forked from s_ranjbar/city_retrofit
372 lines
14 KiB
Python
372 lines
14 KiB
Python
import time
|
|
|
|
from .exceptions import EOF, TIMEOUT
|
|
|
|
class Expecter(object):
|
|
def __init__(self, spawn, searcher, searchwindowsize=-1):
|
|
self.spawn = spawn
|
|
self.searcher = searcher
|
|
# A value of -1 means to use the figure from spawn, which should
|
|
# be None or a positive number.
|
|
if searchwindowsize == -1:
|
|
searchwindowsize = spawn.searchwindowsize
|
|
self.searchwindowsize = searchwindowsize
|
|
self.lookback = None
|
|
if hasattr(searcher, 'longest_string'):
|
|
self.lookback = searcher.longest_string
|
|
|
|
def do_search(self, window, freshlen):
|
|
spawn = self.spawn
|
|
searcher = self.searcher
|
|
if freshlen > len(window):
|
|
freshlen = len(window)
|
|
index = searcher.search(window, freshlen, self.searchwindowsize)
|
|
if index >= 0:
|
|
spawn._buffer = spawn.buffer_type()
|
|
spawn._buffer.write(window[searcher.end:])
|
|
spawn.before = spawn._before.getvalue()[
|
|
0:-(len(window) - searcher.start)]
|
|
spawn._before = spawn.buffer_type()
|
|
spawn._before.write(window[searcher.end:])
|
|
spawn.after = window[searcher.start:searcher.end]
|
|
spawn.match = searcher.match
|
|
spawn.match_index = index
|
|
# Found a match
|
|
return index
|
|
elif self.searchwindowsize or self.lookback:
|
|
maintain = self.searchwindowsize or self.lookback
|
|
if spawn._buffer.tell() > maintain:
|
|
spawn._buffer = spawn.buffer_type()
|
|
spawn._buffer.write(window[-maintain:])
|
|
|
|
def existing_data(self):
|
|
# First call from a new call to expect_loop or expect_async.
|
|
# self.searchwindowsize may have changed.
|
|
# Treat all data as fresh.
|
|
spawn = self.spawn
|
|
before_len = spawn._before.tell()
|
|
buf_len = spawn._buffer.tell()
|
|
freshlen = before_len
|
|
if before_len > buf_len:
|
|
if not self.searchwindowsize:
|
|
spawn._buffer = spawn.buffer_type()
|
|
window = spawn._before.getvalue()
|
|
spawn._buffer.write(window)
|
|
elif buf_len < self.searchwindowsize:
|
|
spawn._buffer = spawn.buffer_type()
|
|
spawn._before.seek(
|
|
max(0, before_len - self.searchwindowsize))
|
|
window = spawn._before.read()
|
|
spawn._buffer.write(window)
|
|
else:
|
|
spawn._buffer.seek(max(0, buf_len - self.searchwindowsize))
|
|
window = spawn._buffer.read()
|
|
else:
|
|
if self.searchwindowsize:
|
|
spawn._buffer.seek(max(0, buf_len - self.searchwindowsize))
|
|
window = spawn._buffer.read()
|
|
else:
|
|
window = spawn._buffer.getvalue()
|
|
return self.do_search(window, freshlen)
|
|
|
|
def new_data(self, data):
|
|
# A subsequent call, after a call to existing_data.
|
|
spawn = self.spawn
|
|
freshlen = len(data)
|
|
spawn._before.write(data)
|
|
if not self.searchwindowsize:
|
|
if self.lookback:
|
|
# search lookback + new data.
|
|
old_len = spawn._buffer.tell()
|
|
spawn._buffer.write(data)
|
|
spawn._buffer.seek(max(0, old_len - self.lookback))
|
|
window = spawn._buffer.read()
|
|
else:
