Mercurial > public > mercurial-scm > hg
comparison mercurial/wireprototypes.py @ 37781:352932a11905
wireproto: move command registration types to wireprototypes
These are shared across wire protocol implementations. wireprototypes
is our module for common code.
Differential Revision: https://phab.mercurial-scm.org/D3396
| author | Gregory Szorc <gregory.szorc@gmail.com> |
|---|---|
| date | Mon, 16 Apr 2018 21:52:33 -0700 |
| parents | 564a3eec6e63 |
| children | 9d818539abfa |
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| 37780:8acd3a9ac4fd | 37781:352932a11905 |
|---|---|
| 239 | 239 |
| 240 The argument is the permission required to proceed. If the client | 240 The argument is the permission required to proceed. If the client |
| 241 doesn't have that permission, the exception should raise or abort | 241 doesn't have that permission, the exception should raise or abort |
| 242 in a protocol specific manner. | 242 in a protocol specific manner. |
| 243 """ | 243 """ |
| 244 | |
| 245 class commandentry(object): | |
| 246 """Represents a declared wire protocol command.""" | |
| 247 def __init__(self, func, args='', transports=None, | |
| 248 permission='push'): | |
| 249 self.func = func | |
| 250 self.args = args | |
| 251 self.transports = transports or set() | |
| 252 self.permission = permission | |
| 253 | |
| 254 def _merge(self, func, args): | |
| 255 """Merge this instance with an incoming 2-tuple. | |
| 256 | |
| 257 This is called when a caller using the old 2-tuple API attempts | |
| 258 to replace an instance. The incoming values are merged with | |
| 259 data not captured by the 2-tuple and a new instance containing | |
| 260 the union of the two objects is returned. | |
| 261 """ | |
| 262 return commandentry(func, args=args, transports=set(self.transports), | |
| 263 permission=self.permission) | |
| 264 | |
| 265 # Old code treats instances as 2-tuples. So expose that interface. | |
| 266 def __iter__(self): | |
| 267 yield self.func | |
| 268 yield self.args | |
| 269 | |
| 270 def __getitem__(self, i): | |
| 271 if i == 0: | |
| 272 return self.func | |
| 273 elif i == 1: | |
| 274 return self.args | |
| 275 else: | |
| 276 raise IndexError('can only access elements 0 and 1') | |
| 277 | |
| 278 class commanddict(dict): | |
| 279 """Container for registered wire protocol commands. | |
| 280 | |
| 281 It behaves like a dict. But __setitem__ is overwritten to allow silent | |
| 282 coercion of values from 2-tuples for API compatibility. | |
| 283 """ | |
| 284 def __setitem__(self, k, v): | |
| 285 if isinstance(v, commandentry): | |
| 286 pass | |
| 287 # Cast 2-tuples to commandentry instances. | |
| 288 elif isinstance(v, tuple): | |
| 289 if len(v) != 2: | |
| 290 raise ValueError('command tuples must have exactly 2 elements') | |
| 291 | |
| 292 # It is common for extensions to wrap wire protocol commands via | |
| 293 # e.g. ``wireproto.commands[x] = (newfn, args)``. Because callers | |
| 294 # doing this aren't aware of the new API that uses objects to store | |
| 295 # command entries, we automatically merge old state with new. | |
| 296 if k in self: | |
| 297 v = self[k]._merge(v[0], v[1]) | |
| 298 else: | |
| 299 # Use default values from @wireprotocommand. | |
| 300 v = commandentry(v[0], args=v[1], | |
| 301 transports=set(TRANSPORTS), | |
| 302 permission='push') | |
| 303 else: | |
| 304 raise ValueError('command entries must be commandentry instances ' | |
| 305 'or 2-tuples') | |
| 306 | |
| 307 return super(commanddict, self).__setitem__(k, v) | |
| 308 | |
| 309 def commandavailable(self, command, proto): | |
| 310 """Determine if a command is available for the requested protocol.""" | |
| 311 assert proto.name in TRANSPORTS | |
| 312 | |
| 313 entry = self.get(command) | |
| 314 | |
| 315 if not entry: | |
| 316 return False | |
| 317 | |
| 318 if proto.name not in entry.transports: | |
| 319 return False | |
| 320 | |
| 321 return True |