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| 1 | +# |
| 2 | +# Start of posixfile.py |
| 3 | +# |
| 4 | + |
| 5 | +# |
| 6 | +# Extended file operations |
| 7 | +# |
| 8 | +# f = posixfile.open(filename, mode) |
| 9 | +# |
| 10 | +# f.file() |
| 11 | +# will return the original builtin file object |
| 12 | +# |
| 13 | +# f.dup() |
| 14 | +# will return a new file object based on a new filedescriptor |
| 15 | +# |
| 16 | +# f.dup2(fd) |
| 17 | +# will return a new file object based on the given filedescriptor |
| 18 | +# |
| 19 | +# f.flags(mode) |
| 20 | +# will turn on the associated flag (merge) |
| 21 | +# mode can contain the following characters: |
| 22 | +# |
| 23 | +# (character representing a flag) |
| 24 | +# a append only flag |
| 25 | +# c close on exec flag |
| 26 | +# n no delay flag |
| 27 | +# s synchronization flag |
| 28 | +# (modifiers) |
| 29 | +# ! turn flags 'off' instead of default 'on' |
| 30 | +# = copy flags 'as is' instead of default 'merge' |
| 31 | +# ? return a string in which the characters represent the flags |
| 32 | +# that are set |
| 33 | +# |
| 34 | +# note: - the '!' and '=' modifiers are mutually exclusive. |
| 35 | +# - the '?' modifier will return the status of the flags after they |
| 36 | +# have been changed by other characters in the mode string |
| 37 | +# |
| 38 | +# f.lock(mode [, len [, start [, whence]]]) |
| 39 | +# will (un)lock a region |
| 40 | +# mode can contain the following characters: |
| 41 | +# |
| 42 | +# (character representing type of lock) |
| 43 | +# u unlock |
| 44 | +# r read lock |
| 45 | +# w write lock |
| 46 | +# (modifiers) |
| 47 | +# | wait until the lock can be granted |
| 48 | +# ? return the first lock conflicting with the requested lock |
| 49 | +# or 'None' if there is no conflict. The lock returned is in the |
| 50 | +# format (mode, len, start, whence, pid) where mode is a |
| 51 | +# character representing the type of lock ('r' or 'w') |
| 52 | +# |
| 53 | +# note: - the '?' modifier prevents a region from being locked; it is |
| 54 | +# query only |
| 55 | +# |
| 56 | + |
| 57 | +class _posixfile_: |
| 58 | + # |
| 59 | + # Internal routines |
| 60 | + # |
| 61 | + def __repr__(self): |
| 62 | + return repr(self._file_) |
| 63 | + |
| 64 | + def __del__(self): |
| 65 | + self._file_.close() |
| 66 | + |
| 67 | + # |
| 68 | + # Initialization routines |
| 69 | + # |
| 70 | + def open(self, name, mode): |
| 71 | + import __builtin__ |
| 72 | + |
| 73 | + self._name_ = name |
| 74 | + self._mode_ = mode |
| 75 | + self._file_ = __builtin__.open(name, mode) |
| 76 | + # Copy basic file methods |
| 77 | + for method in self._file_.__methods__: |
| 78 | + setattr(self, method, getattr(self._file_, method)) |
| 79 | + return self |
| 80 | + |
| 81 | + # |
| 82 | + # New methods |
| 83 | + # |
| 84 | + def file(self): |
| 85 | + return self._file_ |
| 86 | + |
| 87 | + def dup(self): |
| 88 | + import posix |
| 89 | + |
| 90 | + try: ignore = posix.fdopen |
| 91 | + except: raise AttributeError, 'dup() method unavailable' |
| 92 | + |
| 93 | + return posix.fdopen(posix.dup(self._file_.fileno()), self._mode_) |
| 94 | + |