|
|
# copy the whole buffer (really slow for large datasets).
|
|
spawn._buffer.write(data)
|
|
window = spawn.buffer
|
|
else:
|
|
if len(data) >= self.searchwindowsize or not spawn._buffer.tell():
|
|
window = data[-self.searchwindowsize:]
|
|
spawn._buffer = spawn.buffer_type()
|
|
spawn._buffer.write(window[-self.searchwindowsize:])
|
|
else:
|
|
spawn._buffer.write(data)
|
|
new_len = spawn._buffer.tell()
|
|
spawn._buffer.seek(max(0, new_len - self.searchwindowsize))
|
|
window = spawn._buffer.read()
|
|
return self.do_search(window, freshlen)
|
|
|
|
def eof(self, err=None):
|
|
spawn = self.spawn
|
|
|
|
spawn.before = spawn._before.getvalue()
|
|
spawn._buffer = spawn.buffer_type()
|
|
spawn._before = spawn.buffer_type()
|
|
spawn.after = EOF
|
|
index = self.searcher.eof_index
|
|
if index >= 0:
|
|
spawn.match = EOF
|
|
spawn.match_index = index
|
|
return index
|
|
else:
|
|
spawn.match = None
|
|
spawn.match_index = None
|
|
msg = str(spawn)
|
|
msg += '\nsearcher: %s' % self.searcher
|
|
if err is not None:
|
|
msg = str(err) + '\n' + msg
|
|
|
|
exc = EOF(msg)
|
|
exc.__cause__ = None # in Python 3.x we can use "raise exc from None"
|
|
raise exc
|
|
|
|
def timeout(self, err=None):
|
|
spawn = self.spawn
|
|
|
|
spawn.before = spawn._before.getvalue()
|
|
spawn.after = TIMEOUT
|
|
index = self.searcher.timeout_index
|
|
if index >= 0:
|
|
spawn.match = TIMEOUT
|
|
spawn.match_index = index
|
|
return index
|
|
else:
|
|
spawn.match = None
|
|
spawn.match_index = None
|
|
msg = str(spawn)
|
|
msg += '\nsearcher: %s' % self.searcher
|
|
if err is not None:
|
|
msg = str(err) + '\n' + msg
|
|
|
|
exc = TIMEOUT(msg)
|
|
exc.__cause__ = None # in Python 3.x we can use "raise exc from None"
|
|
raise exc
|
|
|
|
def errored(self):
|
|
spawn = self.spawn
|
|
spawn.before = spawn._before.getvalue()
|
|
spawn.after = None
|
|
spawn.match = None
|
|
spawn.match_index = None
|
|
|
|
def expect_loop(self, timeout=-1):
|
|
"""Blocking expect"""
|
|
spawn = self.spawn
|
|
|
|
if timeout is not None:
|
|
end_time = time.time() + timeout
|
|
|
|
try:
|
|
idx = self.existing_data()
|
|
if idx is not None:
|
|
return idx
|
|
while True:
|
|
# No match at this point
|
|
if (timeout is not None) and (timeout < 0):
|
|
return self.timeout()
|
|
# Still have time left, so read more data
|
|
incoming = spawn.read_nonblocking(spawn.maxread, timeout)
|
|
if self.spawn.delayafterread is not None:
|
|
time.sleep(self.spawn.delayafterread)
|
|
idx = self.new_data(incoming)
|
|
# Keep reading until exception or return.
|
|
if idx is not None:
|
|
return idx
|
|
if timeout is not None:
|
|
timeout = end_time - time.time()
|
|
except EOF as e:
|
|
return self.eof(e)
|
|
except TIMEOUT as e:
|
|
return self.timeout(e)
|
|
except:
|
|
self.errored()
|
|
raise
|
|
|
|
|
|
class searcher_string(object):
|
|
'''This is a plain string search helper for the spawn.expect_any() method.
|
|
This helper class is for speed. For more powerful regex patterns
|
|
see the helper class, searcher_re.
|
|
|
|
Attributes:
|
|
|
|
eof_index - index of EOF, or -1
|
|
timeout_index - index of TIMEOUT, or -1
|
|
|
|
After a successful match by the search() method the following attributes
|
|
are available:
|
|
|
|
start - index into the buffer, first byte of match
|
|
end - index into the buffer, first byte after match
|
|
match - the matching string itself
|
|
|
|
'''
|
|
|
|
def __init__(self, strings):
|
|
'''This creates an instance of searcher_string. This argument 'strings'
|
|
may be a list; a sequence of strings; or the EOF or TIMEOUT types. '''
|
|
|
|
self.eof_index = -1
|
|
self.timeout_index = -1
|
|
self._strings = []
|
|
self.longest_string = 0
|
|
for n, s in enumerate(strings):
|
|
if s is EOF:
|
|
self.eof_index = n
|
|
continue
|
|
if s is TIMEOUT:
|
|
self.timeout_index = n
|
|
continue
|
|
self._strings.append((n, s))
|
|
if len(s) > self.longest_string:
|
|
self.longest_string = len(s)
|
|
|
|
def __str__(self):
|
|
'''This returns a human-readable string that represents the state of
|
|
the object.'''
|
|
|
|
ss = [(ns[0], ' %d: %r' % ns) for ns in self._strings]
|
|
ss.append((-1, 'searcher_string:'))
|
|
if self.eof_index >= 0:
|
|
ss.append((self.eof_index, ' %d: EOF' % self.eof_index))
|
|
if self.timeout_index >= 0:
|
|
ss.append((self.timeout_index,
|
|
' %d: TIMEOUT' % self.timeout_index))
|
|
ss.sort()
|
|
ss = list(zip(*ss))[1]
|
|
return '\n'.join(ss)
|
|
|
|
def search(self, buffer, freshlen, searchwindowsize=None):
|
|
'''This searches 'buffer' for the first occurrence of one of the search
|
|
strings. 'freshlen' must indicate the number of bytes at the end of
|
|
'buffer' which have not been searched before. It helps to avoid
|
|
searching the same, possibly big, buffer over and over again.
