mirror of https://github.com/python/cpython
Issue1395: Universal mode used to duplicate newlines when using read(1).
"Universal newline" is now an incremental decoder wrapping the initial one, with its own additional buffer (if '\r' is seen at the end of the input). A decoder allows the tell() funtion to record the state of the translation. This also simplifies the readline() process. Now test_netrc passes on Windows, as well as many new tests in test_io.py
This commit is contained in:
Amaury Forgeot d'Arc
parent
74c29c71b1
commit
1ff9910f59
205
Lib/io.py
205
Lib/io.py
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@ -1041,6 +1041,84 @@ class TextIOBase(IOBase):
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return None
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class IncrementalNewlineDecoder(codecs.IncrementalDecoder):
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"""Codec used when reading a file in universal newlines mode.
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It wraps another incremental decoder, translating \\r\\n and \\r into \\n.
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It also records the types of newlines encountered.
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When used with translate=False, it ensures that the newline sequence is
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returned in one piece.
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"""
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def __init__(self, decoder, translate, errors='strict'):
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codecs.IncrementalDecoder.__init__(self, errors=errors)
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self.buffer = b''
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self.translate = translate
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self.decoder = decoder
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self.seennl = 0
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def decode(self, input, final=False):
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# decode input (with the eventual \r from a previous pass)
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if self.buffer:
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input = self.buffer + input
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output = self.decoder.decode(input, final=final)
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# retain last \r even when not translating data:
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# then readline() is sure to get \r\n in one pass
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if output.endswith("\r") and not final:
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output = output[:-1]
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self.buffer = b'\r'
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else:
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self.buffer = b''
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# Record which newlines are read
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crlf = output.count('\r\n')
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cr = output.count('\r') - crlf
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lf = output.count('\n') - crlf
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self.seennl |= (lf and self._LF) | (cr and self._CR) \
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| (crlf and self._CRLF)
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if self.translate:
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if crlf:
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output = output.replace("\r\n", "\n")
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if cr:
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output = output.replace("\r", "\n")
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return output
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def getstate(self):
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buf, flag = self.decoder.getstate()
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return buf + self.buffer, flag
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def setstate(self, state):
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buf, flag = state
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if buf.endswith(b'\r'):
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self.buffer = b'\r'
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buf = buf[:-1]
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else:
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self.buffer = b''
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self.decoder.setstate((buf, flag))
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def reset(self):
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self.buffer = b''
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self.decoder.reset()
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_LF = 1
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_CR = 2
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_CRLF = 4
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@property
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def newlines(self):
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return (None,
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"\n",
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"\r",
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("\r", "\n"),
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"\r\n",
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("\n", "\r\n"),
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("\r", "\r\n"),
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("\r", "\n", "\r\n")
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)[self.seennl]
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class TextIOWrapper(TextIOBase):
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"""Buffered text stream.
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@ -1077,7 +1155,6 @@ class TextIOWrapper(TextIOBase):
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self._readnl = newline
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self._writetranslate = newline != ''
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self._writenl = newline or os.linesep
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self._seennl = 0
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self._decoder = None
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self._pending = ""
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self._snapshot = None
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@ -1124,6 +1201,7 @@ class TextIOWrapper(TextIOBase):
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if not isinstance(s, str):
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raise TypeError("can't write %s to text stream" %
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s.__class__.__name__)
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length = len(s)
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haslf = "\n" in s
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if haslf and self._writetranslate and self._writenl != "\n":
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s = s.replace("\n", self._writenl)
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@ -1132,15 +1210,20 @@ class TextIOWrapper(TextIOBase):
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self.buffer.write(b)
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if haslf and self.isatty():
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self.flush()
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self._snapshot = self._decoder = None
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return len(s)
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self._snapshot = None
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if self._decoder:
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self._decoder.reset()
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return length
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def _get_decoder(self):
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make_decoder = codecs.getincrementaldecoder(self._encoding)
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if make_decoder is None:
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raise IOError("Can't find an incremental decoder for encoding %s" %
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self._encoding)
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decoder = self._decoder = make_decoder() # XXX: errors
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decoder = make_decoder() # XXX: errors
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if self._readuniversal:
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decoder = IncrementalNewlineDecoder(decoder, self._readtranslate)
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self._decoder = decoder
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return decoder
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def _read_chunk(self):
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@ -1220,7 +1303,8 @@ class TextIOWrapper(TextIOBase):
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pos = self.buffer.seek(0, 2)
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self._snapshot = None
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self._pending = ""
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self._decoder = None
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if self._decoder:
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self._decoder.reset()
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return pos
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if whence != 0:
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raise ValueError("Invalid whence (%r, should be 0, 1 or 2)" %
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@ -1234,7 +1318,8 @@ class TextIOWrapper(TextIOBase):
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self.buffer.seek(pos)
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self._snapshot = None
