blob: 520463a86939d1392b102d1f248c28b8bd4cb586 [file] [log] [blame]
#! /usr/bin/env python3
"""Read/write support for Maildir, mbox, MH, Babyl, and MMDF mailboxes."""
# Notes for authors of new mailbox subclasses:
#
# Remember to fsync() changes to disk before closing a modified file
# or returning from a flush() method. See functions _sync_flush() and
# _sync_close().
import sys
import os
import time
import calendar
import socket
import errno
import copy
import email
import email.message
import email.generator
import io
try:
if sys.platform == 'os2emx':
# OS/2 EMX fcntl() not adequate
raise ImportError
import fcntl
except ImportError:
fcntl = None
__all__ = [ 'Mailbox', 'Maildir', 'mbox', 'MH', 'Babyl', 'MMDF',
'Message', 'MaildirMessage', 'mboxMessage', 'MHMessage',
'BabylMessage', 'MMDFMessage']
class Mailbox:
"""A group of messages in a particular place."""
def __init__(self, path, factory=None, create=True):
"""Initialize a Mailbox instance."""
self._path = os.path.abspath(os.path.expanduser(path))
self._factory = factory
def add(self, message):
"""Add message and return assigned key."""
raise NotImplementedError('Method must be implemented by subclass')
def remove(self, key):
"""Remove the keyed message; raise KeyError if it doesn't exist."""
raise NotImplementedError('Method must be implemented by subclass')
def __delitem__(self, key):
self.remove(key)
def discard(self, key):
"""If the keyed message exists, remove it."""
try:
self.remove(key)
except KeyError:
pass
def __setitem__(self, key, message):
"""Replace the keyed message; raise KeyError if it doesn't exist."""
raise NotImplementedError('Method must be implemented by subclass')
def get(self, key, default=None):
"""Return the keyed message, or default if it doesn't exist."""
try:
return self.__getitem__(key)
except KeyError:
return default
def __getitem__(self, key):
"""Return the keyed message; raise KeyError if it doesn't exist."""
if not self._factory:
return self.get_message(key)
else:
return self._factory(self.get_file(key))
def get_message(self, key):
"""Return a Message representation or raise a KeyError."""
raise NotImplementedError('Method must be implemented by subclass')
def get_string(self, key):
"""Return a string representation or raise a KeyError."""
raise NotImplementedError('Method must be implemented by subclass')
def get_file(self, key):
"""Return a file-like representation or raise a KeyError."""
raise NotImplementedError('Method must be implemented by subclass')
def iterkeys(self):
"""Return an iterator over keys."""
raise NotImplementedError('Method must be implemented by subclass')
def keys(self):
"""Return a list of keys."""
return list(self.iterkeys())
def itervalues(self):
"""Return an iterator over all messages."""
for key in self.keys():
try:
value = self[key]
except KeyError:
continue
yield value
def __iter__(self):
return self.itervalues()
def values(self):
"""Return a list of messages. Memory intensive."""
return list(self.itervalues())
def iteritems(self):
"""Return an iterator over (key, message) tuples."""
for key in self.keys():
try:
value = self[key]
except KeyError:
continue
yield (key, value)
def items(self):
"""Return a list of (key, message) tuples. Memory intensive."""
return list(self.iteritems())
def __contains__(self, key):
"""Return True if the keyed message exists, False otherwise."""
raise NotImplementedError('Method must be implemented by subclass')
def __len__(self):
"""Return a count of messages in the mailbox."""
raise NotImplementedError('Method must be implemented by subclass')
def clear(self):
"""Delete all messages."""
for key in self.keys():
self.discard(key)
def pop(self, key, default=None):
"""Delete the keyed message and return it, or default."""
try:
result = self[key]
except KeyError:
return default
self.discard(key)
return result
def popitem(self):
"""Delete an arbitrary (key, message) pair and return it."""
for key in self.keys():
return (key, self.pop(key)) # This is only run once.
else:
raise KeyError('No messages in mailbox')
def update(self, arg=None):
"""Change the messages that correspond to certain keys."""
if hasattr(arg, 'iteritems'):
source = arg.items()
elif hasattr(arg, 'items'):
source = arg.items()
else:
source = arg
bad_key = False
for key, message in source:
try:
self[key] = message
except KeyError:
bad_key = True
if bad_key:
raise KeyError('No message with key(s)')
def flush(self):
"""Write any pending changes to the disk."""
raise NotImplementedError('Method must be implemented by subclass')
def lock(self):
"""Lock the mailbox."""
raise NotImplementedError('Method must be implemented by subclass')
def unlock(self):
"""Unlock the mailbox if it is locked."""
raise NotImplementedError('Method must be implemented by subclass')
def close(self):
"""Flush and close the mailbox."""
raise NotImplementedError('Method must be implemented by subclass')
def _dump_message(self, message, target, mangle_from_=False):
# This assumes the target file is open in *text* mode with the
# desired encoding and newline setting.
"""Dump message contents to target file."""
if isinstance(message, email.message.Message):
buffer = io.StringIO()
gen = email.generator.Generator(buffer, mangle_from_, 0)
gen.flatten(message)
buffer.seek(0)
data = buffer.read()
##data = data.replace('\n', os.linesep)
target.write(data)
elif isinstance(message, str):
if mangle_from_:
message = message.replace('\nFrom ', '\n>From ')
##message = message.replace('\n', os.linesep)
target.write(message)
elif hasattr(message, 'read'):
while True:
line = message.readline()
if not line:
break
if mangle_from_ and line.startswith('From '):
line = '>From ' + line[5:]
##line = line.replace('\n', os.linesep)
target.write(line)
else:
raise TypeError('Invalid message type: %s' % type(message))
class Maildir(Mailbox):
"""A qmail-style Maildir mailbox."""
colon = ':'
def __init__(self, dirname, factory=None, create=True):
"""Initialize a Maildir instance."""
Mailbox.__init__(self, dirname, factory, create)
if not os.path.exists(self._path):
if create:
os.mkdir(self._path, 0o700)
os.mkdir(os.path.join(self._path, 'tmp'), 0o700)
os.mkdir(os.path.join(self._path, 'new'), 0o700)
os.mkdir(os.path.join(self._path, 'cur'), 0o700)
else:
raise NoSuchMailboxError(self._path)
self._toc = {}
self._last_read = None # Records last time we read cur/new
# NOTE: we manually invalidate _last_read each time we do any
# modifications ourselves, otherwise we might get tripped up by
# bogus mtime behaviour on some systems (see issue #6896).
def add(self, message):
"""Add message and return assigned key."""
tmp_file = self._create_tmp()
try:
self._dump_message(message, tmp_file)
finally:
_sync_close(tmp_file)
if isinstance(message, MaildirMessage):
subdir = message.get_subdir()
suffix = self.colon + message.get_info()
if suffix == self.colon:
suffix = ''
else:
subdir = 'new'
suffix = ''
uniq = os.path.basename(tmp_file.name).split(self.colon)[0]
dest = os.path.join(self._path, subdir, uniq + suffix)
try:
if hasattr(os, 'link'):
os.link(tmp_file.name, dest)
os.remove(tmp_file.name)
else:
os.rename(tmp_file.name, dest)
except OSError as e:
os.remove(tmp_file.name)
if e.errno == errno.EEXIST:
raise ExternalClashError('Name clash with existing message: %s'
% dest)
else:
raise
if isinstance(message, MaildirMessage):
os.utime(dest, (os.path.getatime(dest), message.get_date()))
# Invalidate cached toc
self._last_read = None
return uniq
def remove(self, key):
"""Remove the keyed message; raise KeyError if it doesn't exist."""
os.remove(os.path.join(self._path, self._lookup(key)))
# Invalidate cached toc (only on success)
self._last_read = None
def discard(self, key):
"""If the keyed message exists, remove it."""
