501 lines
16 KiB
Python
501 lines
16 KiB
Python
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""" Adobe character mapping (CMap) support.
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CMaps provide the mapping between character codes and Unicode
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code-points to character ids (CIDs).
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More information is available on the Adobe website:
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http://opensource.adobe.com/wiki/display/cmap/CMap+Resources
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"""
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import gzip
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import logging
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import os
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import os.path
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import pickle as pickle
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import struct
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import sys
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from typing import (
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Any,
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BinaryIO,
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Dict,
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Iterable,
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Iterator,
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List,
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MutableMapping,
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Optional,
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TextIO,
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Tuple,
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Union,
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cast,
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Set,
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)
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from .encodingdb import name2unicode
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from .psparser import KWD
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from .psparser import PSEOF
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from .psparser import PSKeyword
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from .psparser import PSLiteral
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from .psparser import PSStackParser
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from .psparser import PSSyntaxError
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from .psparser import literal_name
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from .utils import choplist
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from .utils import nunpack
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log = logging.getLogger(__name__)
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class CMapError(Exception):
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pass
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class CMapBase:
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debug = 0
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def __init__(self, **kwargs: object) -> None:
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self.attrs: MutableMapping[str, object] = kwargs.copy()
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def is_vertical(self) -> bool:
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return self.attrs.get("WMode", 0) != 0
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def set_attr(self, k: str, v: object) -> None:
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self.attrs[k] = v
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def add_code2cid(self, code: str, cid: int) -> None:
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pass
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def add_cid2unichr(self, cid: int, code: Union[PSLiteral, bytes, int]) -> None:
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pass
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def use_cmap(self, cmap: "CMapBase") -> None:
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pass
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def decode(self, code: bytes) -> Iterable[int]:
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raise NotImplementedError
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class CMap(CMapBase):
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def __init__(self, **kwargs: Union[str, int]) -> None:
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CMapBase.__init__(self, **kwargs)
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self.code2cid: Dict[int, object] = {}
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def __repr__(self) -> str:
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return "<CMap: %s>" % self.attrs.get("CMapName")
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def use_cmap(self, cmap: CMapBase) -> None:
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assert isinstance(cmap, CMap), str(type(cmap))
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def copy(dst: Dict[int, object], src: Dict[int, object]) -> None:
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for (k, v) in src.items():
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if isinstance(v, dict):
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d: Dict[int, object] = {}
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dst[k] = d
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copy(d, v)
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else:
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dst[k] = v
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copy(self.code2cid, cmap.code2cid)
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def decode(self, code: bytes) -> Iterator[int]:
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log.debug("decode: %r, %r", self, code)
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d = self.code2cid
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for i in iter(code):
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if i in d:
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x = d[i]
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if isinstance(x, int):
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yield x
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d = self.code2cid
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else:
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d = cast(Dict[int, object], x)
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else:
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d = self.code2cid
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def dump(
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self,
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out: TextIO = sys.stdout,
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code2cid: Optional[Dict[int, object]] = None,
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code: Tuple[int, ...] = (),
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) -> None:
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if code2cid is None:
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code2cid = self.code2cid
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code = ()
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for (k, v) in sorted(code2cid.items()):
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c = code + (k,)
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if isinstance(v, int):
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out.write("code %r = cid %d\n" % (c, v))
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else:
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self.dump(out=out, code2cid=cast(Dict[int, object], v), code=c)
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class IdentityCMap(CMapBase):
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def decode(self, code: bytes) -> Tuple[int, ...]:
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n = len(code) // 2
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if n:
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return struct.unpack(">%dH" % n, code)
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else:
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return ()
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class IdentityCMapByte(IdentityCMap):
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def decode(self, code: bytes) -> Tuple[int, ...]:
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n = len(code)
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if n:
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return struct.unpack(">%dB" % n, code)
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else:
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return ()
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class UnicodeMap(CMapBase):
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def __init__(self, **kwargs: Union[str, int]) -> None:
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CMapBase.__init__(self, **kwargs)