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self._pending = ""
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self._decoder = None
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if self._decoder:
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self._decoder.reset()
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return pos
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decoder = self._decoder or self._get_decoder()
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decoder.set_state(("", ds))
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@ -1253,7 +1338,7 @@ class TextIOWrapper(TextIOBase):
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res += decoder.decode(self.buffer.read(), True)
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self._pending = ""
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self._snapshot = None
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return self._replacenl(res)
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return res
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else:
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while len(res) < n:
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readahead, pending = self._read_chunk()
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@ -1261,7 +1346,7 @@ class TextIOWrapper(TextIOBase):
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if not readahead:
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break
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self._pending = res[n:]
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return self._replacenl(res[:n])
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return res[:n]
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def __next__(self):
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self._telling = False
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@ -1285,62 +1370,55 @@ class TextIOWrapper(TextIOBase):
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line = self._pending
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start = 0
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cr_eof = False
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decoder = self._decoder or self._get_decoder()
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pos = endpos = None
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ending = None
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while True:
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if self._readuniversal:
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if self._readtranslate:
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# Newlines are already translated, only search for \n
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pos = line.find('\n', start)
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if pos >= 0:
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endpos = pos + 1
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break
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else:
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start = len(line)
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elif self._readuniversal:
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# Universal newline search. Find any of \r, \r\n, \n
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# The decoder ensures that \r\n are not split in two pieces
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# In C we'd look for these in parallel of course.
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nlpos = line.find("\n", start)
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crpos = line.find("\r", start)
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if crpos == -1:
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if nlpos == -1:
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# Nothing found
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start = len(line)
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else:
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# Found \n
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pos = nlpos
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endpos = pos + 1
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ending = self._LF
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endpos = nlpos + 1
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break
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elif nlpos == -1:
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if crpos == len(line) - 1:
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# Found \r at end of buffer, must keep reading
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start = crpos
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cr_eof = True
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else:
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# Found lone \r
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ending = self._CR
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pos = crpos
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endpos = pos + 1
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break
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# Found lone \r
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endpos = crpos + 1
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break
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elif nlpos < crpos:
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# Found \n
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pos = nlpos
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endpos = pos + 1
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ending = self._LF
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endpos = nlpos + 1
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break
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elif nlpos == crpos + 1:
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# Found \r\n
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ending = self._CRLF
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pos = crpos
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endpos = pos + 2
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endpos = crpos + 2
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break
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else:
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# Found \r
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pos = crpos
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endpos = pos + 1
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ending = self._CR
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endpos = crpos + 1
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break
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else:
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# non-universal
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pos = line.find(self._readnl)
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if pos >= 0:
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endpos = pos+len(self._readnl)
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ending = self._nlflag(self._readnl)
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endpos = pos + len(self._readnl)
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break
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# No line ending seen yet - get more data
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@ -1356,65 +1434,14 @@ class TextIOWrapper(TextIOBase):
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# end of file
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self._pending = ''
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self._snapshot = None
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if cr_eof:
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self._seennl |= self._CR
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return line[:-1] + '\n'
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else:
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return line
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return line
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self._pending = line[endpos:]
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if self._readtranslate:
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self._seennl |= ending
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if ending != self._LF:
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return line[:pos] + '\n'
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else:
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return line[:endpos]
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else:
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return line[:endpos]
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return line[:endpos]
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def _replacenl(self, data):
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# Replace newlines in data as needed and record that they have
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# been seen.
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if not self._readtranslate:
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return data
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if self._readuniversal:
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crlf = data.count('\r\n')
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cr = data.count('\r') - crlf
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lf = data.count('\n') - crlf
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self._seennl |= (lf and self._LF) | (cr and self._CR) \
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| (crlf and self._CRLF)
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if crlf:
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data = data.replace("\r\n", "\n")
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if cr:
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data = data.replace("\r", "\n")
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elif self._readnl == '\n':
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# Only need to detect if \n was seen.