# This overrides an inapplicable implementation in the superclass.
try:
self.remove(key)
except KeyError:
pass
except OSError as e:
if e.errno != errno.ENOENT:
raise
def __setitem__(self, key, message):
"""Replace the keyed message; raise KeyError if it doesn't exist."""
old_subpath = self._lookup(key)
temp_key = self.add(message)
temp_subpath = self._lookup(temp_key)
if isinstance(message, MaildirMessage):
# temp's subdir and suffix were specified by message.
dominant_subpath = temp_subpath
else:
# temp's subdir and suffix were defaults from add().
dominant_subpath = old_subpath
subdir = os.path.dirname(dominant_subpath)
if self.colon in dominant_subpath:
suffix = self.colon + dominant_subpath.split(self.colon)[-1]
else:
suffix = ''
self.discard(key)
new_path = os.path.join(self._path, subdir, key + suffix)
os.rename(os.path.join(self._path, temp_subpath), new_path)
if isinstance(message, MaildirMessage):
os.utime(new_path, (os.path.getatime(new_path),
message.get_date()))
# Invalidate cached toc
self._last_read = None
def get_message(self, key):
"""Return a Message representation or raise a KeyError."""
subpath = self._lookup(key)
f = open(os.path.join(self._path, subpath), 'r', newline='')
try:
if self._factory:
msg = self._factory(f)
else:
msg = MaildirMessage(f)
finally:
f.close()
subdir, name = os.path.split(subpath)
msg.set_subdir(subdir)
if self.colon in name:
msg.set_info(name.split(self.colon)[-1])
msg.set_date(os.path.getmtime(os.path.join(self._path, subpath)))
return msg
def get_string(self, key):
"""Return a string representation or raise a KeyError."""
f = open(os.path.join(self._path, self._lookup(key)), 'r', newline='')
try:
return f.read()
finally:
f.close()
def get_file(self, key):
"""Return a file-like representation or raise a KeyError."""
f = open(os.path.join(self._path, self._lookup(key)), 'r', newline='')
return _ProxyFile(f)
def iterkeys(self):
"""Return an iterator over keys."""
self._refresh()
for key in self._toc:
try:
self._lookup(key)
except KeyError:
continue
yield key
def __contains__(self, key):
"""Return True if the keyed message exists, False otherwise."""
self._refresh()
return key in self._toc
def __len__(self):
"""Return a count of messages in the mailbox."""
self._refresh()
return len(self._toc)
def flush(self):
"""Write any pending changes to disk."""
# Maildir changes are always written immediately, so there's nothing
# to do except invalidate our cached toc.
self._last_read = None
def lock(self):
"""Lock the mailbox."""
return
def unlock(self):
"""Unlock the mailbox if it is locked."""
return
def close(self):
"""Flush and close the mailbox."""
return
def list_folders(self):
"""Return a list of folder names."""
result = []
for entry in os.listdir(self._path):
if len(entry) > 1 and entry[0] == '.' and \
os.path.isdir(os.path.join(self._path, entry)):
result.append(entry[1:])
return result
def get_folder(self, folder):
"""Return a Maildir instance for the named folder."""
return Maildir(os.path.join(self._path, '.' + folder),
factory=self._factory,
create=False)
def add_folder(self, folder):
"""Create a folder and return a Maildir instance representing it."""
path = os.path.join(self._path, '.' + folder)
result = Maildir(path, factory=self._factory)
maildirfolder_path = os.path.join(path, 'maildirfolder')
if not os.path.exists(maildirfolder_path):
os.close(os.open(maildirfolder_path, os.O_CREAT | os.O_WRONLY,
0o666))
return result
def remove_folder(self, folder):
"""Delete the named folder, which must be empty."""
path = os.path.join(self._path, '.' + folder)
for entry in os.listdir(os.path.join(path, 'new')) + \
os.listdir(os.path.join(path, 'cur')):
if len(entry) < 1 or entry[0] != '.':
raise NotEmptyError('Folder contains message(s): %s' % folder)
for entry in os.listdir(path):
if entry != 'new' and entry != 'cur' and entry != 'tmp' and \
os.path.isdir(os.path.join(path, entry)):
raise NotEmptyError("Folder contains subdirectory '%s': %s" %
(folder, entry))
for root, dirs, files in os.walk(path, topdown=False):
for entry in files:
os.remove(os.path.join(root, entry))
for entry in dirs:
os.rmdir(os.path.join(root, entry))
os.rmdir(path)
def clean(self):
"""Delete old files in "tmp"."""
now = time.time()
for entry in os.listdir(os.path.join(self._path, 'tmp')):
path = os.path.join(self._path, 'tmp', entry)
if now - os.path.getatime(path) > 129600: # 60 * 60 * 36
os.remove(path)
_count = 1 # This is used to generate unique file names.
def _create_tmp(self):
"""Create a file in the tmp subdirectory and open and return it."""
now = time.time()
hostname = socket.gethostname()
if '/' in hostname:
hostname = hostname.replace('/', r'\057')
if ':' in hostname:
hostname = hostname.replace(':', r'\072')
uniq = "%s.M%sP%sQ%s.%s" % (int(now), int(now % 1 * 1e6), os.getpid(),
Maildir._count, hostname)
path = os.path.join(self._path, 'tmp', uniq)
try:
os.stat(path)
except OSError as e:
if e.errno == errno.ENOENT:
Maildir._count += 1
try:
return _create_carefully(path)
except OSError as e:
if e.errno != errno.EEXIST:
raise
else:
raise
# Fall through to here if stat succeeded or open raised EEXIST.
raise ExternalClashError('Name clash prevented file creation: %s' %
path)
def _refresh(self):
"""Update table of contents mapping."""
