def read_header_value(event_name):
"""
Read and emit characters of a (possibly multi-line) header value.
Note that the header is not "demangled" in any way, only the newlines are
removed.
"""
auto = Automaton()
start = auto.start()
start.set_name(event_name)
start.mark_enter()
line, end = newline()
auto.join(start, line)
start.loop_fallback()
continuation = auto.add_state()
continuation.loop("HorizWhitespace", LabelType.Special)
continuation.add_fallback(start)
end.add_transition("HorizWhitespace", LabelType.Special, continuation)
return auto, end, False
def read_boundary():
"""
Read a boundary=value from a header.
This is meant for content type header (we ignore the actual content type)
"""
# States:
# * We linger in read_until_colon first, then transition to waiting_word.
# * The waiting_word is responsible to find the 'boundary=' word
# * Then in_boundary accumulates the actual boundary
# If we leave it, it means it is somehow unknown and we loop back to
# waiting for another colon.
#
# And then to complicate things, there might be a newline that either means
# end of the header or it may be a header continuation. In the latter case,
# we need to distinguish the state of somewhere before or after colon.
auto = Automaton()
line, end = newline()
read_until_colon = auto.start()
waiting_word = auto.add_state()
# Target od waiting_word's path
equals = auto.add_state()
in_boundary = auto.add_state("Boundary")
equals.add_fallback(in_boundary)
in_boundary.mark_enter()
# Including newlines, yes - they'll be handled later.
in_boundary.add_transition("Whitespace",
LabelType.Special,
read_until_colon,
fallthrough=True)
in_boundary.add_transition(';',
LabelType.Char,
read_until_colon,
fallthrough=True)
in_boundary.loop_fallback()
waiting_word.set_path("boundary=", True)
waiting_word.loop("HorizWhitespace", LabelType.Special)
waiting_line, waiting_end = newline()
auto.join(waiting_word, waiting_line)
waiting_continuation = auto.add_state()
waiting_continuation.loop("HorizWhitespace", LabelType.Special)
waiting_continuation.add_fallback(waiting_word, fallthrough=True)
waiting_word.add_fallback(read_until_colon, fallthrough=True)
waiting_end.add_transition("HorizWhitespace", LabelType.Special,
waiting_continuation)
waiting_end.add_fallback(end, fallthrough=True)
read_until_colon.add_transition(';', LabelType.Char, waiting_word)
auto.join(read_until_colon, line)
continuation = auto.add_state()
continuation.loop("HorizWhitespace", LabelType.Special)
continuation.add_fallback(read_until_colon, fallthrough=True)
end.add_transition("HorizWhitespace", LabelType.Special, continuation)
read_until_colon.loop_fallback()
return auto, end, False