diff options
Diffstat (limited to 'Lib/shutil.py')
| -rw-r--r-- | Lib/shutil.py | 72 |
1 files changed, 39 insertions, 33 deletions
diff --git a/Lib/shutil.py b/Lib/shutil.py index 09a5727..a4aa0df 100644 --- a/Lib/shutil.py +++ b/Lib/shutil.py @@ -43,15 +43,16 @@ try: except ImportError: getgrnam = None +_WINDOWS = os.name == 'nt' posix = nt = None if os.name == 'posix': import posix -elif os.name == 'nt': +elif _WINDOWS: import nt -COPY_BUFSIZE = 1024 * 1024 if os.name == 'nt' else 16 * 1024 +COPY_BUFSIZE = 1024 * 1024 if _WINDOWS else 16 * 1024 _HAS_SENDFILE = posix and hasattr(os, "sendfile") -_HAS_FCOPYFILE = posix and hasattr(posix, "_fcopyfile") # OSX +_HAS_FCOPYFILE = posix and hasattr(posix, "_fcopyfile") # macOS __all__ = ["copyfileobj", "copyfile", "copymode", "copystat", "copy", "copy2", "copytree", "move", "rmtree", "Error", "SpecialFileError", @@ -88,9 +89,9 @@ class _GiveupOnFastCopy(Exception): file copy when fast-copy functions fail to do so. """ -def _fastcopy_osx(fsrc, fdst, flags): +def _fastcopy_fcopyfile(fsrc, fdst, flags): """Copy a regular file content or metadata by using high-performance - fcopyfile(3) syscall (OSX). + fcopyfile(3) syscall (macOS). """ try: infd = fsrc.fileno() @@ -168,8 +169,11 @@ def _fastcopy_sendfile(fsrc, fdst): break # EOF offset += sent -def _copybinfileobj(fsrc, fdst, length=COPY_BUFSIZE): - """Copy 2 regular file objects open in binary mode.""" +def _copyfileobj_readinto(fsrc, fdst, length=COPY_BUFSIZE): + """readinto()/memoryview() based variant of copyfileobj(). + *fsrc* must support readinto() method and both files must be + open in binary mode. + """ # Localize variable access to minimize overhead. fsrc_readinto = fsrc.readinto fdst_write = fdst.write @@ -179,28 +183,21 @@ def _copybinfileobj(fsrc, fdst, length=COPY_BUFSIZE): if not n: break elif n < length: - fdst_write(mv[:n]) + with mv[:n] as smv: + fdst.write(smv) else: fdst_write(mv) -def _is_binary_files_pair(fsrc, fdst): - return hasattr(fsrc, 'readinto') and \ - isinstance(fsrc, io.BytesIO) or 'b' in getattr(fsrc, 'mode', '') and \ - isinstance(fdst, io.BytesIO) or 'b' in getattr(fdst, 'mode', '') - def copyfileobj(fsrc, fdst, length=COPY_BUFSIZE): """copy data from file-like object fsrc to file-like object fdst""" - if _is_binary_files_pair(fsrc, fdst): - _copybinfileobj(fsrc, fdst, length=length) - else: - # Localize variable access to minimize overhead. - fsrc_read = fsrc.read - fdst_write = fdst.write - while 1: - buf = fsrc_read(length) - if not buf: - break - fdst_write(buf) + # Localize variable access to minimize overhead. + fsrc_read = fsrc.read + fdst_write = fdst.write + while True: + buf = fsrc_read(length) + if not buf: + break + fdst_write(buf) def _samefile(src, dst): # Macintosh, Unix. @@ -215,7 +212,7 @@ def _samefile(src, dst): os.path.normcase(os.path.abspath(dst))) def copyfile(src, dst, *, follow_symlinks=True): - """Copy data from src to dst. + """Copy data from src to dst in the most efficient way possible. If follow_symlinks is not set and src is a symbolic link, a new symlink will be created instead of copying the file it points to. @@ -224,7 +221,8 @@ def copyfile(src, dst, *, follow_symlinks=True): if _samefile(src, dst): raise SameFileError("{!r} and {!r} are the same file".format(src, dst)) - for fn in [src, dst]: + file_size = 0 + for i, fn in enumerate([src, dst]): try: st = os.stat(fn) except OSError: @@ -234,26 +232,34 @@ def copyfile(src, dst, *, follow_symlinks=True): # XXX What about other special files? (sockets, devices...) if stat.S_ISFIFO(st.st_mode): raise SpecialFileError("`%s` is a named pipe" % fn) + if _WINDOWS and i == 0: + file_size = st.st_size if not follow_symlinks and os.path.islink(src): os.symlink(os.readlink(src), dst) else: with open(src, 'rb') as fsrc, open(dst, 'wb') as fdst: - if _HAS_SENDFILE: + # macOS + if _HAS_FCOPYFILE: try: - _fastcopy_sendfile(fsrc, fdst) + _fastcopy_fcopyfile(fsrc, fdst, posix._COPYFILE_DATA) return dst except _GiveupOnFastCopy: pass - - if _HAS_FCOPYFILE: + # Linux / Solaris + elif _HAS_SENDFILE: try: - _fastcopy_osx(fsrc, fdst, posix._COPYFILE_DATA) + _fastcopy_sendfile(fsrc, fdst) return dst except _GiveupOnFastCopy: pass + # Windows, see: + # https://github.com/python/cpython/pull/7160#discussion_r195405230 + elif _WINDOWS and file_size > 0: + _copyfileobj_readinto(fsrc, fdst, min(file_size, COPY_BUFSIZE)) + return dst - _copybinfileobj(fsrc, fdst) + copyfileobj(fsrc, fdst) return dst @@ -1147,7 +1153,7 @@ if hasattr(os, 'statvfs'): used = (st.f_blocks - st.f_bfree) * st.f_frsize return _ntuple_diskusage(total, used, free) -elif os.name == 'nt': +elif _WINDOWS: __all__.append('disk_usage') _ntuple_diskusage = collections.namedtuple('usage', 'total used free') |