if self._last_read is not None:
for subdir in ('new', 'cur'):
mtime = os.path.getmtime(os.path.join(self._path, subdir))
if mtime > self._last_read:
break
else:
return
# We record the current time - 1sec so that, if _refresh() is called
# again in the same second, we will always re-read the mailbox
# just in case it's been modified. (os.path.mtime() only has
# 1sec resolution.) This results in a few unnecessary re-reads
# when _refresh() is called multiple times in the same second,
# but once the clock ticks over, we will only re-read as needed.
now = time.time() - 1
self._toc = {}
def update_dir (subdir):
path = os.path.join(self._path, subdir)
for entry in os.listdir(path):
p = os.path.join(path, entry)
if os.path.isdir(p):
continue
uniq = entry.split(self.colon)[0]
self._toc[uniq] = os.path.join(subdir, entry)
update_dir('new')
update_dir('cur')
self._last_read = now
def _lookup(self, key):
"""Use TOC to return subpath for given key, or raise a KeyError."""
try:
if os.path.exists(os.path.join(self._path, self._toc[key])):
return self._toc[key]
except KeyError:
pass
self._refresh()
try:
return self._toc[key]
except KeyError:
raise KeyError('No message with key: %s' % key)
# This method is for backward compatibility only.
def next(self):
"""Return the next message in a one-time iteration."""
if not hasattr(self, '_onetime_keys'):
self._onetime_keys = iter(self.keys())
while True:
try:
return self[next(self._onetime_keys)]
except StopIteration:
return None
except KeyError:
continue
class _singlefileMailbox(Mailbox):
"""A single-file mailbox."""
def __init__(self, path, factory=None, create=True):
"""Initialize a single-file mailbox."""
Mailbox.__init__(self, path, factory, create)
try:
f = open(self._path, 'r+', newline='')
except IOError as e:
if e.errno == errno.ENOENT:
if create:
f = open(self._path, 'w+', newline='')
else:
raise NoSuchMailboxError(self._path)
elif e.errno == errno.EACCES:
f = open(self._path, 'r', newline='')
else:
raise
self._file = f
self._toc = None
self._next_key = 0
self._pending = False # No changes require rewriting the file.
self._locked = False
self._file_length = None # Used to record mailbox size
def add(self, message):
"""Add message and return assigned key."""
self._lookup()
self._toc[self._next_key] = self._append_message(message)
self._next_key += 1
self._pending = True
return self._next_key - 1
def remove(self, key):
"""Remove the keyed message; raise KeyError if it doesn't exist."""
self._lookup(key)
del self._toc[key]
self._pending = True
def __setitem__(self, key, message):
"""Replace the keyed message; raise KeyError if it doesn't exist."""
self._lookup(key)
self._toc[key] = self._append_message(message)
self._pending = True
def iterkeys(self):
"""Return an iterator over keys."""
self._lookup()
for key in self._toc.keys():
yield key
def __contains__(self, key):
"""Return True if the keyed message exists, False otherwise."""
self._lookup()
return key in self._toc
def __len__(self):
"""Return a count of messages in the mailbox."""
self._lookup()
return len(self._toc)
def lock(self):
"""Lock the mailbox."""
if not self._locked:
_lock_file(self._file)
self._locked = True
def unlock(self):
"""Unlock the mailbox if it is locked."""
if self._locked:
_unlock_file(self._file)
self._locked = False
def flush(self):
"""Write any pending changes to disk."""
if not self._pending:
return
# In order to be writing anything out at all, self._toc must
# already have been generated (and presumably has been modified
# by adding or deleting an item).
assert self._toc is not None
# Check length of self._file; if it's changed, some other process
# has modified the mailbox since we scanned it.
self._file.seek(0, 2)
cur_len = self._file.tell()
if cur_len != self._file_length:
raise ExternalClashError('Size of mailbox file changed '
'(expected %i, found %i)' %
(self._file_length, cur_len))
new_file = _create_temporary(self._path)
try:
new_toc = {}
self._pre_mailbox_hook(new_file)
for key in sorted(self._toc.keys()):
start, stop = self._toc[key]
self._file.seek(start)
self._pre_message_hook(new_file)
new_start = new_file.tell()
while True:
buffer = self._file.read(min(4096,
stop - self._file.tell()))
if not buffer:
break
new_file.write(buffer)
new_toc[key] = (new_start, new_file.tell())
self._post_message_hook(new_file)
except:
new_file.close()
os.remove(new_file.name)
raise
_sync_close(new_file)
# self._file is about to get replaced, so no need to sync.
self._file.close()
try:
os.rename(new_file.name, self._path)
except OSError as e:
if e.errno == errno.EEXIST or \
(os.name == 'os2' and e.errno == errno.EACCES):
os.remove(self._path)
os.rename(new_file.name, self._path)
else:
raise
self._file = open(self._path, 'rb+')
self._toc = new_toc
self._pending = False
if self._locked:
_lock_file(self._file, dotlock=False)
def _pre_mailbox_hook(self, f):
"""Called before writing the mailbox to file f."""
return
def _pre_message_hook(self, f):
"""Called before writing each message to file f."""
return
def _post_message_hook(self, f):
"""Called after writing each message to file f."""
return
def close(self):
"""Flush and close the mailbox."""
self.flush()
if self._locked:
self.unlock()
self._file.close() # Sync has been done by self.flush() above.
def _lookup(self, key=None):
"""Return (start, stop) or raise KeyError."""
if self._toc is None:
self._generate_toc()
if key is not None:
try:
return self._toc[key]
except KeyError:
raise KeyError('No message with key: %s' % key)
def _append_message(self, message):
"""Append message to mailbox and return (start, stop) offsets."""
self._file.seek(0, 2)
self._pre_message_hook(self._file)
offsets = self._install_message(message)
self._post_message_hook(self._file)
self._file.flush()
self._file_length = self._file.tell() # Record current length of mailbox
return offsets
class _mboxMMDF(_singlefileMailbox):
"""An mbox or MMDF mailbox."""
_mangle_from_ = True
def get_message(self, key):
"""Return a Message representation or raise a KeyError."""
start, stop = self._lookup(key)
self._file.seek(start)
from_line = self._file.readline().replace(os.linesep, '')
string = self._file.read(stop - self._file.tell())
msg = self._message_factory(string.replace(os.linesep, '\n'))
msg.set_from(from_line[5:])
return msg
def get_string(self, key, from_=False):
"""Return a string representation or raise a KeyError."""
start, stop = self._lookup(key)
self._file.seek(start)
if not from_:
self._file.readline()
string = self._file.read(stop - self._file.tell())
return string.replace(os.linesep, '\n')
def get_file(self, key, from_=False):
"""Return a file-like representation or raise a KeyError."""
start, stop = self._lookup(key)
self._file.seek(start)
if not from_:
self._file.readline()
return _PartialFile(self._file, self._file.tell(), stop)
def _install_message(self, message):
"""Format a message and blindly write to self._file."""
from_line = None
if isinstance(message, str) and message.startswith('From '):
newline = message.find('\n')
if newline != -1:
from_line = message[:newline]
message = message[newline + 1:]
else:
from_line = message
message = ''
elif isinstance(message, _mboxMMDFMessage):
from_line = 'From ' + message.get_from()
elif isinstance(message, email.message.Message):
from_line = message.get_unixfrom() # May be None.
if from_line is None:
from_line = 'From MAILER-DAEMON %s' % time.asctime(time.gmtime())
start = self._file.tell()
self._file.write(from_line + os.linesep)
self._dump_message(message, self._file, self._mangle_from_)
stop = self._file.tell()
return (start, stop)
class mbox(_mboxMMDF):
"""A classic mbox mailbox."""
