from fontTools.misc.textTools import bytechr, byteord, bytesjoin, tobytes, tostr
from fontTools.misc import eexec
from .psOperators import (
PSOperators,
ps_StandardEncoding,
ps_array,
ps_boolean,
ps_dict,
ps_integer,
ps_literal,
ps_mark,
ps_name,
ps_operator,
ps_procedure,
ps_procmark,
ps_real,
ps_string,
)
import re
from collections.abc import Callable
from string import whitespace
import logging
log = logging.getLogger(__name__)
ps_special = b"()<>[]{}%" # / is one too, but we take care of that one differently
skipwhiteRE = re.compile(bytesjoin([b"[", whitespace, b"]*"]))
endofthingPat = bytesjoin([b"[^][(){}<>/%", whitespace, b"]*"])
endofthingRE = re.compile(endofthingPat)
commentRE = re.compile(b"%[^\n\r]*")
# XXX This not entirely correct as it doesn't allow *nested* embedded parens:
stringPat = rb"""
\(
(
(
[^()]* \ [()]
)
|
(
[^()]* \( [^()]* \)
)
)*
[^()]*
\)
"""
stringPat = b"".join(stringPat.split())
stringRE = re.compile(stringPat)
hexstringRE = re.compile(bytesjoin([b"<[", whitespace, b"0-9A-Fa-f]*>"]))
[docs]
class PSTokenError(Exception):
pass
[docs]
class PSError(Exception):
pass
[docs]
class PSTokenizer(object):
def __init__(self, buf=b"", encoding="ascii"):
# Force self.buf to be a byte string
buf = tobytes(buf)
self.buf = buf
self.len = len(buf)
self.pos = 0
self.closed = False
self.encoding = encoding
[docs]
def read(self, n=-1):
"""Read at most 'n' bytes from the buffer, or less if the read
hits EOF before obtaining 'n' bytes.
If 'n' is negative or omitted, read all data until EOF is reached.
"""
if self.closed:
raise ValueError("I/O operation on closed file")
if n is None or n < 0:
newpos = self.len
else:
newpos = min(self.pos + n, self.len)
r = self.buf[self.pos : newpos]
self.pos = newpos
return r
[docs]
def close(self):
if not self.closed:
self.closed = True
del self.buf, self.pos
[docs]
def getnexttoken(
self,
# localize some stuff, for performance
len=len,
ps_special=ps_special,
stringmatch=stringRE.match,
hexstringmatch=hexstringRE.match,
commentmatch=commentRE.match,
endmatch=endofthingRE.match,
):
self.skipwhite()
if self.pos >= self.len:
return None, None
pos = self.pos
buf = self.buf
char = bytechr(byteord(buf[pos]))
if char in ps_special:
if char in b"{}[]":
tokentype = "do_special"
token = char
elif char == b"%":
tokentype = "do_comment"
_, nextpos = commentmatch(buf, pos).span()
token = buf[pos:nextpos]
elif char == b"(":
tokentype = "do_string"
m = stringmatch(buf, pos)
if m is None:
raise PSTokenError("bad string at character %d" % pos)
_, nextpos = m.span()
token = buf[pos:nextpos]
elif char == b"<":
tokentype = "do_hexstring"
m = hexstringmatch(buf, pos)
if m is None:
raise PSTokenError("bad hexstring at character %d" % pos)
_, nextpos = m.span()
token = buf[pos:nextpos]
else:
raise PSTokenError("bad token at character %d" % pos)
else:
if char == b"/":
tokentype = "do_literal"
m = endmatch(buf, pos + 1)
else:
tokentype = ""
m = endmatch(buf, pos)
if m is None:
raise PSTokenError("bad token at character %d" % pos)
_, nextpos = m.span()
token = buf[pos:nextpos]
self.pos = pos + len(token)
token = tostr(token, encoding=self.encoding)
return tokentype, token
[docs]
def skipwhite(self, whitematch=skipwhiteRE.match):
_, nextpos = whitematch(self.buf, self.pos).span()
self.pos = nextpos
[docs]
def starteexec(self):
self.pos = self.pos + 1
self.dirtybuf = self.buf[self.pos :]
self.buf, R = eexec.decrypt(self.dirtybuf, 55665)
self.len = len(self.buf)
self.pos = 4
[docs]
def stopeexec(self):
if not hasattr(self, "dirtybuf"):
return
self.buf = self.dirtybuf
del self.dirtybuf
[docs]
class PSInterpreter(PSOperators):
def __init__(self, encoding="ascii"):
systemdict = {}
userdict = {}
self.encoding = encoding
self.dictstack = [systemdict, userdict]
self.stack = []
self.proclevel = 0
self.procmark = ps_procmark()
self.fillsystemdict()
[docs]
def fillsystemdict(self):
systemdict = self.dictstack[0]
systemdict["["] = systemdict["mark"] = self.mark = ps_mark()
systemdict["]"] = ps_operator("]", self.do_makearray)
systemdict["true"] = ps_boolean(1)
systemdict["false"] = ps_boolean(0)
systemdict["StandardEncoding"] = ps_array(ps_StandardEncoding)
systemdict["FontDirectory"] = ps_dict({})
self.suckoperators(systemdict, self.__class__)
[docs]
def suckoperators(self, systemdict, klass):
for name in dir(klass):
attr = getattr(self, name)
if isinstance(attr, Callable) and name[:3] == "ps_":
name = name[3:]
systemdict[name] = ps_operator(name, attr)
