Author: Brian Kearns <bdkea...@gmail.com>
Branch: use-file-star-for-file
Changeset: r73579:01b77e9f28ef
Date: 2014-09-17 11:55 -0400
http://bitbucket.org/pypy/pypy/changeset/01b77e9f28ef/
Log: rewrite fgets loop more like cpython
diff --git a/rpython/rlib/rfile.py b/rpython/rlib/rfile.py
--- a/rpython/rlib/rfile.py
+++ b/rpython/rlib/rfile.py
@@ -52,8 +52,6 @@
BUFSIZ = config['BUFSIZ']
EOF = config['EOF']
-BASE_LINE_SIZE = 100
-
NEWLINE_UNKNOWN = 0
NEWLINE_CR = 1
NEWLINE_LF = 2
@@ -446,56 +444,66 @@
rffi.keep_buffer_alive_until_here(raw_buf, gc_buf)
return s.build()
- def _get_line_fgets_single(self, raw_buf):
+ def _get_line_fgets(self):
ll_file = self._ll_file
- for i in range(BASE_LINE_SIZE):
- raw_buf[i] = '\n'
- result = c_fgets(raw_buf, BASE_LINE_SIZE, ll_file)
- if not result:
- c_clearerr(ll_file)
- if self._signal_checker is not None:
- self._signal_checker()
- return 0
+ s = None
+ buffersize = 100
+ remainsize = buffersize
+ raw_buf, gc_buf = rffi.alloc_buffer(remainsize)
+ try:
+ while True:
+ for i in range(remainsize):
+ raw_buf[i] = '\n'
- # Assume that fgets() works as documented, and additionally
- # never writes beyond the final \0, which the CPython
- # fileobject.c says appears to be the case everywhere.
- # The only case where the buffer was not big enough is the
- # case where the buffer is full, ends with \0, and doesn't
- # end with \n\0.
+ p = c_fgets(raw_buf, remainsize, ll_file)
+ if not p:
+ c_clearerr(ll_file)
+ if self._signal_checker is not None:
+ self._signal_checker()
+ p = 0
+ break
- p = 0
- while raw_buf[p] != '\n':
- p += 1
- if p == BASE_LINE_SIZE:
- # fgets read whole buffer without finding newline
- return -1
- # p points to first \n
+ # Assume that fgets() works as documented, and additionally
+ # never writes beyond the final \0, which the CPython
+ # fileobject.c says appears to be the case everywhere.
+ # The only case where the buffer was not big enough is the
+ # case where the buffer is full, ends with \0, and doesn't
+ # end with \n\0.
- if p + 1 < BASE_LINE_SIZE and raw_buf[p + 1] == '\0':
- # \n followed by \0, fgets read and found newline
- return p + 1
- else:
- # \n not followed by \0, fgets read but didnt find newline
- assert p > 0 and raw_buf[p - 1] == '\0'
- return p - 1
+ p = 0
+ while raw_buf[p] != '\n':
+ p += 1
+ if p == remainsize:
+ # fgets read whole buffer without finding newline
+ p = -1
+ break
- def _get_line_fgets(self):
- # XXX use buffer size logic from cpython
- with rffi.scoped_alloc_buffer(BASE_LINE_SIZE) as buf:
- c = self._get_line_fgets_single(buf.raw)
- if c >= 0:
- return buf.str(c)
+ if p != -1:
+ # p points to first \n
+ if p + 1 < remainsize and raw_buf[p + 1] == '\0':
+ # \n followed by \0, fgets read and found newline
+ p += 1
+ else:
+ # \n not followed by \0, fgets read but didnt find
newline
+ assert p > 0 and raw_buf[p - 1] == '\0'
+ p -= 1
+ break
- # this is the rare case: the line is longer than BASE_LINE_SIZE
- s = StringBuilder()
- while True:
- s.append_charpsize(buf.raw, BASE_LINE_SIZE - 1)
- c = self._get_line_fgets_single(buf.raw)
- if c >= 0:
- break
- s.append_charpsize(buf.raw, c)
+ # fgets overwrote all the newlines (entire buffer)
+ assert raw_buf[remainsize - 1] == '\0'
+ if s is None:
+ s = StringBuilder()
+ s.append_charpsize(raw_buf, remainsize - 1)
+ buffersize += buffersize >> 2
+ remainsize = buffersize - s.getlength()
+ rffi.keep_buffer_alive_until_here(raw_buf, gc_buf)
+ raw_buf, gc_buf = rffi.alloc_buffer(remainsize)
+ if s is None:
+ return rffi.str_from_buffer(raw_buf, gc_buf, remainsize, p)
+ s.append_charpsize(raw_buf, p)
+ finally:
+ rffi.keep_buffer_alive_until_here(raw_buf, gc_buf)
return s.build()
def _get_line_getc(self, raw_buf, remainsize, state):
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