from os import unlink, path, mkdir import json import uuid as uuid_builder from threading import Lock from copy import deepcopy import logging import time import threading # Is there an existing library to ensure some data store (JSON etc) is in sync with CRUD methods? # Open a github issue if you know something :) # https://stackoverflow.com/questions/6190468/how-to-trigger-function-on-value-change class ChangeDetectionStore: lock = Lock() def __init__(self, datastore_path="/datastore", include_default_watches=True): self.needs_write = False self.datastore_path = datastore_path self.json_store_path = "{}/url-watches.json".format(self.datastore_path) self.stop_thread = False self.__data = { 'note': "Hello! If you change this file manually, please be sure to restart your changedetection.io instance!", 'watching': {}, 'settings': { 'headers': { 'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36', 'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9', 'Accept-Encoding': 'gzip, deflate', # No support for brolti in python requests yet. 'Accept-Language': 'en-GB,en-US;q=0.9,en;' }, 'requests': { 'timeout': 15, # Default 15 seconds 'minutes_between_check': 3 * 60, # Default 3 hours 'workers': 10 # Number of threads, lower is better for slow connections }, 'application': { 'password': False, 'extract_title_as_title': False, 'notification_urls': [], # Apprise URL list # Custom notification content 'notification_title': 'ChangeDetection.io Notification - {watch_url}', 'notification_body': '{base_url}' } } } # Base definition for all watchers self.generic_definition = { 'url': None, 'tag': None, 'last_checked': 0, 'last_changed': 0, 'paused': False, 'last_viewed': 0, # history key value of the last viewed via the [diff] link 'newest_history_key': "", 'title': None, # Re #110, so then if this is set to None, we know to use the default value instead # Requires setting to None on submit if it's the same as the default 'minutes_between_check': None, 'previous_md5': "", 'uuid': str(uuid_builder.uuid4()), 'headers': {}, # Extra headers to send 'history': {}, # Dict of timestamp and output stripped filename 'ignore_text': [], # List of text to ignore when calculating the comparison checksum 'notification_urls': [], # List of URLs to add to the notification Queue (Usually AppRise) 'css_filter': "", } if path.isfile('backend/source.txt'): with open('backend/source.txt') as f: # Should be set in Dockerfile to look for /source.txt , this will give us the git commit # # So when someone gives us a backup file to examine, we know exactly what code they were running. self.__data['build_sha'] = f.read() try: # @todo retest with ", encoding='utf-8'" with open(self.json_store_path) as json_file: from_disk = json.load(json_file) # @todo isnt there a way todo this dict.update recursively? # Problem here is if the one on the disk is missing a sub-struct, it wont be present anymore. if 'watching' in from_disk: self.__data['watching'].update(from_disk['watching']) if 'app_guid' in from_disk: self.__data['app_guid'] = from_disk['app_guid'] if 'settings' in from_disk: if 'headers' in from_disk['settings']: self.__data['settings']['headers'].update(from_disk['settings']['headers']) if 'requests' in from_disk['settings']: self.__data['settings']['requests'].update(from_disk['settings']['requests']) if 'application' in from_disk['settings']: self.__data['settings']['application'].update(from_disk['settings']['application']) # Reinitialise each `watching` with our generic_definition in the case that we add a new var in the future. # @todo pretty sure theres a python we todo this with an abstracted(?) object! for uuid, watch in self.__data['watching'].items(): _blank = deepcopy(self.generic_definition) _blank.update(watch) self.__data['watching'].update({uuid: _blank}) self.__data['watching'][uuid]['newest_history_key'] = self.get_newest_history_key(uuid) print("Watching:", uuid, self.__data['watching'][uuid]['url']) # First time ran, doesnt exist. except (FileNotFoundError, json.decoder.JSONDecodeError): if include_default_watches: print("Creating JSON store at", self.datastore_path) self.add_watch(url='http://www.quotationspage.com/random.php', tag='test') self.add_watch(url='https://news.ycombinator.com/', tag='Tech news') self.add_watch(url='https://www.gov.uk/coronavirus', tag='Covid') self.add_watch(url='https://changedetection.io', tag='Tech news') self.__data['version_tag'] = "0.38.1" # Helper to remove password protection password_reset_lockfile = "{}/removepassword.lock".format(self.datastore_path) if path.isfile(password_reset_lockfile): self.__data['settings']['application']['password'] = False unlink(password_reset_lockfile) if not 'app_guid' in self.__data: import sys import os if "pytest" in sys.modules or "PYTEST_CURRENT_TEST" in os.environ: self.__data['app_guid'] = "test-" + str(uuid_builder.uuid4()) else: self.__data['app_guid'] = str(uuid_builder.uuid4()) self.needs_write = True # Finally start the thread that will manage periodic data saves to JSON save_data_thread = threading.Thread(target=self.save_datastore).start() # Returns the newest key, but if theres only 1 record, then it's counted as not being new, so return 0. def get_newest_history_key(self, uuid): if len(self.__data['watching'][uuid]['history']) == 1: return 0 dates = list(self.__data['watching'][uuid]['history'].keys()) # Convert to int, sort and back to str again dates = [int(i) for i in dates] dates.sort(reverse=True) if len(dates): # always keyed as str return str(dates[0]) return 0 def set_last_viewed(self, uuid, timestamp): self.data['watching'][uuid].update({'last_viewed': int(timestamp)}) self.needs_write = True def update_watch(self, uuid, update_obj): # Skip if 'paused' state if self.