contrib/revsetbenchmarks.sh

util: add the code path to "cachefunc()" for the function taking no arguments

Before this patch, "util.cachefunc()" caches the value returned by the
specified function into dictionary "cache", even if the specified
function takes no arguments.

In such case, "cache" has at most one entry, and distinction between
entries in "cache" is meaningless.

This patch adds the code path to "cachefunc()" for the function taking
no arguments for efficiency: to store only one cached value, using
list "cache" is a little faster than using dictionary "cache".

#!/usr/bin/env bash

# Measure the performance of a list of revsets against multiple revisions
# defined by parameter. Checkout one by one and run perfrevset with every
# revset in the list to benchmark its performance.
#
# - First argument is a revset of mercurial own repo to runs against.
# - Second argument is the file from which the revset array will be taken
#   If second argument is omitted read it from standard input
#
# You should run this from the root of your mercurial repository.
#
# This script also does one run of the current version of mercurial installed
# to compare performance.

HG="hg update"
PERF="./hg --config extensions.perf=contrib/perf.py perfrevset"
BASE_PERF="hg --config extensions.perf=contrib/perf.py perfrevset"

TARGETS=$1
shift
# read from a file or from standard output
if [ $# -ne 0 ]; then
    readarray REVSETS < $1
else
    readarray REVSETS
fi

hg update --quiet

echo "Starting time benchmarking"
echo

echo "Revsets to benchmark"
echo "----------------------------"

for (( j = 0; j < ${#REVSETS[@]}; j++ ));
do
  echo "${j}) ${REVSETS[$j]}"
done

echo "----------------------------"
echo

# Benchmark baseline
echo "Benchmarking baseline"

for (( j = 0; j < ${#REVSETS[@]}; j++ ));
  do
    echo -n "${j}) "
    $BASE_PERF "${REVSETS[$j]}"
done

echo
echo

# Benchmark revisions
for i in $(hg log --template='{rev}\n' --rev $TARGETS);
do
  echo "----------------------------"
  echo -n "Revision: "
  hg log -r $i --template "{desc|firstline}"

  echo "----------------------------"
  $HG $i
  for (( j = 0; j < ${#REVSETS[@]}; j++ ));
  do
    echo -n "${j}) "
    $PERF "${REVSETS[$j]}"
  done
  echo "----------------------------"
done

$HG

# Benchmark current code
echo "Benchmarking current code"

for (( j = 0; j < ${#REVSETS[@]}; j++ ));
  do
    echo -n "${j}) "
    $PERF "${REVSETS[$j]}"
done


echo
echo "Time benchmarking finished"