view contrib/packagelib.sh @ 29567:7e2b389418da

perf: import newer modules separately for earlier Mercurial

demandimport of early Mercurial loads an imported module immediately,
if a module is imported absolutely by "from a import b" style. Recent
perf.py satisfies this condition, because it does:

  - have "from __future__ import absolute_import" line
  - use "from a import b" style for modules in "mercurial" package

Before this patch, importing modules below prevents perf.py from being
loaded by earlier Mercurial, because these aren't available in such
Mercurial, even though there are some code paths for Mercurial earlier
than 1.9.

  - branchmap 2.5 (or bcee63733aad)
  - repoview  2.5 (or 3a6ddacb7198)
  - obsolete  2.3 (or ad0d6c2b3279)
  - scmutil   1.9 (or 8b252e826c68)

For example, setting "_prereadsize" attribute in perfindex() and
perfnodelookup() is effective only with Mercurial earlier than 1.8 (or
61c9bc3da402).

After this patch, "mercurial.error" is the only blocker in "from
mercurial import" statement for loading perf.py with Mercurial earlier
than 1.2. This patch ignores it, because just importing it separately
isn't enough.

# Extract version number into 4 parts, some of which may be empty:
#
# version: the numeric part of the most recent tag. Will always look like 1.3.
#
# type: if an rc build, "rc", otherwise empty
#
# distance: the distance from the nearest tag, or empty if built from a tag
#
# node: the node|short hg was built from, or empty if built from a tag
gethgversion() {
    make clean
    make local || make local PURE=--pure
    HG="$PWD/hg"

    $HG version > /dev/null || { echo 'abort: hg version failed!'; exit 1 ; }

    hgversion=`$HG version | sed -ne 's/.*(version \(.*\))$/\1/p'`

    if echo $hgversion | grep + > /dev/null 2>&1 ; then
        tmp=`echo $hgversion | cut -d+ -f 2`
        hgversion=`echo $hgversion | cut -d+ -f 1`
        distance=`echo $tmp | cut -d- -f 1`
        node=`echo $tmp | cut -d- -f 2`
    else
        distance=''
        node=''
    fi
    if echo $hgversion | grep -- '-' > /dev/null 2>&1; then
        version=`echo $hgversion | cut -d- -f1`
        type=`echo $hgversion | cut -d- -f2`
    else
        version=$hgversion
        type=''
    fi
}