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self.cid2unichr: Dict[int, str] = {}
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def __repr__(self) -> str:
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return "<UnicodeMap: %s>" % self.attrs.get("CMapName")
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def get_unichr(self, cid: int) -> str:
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log.debug("get_unichr: %r, %r", self, cid)
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return self.cid2unichr[cid]
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def dump(self, out: TextIO = sys.stdout) -> None:
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for (k, v) in sorted(self.cid2unichr.items()):
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out.write("cid %d = unicode %r\n" % (k, v))
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class IdentityUnicodeMap(UnicodeMap):
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def get_unichr(self, cid: int) -> str:
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"""Interpret character id as unicode codepoint"""
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log.debug("get_unichr: %r, %r", self, cid)
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return chr(cid)
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class FileCMap(CMap):
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def add_code2cid(self, code: str, cid: int) -> None:
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assert isinstance(code, str) and isinstance(cid, int), str(
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(type(code), type(cid))
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)
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d = self.code2cid
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for c in code[:-1]:
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ci = ord(c)
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if ci in d:
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d = cast(Dict[int, object], d[ci])
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else:
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t: Dict[int, object] = {}
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d[ci] = t
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d = t
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ci = ord(code[-1])
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d[ci] = cid
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class FileUnicodeMap(UnicodeMap):
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def add_cid2unichr(self, cid: int, code: Union[PSLiteral, bytes, int]) -> None:
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assert isinstance(cid, int), str(type(cid))
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if isinstance(code, PSLiteral):
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# Interpret as an Adobe glyph name.
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assert isinstance(code.name, str)
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self.cid2unichr[cid] = name2unicode(code.name)
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elif isinstance(code, bytes):
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# Interpret as UTF-16BE.
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self.cid2unichr[cid] = code.decode("UTF-16BE", "ignore")
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elif isinstance(code, int):
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self.cid2unichr[cid] = chr(code)
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else:
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raise TypeError(code)
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class PyCMap(CMap):
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def __init__(self, name: str, module: Any) -> None:
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super().__init__(CMapName=name)
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self.code2cid = module.CODE2CID
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if module.IS_VERTICAL:
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self.attrs["WMode"] = 1
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class PyUnicodeMap(UnicodeMap):
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def __init__(self, name: str, module: Any, vertical: bool) -> None:
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super().__init__(CMapName=name)
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if vertical:
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self.cid2unichr = module.CID2UNICHR_V
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self.attrs["WMode"] = 1
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else:
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self.cid2unichr = module.CID2UNICHR_H
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class CMapDB:
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_cmap_cache: Dict[str, PyCMap] = {}
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_umap_cache: Dict[str, List[PyUnicodeMap]] = {}
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class CMapNotFound(CMapError):
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pass
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@classmethod
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def _load_data(cls, name: str) -> Any:
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name = name.replace("\0", "")
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filename = "%s.pickle.gz" % name
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log.debug("loading: %r", name)
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cmap_paths = (
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os.environ.get("CMAP_PATH", "/usr/share/pdfminer/"),
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os.path.join(os.path.dirname(__file__), "cmap"),
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)
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for directory in cmap_paths:
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path = os.path.join(directory, filename)
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if os.path.exists(path):
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gzfile = gzip.open(path)
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try:
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return type(str(name), (), pickle.loads(gzfile.read()))
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finally:
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gzfile.close()
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else:
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raise CMapDB.CMapNotFound(name)
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@classmethod
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def get_cmap(cls, name: str) -> CMapBase:
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if name == "Identity-H":
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return IdentityCMap(WMode=0)
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elif name == "Identity-V":
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return IdentityCMap(WMode=1)
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elif name == "OneByteIdentityH":
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return IdentityCMapByte(WMode=0)
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elif name == "OneByteIdentityV":
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return IdentityCMapByte(WMode=1)
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try:
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return cls._cmap_cache[name]
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except KeyError:
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pass
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data = cls._load_data(name)
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cls._cmap_cache[name] = cmap = PyCMap(name, data)
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return cmap
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@classmethod
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def get_unicode_map(cls, name: str, vertical: bool = False) -> UnicodeMap:
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try:
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return cls._umap_cache[name][vertical]
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except KeyError:
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pass
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data = cls._load_data("to-unicode-%s" % name)
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cls._umap_cache[name] = [PyUnicodeMap(name, data, v) for v in (False, True)]
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return cls._umap_cache[name][vertical]
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class CMapParser(PSStackParser[PSKeyword]):
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def __init__(self, cmap: CMapBase, fp: BinaryIO) -> None:
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PSStackParser.__init__(self, fp)
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self.cmap = cmap
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# some ToUnicode maps don't have "begincmap" keyword.