for baseclass in klass.__bases__:
self.suckoperators(systemdict, baseclass)
[docs]
def interpret(self, data, getattr=getattr):
tokenizer = self.tokenizer = PSTokenizer(data, self.encoding)
getnexttoken = tokenizer.getnexttoken
do_token = self.do_token
handle_object = self.handle_object
try:
while 1:
tokentype, token = getnexttoken()
if not token:
break
if tokentype:
handler = getattr(self, tokentype)
object = handler(token)
else:
object = do_token(token)
if object is not None:
handle_object(object)
tokenizer.close()
self.tokenizer = None
except:
if self.tokenizer is not None:
log.debug(
"ps error:\n"
"- - - - - - -\n"
"%s\n"
">>>\n"
"%s\n"
"- - - - - - -",
self.tokenizer.buf[self.tokenizer.pos - 50 : self.tokenizer.pos],
self.tokenizer.buf[self.tokenizer.pos : self.tokenizer.pos + 50],
)
raise
[docs]
def handle_object(self, object):
if not (self.proclevel or object.literal or object.type == "proceduretype"):
if object.type != "operatortype":
object = self.resolve_name(object.value)
if object.literal:
self.push(object)
else:
if object.type == "proceduretype":
self.call_procedure(object)
else:
object.function()
else:
self.push(object)
[docs]
def call_procedure(self, proc):
handle_object = self.handle_object
for item in proc.value:
handle_object(item)
[docs]
def resolve_name(self, name):
dictstack = self.dictstack
for i in range(len(dictstack) - 1, -1, -1):
if name in dictstack[i]:
return dictstack[i][name]
raise PSError("name error: " + str(name))
[docs]
def do_token(
self,
token,
int=int,
float=float,
ps_name=ps_name,
ps_integer=ps_integer,
ps_real=ps_real,
):
try:
num = int(token)
except (ValueError, OverflowError):
try:
num = float(token)
except (ValueError, OverflowError):
if "#" in token:
hashpos = token.find("#")
try:
base = int(token[:hashpos])
num = int(token[hashpos + 1 :], base)
except (ValueError, OverflowError):
return ps_name(token)
else:
return ps_integer(num)
else:
return ps_name(token)
else:
return ps_real(num)
else:
return ps_integer(num)
[docs]
def do_literal(self, token):
return ps_literal(token[1:])
[docs]
def do_string(self, token):
return ps_string(token[1:-1])
[docs]
def do_hexstring(self, token):
hexStr = "".join(token[1:-1].split())
if len(hexStr) % 2:
hexStr = hexStr + "0"
cleanstr = []
for i in range(0, len(hexStr), 2):
cleanstr.append(chr(int(hexStr[i : i + 2], 16)))
cleanstr = "".join(cleanstr)
return ps_string(cleanstr)
[docs]
def do_special(self, token):
if token == "{":
self.proclevel = self.proclevel + 1
return self.procmark
elif token == "}":
proc = []
while 1:
topobject = self.pop()
if topobject == self.procmark:
break
proc.append(topobject)
self.proclevel = self.proclevel - 1
proc.reverse()
return ps_procedure(proc)
elif token == "[":
return self.mark
elif token == "]":
return ps_name("]")
else:
raise PSTokenError("huh?")
[docs]
def push(self, object):
self.stack.append(object)
[docs]
def pop(self, *types):
stack = self.stack
if not stack:
raise PSError("stack underflow")
object = stack[-1]
if types:
if object.type not in types:
raise PSError(
"typecheck, expected %s, found %s" % (repr(types), object.type)
)
del stack[-1]
return object
[docs]
def do_makearray(self):
array = []
while 1:
topobject = self.pop()
if topobject == self.mark:
break
array.append(topobject)
array.reverse()
self.push(ps_array(array))
[docs]
def close(self):
"""Remove circular references."""
del self.stack
del self.dictstack
[docs]
def unpack_item(item):
tp = type(item.value)
if tp == dict:
newitem = {}
for key, value in item.value.items():
newitem[key] = unpack_item(value)
elif tp == list:
newitem = [None] * len(item.value)
for i in range(len(item.value)):
newitem[i] = unpack_item(item.value[i])
if item.type == "proceduretype":
newitem = tuple(newitem)
else:
newitem = item.value
return newitem
[docs]
def suckfont(data, encoding="ascii"):
m = re.search(rb"/FontName\s+/([^ \t\n\r]+)\s+def", data)
if m:
fontName = m.group(1)
fontName = fontName.decode()
else:
fontName = None
interpreter = PSInterpreter(encoding=encoding)
interpreter.interpret(
b"/Helvetica 4 dict dup /Encoding StandardEncoding put definefont pop"
)
interpreter.interpret(data)
fontdir = interpreter.dictstack[0]["FontDirectory"].value
if fontName in fontdir:
rawfont = fontdir[fontName]
else:
# fall back, in case fontName wasn't found
fontNames = list(fontdir.keys())
if len(fontNames) > 1:
fontNames.remove("Helvetica")
fontNames.sort()
rawfont = fontdir[fontNames[0]]
interpreter.close()
return unpack_item(rawfont)