hydrus/hydrus/core/HydrusLogger.py

167 lines
4.0 KiB
Python

import os
import sys
import threading
import time
from hydrus.core import HydrusConstants as HC
class HydrusLogger( object ):
def __init__( self, db_dir, prefix ):
self._db_dir = db_dir
self._prefix = prefix
self._lock = threading.Lock()
self._log_closed = False
self._problem_with_previous_stdout = False
self._previous_sys_stdout = None
self._previous_sys_stderr = None
def __enter__( self ):
self._previous_sys_stdout = sys.stdout
self._previous_sys_stderr = sys.stderr
self._problem_with_previous_stdout = False
self._OpenLog()
sys.stdout = self
sys.stderr = self
return self
def __exit__( self, exc_type, exc_val, exc_tb ):
self._CloseLog()
sys.stdout = self._previous_sys_stdout
sys.stderr = self._previous_sys_stderr
self._previous_sys_stdout = None
self._previous_sys_stderr = None
self._log_closed = True
return False
def _CloseLog( self ) -> None:
self._log_file.close()
def _GetLogPath( self ) -> str:
current_time_struct = time.localtime()
( current_year, current_month ) = ( current_time_struct.tm_year, current_time_struct.tm_mon )
log_filename = '{} - {}-{:02}.log'.format( self._prefix, current_year, current_month )
log_path = os.path.join( self._db_dir, log_filename )
return log_path
def _OpenLog( self ) -> None:
self._log_path = self._GetLogPath()
is_new_file = not os.path.exists( self._log_path )
self._log_file = open( self._log_path, 'a', encoding = 'utf-8' )
if is_new_file:
self._log_file.write( HC.UNICODE_BYTE_ORDER_MARK ) # Byte Order Mark, BOM, to help reader software interpret this as utf-8
def _SwitchToANewLogFileIfDue( self ) -> None:
correct_log_path = self._GetLogPath()
if correct_log_path != self._log_path:
self._CloseLog()
self._OpenLog()
def flush( self ) -> None:
if self._log_closed:
return
with self._lock:
if not self._problem_with_previous_stdout:
try:
self._previous_sys_stdout.flush()
except IOError:
self._problem_with_previous_stdout = True
self._log_file.flush()
self._SwitchToANewLogFileIfDue()
def isatty( self ) -> bool:
return False
def write( self, value ) -> None:
if self._log_closed:
return
with self._lock:
if value in ( '\n', '\n' ):
prefix = ''
else:
prefix = 'v{}, {}: '.format( HC.SOFTWARE_VERSION, time.strftime( '%Y-%m-%d %H:%M:%S' ) )
message = prefix + value
if not self._problem_with_previous_stdout:
try:
self._previous_sys_stdout.write( message )
except:
self._problem_with_previous_stdout = True
self._log_file.write( message )