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self._in_cmap = True
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self._warnings: Set[str] = set()
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return
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def run(self) -> None:
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try:
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self.nextobject()
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except PSEOF:
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pass
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return
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KEYWORD_BEGINCMAP = KWD(b"begincmap")
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KEYWORD_ENDCMAP = KWD(b"endcmap")
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KEYWORD_USECMAP = KWD(b"usecmap")
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KEYWORD_DEF = KWD(b"def")
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KEYWORD_BEGINCODESPACERANGE = KWD(b"begincodespacerange")
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KEYWORD_ENDCODESPACERANGE = KWD(b"endcodespacerange")
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KEYWORD_BEGINCIDRANGE = KWD(b"begincidrange")
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KEYWORD_ENDCIDRANGE = KWD(b"endcidrange")
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KEYWORD_BEGINCIDCHAR = KWD(b"begincidchar")
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KEYWORD_ENDCIDCHAR = KWD(b"endcidchar")
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KEYWORD_BEGINBFRANGE = KWD(b"beginbfrange")
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KEYWORD_ENDBFRANGE = KWD(b"endbfrange")
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KEYWORD_BEGINBFCHAR = KWD(b"beginbfchar")
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KEYWORD_ENDBFCHAR = KWD(b"endbfchar")
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KEYWORD_BEGINNOTDEFRANGE = KWD(b"beginnotdefrange")
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KEYWORD_ENDNOTDEFRANGE = KWD(b"endnotdefrange")
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def do_keyword(self, pos: int, token: PSKeyword) -> None:
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"""ToUnicode CMaps
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See Section 5.9.2 - ToUnicode CMaps of the PDF Reference.
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"""
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if token is self.KEYWORD_BEGINCMAP:
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self._in_cmap = True
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self.popall()
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return
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elif token is self.KEYWORD_ENDCMAP:
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self._in_cmap = False
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return
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if not self._in_cmap:
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return
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if token is self.KEYWORD_DEF:
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try:
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((_, k), (_, v)) = self.pop(2)
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self.cmap.set_attr(literal_name(k), v)
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except PSSyntaxError:
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pass
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return
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if token is self.KEYWORD_USECMAP:
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try:
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((_, cmapname),) = self.pop(1)
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self.cmap.use_cmap(CMapDB.get_cmap(literal_name(cmapname)))
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except PSSyntaxError:
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pass
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except CMapDB.CMapNotFound:
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pass
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return
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if token is self.KEYWORD_BEGINCODESPACERANGE:
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self.popall()
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return
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if token is self.KEYWORD_ENDCODESPACERANGE:
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self.popall()
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return
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if token is self.KEYWORD_BEGINCIDRANGE:
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self.popall()
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return
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if token is self.KEYWORD_ENDCIDRANGE:
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objs = [obj for (__, obj) in self.popall()]
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for (start_byte, end_byte, cid) in choplist(3, objs):
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if not isinstance(start_byte, bytes):
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self._warn_once("The start object of begincidrange is not a byte.")
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continue
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if not isinstance(end_byte, bytes):
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self._warn_once("The end object of begincidrange is not a byte.")
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continue
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if not isinstance(cid, int):
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self._warn_once("The cid object of begincidrange is not a byte.")
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continue
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if len(start_byte) != len(end_byte):
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self._warn_once(
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"The start and end byte of begincidrange have "
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"different lengths."
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)
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continue
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start_prefix = start_byte[:-4]
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end_prefix = end_byte[:-4]
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if start_prefix != end_prefix:
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self._warn_once(
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"The prefix of the start and end byte of "
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"begincidrange are not the same."
