Add third_party/pexpect

third_party/pexpect/pexpect/expect.py

Index: third_party/pexpect/pexpect/expect.py
diff --git a/third_party/pexpect/pexpect/expect.py b/third_party/pexpect/pexpect/expect.py
new file mode 100644
index 0000000000000000000000000000000000000000..6fde9e8241db3ad3d3f1858cb3604422a3fdf862
--- /dev/null
+++ b/third_party/pexpect/pexpect/expect.py
@@ -0,0 +1,297 @@
+import time
+
+from .exceptions import EOF, TIMEOUT
+
+class Expecter(object):
+    def __init__(self, spawn, searcher, searchwindowsize=-1):
+        self.spawn = spawn
+        self.searcher = searcher
+        if searchwindowsize == -1:
+            searchwindowsize = spawn.searchwindowsize
+        self.searchwindowsize = searchwindowsize
+    
+    def new_data(self, data):
+        spawn = self.spawn
+        searcher = self.searcher
+
+        incoming = spawn.buffer + data
+        freshlen = len(data)
+        index = searcher.search(incoming, freshlen, self.searchwindowsize)
+        if index >= 0:
+            spawn.buffer = incoming[searcher.end:]
+            spawn.before = incoming[: searcher.start]
+            spawn.after = incoming[searcher.start: searcher.end]
+            spawn.match = searcher.match
+            spawn.match_index = index
+            # Found a match
+            return index
+    
+        spawn.buffer = incoming
+    
+    def eof(self, err=None):
+        spawn = self.spawn
+        from . import EOF
+
+        spawn.before = spawn.buffer
+        spawn.buffer = spawn.string_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)
+            if err is not None:
+                msg = str(err) + '\n' + msg
+            raise EOF(msg)
+    
+    def timeout(self, err=None):
+        spawn = self.spawn
+        from . import TIMEOUT
+
+        spawn.before = spawn.buffer
+        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)
+            if err is not None:
+                msg = str(err) + '\n' + msg
+            raise TIMEOUT(msg)
+
+    def errored(self):
+        spawn = self.spawn
+        spawn.before = spawn.buffer
+        spawn.after = None
+        spawn.match = None
+        spawn.match_index = None
+    
+    def expect_loop(self, timeout=-1):
+        """Blocking expect"""
+        spawn = self.spawn
+        from . import EOF, TIMEOUT
+
+        if timeout is not None:
+            end_time = time.time() + timeout
+
+        try:
+            incoming = spawn.buffer
+            spawn.buffer = spawn.string_type()  # Treat buffer as new data
+            while True:
+                idx = self.new_data(incoming)
+                # Keep reading until exception or return.
+                if idx is not None:
+                    return idx
+                # 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)
+                time.sleep(0.0001)
+                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 = []
+        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))
+
+    def __str__(self):
+        '''This returns a human-readable string that represents the state of
+        the object.'''
+
+        ss = [(ns[0], '    %d: "%s"' % 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 occurence 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 succesful 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 zip(list(range(len(patterns))), 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:
+            try:
+                ss.append((n, '    %d: re.compile("%s")' % (n, s.pattern)))
+            except UnicodeEncodeError:
+                # for test cases that display __str__ of searches, dont throw
+                # another exception just because stdout is ascii-only, using
+                # repr()
+                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 occurence 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