upstream/mercurial-mirror Files · mercurial/scmposix.py

revlog: make compressed size comparisons consistent...

revlog: make compressed size comparisons consistent revlog.compress() compares the compressed size to the input size and throws away the compressed data if it is larger than the input. This is the correct thing to do, as storing compressed data that is larger than the input takes up more storage space and makes reading slower. However, the comparison was implemented inconsistently. For the streaming compression mode, we threw away the result if it was greater than or equal to the input size. But for the one-shot compression, we threw away the compression only if it was greater than the input size! This patch changes the comparison for the simple case so it is consistent with the streaming case. As a few tests demonstrate, this adds 1 byte to some revlog entries. This is because of an added 'u' header on the chunk. It seems somewhat wrong to increase the revlog size here. However, IMO the cost of 1 byte in storage is insignificant compared to the performance gains of avoiding decompression. This patch should invite questions around the heuristic for throwing away compressed data. For example, I'd argue we should be more liberal about rejecting compressed data, additionally doing so where the number of bytes saved fails to reach a threshold. But we can have this discussion another time.

Pulkit Goyal - - Load All Authors

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      from __future__ import absolute_import

      import array

      import errno

      import fcntl

      import os

      import sys

      from . import (

          encoding,

          osutil,

          pycompat,

      )

      def _rcfiles(path):

          rcs = [os.path.join(path, 'hgrc')]

          rcdir = os.path.join(path, 'hgrc.d')

          try:

              rcs.extend([os.path.join(rcdir, f)

                          for f, kind in osutil.listdir(rcdir)

                          if f.endswith(".rc")])

          except OSError:

              pass

          return rcs

      def systemrcpath():

          path = []

          if pycompat.sysplatform == 'plan9':

              root = 'lib/mercurial'

          else:

              root = 'etc/mercurial'

          # old mod_python does not set sys.argv

          if len(getattr(sys, 'argv', [])) > 0:

              p = os.path.dirname(os.path.dirname(pycompat.sysargv[0]))

              if p != '/':

                  path.extend(_rcfiles(os.path.join(p, root)))

          path.extend(_rcfiles('/' + root))

          return path

      def userrcpath():

          if pycompat.sysplatform == 'plan9':

              return [encoding.environ['home'] + '/lib/hgrc']

          else:

              return [os.path.expanduser('~/.hgrc')]

      def termsize(ui):

          try:

              import termios

              TIOCGWINSZ = termios.TIOCGWINSZ  # unavailable on IRIX (issue3449)

          except (AttributeError, ImportError):

              return 80, 24

          for dev in (ui.ferr, ui.fout, ui.fin):

              try:

                  try:

                      fd = dev.fileno()

                  except AttributeError:

                      continue

                  if not os.isatty(fd):

                      continue

                  arri = fcntl.ioctl(fd, TIOCGWINSZ, '\0' * 8)

                  height, width = array.array('h', arri)[:2]

                  if width > 0 and height > 0:

                      return width, height

              except ValueError:

                  pass

              except IOError as e:

                  if e[0] == errno.EINVAL:

                      pass

                  else:

                      raise

          return 80, 24

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				from __future__ import absolute_import

				import array
				import errno
				import fcntl
				import os
				import sys

				from . import (
				encoding,
				osutil,
				pycompat,
				)

				def _rcfiles(path):
				rcs = [os.path.join(path, 'hgrc')]
				rcdir = os.path.join(path, 'hgrc.d')
				try:
				rcs.extend([os.path.join(rcdir, f)
				for f, kind in osutil.listdir(rcdir)
				if f.endswith(".rc")])
				except OSError:
				pass
				return rcs

				def systemrcpath():
				path = []
				if pycompat.sysplatform == 'plan9':
				root = 'lib/mercurial'
				else:
				root = 'etc/mercurial'
				# old mod_python does not set sys.argv
				if len(getattr(sys, 'argv', [])) > 0:
				p = os.path.dirname(os.path.dirname(pycompat.sysargv[0]))
				if p != '/':
				path.extend(_rcfiles(os.path.join(p, root)))
				path.extend(_rcfiles('/' + root))
				return path

				def userrcpath():
				if pycompat.sysplatform == 'plan9':
				return [encoding.environ['home'] + '/lib/hgrc']
				else:
				return [os.path.expanduser('~/.hgrc')]

				def termsize(ui):
				try:
				import termios
				TIOCGWINSZ = termios.TIOCGWINSZ # unavailable on IRIX (issue3449)
				except (AttributeError, ImportError):
				return 80, 24

				for dev in (ui.ferr, ui.fout, ui.fin):
				try:
				try:
				fd = dev.fileno()
				except AttributeError:
				continue
				if not os.isatty(fd):
				continue
				arri = fcntl.ioctl(fd, TIOCGWINSZ, '\0' * 8)
				height, width = array.array('h', arri)[:2]
				if width > 0 and height > 0:
				return width, height
				except ValueError:
				pass
				except IOError as e:
				if e[0] == errno.EINVAL:
				pass
				else:
				raise
				return 80, 24