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if data.count('\n'):
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self._seennl |= self._LF
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else:
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newdata = data.replace(self._readnl, '\n')
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if newdata is not data:
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self._seennl |= self._nlflag(self._readnl)
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data = newdata
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return data
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_LF = 1
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_CR = 2
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_CRLF = 4
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@property
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def newlines(self):
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return (None,
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"\n",
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"\r",
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("\r", "\n"),
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"\r\n",
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("\n", "\r\n"),
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("\r", "\r\n"),
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("\r", "\n", "\r\n")
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)[self._seennl]
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def _nlflag(self, nlstr):
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return [None, "\n", "\r", None, "\r\n"].index(nlstr)
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return self._decoder.newlines if self._decoder else None
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class StringIO(TextIOWrapper):
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@ -489,6 +489,10 @@ class BufferedRandomTest(unittest.TestCase):
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class TextIOWrapperTest(unittest.TestCase):
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def setUp(self):
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self.testdata = b"AAA\r\nBBB\rCCC\r\nDDD\nEEE\r\n"
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self.normalized = b"AAA\nBBB\nCCC\nDDD\nEEE\n".decode("ascii")
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def tearDown(self):
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test_support.unlink(test_support.TESTFN)
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@ -496,14 +500,14 @@ class TextIOWrapperTest(unittest.TestCase):
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testdata = b"AAA\nBBB\nCCC\rDDD\rEEE\r\nFFF\r\nGGG"
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normalized = testdata.replace(b"\r\n", b"\n").replace(b"\r", b"\n")
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for newline, expected in [
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(None, normalized.decode("ASCII").splitlines(True)),
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("", testdata.decode("ASCII").splitlines(True)),
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(None, normalized.decode("ascii").splitlines(True)),
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("", testdata.decode("ascii").splitlines(True)),
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("\n", ["AAA\n", "BBB\n", "CCC\rDDD\rEEE\r\n", "FFF\r\n", "GGG"]),
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("\r\n", ["AAA\nBBB\nCCC\rDDD\rEEE\r\n", "FFF\r\n", "GGG"]),
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("\r", ["AAA\nBBB\nCCC\r", "DDD\r", "EEE\r", "\nFFF\r", "\nGGG"]),
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]:
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buf = io.BytesIO(testdata)
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txt = io.TextIOWrapper(buf, encoding="ASCII", newline=newline)
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txt = io.TextIOWrapper(buf, encoding="ascii", newline=newline)
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self.assertEquals(txt.readlines(), expected)
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txt.seek(0)
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self.assertEquals(txt.read(), "".join(expected))
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@ -518,7 +522,7 @@ class TextIOWrapperTest(unittest.TestCase):
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tests = [(None, testdict[os.linesep])] + sorted(testdict.items())
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for newline, expected in tests:
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buf = io.BytesIO()
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txt = io.TextIOWrapper(buf, encoding="ASCII", newline=newline)
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txt = io.TextIOWrapper(buf, encoding="ascii", newline=newline)
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txt.write("AAA\nB")
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txt.write("BB\nCCC\n")
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txt.write("X\rY\r\nZ")
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@ -568,14 +572,14 @@ class TextIOWrapperTest(unittest.TestCase):
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testdata = b"AAA\nBBB\nCCC\rDDD\rEEE\r\nFFF\r\nGGG"
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normalized = testdata.replace(b"\r\n", b"\n").replace(b"\r", b"\n")
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for newline, expected in [
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(None, normalized.decode("ASCII").splitlines(True)),
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("", testdata.decode("ASCII").splitlines(True)),
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(None, normalized.decode("ascii").splitlines(True)),
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("", testdata.decode("ascii").splitlines(True)),
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("\n", ["AAA\n", "BBB\n", "CCC\rDDD\rEEE\r\n", "FFF\r\n", "GGG"]),
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("\r\n", ["AAA\nBBB\nCCC\rDDD\rEEE\r\n", "FFF\r\n", "GGG"]),
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("\r", ["AAA\nBBB\nCCC\r", "DDD\r", "EEE\r", "\nFFF\r", "\nGGG"]),
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]:
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buf = io.BytesIO(testdata)
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txt = io.TextIOWrapper(buf, encoding="ASCII", newline=newline)
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txt = io.TextIOWrapper(buf, encoding="ascii", newline=newline)
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self.assertEquals(txt.readlines(), expected)
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txt.seek(0)
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self.assertEquals(txt.read(), "".join(expected))
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@ -600,7 +604,7 @@ class TextIOWrapperTest(unittest.TestCase):
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("\r\n", "\r\n", data_crlf),
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]:
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buf = io.BytesIO()
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txt = io.TextIOWrapper(buf, encoding="ASCII", newline=newline)
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txt = io.TextIOWrapper(buf, encoding="ascii", newline=newline)
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txt.write(data)
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txt.close()
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self.assertEquals(buf.getvalue(), expected)
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@ -745,6 +749,114 @@ class TextIOWrapperTest(unittest.TestCase):
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print("Reading using readline(): %6.3f seconds" % (t3-t2))
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print("Using readline()+tell(): %6.3f seconds" % (t4-t3))
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def testReadOneByOne(self):
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txt = io.TextIOWrapper(io.BytesIO(b"AA\r\nBB"))
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reads = ""
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while True:
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c = txt.read(1)
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if not c:
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break
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reads += c
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self.assertEquals(reads, "AA\nBB")
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# read in amounts equal to TextIOWrapper._CHUNK_SIZE which is 128.