_mangle_from_ = True
def __init__(self, path, factory=None, create=True):
"""Initialize an mbox mailbox."""
self._message_factory = mboxMessage
_mboxMMDF.__init__(self, path, factory, create)
def _pre_message_hook(self, f):
"""Called before writing each message to file f."""
if f.tell() != 0:
f.write(os.linesep)
def _generate_toc(self):
"""Generate key-to-(start, stop) table of contents."""
starts, stops = [], []
self._file.seek(0)
while True:
line_pos = self._file.tell()
line = self._file.readline()
if line.startswith('From '):
if len(stops) < len(starts):
stops.append(line_pos - len(os.linesep))
starts.append(line_pos)
elif not line:
stops.append(line_pos)
break
self._toc = dict(enumerate(zip(starts, stops)))
self._next_key = len(self._toc)
self._file_length = self._file.tell()
class MMDF(_mboxMMDF):
"""An MMDF mailbox."""
def __init__(self, path, factory=None, create=True):
"""Initialize an MMDF mailbox."""
self._message_factory = MMDFMessage
_mboxMMDF.__init__(self, path, factory, create)
def _pre_message_hook(self, f):
"""Called before writing each message to file f."""
f.write('\001\001\001\001' + os.linesep)
def _post_message_hook(self, f):
"""Called after writing each message to file f."""
f.write(os.linesep + '\001\001\001\001' + os.linesep)
def _generate_toc(self):
"""Generate key-to-(start, stop) table of contents."""
starts, stops = [], []
self._file.seek(0)
next_pos = 0
while True:
line_pos = next_pos
line = self._file.readline()
next_pos = self._file.tell()
if line.startswith('\001\001\001\001' + os.linesep):
starts.append(next_pos)
while True:
line_pos = next_pos
line = self._file.readline()
next_pos = self._file.tell()
if line == '\001\001\001\001' + os.linesep:
stops.append(line_pos - len(os.linesep))
break
elif not line:
stops.append(line_pos)
break
elif not line:
break
self._toc = dict(enumerate(zip(starts, stops)))
self._next_key = len(self._toc)
self._file.seek(0, 2)
self._file_length = self._file.tell()
class MH(Mailbox):
"""An MH mailbox."""
def __init__(self, path, factory=None, create=True):
"""Initialize an MH instance."""
Mailbox.__init__(self, path, factory, create)
if not os.path.exists(self._path):
if create:
os.mkdir(self._path, 0o700)
os.close(os.open(os.path.join(self._path, '.mh_sequences'),
os.O_CREAT | os.O_EXCL | os.O_WRONLY, 0o600))
else:
raise NoSuchMailboxError(self._path)
self._locked = False
def add(self, message):
"""Add message and return assigned key."""
keys = self.keys()
if len(keys) == 0:
new_key = 1
else:
new_key = max(keys) + 1
new_path = os.path.join(self._path, str(new_key))
f = _create_carefully(new_path)
try:
if self._locked:
_lock_file(f)
try:
self._dump_message(message, f)
if isinstance(message, MHMessage):
self._dump_sequences(message, new_key)
finally:
if self._locked:
_unlock_file(f)
finally:
_sync_close(f)
return new_key
def remove(self, key):
"""Remove the keyed message; raise KeyError if it doesn't exist."""
path = os.path.join(self._path, str(key))
try:
f = open(path, 'rb+')
except IOError as e:
if e.errno == errno.ENOENT:
raise KeyError('No message with key: %s' % key)
else:
raise
else:
f.close()
os.remove(path)
def __setitem__(self, key, message):
"""Replace the keyed message; raise KeyError if it doesn't exist."""
path = os.path.join(self._path, str(key))
try:
f = open(path, 'r+', newline='')
except IOError as e:
if e.errno == errno.ENOENT:
raise KeyError('No message with key: %s' % key)
else:
raise
try:
if self._locked:
_lock_file(f)
try:
os.close(os.open(path, os.O_WRONLY | os.O_TRUNC))
self._dump_message(message, f)
if isinstance(message, MHMessage):
self._dump_sequences(message, key)
finally:
if self._locked:
_unlock_file(f)
finally:
_sync_close(f)
def get_message(self, key):
"""Return a Message representation or raise a KeyError."""
try:
if self._locked:
f = open(os.path.join(self._path, str(key)), 'r+', newline='')
else:
f = open(os.path.join(self._path, str(key)), 'r', newline='')
except IOError as e:
if e.errno == errno.ENOENT:
raise KeyError('No message with key: %s' % key)
else:
raise
try:
if self._locked:
_lock_file(f)
try:
msg = MHMessage(f)
finally:
if self._locked:
_unlock_file(f)
finally:
f.close()
for name, key_list in self.get_sequences().items():
if key in key_list:
msg.add_sequence(name)
return msg
def get_string(self, key):
"""Return a string representation or raise a KeyError."""
try:
if self._locked:
f = open(os.path.join(self._path, str(key)), 'r+', newline='')
else:
f = open(os.path.join(self._path, str(key)), 'r', newline='')
except IOError as e:
if e.errno == errno.ENOENT:
raise KeyError('No message with key: %s' % key)
else:
raise
try:
if self._locked:
_lock_file(f)
try:
return f.read()
finally:
if self._locked:
_unlock_file(f)
finally:
f.close()
def get_file(self, key):
"""Return a file-like representation or raise a KeyError."""
try:
f = open(os.path.join(self._path, str(key)), 'r', newline='')
except IOError as e:
if e.errno == errno.ENOENT:
raise KeyError('No message with key: %s' % key)
else:
raise
return _ProxyFile(f)
def iterkeys(self):
"""Return an iterator over keys."""
return iter(sorted(int(entry) for entry in os.listdir(self._path)
if entry.isdigit()))
def __contains__(self, key):
"""Return True if the keyed message exists, False otherwise."""
return os.path.exists(os.path.join(self._path, str(key)))
def __len__(self):
"""Return a count of messages in the mailbox."""
return len(list(self.keys()))
def lock(self):
"""Lock the mailbox."""
if not self._locked:
self._file = open(os.path.join(self._path, '.mh_sequences'), 'rb+')
_lock_file(self._file)
self._locked = True
def unlock(self):
"""Unlock the mailbox if it is locked."""
