1 #!/usr/bin/env python 2 # 3 # Copyright 2011, Google Inc. 4 # All rights reserved. 5 # 6 # Redistribution and use in source and binary forms, with or without 7 # modification, are permitted provided that the following conditions are 8 # met: 9 # 10 # * Redistributions of source code must retain the above copyright 11 # notice, this list of conditions and the following disclaimer. 12 # * Redistributions in binary form must reproduce the above 13 # copyright notice, this list of conditions and the following disclaimer 14 # in the documentation and/or other materials provided with the 15 # distribution. 16 # * Neither the name of Google Inc. nor the names of its 17 # contributors may be used to endorse or promote products derived from 18 # this software without specific prior written permission. 19 # 20 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 23 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 24 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 25 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 26 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 30 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 32 33 """Memorizing file. 34 35 A memorizing file wraps a file and memorizes lines read by readline. 36 """ 37 38 39 import sys 40 41 42 class MemorizingFile(object): 43 """MemorizingFile wraps a file and memorizes lines read by readline. 44 45 Note that data read by other methods are not memorized. This behavior 46 is good enough for memorizing lines SimpleHTTPServer reads before 47 the control reaches WebSocketRequestHandler. 48 """ 49 50 def __init__(self, file_, max_memorized_lines=sys.maxint): 51 """Construct an instance. 52 53 Args: 54 file_: the file object to wrap. 55 max_memorized_lines: the maximum number of lines to memorize. 56 Only the first max_memorized_lines are memorized. 57 Default: sys.maxint. 58 """ 59 60 self._file = file_ 61 self._memorized_lines = [] 62 self._max_memorized_lines = max_memorized_lines 63 self._buffered = False 64 self._buffered_line = None 65 66 def __getattribute__(self, name): 67 if name in ('_file', '_memorized_lines', '_max_memorized_lines', 68 '_buffered', '_buffered_line', 'readline', 69 'get_memorized_lines'): 70 return object.__getattribute__(self, name) 71 return self._file.__getattribute__(name) 72 73 def readline(self, size=-1): 74 """Override file.readline and memorize the line read. 75 76 Note that even if size is specified and smaller than actual size, 77 the whole line will be read out from underlying file object by 78 subsequent readline calls. 79 """ 80 81 if self._buffered: 82 line = self._buffered_line 83 self._buffered = False 84 else: 85 line = self._file.readline() 86 if line and len(self._memorized_lines) < self._max_memorized_lines: 87 self._memorized_lines.append(line) 88 if size >= 0 and size < len(line): 89 self._buffered = True 90 self._buffered_line = line[size:] 91 return line[:size] 92 return line 93 94 def get_memorized_lines(self): 95 """Get lines memorized so far.""" 96 return self._memorized_lines 97 98 99 # vi:sts=4 sw=4 et 100