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def testReadByChunk(self):
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# make sure "\r\n" straddles 128 char boundary.
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txt = io.TextIOWrapper(io.BytesIO(b"A" * 127 + b"\r\nB"))
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reads = ""
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while True:
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c = txt.read(128)
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if not c:
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break
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reads += c
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self.assertEquals(reads, "A"*127+"\nB")
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def test_issue1395_1(self):
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txt = io.TextIOWrapper(io.BytesIO(self.testdata), encoding="ascii")
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# read one char at a time
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reads = ""
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while True:
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c = txt.read(1)
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if not c:
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break
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reads += c
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self.assertEquals(reads, self.normalized)
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def test_issue1395_2(self):
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txt = io.TextIOWrapper(io.BytesIO(self.testdata), encoding="ascii")
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txt._CHUNK_SIZE = 4
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reads = ""
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while True:
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c = txt.read(4)
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if not c:
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break
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reads += c
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self.assertEquals(reads, self.normalized)
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def test_issue1395_3(self):
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txt = io.TextIOWrapper(io.BytesIO(self.testdata), encoding="ascii")
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txt._CHUNK_SIZE = 4
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reads = txt.read(4)
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reads += txt.read(4)
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reads += txt.readline()
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reads += txt.readline()
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reads += txt.readline()
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self.assertEquals(reads, self.normalized)
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def test_issue1395_4(self):
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txt = io.TextIOWrapper(io.BytesIO(self.testdata), encoding="ascii")
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txt._CHUNK_SIZE = 4
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reads = txt.read(4)
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reads += txt.read()
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self.assertEquals(reads, self.normalized)
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def test_issue1395_5(self):
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txt = io.TextIOWrapper(io.BytesIO(self.testdata), encoding="ascii")
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txt._CHUNK_SIZE = 4
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reads = txt.read(4)
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pos = txt.tell()
|
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txt.seek(0)
|
||||
txt.seek(pos)
|
||||
self.assertEquals(txt.read(4), "BBB\n")
|
||||
|
||||
def test_newline_decoder(self):
|
||||
import codecs
|
||||
decoder = codecs.getincrementaldecoder("utf-8")()
|
||||
decoder = io.IncrementalNewlineDecoder(decoder, translate=True)
|
||||
|
||||
self.assertEquals(decoder.decode(b'\xe8\xa2\x88'), "\u8888")
|
||||
|
||||
self.assertEquals(decoder.decode(b'\xe8'), "")
|
||||
self.assertEquals(decoder.decode(b'\xa2'), "")
|
||||
self.assertEquals(decoder.decode(b'\x88'), "\u8888")
|
||||
|
||||
self.assertEquals(decoder.decode(b'\xe8'), "")
|
||||
self.assertRaises(UnicodeDecodeError, decoder.decode, b'', final=True)
|
||||
|
||||
decoder.setstate((b'', 0))
|
||||
self.assertEquals(decoder.decode(b'\n'), "\n")
|
||||
self.assertEquals(decoder.decode(b'\r'), "")
|
||||
self.assertEquals(decoder.decode(b'', final=True), "\n")
|
||||
self.assertEquals(decoder.decode(b'\r', final=True), "\n")
|
||||
|
||||
self.assertEquals(decoder.decode(b'\r'), "")
|
||||
self.assertEquals(decoder.decode(b'a'), "\na")
|
||||
|
||||
self.assertEquals(decoder.decode(b'\r\r\n'), "\n\n")
|
||||
self.assertEquals(decoder.decode(b'\r'), "")
|
||||
self.assertEquals(decoder.decode(b'\r'), "\n")
|
||||
self.assertEquals(decoder.decode(b'\na'), "\na")
|
||||
|
||||
self.assertEquals(decoder.decode(b'\xe8\xa2\x88\r\n'), "\u8888\n")
|
||||
self.assertEquals(decoder.decode(b'\xe8\xa2\x88'), "\u8888")
|
||||
self.assertEquals(decoder.decode(b'\n'), "\n")
|
||||
self.assertEquals(decoder.decode(b'\xe8\xa2\x88\r'), "\u8888")
|
||||
self.assertEquals(decoder.decode(b'\n'), "\n")
|
||||
|
||||
# XXX Tests for open()
|
||||
|
||||
|
|
|
|||
|
|
@ -867,7 +867,7 @@ static PyGetSetDef fileio_getsetlist[] = {
|
|||
|
||||
PyTypeObject PyFileIO_Type = {
|
||||
PyVarObject_HEAD_INIT(&PyType_Type, 0)
|
||||
"FileIO",
|
||||
"_FileIO",
|
||||
sizeof(PyFileIOObject),
|
||||
0,
|
||||
(destructor)fileio_dealloc, /* tp_dealloc */
|
||||
|
|
|
|||
Loading…
Reference in New Issue