if self._locked:
_unlock_file(self._file)
_sync_close(self._file)
del self._file
self._locked = False
def flush(self):
"""Write any pending changes to the disk."""
return
def close(self):
"""Flush and close the mailbox."""
if self._locked:
self.unlock()
def list_folders(self):
"""Return a list of folder names."""
result = []
for entry in os.listdir(self._path):
if os.path.isdir(os.path.join(self._path, entry)):
result.append(entry)
return result
def get_folder(self, folder):
"""Return an MH instance for the named folder."""
return MH(os.path.join(self._path, folder),
factory=self._factory, create=False)
def add_folder(self, folder):
"""Create a folder and return an MH instance representing it."""
return MH(os.path.join(self._path, folder),
factory=self._factory)
def remove_folder(self, folder):
"""Delete the named folder, which must be empty."""
path = os.path.join(self._path, folder)
entries = os.listdir(path)
if entries == ['.mh_sequences']:
os.remove(os.path.join(path, '.mh_sequences'))
elif entries == []:
pass
else:
raise NotEmptyError('Folder not empty: %s' % self._path)
os.rmdir(path)
def get_sequences(self):
"""Return a name-to-key-list dictionary to define each sequence."""
results = {}
f = open(os.path.join(self._path, '.mh_sequences'), 'r', newline='')
try:
all_keys = set(self.keys())
for line in f:
try:
name, contents = line.split(':')
keys = set()
for spec in contents.split():
if spec.isdigit():
keys.add(int(spec))
else:
start, stop = (int(x) for x in spec.split('-'))
keys.update(range(start, stop + 1))
results[name] = [key for key in sorted(keys) \
if key in all_keys]
if len(results[name]) == 0:
del results[name]
except ValueError:
raise FormatError('Invalid sequence specification: %s' %
line.rstrip())
finally:
f.close()
return results
def set_sequences(self, sequences):
"""Set sequences using the given name-to-key-list dictionary."""
f = open(os.path.join(self._path, '.mh_sequences'), 'r+', newline='')
try:
os.close(os.open(f.name, os.O_WRONLY | os.O_TRUNC))
for name, keys in sequences.items():
if len(keys) == 0:
continue
f.write('%s:' % name)
prev = None
completing = False
for key in sorted(set(keys)):
if key - 1 == prev:
if not completing:
completing = True
f.write('-')
elif completing:
completing = False
f.write('%s %s' % (prev, key))
else:
f.write(' %s' % key)
prev = key
if completing:
f.write(str(prev) + '\n')
else:
f.write('\n')
finally:
_sync_close(f)
def pack(self):
"""Re-name messages to eliminate numbering gaps. Invalidates keys."""
sequences = self.get_sequences()
prev = 0
changes = []
for key in self.keys():
if key - 1 != prev:
changes.append((key, prev + 1))
if hasattr(os, 'link'):
os.link(os.path.join(self._path, str(key)),
os.path.join(self._path, str(prev + 1)))
os.unlink(os.path.join(self._path, str(key)))
else:
os.rename(os.path.join(self._path, str(key)),
os.path.join(self._path, str(prev + 1)))
prev += 1
self._next_key = prev + 1
if len(changes) == 0:
return
for name, key_list in sequences.items():
for old, new in changes:
if old in key_list:
key_list[key_list.index(old)] = new
self.set_sequences(sequences)
def _dump_sequences(self, message, key):
"""Inspect a new MHMessage and update sequences appropriately."""
pending_sequences = message.get_sequences()
all_sequences = self.get_sequences()
for name, key_list in all_sequences.items():
if name in pending_sequences:
key_list.append(key)
elif key in key_list:
del key_list[key_list.index(key)]
for sequence in pending_sequences:
if sequence not in all_sequences:
all_sequences[sequence] = [key]
self.set_sequences(all_sequences)
class Babyl(_singlefileMailbox):
"""An Rmail-style Babyl mailbox."""
_special_labels = frozenset(('unseen', 'deleted', 'filed', 'answered',
'forwarded', 'edited', 'resent'))
def __init__(self, path, factory=None, create=True):
"""Initialize a Babyl mailbox."""
_singlefileMailbox.__init__(self, path, factory, create)
self._labels = {}
def add(self, message):
"""Add message and return assigned key."""
key = _singlefileMailbox.add(self, message)
if isinstance(message, BabylMessage):
self._labels[key] = message.get_labels()
return key
def remove(self, key):
"""Remove the keyed message; raise KeyError if it doesn't exist."""
_singlefileMailbox.remove(self, key)
if key in self._labels:
del self._labels[key]
def __setitem__(self, key, message):
"""Replace the keyed message; raise KeyError if it doesn't exist."""
_singlefileMailbox.__setitem__(self, key, message)
if isinstance(message, BabylMessage):
self._labels[key] = message.get_labels()
def get_message(self, key):
"""Return a Message representation or raise a KeyError."""
start, stop = self._lookup(key)
self._file.seek(start)
self._file.readline() # Skip '1,' line specifying labels.
original_headers = io.StringIO()
while True:
line = self._file.readline()
if line == '*** EOOH ***' + os.linesep or not line:
break
original_headers.write(line.replace(os.linesep, '\n'))
visible_headers = io.StringIO()
while True:
line = self._file.readline()
if line == os.linesep or not line:
break
visible_headers.write(line.replace(os.linesep, '\n'))
body = self._file.read(stop - self._file.tell()).replace(os.linesep,
'\n')
msg = BabylMessage(original_headers.getvalue() + body)
msg.set_visible(visible_headers.getvalue())
if key in self._labels:
msg.set_labels(self._labels[key])
return msg
def get_string(self, key):
"""Return a string representation or raise a KeyError."""
start, stop = self._lookup(key)
self._file.seek(start)
self._file.readline() # Skip '1,' line specifying labels.
original_headers = io.StringIO()
while True:
line = self._file.readline()
if line == '*** EOOH ***' + os.linesep or not line:
break
original_headers.write(line.replace(os.linesep, '\n'))
while True:
line = self._file.readline()
if line == os.linesep or not line:
break
return original_headers.getvalue() + \
self._file.read(stop - self._file.tell()).replace(os.linesep,
'\n')
def get_file(self, key):
"""Return a file-like representation or raise a KeyError."""
return io.StringIO(self.get_string(key).replace('\n',
os.linesep))
def get_labels(self):
"""Return a list of user-defined labels in the mailbox."""
self._lookup()
labels = set()
for label_list in self._labels.values():
labels.update(label_list)
labels.difference_update(self._special_labels)
return list(labels)
def _generate_toc(self):
"""Generate key-to-(start, stop) table of contents."""
