _request_wrapper(http_method: str, not_found_msg: str ) -> Callable[..., Callable[[TaskHandler], None]]: + """Wrapper for do_GET… and do_POST… handlers, to init and clean up. + + Among other things, conditionally cleans all caches, but only on POST + requests, as only those are expected to change the states of objects + that may be cached, and certainly only those are expected to write any + changes to the database. We want to call them as early though as + possible here, either exactly after the specific request handler + returns successfully, or right after any exception is triggered – + otherwise, race conditions become plausible. + + Note that otherwise any POST attempt, even a failed one, may end in + problematic inconsistencies: + + - if the POST handler experiences an Exception, changes to objects + won't get written to the DB, but the changed objects may remain in + the cache and affect other objects despite their possibly illegal + state + + - even if an object was just saved to the DB, we cannot be sure its + current state is completely identical to what we'd get if loading it + fresh from the DB (e.g. currently Process.n_owners is only updated + when loaded anew via .from_table_row, nor is its state written to + the DB by .save; a questionable design choice, but proof that we + have no guarantee that objects' .save stores all their states we'd + prefer at their most up-to-date. + """ + + def clear_caches() -> None: + for cls in (Day, Todo, Condition, Process, ProcessStep): + assert hasattr(cls, 'empty_cache') + cls.empty_cache() + def decorator(f: Callable[..., str | None] ) -> Callable[[TaskHandler], None]: def wrapper(self: TaskHandler) -> None: @@ -193,6 +226,8 @@ class TaskHandler(BaseHTTPRequestHandler): if hasattr(self, handler_name): handler = getattr(self, handler_name) redir_target = f(self, handler) + if 'POST' == http_method: + clear_caches() if redir_target: self.send_response(302) self.send_header('Location', redir_target) @@ -201,9 +236,8 @@ class TaskHandler(BaseHTTPRequestHandler): msg = f'{not_found_msg}: {self._site}' raise NotFoundException(msg) except HandledException as error: - for cls in (Day, Todo, Condition, Process, ProcessStep): - assert hasattr(cls, 'empty_cache') - cls.empty_cache() + if 'POST' == http_method: + clear_caches() ctx = {'msg': error} self._send_page(ctx, 'msg', error.http_code) finally: @@ -400,23 +434,7 @@ class TaskHandler(BaseHTTPRequestHandler): todos = [t for t in todos_by_date_range if comment_pattern in t.comment and ((not process_id) or t.process.id_ == process_id)] - if sort_by == 'doneness': - todos.sort(key=lambda t: t.is_done) - elif sort_by == '-doneness': - todos.sort(key=lambda t: t.is_done, reverse=True) - elif sort_by == 'title': - todos.sort(key=lambda t: t.title_then) - elif sort_by == '-title': - todos.sort(key=lambda t: t.title_then, reverse=True) - elif sort_by == 'comment': - todos.sort(key=lambda t: t.comment) - elif sort_by == '-comment': - todos.sort(key=lambda t: t.comment, reverse=True) - elif sort_by == '-date': - todos.sort(key=lambda t: t.date, reverse=True) - else: - todos.sort(key=lambda t: t.date) - sort_by = 'title' + sort_by = Todo.sort_by(todos, sort_by) return {'start': start, 'end': end, 'process_id': process_id, 'comment_pattern': comment_pattern, 'todos': todos, 'all_processes': Process.all(self.conn), 'sort_by': sort_by} @@ -424,17 +442,9 @@ class TaskHandler(BaseHTTPRequestHandler): def do_GET_conditions(self) -> dict[str, object]: """Show all Conditions.""" pattern = self._params.get_str('pattern') - conditions = Condition.matching(self.conn, pattern) sort_by = self._params.get_str('sort_by') - if sort_by == 'is_active': - conditions.sort(key=lambda c: c.is_active) - elif sort_by == '-is_active': - conditions.sort(key=lambda c: c.is_active, reverse=True) - elif sort_by == '-title': - conditions.sort(key=lambda c: c.title.newest, reverse=True) - else: - conditions.sort(key=lambda c: c.title.newest) - sort_by = 'title' + conditions = Condition.matching(self.conn, pattern) + sort_by = Condition.sort_by(conditions, sort_by) return {'conditions': conditions, 'sort_by': sort_by, 'pattern': pattern} @@ -462,15 +472,22 @@ class TaskHandler(BaseHTTPRequestHandler): @_get_item(Process) def do_GET_process(self, process: Process) -> dict[str, object]: """Show Process of ?id=.""" + owner_ids = self._params.get_all_int('step_to') + owned_ids = self._params.get_all_int('has_step') title_64 = self._params.get_str('title_b64') if title_64: - title = b64decode(title_64.encode()).decode() + try: + title = b64decode(title_64.encode()).decode() + except binascii_Exception as exc: + msg = 'invalid base64 for ?title_b64=' + raise BadFormatException(msg) from exc process.title.set(title) + preset_top_step = None owners = process.used_as_step_by(self.conn) - for step_id in self._params.get_all_int('step_to'): + for step_id in owner_ids: owners += [Process.by_id(self.conn, step_id)] - preset_top_step = None - for process_id in self._params.get_all_int('has_step'): + for process_id in owned_ids: + Process.by_id(self.conn, process_id) # to ensure ID exists preset_top_step = process_id return {'process': process, 'is_new': process.id_ is None, 'preset_top_step': preset_top_step, @@ -497,25 +514,9 @@ class TaskHandler(BaseHTTPRequestHandler): def do_GET_processes(self) -> dict[str, object]: """Show all Processes.""" pattern = self._params.get_str('pattern') - processes = Process.matching(self.conn, pattern) sort_by = self._params.get_str('sort_by') - if sort_by == 'steps': - processes.sort(key=lambda p: len(p.explicit_steps)) - elif sort_by == '-steps': - processes.sort(key=lambda p: len(p.explicit_steps), reverse=True) - elif sort_by == 'owners': - processes.sort(key=lambda p: p.n_owners or 0) - elif sort_by == '-owners': - processes.sort(key=lambda p: p.n_owners or 0, reverse=True) - elif sort_by == 'effort': - processes.sort(key=lambda p: p.effort.newest) - elif sort_by == '-effort': - processes.sort(key=lambda p: p.effort.newest, reverse=True) - elif sort_by == '-title': - processes.sort(key=lambda p: p.title.newest, reverse=True) - else: - processes.sort(key=lambda p: p.title.newest) - sort_by = 'title' + processes = Process.matching(self.conn, pattern) + sort_by = Process.sort_by(processes, sort_by) return {'processes': processes, 'sort_by': sort_by, 'pattern': pattern} # POST handlers