Author: Armin Rigo <[email protected]>
Branch:
Changeset: r44690:69b1b4b69b35
Date: 2011-06-04 09:52 +0200
http://bitbucket.org/pypy/pypy/changeset/69b1b4b69b35/
Log: merge heads
diff --git a/pypy/rlib/streamio.py b/pypy/rlib/streamio.py
--- a/pypy/rlib/streamio.py
+++ b/pypy/rlib/streamio.py
@@ -141,7 +141,8 @@
def construct_stream_tower(stream, buffering, universal, reading, writing,
binary):
if buffering == 0: # no buffering
- pass
+ if reading: # force some minimal buffering for readline()
+ stream = ReadlineInputStream(stream)
elif buffering == 1: # line-buffering
if writing:
stream = LineBufferingOutputStream(stream)
@@ -749,6 +750,113 @@
flush_buffers=False)
+class ReadlineInputStream(Stream):
+
+ """Minimal buffering input stream.
+
+ Only does buffering for readline(). The other kinds of reads, and
+ all writes, are not buffered at all.
+ """
+
+ bufsize = 2**13 # 8 K
+
+ def __init__(self, base, bufsize=-1):
+ self.base = base
+ self.do_read = base.read # function to fill buffer some more
+ self.do_seek = base.seek # seek to a byte offset
+ if bufsize == -1: # Get default from the class
+ bufsize = self.bufsize
+ self.bufsize = bufsize # buffer size (hint only)
+ self.buf = None # raw data (may contain "\n")
+ self.bufstart = 0
+
+ def flush_buffers(self):
+ if self.buf is not None:
+ try:
+ self.do_seek(self.bufstart-len(self.buf), 1)
+ except MyNotImplementedError:
+ pass
+ else:
+ self.buf = None
+ self.bufstart = 0
+
+ def readline(self):
+ if self.buf is not None:
+ i = self.buf.find('\n', self.bufstart)
+ else:
+ self.buf = ''
+ i = -1
+ #
+ if i < 0:
+ self.buf = self.buf[self.bufstart:]
+ self.bufstart = 0
+ while True:
+ bufsize = max(self.bufsize, len(self.buf) >> 2)
+ data = self.do_read(bufsize)
+ if not data:
+ result = self.buf # end-of-file reached
+ self.buf = None
+ return result
+ startsearch = len(self.buf) # there is no '\n' in buf so far
+ self.buf += data
+ i = self.buf.find('\n', startsearch)
+ if i >= 0:
+ break
+ #
+ i += 1
+ result = self.buf[self.bufstart:i]
+ self.bufstart = i
+ return result
+
+ def peek(self):
+ if self.buf is None:
+ return ''
+ if self.bufstart > 0:
+ self.buf = self.buf[self.bufstart:]
+ self.bufstart = 0
+ return self.buf
+
+ def tell(self):
+ pos = self.base.tell()
+ if self.buf is not None:
+ pos -= (len(self.buf) - self.bufstart)
+ return pos
+
+ def readall(self):
+ result = self.base.readall()
+ if self.buf is not None:
+ result = self.buf[self.bufstart:] + result
+ self.buf = None
+ self.bufstart = 0
+ return result
+
+ def read(self, n):
+ if self.buf is None:
+ return self.do_read(n)
+ else:
+ m = n - (len(self.buf) - self.bufstart)
+ start = self.bufstart
+ if m > 0:
+ result = self.buf[start:] + self.do_read(m)
+ self.buf = None
+ self.bufstart = 0
+ return result
+ elif n >= 0:
+ self.bufstart = start + n
+ return self.buf[start : self.bufstart]
+ else:
+ return ''
+
+ seek = PassThrough("seek", flush_buffers=True)
+ write = PassThrough("write", flush_buffers=True)
+ truncate = PassThrough("truncate", flush_buffers=True)
+ flush = PassThrough("flush", flush_buffers=True)
+ flushable = PassThrough("flushable", flush_buffers=False)
+ close = PassThrough("close", flush_buffers=False)
+ try_to_find_file_descriptor = PassThrough("try_to_find_file_descriptor",
+ flush_buffers=False)
+
+
class BufferingOutputStream(Stream):
"""Standard buffering output stream.
diff --git a/pypy/rlib/test/test_streamio.py b/pypy/rlib/test/test_streamio.py
--- a/pypy/rlib/test/test_streamio.py
+++ b/pypy/rlib/test/test_streamio.py
@@ -1008,6 +1008,75 @@
assert base.buf == data
+class TestReadlineInputStream:
+
+ packets = ["a", "b", "\n", "def", "\nxy\npq\nuv", "wx"]
+ lines = ["ab\n", "def\n", "xy\n", "pq\n", "uvwx"]
+
+ def makeStream(self, seek=False, tell=False, bufsize=-1):
+ base = TSource(self.packets)
+ self.source = base
+ def f(*args):
+ if seek is False:
+ raise NotImplementedError # a bug!
+ if seek is None:
+ raise streamio.MyNotImplementedError # can be caught
+ raise ValueError(seek) # uh?
+ if not tell:
+ base.tell = f
+ if not seek:
+ base.seek = f
+ return streamio.ReadlineInputStream(base, bufsize)
+
+ def test_readline(self):
+ for file in [self.makeStream(), self.makeStream(bufsize=2)]:
+ i = 0
+ while 1:
+ r = file.readline()
+ if r == "":
+ break
+ assert self.lines[i] == r
+ i += 1
+ assert i == len(self.lines)
+
+ def test_readline_and_read_interleaved(self):
+ for file in [self.makeStream(seek=True),
+ self.makeStream(seek=True, bufsize=2)]:
+ i = 0
+ while 1:
+ firstchar = file.read(1)
+ if firstchar == "":
+ break
+ r = file.readline()
+ assert r != ""
+ assert self.lines[i] == firstchar + r
+ i += 1
+ assert i == len(self.lines)
+
+ def test_readline_and_read_interleaved_no_seek(self):
+ for file in [self.makeStream(seek=None),
+ self.makeStream(seek=None, bufsize=2)]:
+ i = 0
+ while 1:
+ firstchar = file.read(1)
+ if firstchar == "":
+ break
+ r = file.readline()
+ assert r != ""
+ assert self.lines[i] == firstchar + r
+ i += 1
+ assert i == len(self.lines)
+
+ def test_readline_and_readall(self):
+ file = self.makeStream(seek=True, tell=True, bufsize=2)
+ r = file.readline()
+ assert r == 'ab\n'
+ assert file.tell() == 3
+ r = file.readall()
+ assert r == 'def\nxy\npq\nuvwx'
+ r = file.readall()
+ assert r == ''
+
# Speed test
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