starts, stops = [], []
self._file.seek(0)
next_pos = 0
label_lists = []
while True:
line_pos = next_pos
line = self._file.readline()
next_pos = self._file.tell()
if line == '\037\014' + os.linesep:
if len(stops) < len(starts):
stops.append(line_pos - len(os.linesep))
starts.append(next_pos)
labels = [label.strip() for label
in self._file.readline()[1:].split(',')
if label.strip()]
label_lists.append(labels)
elif line == '\037' or line == '\037' + os.linesep:
if len(stops) < len(starts):
stops.append(line_pos - len(os.linesep))
elif not line:
stops.append(line_pos - len(os.linesep))
break
self._toc = dict(enumerate(zip(starts, stops)))
self._labels = dict(enumerate(label_lists))
self._next_key = len(self._toc)
self._file.seek(0, 2)
self._file_length = self._file.tell()
def _pre_mailbox_hook(self, f):
"""Called before writing the mailbox to file f."""
f.write('BABYL OPTIONS:%sVersion: 5%sLabels:%s%s\037' %
(os.linesep, os.linesep, ','.join(self.get_labels()),
os.linesep))
def _pre_message_hook(self, f):
"""Called before writing each message to file f."""
f.write('\014' + os.linesep)
def _post_message_hook(self, f):
"""Called after writing each message to file f."""
f.write(os.linesep + '\037')
def _install_message(self, message):
"""Write message contents and return (start, stop)."""
start = self._file.tell()
if isinstance(message, BabylMessage):
special_labels = []
labels = []
for label in message.get_labels():
if label in self._special_labels:
special_labels.append(label)
else:
labels.append(label)
self._file.write('1')
for label in special_labels:
self._file.write(', ' + label)
self._file.write(',,')
for label in labels:
self._file.write(' ' + label + ',')
self._file.write(os.linesep)
else:
self._file.write('1,,' + os.linesep)
if isinstance(message, email.message.Message):
orig_buffer = io.StringIO()
orig_generator = email.generator.Generator(orig_buffer, False, 0)
orig_generator.flatten(message)
orig_buffer.seek(0)
while True:
line = orig_buffer.readline()
self._file.write(line.replace('\n', os.linesep))
if line == '\n' or not line:
break
self._file.write('*** EOOH ***' + os.linesep)
if isinstance(message, BabylMessage):
vis_buffer = io.StringIO()
vis_generator = email.generator.Generator(vis_buffer, False, 0)
vis_generator.flatten(message.get_visible())
while True:
line = vis_buffer.readline()
self._file.write(line.replace('\n', os.linesep))
if line == '\n' or not line:
break
else:
orig_buffer.seek(0)
while True:
line = orig_buffer.readline()
self._file.write(line.replace('\n', os.linesep))
if line == '\n' or not line:
break
while True:
buffer = orig_buffer.read(4096) # Buffer size is arbitrary.
if not buffer:
break
self._file.write(buffer.replace('\n', os.linesep))
elif isinstance(message, str):
body_start = message.find('\n\n') + 2
if body_start - 2 != -1:
self._file.write(message[:body_start].replace('\n',
os.linesep))
self._file.write('*** EOOH ***' + os.linesep)
self._file.write(message[:body_start].replace('\n',
os.linesep))
self._file.write(message[body_start:].replace('\n',
os.linesep))
else:
self._file.write('*** EOOH ***' + os.linesep + os.linesep)
self._file.write(message.replace('\n', os.linesep))
elif hasattr(message, 'readline'):
original_pos = message.tell()
first_pass = True
while True:
line = message.readline()
self._file.write(line.replace('\n', os.linesep))
if line == '\n' or not line:
self._file.write('*** EOOH ***' + os.linesep)
if first_pass:
first_pass = False
message.seek(original_pos)
else:
break
while True:
buffer = message.read(4096) # Buffer size is arbitrary.
if not buffer:
break
self._file.write(buffer.replace('\n', os.linesep))
else:
raise TypeError('Invalid message type: %s' % type(message))
stop = self._file.tell()
return (start, stop)
class Message(email.message.Message):
"""Message with mailbox-format-specific properties."""
def __init__(self, message=None):
"""Initialize a Message instance."""
if isinstance(message, email.message.Message):
self._become_message(copy.deepcopy(message))
if isinstance(message, Message):
message._explain_to(self)
elif isinstance(message, str):
self._become_message(email.message_from_string(message))
elif hasattr(message, "read"):
self._become_message(email.message_from_file(message))
elif message is None:
email.message.Message.__init__(self)
else:
raise TypeError('Invalid message type: %s' % type(message))
def _become_message(self, message):
"""Assume the non-format-specific state of message."""
for name in ('_headers', '_unixfrom', '_payload', '_charset',
'preamble', 'epilogue', 'defects', '_default_type'):
self.__dict__[name] = message.__dict__[name]
def _explain_to(self, message):
"""Copy format-specific state to message insofar as possible."""
if isinstance(message, Message):
return # There's nothing format-specific to explain.
else:
raise TypeError('Cannot convert to specified type')
class MaildirMessage(Message):
"""Message with Maildir-specific properties."""
def __init__(self, message=None):
"""Initialize a MaildirMessage instance."""
self._subdir = 'new'
self._info = ''
self._date = time.time()
Message.__init__(self, message)
def get_subdir(self):
"""Return 'new' or 'cur'."""
return self._subdir
def set_subdir(self, subdir):
"""Set subdir to 'new' or 'cur'."""
if subdir == 'new' or subdir == 'cur':
self._subdir = subdir
else:
raise ValueError("subdir must be 'new' or 'cur': %s" % subdir)
def get_flags(self):
"""Return as a string the flags that are set."""
if self._info.startswith('2,'):
return self._info[2:]
else:
return ''
def set_flags(self, flags):
"""Set the given flags and unset all others."""
self._info = '2,' + ''.join(sorted(flags))
def add_flag(self, flag):
"""Set the given flag(s) without changing others."""
self.set_flags(''.join(set(self.get_flags()) | set(flag)))
def remove_flag(self, flag):
"""Unset the given string flag(s) without changing others."""
if self.get_flags():
self.set_flags(''.join(set(self.get_flags()) - set(flag)))
def get_date(self):
"""Return delivery date of message, in seconds since the epoch."""
return self._date
def set_date(self, date):
"""Set delivery date of message, in seconds since the epoch."""
try:
self._date = float(date)
except ValueError:
raise TypeError("can't convert to float: %s" % date)
def get_info(self):
"""Get the message's "info" as a string."""
return self._info
def set_info(self, info):
"""Set the message's "info" string."""
if isinstance(info, str):
self._info = info
else:
raise TypeError('info must be a string: %s' % type(info))
def _explain_to(self, message):
"""Copy Maildir-specific state to message insofar as possible."""
