import os
import time
[docs]class RotatingLog:
"""
An `open()` replacement that will automatically open and write
to a new file if the prior file is too large or after a time interval.
"""
[docs] def __init__(self, path="./log_file", hourInterval=24, megabyteLimit=1024):
"""
Args:
path: a full or partial path with file name.
hourInterval: the number of hours at which to rotate the file.
megabyteLimit: the number of megabytes of file size the log may
grow to, after which the log is rotated. Note: The log file
may get a bit larger than limit do to writing out whole lines
(last line may exceed megabyteLimit or "megabyteGuidline").
"""
self.path = path
self.timeInterval = None
self.timeLimit = None
self.sizeLimit = None
if hourInterval is not None:
self.timeInterval = hourInterval*60*60
self.timeLimit = time.time()+self.timeInterval
if megabyteLimit is not None:
self.sizeLimit = megabyteLimit*1024*1024
def __del__(self):
self.close()
[docs] def close(self):
if hasattr(self, "file"):
self.file.flush()
self.file.close()
self.closed = self.file.closed
del self.file
else:
self.closed = 1
[docs] def shouldRotate(self):
"""
Returns a bool about whether a new log file should
be created and written to (while at the same time
stopping output to the old log file and closing it).
"""
if not hasattr(self, "file"):
return 1
if self.timeLimit is not None and time.time() > self.timeLimit:
return 1
if self.sizeLimit is not None and self.file.tell() > self.sizeLimit:
return 1
return 0
[docs] def filePath(self):
dateString=time.strftime("%Y_%m_%d_%H", time.localtime())
for i in range(26):
path="%s_%s_%s.log"%(self.path, dateString, chr(i+97))
if not os.path.exists(path) or os.stat(path)[6] < self.sizeLimit:
return path
# Hmm, 26 files are full? throw the rest in z:
# Maybe we should clear the self.sizeLimit here... maybe.
return path
[docs] def rotate(self):
"""
Rotate the log now. You normally shouldn't need to call this.
See write().
"""
path=self.filePath()
file=open(path, "a")
if file:
self.close()
# This should be redundant with "a" open() mode,
# but on some platforms tell() will return 0
# until the first write:
file.seek(0, 2)
self.file=file
# Some of these data members may be expected by some of our clients:
self.closed = self.file.closed
self.mode = self.file.mode
self.name = self.file.name
self.softspace = self.file.softspace
#self.encoding = self.file.encoding # Python 2.3
#self.newlines = self.file.newlines # Python 2.3, maybe
if self.timeLimit is not None and time.time() > self.timeLimit:
self.timeLimit=time.time()+self.timeInterval
else:
# We'll keep writing to the old file, if available.
print("RotatingLog error: Unable to open new log file \"%s\"." % (path,))
[docs] def write(self, data):
"""
Write the data to either the current log or a new one,
depending on the return of shouldRotate() and whether
the new file can be opened.
"""
if self.shouldRotate():
self.rotate()
if hasattr(self, "file"):
r = self.file.write(data)
self.file.flush()
return r
[docs] def flush(self):
return self.file.flush()
[docs] def fileno(self):
return self.file.fileno()
[docs] def isatty(self):
return self.file.isatty()
def __next__(self):
return next(self.file)
next = __next__
[docs] def read(self, size):
return self.file.read(size)
[docs] def readline(self, size):
return self.file.readline(size)
[docs] def readlines(self, sizehint):
return self.file.readlines(sizehint)
[docs] def xreadlines(self):
return self.file.xreadlines()
[docs] def seek(self, offset, whence=0):
return self.file.seek(offset, whence)
[docs] def tell(self):
return self.file.tell()
[docs] def truncate(self, size):
return self.file.truncate(size)
[docs] def writelines(self, sequence):
return self.file.writelines(sequence)
