+import os
+from http.server import BaseHTTPRequestHandler
+
+
+class PlomException(Exception):
+ pass
+
+
+class PlomDB:
+
+ def __init__(self, db_name):
+ self.db_file = db_name + ".json"
+ self.lock_file = db_name+ ".lock"
+ if os.path.exists(self.db_file):
+ with open(self.db_file, "r") as f:
+ self.read_db_file(f)
+
+ def lock(self):
+ if os.path.exists(self.lock_file):
+ raise PlomException('Sorry, lock file!')
+ f = open(self.lock_file, 'w+')
+ f.close()
+
+ def unlock(self):
+ os.remove(self.lock_file)
+
+ def backup(self):
+ import shutil
+ from datetime import datetime, timedelta
+ # collect modification times of numbered .bak files
+ bak_prefix = f'{self.db_file}.bak.'
+ backup_dates = []
+ i = 0
+ bak_as = f'{bak_prefix}{i}'
+ while os.path.exists(bak_as):
+ mod_time = os.path.getmtime(bak_as)
+ backup_dates += [str(datetime.fromtimestamp(mod_time))]
+ i += 1
+ bak_as = f'{bak_prefix}{i}'
+
+ # collect what numbered .bak files to save: the older, the fewer; for each
+ # timedelta, keep the newest file that's older
+ ages_to_keep = [timedelta(minutes=4**i) for i in range(0, 8)]
+ now = datetime.now()
+ to_save = []
+ for age in ages_to_keep:
+ limit = now - age
+ for i, date in enumerate(reversed(backup_dates)):
+ if datetime.strptime(date, '%Y-%m-%d %H:%M:%S.%f') < limit:
+ unreversed_i = len(backup_dates) - i - 1
+ if unreversed_i not in to_save:
+ to_save += [unreversed_i]
+ break
+
+ # remove redundant backup files
+ j = 0
+ for i in to_save:
+ if i != j:
+ source = f'{bak_prefix}{i}'
+ target = f'{bak_prefix}{j}'
+ shutil.move(source, target)
+ j += 1
+ for i in range(j, len(backup_dates)):
+ try:
+ os.remove(f'{bak_prefix}{i}')
+ except FileNotFoundError:
+ pass
+
+ # put copy of current state at end of bak list
+ shutil.copy(self.db_file, f'{bak_prefix}{j}')
+
+ def write_text_to_db(self, text, mode='w'):
+ self.lock()
+ self.backup()
+ with open(self.db_file, mode) as f:
+ f.write(text);
+ self.unlock()
+
+
+class PlomServer(BaseHTTPRequestHandler):
+ header = ''
+ footer = ''
+
+ def run(self, port):
+ from http.server import HTTPServer
+ webServer = HTTPServer(('localhost', port), type(self))
+ print(f"Server started http://localhost:{port}")
+ try:
+ webServer.serve_forever()
+ except KeyboardInterrupt:
+ pass
+ webServer.server_close()
+ print("Server stopped.")
+
+ def fail_400(self, e):
+ page = f'{self.header}ERROR: {e}{self.footer}'
+ self.send_HTML(page, 400)
+
+ def send_HTML(self, html, code=200):
+ self.send_code_and_headers(code, [('Content-type', 'text/html')])
+ self.wfile.write(bytes(html, "utf-8"))
+
+ def send_code_and_headers(self, code, headers=[]):
+ self.send_response(code)
+ for fieldname, content in headers:
+ self.send_header(fieldname, content)
+ self.end_headers()
+
+
+def run_server(port, server_class):
+ from http.server import HTTPServer
+ webServer = HTTPServer(('localhost', port), server_class)
+ print(f"Server started http://localhost:{port}")
+ try:
+ webServer.serve_forever()
+ except KeyboardInterrupt:
+ pass
+ webServer.server_close()
+ print("Server stopped.")
projects / misc / commitdiff