This is an archive of the discontinued Mercurial Phabricator instance.

Differential D1392

bundle2: inline changegroup.readexactly()
ClosedPublic

Authored by indygreg on Nov 14 2017, 1:26 AM.

Details

Reviewers
durin42
Group Reviewers
hg-reviewers
Commits
rHG1fb0846ad792: bundle2: inline changegroup.readexactly()
Summary

Profiling reveals this loop is pretty tight. Literally any
function call elimination can make a big difference.

This commit inlines the relatively trivial changegroup.readexactly()
method inside the loop.

The results with hg perfbundleread on a bundle of the Firefox repo
speak for themselves:

! read(8k)
! wall 0.679730 comb 0.680000 user 0.140000 sys 0.540000 (best of 15)
! read(16k)
! wall 0.577228 comb 0.570000 user 0.080000 sys 0.490000 (best of 17)
! read(32k)
! wall 0.516060 comb 0.520000 user 0.040000 sys 0.480000 (best of 20)
! read(128k)
! wall 0.496378 comb 0.490000 user 0.010000 sys 0.480000 (best of 20)
! bundle2 iterparts()
! wall 3.460903 comb 3.460000 user 2.760000 sys 0.700000 (best of 3)
! wall 3.056811 comb 3.050000 user 2.340000 sys 0.710000 (best of 4)
! bundle2 iterparts() seekable
! wall 4.312722 comb 4.310000 user 3.480000 sys 0.830000 (best of 3)
! wall 4.007676 comb 4.000000 user 3.170000 sys 0.830000 (best of 3)
! bundle2 part seek()
! wall 6.754764 comb 6.740000 user 3.970000 sys 2.770000 (best of 3)
! wall 6.267110 comb 6.250000 user 3.480000 sys 2.770000 (best of 3)
! bundle2 part read(8k)
! wall 3.668004 comb 3.660000 user 2.960000 sys 0.700000 (best of 3)
! wall 3.404164 comb 3.400000 user 2.650000 sys 0.750000 (best of 3)
! bundle2 part read(16k)
! wall 3.489196 comb 3.480000 user 2.750000 sys 0.730000 (best of 3)
! wall 3.197972 comb 3.200000 user 2.490000 sys 0.710000 (best of 4)
! bundle2 part read(32k)
! wall 3.388569 comb 3.380000 user 2.640000 sys 0.740000 (best of 3)
! wall 3.060557 comb 3.060000 user 2.340000 sys 0.720000 (best of 4)
! bundle2 part read(128k)
! wall 3.276415 comb 3.270000 user 2.560000 sys 0.710000 (best of 4)
! wall 2.952209 comb 2.950000 user 2.230000 sys 0.720000 (best of 4)

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

indygreg created this revision.Nov 14 2017, 1:26 AM
durin42 accepted this revision.Nov 20 2017, 6:42 PM
This revision is now accepted and ready to land.Nov 20 2017, 6:42 PM
Closed by commit rHG1fb0846ad792: bundle2: inline changegroup.readexactly() (authored by indygreg). · Explain WhyNov 20 2017, 6:50 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mmercurial/bundle2.py (18 lines)

Diff 3696

mercurial/bundle2.py

Part payload data consists of framed chunks. This function takes Part payload data consists of framed chunks. This function takes
a file handle and emits those chunks. a file handle and emits those chunks.
""" """
dolog = ui.configbool('devel', 'bundle2.debug') dolog = ui.configbool('devel', 'bundle2.debug')
debug = ui.debug debug = ui.debug
headersize = struct.calcsize(_fpayloadsize) headersize = struct.calcsize(_fpayloadsize)
readexactly = changegroup.readexactly readexactly = changegroup.readexactly
read = fh.read
chunksize = _unpack(_fpayloadsize, readexactly(fh, headersize))[0] chunksize = _unpack(_fpayloadsize, readexactly(fh, headersize))[0]
indebug(ui, 'payload chunk size: %i' % chunksize) indebug(ui, 'payload chunk size: %i' % chunksize)
# changegroup.readexactly() is inlined below for performance.
while chunksize: while chunksize:
if chunksize >= 0: if chunksize >= 0:
yield readexactly(fh, chunksize) s = read(chunksize)
if len(s) < chunksize:
raise error.Abort(_('stream ended unexpectedly '
' (got %d bytes, expected %d)') %
(len(s), chunksize))
yield s
elif chunksize == flaginterrupt: elif chunksize == flaginterrupt:
# Interrupt "signal" detected. The regular stream is interrupted # Interrupt "signal" detected. The regular stream is interrupted
# and a bundle2 part follows. Consume it. # and a bundle2 part follows. Consume it.
interrupthandler(ui, fh)() interrupthandler(ui, fh)()
else: else:
raise error.BundleValueError( raise error.BundleValueError(
'negative payload chunk size: %s' % chunksize) 'negative payload chunk size: %s' % chunksize)
chunksize = _unpack(_fpayloadsize, readexactly(fh, headersize))[0] s = read(headersize)
if len(s) < headersize:
raise error.Abort(_('stream ended unexpectedly '
' (got %d bytes, expected %d)') %
(len(s), chunksize))
chunksize = _unpack(_fpayloadsize, s)[0]
# indebug() inlined for performance. # indebug() inlined for performance.
if dolog: if dolog:
debug('bundle2-input: payload chunk size: %i\n' % chunksize) debug('bundle2-input: payload chunk size: %i\n' % chunksize)
class unbundlepart(unpackermixin): class unbundlepart(unpackermixin):
"""a bundle part read from a bundle""" """a bundle part read from a bundle"""