|
|
|
|
See class spawn for the 'searchwindowsize' argument.
|
|
|
|
If there is a match this returns the index of that string, and sets
|
|
'start', 'end' and 'match'. Otherwise, this returns -1. '''
|
|
|
|
first_match = None
|
|
|
|
# 'freshlen' helps a lot here. Further optimizations could
|
|
# possibly include:
|
|
#
|
|
# using something like the Boyer-Moore Fast String Searching
|
|
# Algorithm; pre-compiling the search through a list of
|
|
# strings into something that can scan the input once to
|
|
# search for all N strings; realize that if we search for
|
|
# ['bar', 'baz'] and the input is '...foo' we need not bother
|
|
# rescanning until we've read three more bytes.
|
|
#
|
|
# Sadly, I don't know enough about this interesting topic. /grahn
|
|
|
|
for index, s in self._strings:
|
|
if searchwindowsize is None:
|
|
# the match, if any, can only be in the fresh data,
|
|
# or at the very end of the old data
|
|
offset = -(freshlen + len(s))
|
|
else:
|
|
# better obey searchwindowsize
|
|
offset = -searchwindowsize
|
|
n = buffer.find(s, offset)
|
|
if n >= 0 and (first_match is None or n < first_match):
|
|
first_match = n
|
|
best_index, best_match = index, s
|
|
if first_match is None:
|
|
return -1
|
|
self.match = best_match
|
|
self.start = first_match
|
|
self.end = self.start + len(self.match)
|
|
return best_index
|
|
|
|
|
|
class searcher_re(object):
|
|
'''This is regular expression string search helper for the
|
|
spawn.expect_any() method. This helper class is for powerful
|
|
pattern matching. For speed, see the helper class, searcher_string.
|
|
|
|
Attributes:
|
|
|
|
eof_index - index of EOF, or -1
|
|
timeout_index - index of TIMEOUT, or -1
|
|
|
|
After a successful match by the search() method the following attributes
|
|
are available:
|
|
|
|
start - index into the buffer, first byte of match
|
|
end - index into the buffer, first byte after match
|
|
match - the re.match object returned by a successful re.search
|
|
|
|
'''
|
|
|
|
def __init__(self, patterns):
|
|
'''This creates an instance that searches for 'patterns' Where
|
|
'patterns' may be a list or other sequence of compiled regular
|
|
expressions, or the EOF or TIMEOUT types.'''
|
|
|
|
self.eof_index = -1
|
|
self.timeout_index = -1
|
|
self._searches = []
|
|
for n, s in enumerate(patterns):
|
|
if s is EOF:
|
|
self.eof_index = n
|
|
continue
|
|
if s is TIMEOUT:
|
|
self.timeout_index = n
|
|
continue
|
|
self._searches.append((n, s))
|
|
|
|
def __str__(self):
|
|
'''This returns a human-readable string that represents the state of
|
|
the object.'''
|
|
|
|
#ss = [(n, ' %d: re.compile("%s")' %
|
|
# (n, repr(s.pattern))) for n, s in self._searches]
|
|
ss = list()
|
|
for n, s in self._searches:
|
|
ss.append((n, ' %d: re.compile(%r)' % (n, s.pattern)))
|
|
ss.append((-1, 'searcher_re:'))
|
|
if self.eof_index >= 0:
|
|
ss.append((self.eof_index, ' %d: EOF' % self.eof_index))
|
|
if self.timeout_index >= 0:
|
|
ss.append((self.timeout_index, ' %d: TIMEOUT' %
|
|
self.timeout_index))
|
|
ss.sort()
|
|
ss = list(zip(*ss))[1]
|
|
return '\n'.join(ss)
|
|
|
|
def search(self, buffer, freshlen, searchwindowsize=None):
|
|
'''This searches 'buffer' for the first occurrence of one of the regular
|
|
expressions. 'freshlen' must indicate the number of bytes at the end of
|
|
'buffer' which have not been searched before.
|
|
|
|
See class spawn for the 'searchwindowsize' argument.
|
|
|
|
If there is a match this returns the index of that string, and sets
|
|
'start', 'end' and 'match'. Otherwise, returns -1.'''
|
|
|
|
first_match = None
|
|
# 'freshlen' doesn't help here -- we cannot predict the
|
|
# length of a match, and the re module provides no help.
|
|
if searchwindowsize is None:
|
|
searchstart = 0
|
|
else:
|
|
searchstart = max(0, len(buffer) - searchwindowsize)
|
|
for index, s in self._searches:
|
|
match = s.search(buffer, searchstart)
|
|
if match is None:
|
|
continue
|
|
n = match.start()
|
|
if first_match is None or n < first_match:
|
|
first_match = n
|
|
the_match = match
|
|
best_index = index
|
|
if first_match is None:
|
|
return -1
|
|
self.start = first_match
|
|
self.match = the_match
|
|
self.end = self.match.end()
|
|
return best_index
|