__data['watching'][uuid]['paused']: return with self.lock: # In python 3.9 we have the |= dict operator, but that still will lose data on nested structures... for dict_key, d in self.generic_definition.items(): if isinstance(d, dict): if update_obj is not None and dict_key in update_obj: self.__data['watching'][uuid][dict_key].update(update_obj[dict_key]) del (update_obj[dict_key]) self.__data['watching'][uuid].update(update_obj) self.__data['watching'][uuid]['newest_history_key'] = self.get_newest_history_key(uuid) self.needs_write = True @property def data(self): has_unviewed = False for uuid, v in self.__data['watching'].items(): self.__data['watching'][uuid]['newest_history_key'] = self.get_newest_history_key(uuid) if int(v['newest_history_key']) <= int(v['last_viewed']): self.__data['watching'][uuid]['viewed'] = True else: self.__data['watching'][uuid]['viewed'] = False has_unviewed = True # #106 - Be sure this is None on empty string, False, None, etc if not self.__data['watching'][uuid]['title']: self.__data['watching'][uuid]['title'] = None self.__data['has_unviewed'] = has_unviewed return self.__data def get_all_tags(self): tags = [] for uuid, watch in self.data['watching'].items(): # Support for comma separated list of tags. for tag in watch['tag'].split(','): tag = tag.strip() if tag not in tags: tags.append(tag) tags.sort() return tags def unlink_history_file(self, path): try: unlink(path) except (FileNotFoundError, IOError): pass # Delete a single watch by UUID def delete(self, uuid): with self.lock: if uuid == 'all': self.__data['watching'] = {} # GitHub #30 also delete history records for uuid in self.data['watching']: for path in self.data['watching'][uuid]['history'].values(): self.unlink_history_file(path) else: for path in self.data['watching'][uuid]['history'].values(): self.unlink_history_file(path) del self.data['watching'][uuid] self.needs_write = True def url_exists(self, url): # Probably their should be dict... for watch in self.data['watching'].values(): if watch['url'] == url: return True return False def get_val(self, uuid, val): # Probably their should be dict... return self.data['watching'][uuid].get(val) # Remove a watchs data but keep the entry (URL etc) def scrub_watch(self, uuid, limit_timestamp = False): import hashlib del_timestamps = [] changes_removed = 0 for timestamp, path in self.data['watching'][uuid]['history'].items(): if not limit_timestamp or (limit_timestamp is not False and int(timestamp) > limit_timestamp): self.unlink_history_file(path) del_timestamps.append(timestamp) changes_removed += 1 if not limit_timestamp: self.data['watching'][uuid]['last_checked'] = 0 self.data['watching'][uuid]['last_changed'] = 0 self.data['watching'][uuid]['previous_md5'] = 0 for timestamp in del_timestamps: del self.data['watching'][uuid]['history'][str(timestamp)] # If there was a limitstamp, we need to reset some meta data about the entry # This has to happen after we remove the others from the list if limit_timestamp: newest_key = self.get_newest_history_key(uuid) if newest_key: self.data['watching'][uuid]['last_checked'] = int(newest_key) # @todo should be the original value if it was less than newest key self.data['watching'][uuid]['last_changed'] = int(newest_key) try: with open(self.data['watching'][uuid]['history'][str(newest_key)], "rb") as fp: content = fp.read() self.data['watching'][uuid]['previous_md5'] = hashlib.md5(content).hexdigest() except (FileNotFoundError, IOError): self.data['watching'][uuid]['previous_md5'] = False pass self.needs_write = True return changes_removed def add_watch(self, url, tag): with self.lock: # @todo use a common generic version of this new_uuid = str(uuid_builder.uuid4()) _blank = deepcopy(self.generic_definition) _blank.update({ 'url': url, 'tag': tag, 'uuid': new_uuid }) self.data['watching'][new_uuid] = _blank # Get the directory ready output_path = "{}/{}".format(self.datastore_path, new_uuid) try: mkdir(output_path) except FileExistsError: print(output_path, "already exists.") self.sync_to_json() return new_uuid # Save some text file to the appropriate path and bump the history # result_obj from fetch_site_status.run() def save_history_text(self, uuid, result_obj, contents): output_path = "{}/{}".format(self.datastore_path, uuid) fname = "{}/{}-{}.stripped.txt".format(output_path, result_obj['previous_md5'], str(time.time())) with open(fname, 'w') as f: f.write(contents) f.close() # Update history with the stripped text for future reference, this will also mean we save the first # Should always be keyed by string(timestamp) self.update_watch(uuid, {"history": {str(result_obj["last_checked"]): fname}}) return fname def sync_to_json(self): print("Saving..") data ={} try: data = deepcopy(self.__data) except RuntimeError: time.sleep(0.5) print ("! Data changed when writing to JSON, trying again..") self.sync_to_json() return else: with open(self.json_store_path, 'w') as json_file: json.dump(data, json_file, indent=4) logging.info("Re-saved index") self.needs_write = False # Thread runner, this helps with thread/write issues when there are many operations that want to update the JSON # by just running periodically in one thread, according to python, dict updates are threadsafe. def save_datastore(self): while True: if self.stop_thread: print("Shutting down datastore thread") return if self.needs_write: self.sync_to_json() time.sleep(3) # Go through the datastore path and remove any snapshots that are not mentioned in the index # This usually is not used, but can be handy. def remove_unused_snapshots(self): print ("Removing snapshots from datastore that are not in the index..") index=[] for uuid in self.data['watching']: for id in self.data['watching'][uuid]['history']: index.append(self.data['watching'][uuid]['history'][str(id)]) import pathlib # Only in the sub-directories for item in pathlib.Path(self.datastore_path).rglob("*/*txt"): if not str(item) in index: print ("Removing",item) unlink(item)