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 = StringIO.StringIO()
while True:
line = self._file.readline()
if line == '*** EOOH ***' + os.linesep or line == '':
break
original_headers.write(line.replace(os.linesep, '\n'))
while True:
line = self._file.readline()
if line == os.linesep or line == '':
break
return original_headers.getvalue() + \
self._file.read(stop - self._file.tell()).replace(os.linesep,
'\n')
python类seek()的实例源码
def next(self):
while 1:
self.fp.seek(self.seekp)
try:
self._search_start()
except EOFError:
self.seekp = self.fp.tell()
return None
start = self.fp.tell()
self._search_end()
self.seekp = stop = self.fp.tell()
if start != stop:
break
return self.factory(_PartialFile(self.fp, start, stop))
# Recommended to use PortableUnixMailbox instead!
def _append_message(self, message):
"""Append message to mailbox and return (start, stop) offsets."""
self._file.seek(0, 2)
before = self._file.tell()
if len(self._toc) == 0 and not self._pending:
# This is the first message, and the _pre_mailbox_hook
# hasn't yet been called. If self._pending is True,
# messages have been removed, so _pre_mailbox_hook must
# have been called already.
self._pre_mailbox_hook(self._file)
try:
self._pre_message_hook(self._file)
offsets = self._install_message(message)
self._post_message_hook(self._file)
except BaseException:
self._file.truncate(before)
raise
self._file.flush()
self._file_length = self._file.tell() # Record current length of mailbox
return offsets
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 = StringIO.StringIO()
while True:
line = self._file.readline()
if line == '*** EOOH ***' + os.linesep or line == '':
break
original_headers.write(line.replace(os.linesep, '\n'))
visible_headers = StringIO.StringIO()
while True:
line = self._file.readline()
if line == os.linesep or 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 = StringIO.StringIO()
while True:
line = self._file.readline()
if line == '*** EOOH ***' + os.linesep or line == '':
break
original_headers.write(line.replace(os.linesep, '\n'))
while True:
line = self._file.readline()
if line == os.linesep or line == '':
break
return original_headers.getvalue() + \
self._file.read(stop - self._file.tell()).replace(os.linesep,
'\n')
def next(self):
while 1:
self.fp.seek(self.seekp)
try:
self._search_start()
except EOFError:
self.seekp = self.fp.tell()
return None
start = self.fp.tell()
self._search_end()
self.seekp = stop = self.fp.tell()
if start != stop:
break
return self.factory(_PartialFile(self.fp, start, stop))
# Recommended to use PortableUnixMailbox instead!
def _append_message(self, message):
"""Append message to mailbox and return (start, stop) offsets."""
self._file.seek(0, 2)
before = self._file.tell()
if len(self._toc) == 0 and not self._pending:
# This is the first message, and the _pre_mailbox_hook
# hasn't yet been called. If self._pending is True,
# messages have been removed, so _pre_mailbox_hook must
# have been called already.
self._pre_mailbox_hook(self._file)
try:
self._pre_message_hook(self._file)
offsets = self._install_message(message)
self._post_message_hook(self._file)
except BaseException:
self._file.truncate(before)
raise
self._file.flush()
self._file_length = self._file.tell() # Record current length of mailbox
return offsets
def get_bytes(self, key):
"""Return a string representation or raise a KeyError."""
start, stop = self._lookup(key)
self._file.seek(start)
self._file.readline() # Skip b'1,' line specifying labels.
original_headers = io.BytesIO()
while True:
line = self._file.readline()
if line == b'*** EOOH ***' + linesep or not line:
break
original_headers.write(line.replace(linesep, b'\n'))
while True:
line = self._file.readline()
if line == linesep or not line:
break
headers = original_headers.getvalue()
n = stop - self._file.tell()
assert n >= 0
data = self._file.read(n)
data = data.replace(linesep, b'\n')
return headers + data
def _dump_message(self, message, target, mangle_from_=False):
# Most files are opened in binary mode to allow predictable seeking.
# To get native line endings on disk, the user-friendly \n line endings
# used in strings and by email.Message are translated here.
"""Dump message contents to target file."""
