view contrib/tcsh_completion_build.sh @ 32151:4d504e541d3d

rebase: use matcher to optimize manifestmerge

The old merge code would call manifestmerge and calculate the complete diff
between the source to the destination. In many cases, like rebase, the vast
majority of differences between the source and destination are irrelevant
because they are differences between the destination and the common ancestor
only, and therefore don't affect the merge. Since most actions are 'keep', all
the effort to compute them is wasted.

Instead, let's compute the difference between the source and the common ancestor
and only perform the diff of those files against the merge destination. When
using treemanifest, this lets us avoid loading almost the entire tree when
rebasing from a very old ancestor. This speeds up rebase of an old stack of 27
commits by 20x.

In mozilla-central, without treemanifest, when rebasing a commit from
default~100000 to default, this speeds up the manifestmerge step from 2.6s to
1.2s.  However, the additional diff adds an overhead to all manifestmerge calls,
especially for flat manifests. When rebasing a commit from default~1 to default
it appears to add 100ms in mozilla-central. While we could put this optimization
behind a flag, I think the fact that it makes merge O(number of changes being
applied) instead of O(number of changes between X and Y) justifies it.

#!/bin/sh

#
# tcsh_completion_build.sh - script to generate tcsh completion
#
#
# Copyright (C) 2005 TK Soh.
#
# This is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
#
# Description
# -----------
# This script generates a tcsh source file to support completion
# of Mercurial commands and options.
#
# Instruction:
# -----------
# Run this script to generate the tcsh source file, and source
# the file to add command completion support for Mercurial.
#
#    tcsh% tcsh_completion.sh FILE
#    tcsh% source FILE
#
# If FILE is not specified, tcsh_completion will be generated.
#
# Bugs:
# ----
# 1. command specific options are not supported
# 2. hg commands must be specified immediately after 'hg'.
#

tcsh_file=${1-tcsh_completion}

hg_commands=`hg --debug help | \
        sed -e '1,/^list of commands:/d' \
            -e '/^enabled extensions:/,$d' \
            -e '/^additional help topics:/,$d' \
            -e '/^ [^ ]/!d; s/[,:]//g;' | \
        xargs -n5 | \
        sed -e '$!s/$/ \\\\/g; 2,$s/^ */    /g'`

hg_global_options=`hg -v help | \
        sed -e '1,/global/d;/^ *-/!d; s/ [^- ].*//' | \
        sed -e 's/ *$//; $!s/$/ \\\\/g; 2,$s/^ */    /g'`

hg_version=`hg version | sed -e '1q'`

script_name=`basename $0`

cat > $tcsh_file <<END
#
# tcsh completion for Mercurial
#
# This file has been auto-generated by $script_name for
# $hg_version
#
# Copyright (C) 2005 TK Soh.
#
# This is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free
# Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#

complete hg \\
  'n/--cwd/d/' 'n/-R/d/' 'n/--repository/d/' \\
  'C/-/($hg_global_options)/' \\
  'p/1/($hg_commands)/'

END