Mercurial > hg
diff mercurial/util.py @ 47400:9b841267253c
util: add `nb_bytes` argument to `copyfile` to partially copy a file
When set, this allow to copy only the first `nb_bytes` of a file. This will be
useful for censor/strip operation with revlogv2.
Differential Revision: https://phab.mercurial-scm.org/D10798
author | Pierre-Yves David <pierre-yves.david@octobus.net> |
---|---|
date | Sun, 30 May 2021 18:08:52 +0200 |
parents | bcafcd779d2e |
children | 9ea525216edb |
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--- a/mercurial/util.py Sun May 30 16:20:36 2021 +0200 +++ b/mercurial/util.py Sun May 30 18:08:52 2021 +0200 @@ -1909,7 +1909,9 @@ } -def copyfile(src, dest, hardlink=False, copystat=False, checkambig=False): +def copyfile( + src, dest, hardlink=False, copystat=False, checkambig=False, nb_bytes=None +): """copy a file, preserving mode and optionally other stat info like atime/mtime @@ -1918,6 +1920,8 @@ repo.wlock). copystat and checkambig should be exclusive. + + nb_bytes: if set only copy the first `nb_bytes` of the source file. """ assert not (copystat and checkambig) oldstat = None @@ -1937,6 +1941,9 @@ if hardlink: try: oslink(src, dest) + if nb_bytes is not None: + m = "the `nb_bytes` argument is incompatible with `hardlink`" + raise error.ProgrammingError(m) return except (IOError, OSError): pass # fall back to normal copy @@ -1944,6 +1951,9 @@ os.symlink(os.readlink(src), dest) # copytime is ignored for symlinks, but in general copytime isn't needed # for them anyway + if nb_bytes is not None: + m = "cannot use `nb_bytes` on a symlink" + raise error.ProgrammingError(m) else: try: shutil.copyfile(src, dest) @@ -1960,6 +1970,10 @@ oldstat.stat[stat.ST_MTIME] + 1 ) & 0x7FFFFFFF os.utime(dest, (advanced, advanced)) + # We could do something smarter using `copy_file_range` call or similar + if nb_bytes is not None: + with open(dest, mode='r+') as f: + f.truncate(nb_bytes) except shutil.Error as inst: raise error.Abort(stringutil.forcebytestr(inst))