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)
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continue
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svar = start_byte[-4:]
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evar = end_byte[-4:]
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start = nunpack(svar)
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end = nunpack(evar)
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vlen = len(svar)
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for i in range(end - start + 1):
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x = start_prefix + struct.pack(">L", start + i)[-vlen:]
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self.cmap.add_cid2unichr(cid + i, x)
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return
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if token is self.KEYWORD_BEGINCIDCHAR:
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self.popall()
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return
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if token is self.KEYWORD_ENDCIDCHAR:
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objs = [obj for (__, obj) in self.popall()]
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for (cid, code) in choplist(2, objs):
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if isinstance(code, bytes) and isinstance(cid, int):
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self.cmap.add_cid2unichr(cid, code)
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return
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if token is self.KEYWORD_BEGINBFRANGE:
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self.popall()
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return
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if token is self.KEYWORD_ENDBFRANGE:
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objs = [obj for (__, obj) in self.popall()]
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for (start_byte, end_byte, code) in choplist(3, objs):
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if not isinstance(start_byte, bytes):
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self._warn_once("The start object is not a byte.")
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continue
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if not isinstance(end_byte, bytes):
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self._warn_once("The end object is not a byte.")
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continue
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if len(start_byte) != len(end_byte):
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self._warn_once("The start and end byte have different lengths.")
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continue
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start = nunpack(start_byte)
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end = nunpack(end_byte)
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if isinstance(code, list):
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if len(code) != end - start + 1:
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self._warn_once(
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"The difference between the start and end "
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"offsets does not match the code length."
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)
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for cid, unicode_value in zip(range(start, end + 1), code):
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|
self.cmap.add_cid2unichr(cid, unicode_value)
|
||
|
else:
|
||
|
assert isinstance(code, bytes)
|
||
|
var = code[-4:]
|
||
|
base = nunpack(var)
|
||
|
prefix = code[:-4]
|
||
|
vlen = len(var)
|
||
|
for i in range(end - start + 1):
|
||
|
x = prefix + struct.pack(">L", base + i)[-vlen:]
|
||
|
self.cmap.add_cid2unichr(start + i, x)
|
||
|
return
|
||
|
|
||
|
if token is self.KEYWORD_BEGINBFCHAR:
|
||
|
self.popall()
|
||
|
return
|
||
|
|
||
|
if token is self.KEYWORD_ENDBFCHAR:
|
||
|
objs = [obj for (__, obj) in self.popall()]
|
||
|
for (cid, code) in choplist(2, objs):
|
||
|
if isinstance(cid, bytes) and isinstance(code, bytes):
|
||
|
self.cmap.add_cid2unichr(nunpack(cid), code)
|
||
|
return
|
||
|
|
||
|
if token is self.KEYWORD_BEGINNOTDEFRANGE:
|
||
|
self.popall()
|
||
|
return
|
||
|
|
||
|
if token is self.KEYWORD_ENDNOTDEFRANGE:
|
||
|
self.popall()
|
||
|
return
|
||
|
|
||
|
self.push((pos, token))
|
||
|
|
||
|
def _warn_once(self, msg: str) -> None:
|
||
|
"""Warn once for each unique message"""
|
||
|
if msg not in self._warnings:
|
||
|
self._warnings.add(msg)
|
||
|
base_msg = (
|
||
|
"Ignoring (part of) ToUnicode map because the PDF data "
|
||
|
"does not conform to the format. This could result in "
|
||
|
"(cid) values in the output. "
|
||
|
)
|
||
|
log.warning(base_msg + msg)
|
||
|
|
||
|
|
||
|
def main(argv: List[str]) -> None:
|
||
|
from warnings import warn
|
||
|
|
||
|
warn(
|
||
|
"The function main() from cmapdb.py will be removed in 2023. It was probably "
|
||
|
"introduced for testing purposes a long time ago, and no longer relevant. "
|
||
|
"Feel free to create a GitHub issue if you disagree.",
|
||
|
DeprecationWarning,
|
||
|
)
|
||
|
|
||
|
args = argv[1:]
|
||
|
for fname in args:
|
||
|
fp = open(fname, "rb")
|
||
|
cmap = FileUnicodeMap()
|
||
|
CMapParser(cmap, fp).run()
|
||
|
fp.close()
|
||
|
cmap.dump()
|
||
|
return
|
||
|
|
||
|
|
||
|
if __name__ == "__main__":
|
||
|
main(sys.argv)
|