if isinstance(message, MaildirMessage):
message.set_flags(self.get_flags())
message.set_subdir(self.get_subdir())
message.set_date(self.get_date())
elif isinstance(message, _mboxMMDFMessage):
flags = set(self.get_flags())
if 'S' in flags:
message.add_flag('R')
if self.get_subdir() == 'cur':
message.add_flag('O')
if 'T' in flags:
message.add_flag('D')
if 'F' in flags:
message.add_flag('F')
if 'R' in flags:
message.add_flag('A')
message.set_from('MAILER-DAEMON', time.gmtime(self.get_date()))
elif isinstance(message, MHMessage):
flags = set(self.get_flags())
if 'S' not in flags:
message.add_sequence('unseen')
if 'R' in flags:
message.add_sequence('replied')
if 'F' in flags:
message.add_sequence('flagged')
elif isinstance(message, BabylMessage):
flags = set(self.get_flags())
if 'S' not in flags:
message.add_label('unseen')
if 'T' in flags:
message.add_label('deleted')
if 'R' in flags:
message.add_label('answered')
if 'P' in flags:
message.add_label('forwarded')
elif isinstance(message, Message):
pass
else:
raise TypeError('Cannot convert to specified type: %s' %
type(message))
class _mboxMMDFMessage(Message):
"""Message with mbox- or MMDF-specific properties."""
def __init__(self, message=None):
"""Initialize an mboxMMDFMessage instance."""
self.set_from('MAILER-DAEMON', True)
if isinstance(message, email.message.Message):
unixfrom = message.get_unixfrom()
if unixfrom is not None and unixfrom.startswith('From '):
self.set_from(unixfrom[5:])
Message.__init__(self, message)
def get_from(self):
"""Return contents of "From " line."""
return self._from
def set_from(self, from_, time_=None):
"""Set "From " line, formatting and appending time_ if specified."""
if time_ is not None:
if time_ is True:
time_ = time.gmtime()
from_ += ' ' + time.asctime(time_)
self._from = from_
def get_flags(self):
"""Return as a string the flags that are set."""
return self.get('Status', '') + self.get('X-Status', '')
def set_flags(self, flags):
"""Set the given flags and unset all others."""
flags = set(flags)
status_flags, xstatus_flags = '', ''
for flag in ('R', 'O'):
if flag in flags:
status_flags += flag
flags.remove(flag)
for flag in ('D', 'F', 'A'):
if flag in flags:
xstatus_flags += flag
flags.remove(flag)
xstatus_flags += ''.join(sorted(flags))
try:
self.replace_header('Status', status_flags)
except KeyError:
self.add_header('Status', status_flags)
try:
self.replace_header('X-Status', xstatus_flags)
except KeyError:
self.add_header('X-Status', xstatus_flags)
def add_flag(self, flag):
"""Set the given flag(s) without changing others."""
self.set_flags(''.join(set(self.get_flags()) | set(flag)))
def remove_flag(self, flag):
"""Unset the given string flag(s) without changing others."""
if 'Status' in self or 'X-Status' in self:
self.set_flags(''.join(set(self.get_flags()) - set(flag)))
def _explain_to(self, message):
"""Copy mbox- or MMDF-specific state to message insofar as possible."""
if isinstance(message, MaildirMessage):
flags = set(self.get_flags())
if 'O' in flags:
message.set_subdir('cur')
if 'F' in flags:
message.add_flag('F')
if 'A' in flags:
message.add_flag('R')
if 'R' in flags:
message.add_flag('S')
if 'D' in flags:
message.add_flag('T')
del message['status']
del message['x-status']
maybe_date = ' '.join(self.get_from().split()[-5:])
try:
message.set_date(calendar.timegm(time.strptime(maybe_date,
'%a %b %d %H:%M:%S %Y')))
except (ValueError, OverflowError):
pass
elif isinstance(message, _mboxMMDFMessage):
message.set_flags(self.get_flags())
message.set_from(self.get_from())
elif isinstance(message, MHMessage):
flags = set(self.get_flags())
if 'R' not in flags:
message.add_sequence('unseen')
if 'A' in flags:
message.add_sequence('replied')
if 'F' in flags:
message.add_sequence('flagged')
del message['status']
del message['x-status']
elif isinstance(message, BabylMessage):
flags = set(self.get_flags())
if 'R' not in flags:
message.add_label('unseen')
if 'D' in flags:
message.add_label('deleted')
if 'A' in flags:
message.add_label('answered')
del message['status']
del message['x-status']
elif isinstance(message, Message):
pass
else:
raise TypeError('Cannot convert to specified type: %s' %
type(message))
class mboxMessage(_mboxMMDFMessage):
"""Message with mbox-specific properties."""
class MHMessage(Message):
"""Message with MH-specific properties."""
def __init__(self, message=None):
"""Initialize an MHMessage instance."""
self._sequences = []
Message.__init__(self, message)
def get_sequences(self):
"""Return a list of sequences that include the message."""
return self._sequences[:]
def set_sequences(self, sequences):
"""Set the list of sequences that include the message."""
self._sequences = list(sequences)
def add_sequence(self, sequence):
"""Add sequence to list of sequences including the message."""
if isinstance(sequence, str):
if not sequence in self._sequences:
self._sequences.append(sequence)
else:
raise TypeError('sequence must be a string: %s' % type(sequence))
def remove_sequence(self, sequence):
"""Remove sequence from the list of sequences including the message."""
try:
self._sequences.remove(sequence)
except ValueError:
pass
def _explain_to(self, message):
"""Copy MH-specific state to message insofar as possible."""
if isinstance(message, MaildirMessage):
sequences = set(self.get_sequences())
if 'unseen' in sequences:
message.set_subdir('cur')
else:
message.set_subdir('cur')
message.add_flag('S')
if 'flagged' in sequences:
message.add_flag('F')
if 'replied' in sequences:
message.add_flag('R')
elif isinstance(message, _mboxMMDFMessage):
sequences = set(self.get_sequences())
if 'unseen' not in sequences:
message.add_flag('RO')
else:
message.add_flag('O')
if 'flagged' in sequences:
message.add_flag('F')
if 'replied' in sequences:
message.add_flag('A')
elif isinstance(message, MHMessage):
for sequence in self.get_sequences():
message.add_sequence(sequence)
elif isinstance(message, BabylMessage):
sequences = set(self.get_sequences())
if 'unseen' in sequences:
message.add_label('unseen')
if 'replied' in sequences:
message.add_label('answered')
elif isinstance(message, Message):
pass
else:
raise TypeError('Cannot convert to specified type: %s' %
type(message))
class BabylMessage(Message):
"""Message with Babyl-specific properties."""
def __init__(self, message=None):
"""Initialize an BabylMessage instance."""
self._labels = []
self._visible = Message()
Message.__init__(self, message)
def get_labels(self):
"""Return a list of labels on the message."""
return self._labels[:]
def set_labels(self, labels):
"""Set the list of labels on the message."""
self._labels = list(labels)
def add_label(self, label):
"""Add label to list of labels on the message."""
if isinstance(label, str):
if label not in self._labels:
self._labels.append(label)
else:
raise TypeError('label must be a string: %s' % type(label))
def remove_label(self, label):
"""Remove label from the list of labels on the message."""
