Mercurial > hg
comparison mercurial/revlog.py @ 47169:a13f72b9ccfb
revlog: move index reading logic in a dedicated method
They are multiple motivation to do it:
* The logic is complicated enough to deserver its own method.
* We will need to reuse this once we put a docket in use.
* This split the actual reading from the processing of the read data better.
Differential Revision: https://phab.mercurial-scm.org/D10595
| author | Pierre-Yves David <pierre-yves.david@octobus.net> |
|---|---|
| date | Mon, 03 May 2021 12:25:56 +0200 |
| parents | cacb08f357ed |
| children | 6e0ee1810fbd |
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| 47168:cacb08f357ed | 47169:a13f72b9ccfb |
|---|---|
| 444 % self._chunkcachesize | 444 % self._chunkcachesize |
| 445 ) | 445 ) |
| 446 force_nodemap = opts.get(b'devel-force-nodemap', False) | 446 force_nodemap = opts.get(b'devel-force-nodemap', False) |
| 447 return newversionflags, mmapindexthreshold, force_nodemap | 447 return newversionflags, mmapindexthreshold, force_nodemap |
| 448 | 448 |
| 449 def _get_data(self, filepath, mmap_threshold): | |
| 450 """return a file content with or without mmap | |
| 451 | |
| 452 If the file is missing return the empty string""" | |
| 453 try: | |
| 454 with self.opener(filepath) as fp: | |
| 455 if mmap_threshold is not None: | |
| 456 file_size = self.opener.fstat(fp).st_size | |
| 457 if file_size >= mmap_threshold: | |
| 458 # TODO: should .close() to release resources without | |
| 459 # relying on Python GC | |
| 460 return util.buffer(util.mmapread(fp)) | |
| 461 return fp.read() | |
| 462 except IOError as inst: | |
| 463 if inst.errno != errno.ENOENT: | |
| 464 raise | |
| 465 return b'' | |
| 466 | |
| 449 def _loadindex(self): | 467 def _loadindex(self): |
| 450 | 468 |
| 451 newversionflags, mmapindexthreshold, force_nodemap = self._init_opts() | 469 newversionflags, mmapindexthreshold, force_nodemap = self._init_opts() |
| 452 | 470 |
| 453 if self.postfix is None: | 471 if self.postfix is None: |
| 463 self._indexfile = index_file | 481 self._indexfile = index_file |
| 464 self._datafile = data_file | 482 self._datafile = data_file |
| 465 | 483 |
| 466 indexdata = b'' | 484 indexdata = b'' |
| 467 self._initempty = True | 485 self._initempty = True |
| 468 try: | 486 indexdata = self._get_data(self._indexfile, mmapindexthreshold) |
| 469 with self._indexfp() as f: | 487 if len(indexdata) > 0: |
| 470 if ( | 488 versionflags = INDEX_HEADER.unpack(indexdata[:4])[0] |
| 471 mmapindexthreshold is not None | 489 self._initempty = False |
| 472 and self.opener.fstat(f).st_size >= mmapindexthreshold | 490 else: |
| 473 ): | |
| 474 # TODO: should .close() to release resources without | |
| 475 # relying on Python GC | |
| 476 indexdata = util.buffer(util.mmapread(f)) | |
| 477 else: | |
| 478 indexdata = f.read() | |
| 479 if len(indexdata) > 0: | |
| 480 versionflags = INDEX_HEADER.unpack(indexdata[:4])[0] | |
| 481 self._initempty = False | |
| 482 else: | |
| 483 versionflags = newversionflags | |
| 484 except IOError as inst: | |
| 485 if inst.errno != errno.ENOENT: | |
| 486 raise | |
| 487 | |
| 488 versionflags = newversionflags | 491 versionflags = newversionflags |
| 489 | 492 |
| 490 flags = self._format_flags = versionflags & ~0xFFFF | 493 flags = self._format_flags = versionflags & ~0xFFFF |
| 491 fmt = self._format_version = versionflags & 0xFFFF | 494 fmt = self._format_version = versionflags & 0xFFFF |
| 492 | 495 |