| 95 | + def dup2(self, fd): |
| 96 | + import posix |
| 97 | + |
| 98 | + try: ignore = posix.fdopen |
| 99 | + except: raise AttributeError, 'dup() method unavailable' |
| 100 | + |
| 101 | + posix.dup2(self._file_.fileno(), fd) |
| 102 | + return posix.fdopen(fd, self._mode_) |
| 103 | + |
| 104 | + def flags(self, which): |
| 105 | + import fcntl, FCNTL |
| 106 | + |
| 107 | + l_flags = 0 |
| 108 | + if 'n' in which: l_flags = l_flags | FCNTL.O_NDELAY |
| 109 | + if 'a' in which: l_flags = l_flags | FCNTL.O_APPEND |
| 110 | + if 's' in which: l_flags = l_flags | FCNTL.O_SYNC |
| 111 | + |
| 112 | + if '=' not in which: |
| 113 | + cur_fl = fcntl.fcntl(self._file_.fileno(), FCNTL.F_GETFL, 0) |
| 114 | + if '!' in which: l_flags = cur_fl & ~ l_flags |
| 115 | + else: l_flags = cur_fl | l_flags |
| 116 | + |
| 117 | + l_flags = fcntl.fcntl(self._file_.fileno(), FCNTL.F_SETFL, l_flags) |
| 118 | + |
| 119 | + if 'c' in which: |
| 120 | + arg = ('!' not in which) # 1 is close |
| 121 | + l_flags = fcntl.fcntl(self._file_.fileno(), FCNTL.F_SETFD, arg) |
| 122 | + |
| 123 | + if '?' in which: |
| 124 | + which = '' |
| 125 | + l_flags = fcntl.fcntl(self._file_.fileno(), FCNTL.F_GETFL, 0) |
| 126 | + if FCNTL.O_APPEND & l_flags: which = which + 'a' |
| 127 | + if fcntl.fcntl(self._file_.fileno(), FCNTL.F_GETFD, 0) & 1: |
| 128 | + which = which + 'c' |
| 129 | + if FCNTL.O_NDELAY & l_flags: which = which + 'n' |
| 130 | + if FCNTL.O_SYNC & l_flags: which = which + 's' |
| 131 | + return which |
| 132 | + |
| 133 | + def lock(self, how, *args): |
| 134 | + import struct, fcntl, FCNTL |
| 135 | + |
| 136 | + if 'w' in how: l_type = FCNTL.F_WRLCK |
| 137 | + elif 'r' in how: l_type = FCNTL.F_WRLCK |
| 138 | + elif 'u' in how: l_type = FCNTL.F_UNLCK |
| 139 | + else: raise TypeError, 'no type of lock specified' |
| 140 | + |
| 141 | + if '|' in how: cmd = FCNTL.F_SETLKW |
| 142 | + elif '?' in how: cmd = FCNTL.F_GETLK |
| 143 | + else: cmd = FCNTL.F_SETLK |
| 144 | + |
| 145 | + l_whence = 0 |
| 146 | + l_start = 0 |
| 147 | + l_len = 0 |
| 148 | + |
| 149 | + if len(args) == 1: |
| 150 | + l_len = args[0] |
| 151 | + elif len(args) == 2: |
| 152 | + l_len, l_start = args |
| 153 | + elif len(args) == 3: |
| 154 | + l_len, l_start, l_whence = args |
| 155 | + elif len(args) > 3: |
| 156 | + raise TypeError, 'too many arguments' |
| 157 | + |
| 158 | + flock = struct.pack('hhllhh', l_type, l_whence, l_start, l_len, 0, 0) |
| 159 | + flock = fcntl.fcntl(self._file_.fileno(), cmd, flock) |
| 160 | + |
| 161 | + if '?' in how: |
| 162 | + l_type, l_whence, l_start, l_len, l_sysid, l_pid = \ |
| 163 | + struct.unpack('hhllhh', flock) |
| 164 | + if l_type != FCNTL.F_UNLCK: |
| 165 | + if l_type == FCNTL.F_RDLCK: |
| 166 | + return 'r', l_len, l_start, l_whence, l_pid |
| 167 | + else: |
| 168 | + return 'w', l_len, l_start, l_whence, l_pid |
| 169 | + |
| 170 | +# |
| 171 | +# Public routine to obtain a posixfile object |
| 172 | +# |
| 173 | +def open(name, mode): |
| 174 | + return _posixfile_().open(name, mode) |
| 175 | + |
| 176 | +# |
| 177 | +# End of posixfile.py |
| 178 | +# |
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