try:
self._labels.remove(label)
except ValueError:
pass
def get_visible(self):
"""Return a Message representation of visible headers."""
return Message(self._visible)
def set_visible(self, visible):
"""Set the Message representation of visible headers."""
self._visible = Message(visible)
def update_visible(self):
"""Update and/or sensibly generate a set of visible headers."""
for header in self._visible.keys():
if header in self:
self._visible.replace_header(header, self[header])
else:
del self._visible[header]
for header in ('Date', 'From', 'Reply-To', 'To', 'CC', 'Subject'):
if header in self and header not in self._visible:
self._visible[header] = self[header]
def _explain_to(self, message):
"""Copy Babyl-specific state to message insofar as possible."""
if isinstance(message, MaildirMessage):
labels = set(self.get_labels())
if 'unseen' in labels:
message.set_subdir('cur')
else:
message.set_subdir('cur')
message.add_flag('S')
if 'forwarded' in labels or 'resent' in labels:
message.add_flag('P')
if 'answered' in labels:
message.add_flag('R')
if 'deleted' in labels:
message.add_flag('T')
elif isinstance(message, _mboxMMDFMessage):
labels = set(self.get_labels())
if 'unseen' not in labels:
message.add_flag('RO')
else:
message.add_flag('O')
if 'deleted' in labels:
message.add_flag('D')
if 'answered' in labels:
message.add_flag('A')
elif isinstance(message, MHMessage):
labels = set(self.get_labels())
if 'unseen' in labels:
message.add_sequence('unseen')
if 'answered' in labels:
message.add_sequence('replied')
elif isinstance(message, BabylMessage):
message.set_visible(self.get_visible())
for label in self.get_labels():
message.add_label(label)
elif isinstance(message, Message):
pass
else:
raise TypeError('Cannot convert to specified type: %s' %
type(message))
class MMDFMessage(_mboxMMDFMessage):
"""Message with MMDF-specific properties."""
class _ProxyFile:
"""A read-only wrapper of a file."""
def __init__(self, f, pos=None):
"""Initialize a _ProxyFile."""
self._file = f
if pos is None:
self._pos = f.tell()
else:
self._pos = pos
def read(self, size=None):
"""Read bytes."""
return self._read(size, self._file.read)
def readline(self, size=None):
"""Read a line."""
return self._read(size, self._file.readline)
def readlines(self, sizehint=None):
"""Read multiple lines."""
result = []
for line in self:
result.append(line)
if sizehint is not None:
sizehint -= len(line)
if sizehint <= 0:
break
return result
def __iter__(self):
"""Iterate over lines."""
while True:
line = self.readline()
if not line:
raise StopIteration
yield line
def tell(self):
"""Return the position."""
return self._pos
def seek(self, offset, whence=0):
"""Change position."""
if whence == 1:
self._file.seek(self._pos)
self._file.seek(offset, whence)
self._pos = self._file.tell()
def close(self):
"""Close the file."""
if hasattr(self._file, 'close'):
self._file.close()
del self._file
def _read(self, size, read_method):
"""Read size bytes using read_method."""
if size is None:
size = -1
self._file.seek(self._pos)
result = read_method(size)
self._pos = self._file.tell()
return result
def __enter__(self):
"""Context manager protocol support."""
return self
def __exit__(self, *exc):
self.close()
class _PartialFile(_ProxyFile):
"""A read-only wrapper of part of a file."""
def __init__(self, f, start=None, stop=None):
"""Initialize a _PartialFile."""
_ProxyFile.__init__(self, f, start)
self._start = start
self._stop = stop
def tell(self):
"""Return the position with respect to start."""
return _ProxyFile.tell(self) - self._start
def seek(self, offset, whence=0):
"""Change position, possibly with respect to start or stop."""
if whence == 0:
self._pos = self._start
whence = 1
elif whence == 2:
self._pos = self._stop
whence = 1
_ProxyFile.seek(self, offset, whence)
def _read(self, size, read_method):
"""Read size bytes using read_method, honoring start and stop."""
remaining = self._stop - self._pos
if remaining <= 0:
return ''
if size is None or size < 0 or size > remaining:
size = remaining
return _ProxyFile._read(self, size, read_method)
def close(self):
# do *not* close the underlying file object for partial files,
# since it's global to the mailbox object
del self._file
def _lock_file(f, dotlock=True):
"""Lock file f using lockf and dot locking."""
dotlock_done = False
try:
if fcntl:
try:
fcntl.lockf(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
except IOError as e:
if e.errno in (errno.EAGAIN, errno.EACCES):
raise ExternalClashError('lockf: lock unavailable: %s' %
f.name)
else:
raise
if dotlock:
try:
pre_lock = _create_temporary(f.name + '.lock')
pre_lock.close()
except IOError as e:
if e.errno == errno.EACCES:
return # Without write access, just skip dotlocking.
else:
raise
try:
if hasattr(os, 'link'):
os.link(pre_lock.name, f.name + '.lock')
dotlock_done = True
os.unlink(pre_lock.name)
else:
os.rename(pre_lock.name, f.name + '.lock')
dotlock_done = True
except OSError as e:
if e.errno == errno.EEXIST or \
(os.name == 'os2' and e.errno == errno.EACCES):
os.remove(pre_lock.name)
raise ExternalClashError('dot lock unavailable: %s' %
f.name)
else:
raise
except:
if fcntl:
fcntl.lockf(f, fcntl.LOCK_UN)
if dotlock_done:
os.remove(f.name + '.lock')
raise
def _unlock_file(f):
"""Unlock file f using lockf and dot locking."""
if fcntl:
fcntl.lockf(f, fcntl.LOCK_UN)
if os.path.exists(f.name + '.lock'):
os.remove(f.name + '.lock')
def _create_carefully(path):
"""Create a file if it doesn't exist and open for reading and writing."""
fd = os.open(path, os.O_CREAT | os.O_EXCL | os.O_RDWR, 0o666)
try:
return open(path, 'r+', newline='')
finally:
os.close(fd)
def _create_temporary(path):
"""Create a temp file based on path and open for reading and writing."""
return _create_carefully('%s.%s.%s.%s' % (path, int(time.time()),
socket.gethostname(),
os.getpid()))
def _sync_flush(f):
"""Ensure changes to file f are physically on disk."""
f.flush()
if hasattr(os, 'fsync'):
os.fsync(f.fileno())
def _sync_close(f):
"""Close file f, ensuring all changes are physically on disk."""
_sync_flush(f)
f.close()
class Error(Exception):
"""Raised for module-specific errors."""
class NoSuchMailboxError(Error):
"""The specified mailbox does not exist and won't be created."""
class NotEmptyError(Error):
"""The specified mailbox is not empty and deletion was requested."""
class ExternalClashError(Error):
"""Another process caused an action to fail."""
class FormatError(Error):
"""A file appears to have an invalid format."""