Commit 3e99cc5
committed
Port FileLock to Windows
Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>1 parent a6fef36 commit 3e99cc5
1 file changed
Lines changed: 71 additions & 18 deletions
| Original file line number | Diff line number | Diff line change | |
|---|---|---|---|
@@ -2,7 +2,7 @@ | |||
| 2 | 2 | ||
| 3 | 3 | # The MIT License | |
| 4 | 4 | # | |
| 5 | - # Copyright (c) 2015 Sebastian Ramacher | ||
| 5 | + # Copyright (c) 2015-2016 Sebastian Ramacher | ||
| 6 | 6 | # | |
| 7 | 7 | # Permission is hereby granted, free of charge, to any person obtaining a copy | |
| 8 | 8 | # of this software and associated documentation files (the "Software"), to deal | |
@@ -30,33 +30,86 @@ | |||
| 30 | 30 | except ImportError: | |
| 31 | 31 | has_fcntl = False | |
| 32 | 32 | ||
| 33 | + try: | ||
| 34 | + import msvcrt | ||
| 35 | + has_msvcrt = True | ||
| 36 | + except ImportError: | ||
| 37 | + has_msvcrt = False | ||
| 38 | + | ||
| 39 | + | ||
| 40 | + class BaseLock(object): | ||
| 41 | + """Base class for file locking | ||
| 42 | + """ | ||
| 43 | + | ||
| 44 | + def __init__(self, fd): | ||
| 45 | + self.fd = fd | ||
| 46 | + self.locked = False | ||
| 33 | 47 | ||
| 34 | - class FileLock(object): | ||
| 35 | - """Simple file locking | ||
| 48 | + def acquire(self): | ||
| 49 | + pass | ||
| 36 | 50 | ||
| 37 | - On platforms without fcntl, all operations in this class are no-ops. | ||
| 51 | + def release(self): | ||
| 52 | + pass | ||
| 53 | + | ||
| 54 | + def __enter__(self): | ||
| 55 | + self.acquire() | ||
| 56 | + | ||
| 57 | + def __exit__(self, *args): | ||
| 58 | + if self.locked: | ||
| 59 | + self.release() | ||
| 60 | + | ||
| 61 | + def __del__(self): | ||
| 62 | + if self.locked: | ||
| 63 | + self.release() | ||
| 64 | + | ||
| 65 | + | ||
| 66 | + class UnixFileLock(BaseLock): | ||
| 67 | + """Simple file locking for Unix using fcntl | ||
| 38 | 68 | """ | |
| 39 | 69 | ||
| 40 | 70 | def __init__(self, fd, mode=None): | |
| 41 | - if has_fcntl and mode is None: | ||
| 42 | - mode = fcntl.LOCK_EX | ||
| 71 | + super(UnixFileLock, self).__init__(fd) | ||
| 43 | 72 | ||
| 44 | - self.fd = fd | ||
| 73 | + if mode is None: | ||
| 74 | + mode = fcntl.LOCK_EX | ||
| 45 | 75 | self.mode = mode | |
| 76 | + | ||
| 77 | + def acquire(self): | ||
| 78 | + try: | ||
| 79 | + fcntl.flock(self.fd, self.mode) | ||
| 80 | + self.locked = True | ||
| 81 | + except IOError as e: | ||
| 82 | + if e.errno != errno.ENOLCK: | ||
| 83 | + raise e | ||
| 84 | + return self | ||
| 85 | + | ||
| 86 | + def release(self): | ||
| 87 | + fcntl.flock(self.fd, fcntl.LOCK_UN) | ||
| 46 | 88 | self.locked = False | |
| 47 | 89 | ||
| 48 | - def __enter__(self): | ||
| 49 | - if has_fcntl: | ||
| 50 | - try: | ||
| 51 | - fcntl.flock(self.fd, self.mode) | ||
| 52 | - self.locked = True | ||
| 53 | - except IOError as e: | ||
| 54 | - if e.errno != errno.ENOLCK: | ||
| 55 | - raise e | ||
| 90 | + | ||
| 91 | + class WindowsFileLock(BaseLock): | ||
| 92 | + """Simple file locking for Windows using msvcrt | ||
| 93 | + """ | ||
| 94 | + | ||
| 95 | + def __init__(self, fd, mode=None): | ||
| 96 | + super(WindowsFileLock, self).__init__(fd) | ||
| 97 | + | ||
| 98 | + def acquire(self): | ||
| 99 | + msvcrt.locking(self.fd, msvcrt.LK_NBLCK, 1) | ||
| 100 | + self.locked = True | ||
| 56 | 101 | return self | |
| 57 | 102 | ||
| 58 | - def __exit__(self, *args): | ||
| 59 | - if has_fcntl and self.locked: | ||
| 60 | - fcntl.flock(self.fd, fcntl.LOCK_UN) | ||
| 103 | + def release(self): | ||
| 104 | + msvcrt.locking(self.fd, msvcrt.LK_UNLCK, 1) | ||
| 105 | + self.locked = False | ||
| 106 | + | ||
| 107 | + | ||
| 108 | + if has_fcntl: | ||
| 109 | + FileLock = UnixFileLock | ||
| 110 | + elif has_msvcrt: | ||
| 111 | + FileLock = WindowsFileLock | ||
| 112 | + else: | ||
| 113 | + FileLock = BaseLock | ||
| 61 | 114 | ||
| 62 | 115 | # vim: sw=4 ts=4 sts=4 ai et | |
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