if isinstance(message, email.message.Message):
buffer = StringIO.StringIO()
gen = email.generator.Generator(buffer, mangle_from_, 0)
gen.flatten(message)
buffer.seek(0)
target.write(buffer.read().replace('\n', os.linesep))
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 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))
def _append_message(self, message):
"""Append message to mailbox and return (start, stop) offsets."""
self._file.seek(0, 2)
before = self._file.tell()
try:
self._pre_message_hook(self._file)
offsets = self._install_message(message)
self._post_message_hook(self._file)
except BaseException:
self._file.truncate(before)
raise
self._file.flush()
self._file_length = self._file.tell() # Record current length of mailbox
return offsets
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 _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 line == '':
stops.append(line_pos)
break
elif 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()
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 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 _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 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 _search_start(self):
while 1:
pos = self.fp.tell()
line = self.fp.readline()
if not line:
raise EOFError
if line[:5] == 'From ' and self._isrealfromline(line):
self.fp.seek(pos)
return
def _search_end(self):
self.fp.readline() # Throw away header line
while 1:
pos = self.fp.tell()
line = self.fp.readline()
if not line:
return
if line[:5] == 'From ' and self._isrealfromline(line):
self.fp.seek(pos)
return
# An overridable mechanism to test for From-line-ness. You can either
# specify a different regular expression or define a whole new
# _isrealfromline() method. Note that this only gets called for lines
# starting with the 5 characters "From ".
#
# BAW: According to
#http://home.netscape.com/eng/mozilla/2.0/relnotes/demo/content-length.html
# the only portable, reliable way to find message delimiters in a BSD (i.e
# Unix mailbox) style folder is to search for "\n\nFrom .*\n", or at the
# beginning of the file, "^From .*\n". While _fromlinepattern below seems
# like a good idea, in practice, there are too many variations for more
# strict parsing of the line to be completely accurate.
#
# _strict_isrealfromline() is the old version which tries to do stricter
# parsing of the From_ line. _portable_isrealfromline() simply returns
# true, since it's never called if the line doesn't already start with
# "From ".
#
# This algorithm, and the way it interacts with _search_start() and
# _search_end() may not be completely correct, because it doesn't check
# that the two characters preceding "From " are \n\n or the beginning of
# the file. Fixing this would require a more extensive rewrite than is
# necessary. For convenience, we've added a PortableUnixMailbox class
# which does no checking of the format of the 'From' line.
def _search_end(self):
while 1:
pos = self.fp.tell()
line = self.fp.readline()
if not line:
return
if line == '\037\014\n' or line == '\037':
self.fp.seek(pos)
return
## End: classes from the original module (for backward compatibility).
def _dump_message(self, message, target, mangle_from_=False):
# Most files are opened in binary mode to allow predictable seeking.
# To get native line endings on disk, the user-friendly \n line endings
# used in strings and by email.Message are translated here.
"""Dump message contents to target file."""
if isinstance(message, email.message.Message):
buffer = StringIO.StringIO()
gen = email.generator.Generator(buffer, mangle_from_, 0)
gen.flatten(message)
buffer.seek(0)
data = buffer.read().replace('\n', os.linesep)
target.write(data)
if self._append_newline and not data.endswith(os.linesep):
# Make sure the message ends with a newline
target.write(os.linesep)
elif isinstance(message, str):
if mangle_from_:
message = message.replace('\nFrom ', '\n>From ')
message = message.replace('\n', os.linesep)
target.write(message)
if self._append_newline and not message.endswith(os.linesep):
# Make sure the message ends with a newline
target.write(os.linesep)
elif hasattr(message, 'read'):
lastline = None
while True:
line = message.readline()
if line == '':
break
if mangle_from_ and line.startswith('From '):
line = '>From ' + line[5:]
line = line.replace('\n', os.linesep)
target.write(line)
lastline = line
if self._append_newline and lastline and not lastline.endswith(os.linesep):
# Make sure the message ends with a newline
target.write(os.linesep)
else:
raise TypeError('Invalid message type: %s' % type(message))
