tests/test-mq-header-from

findrenames: Optimise "addremove -s100" by matching files by their SHA1 hashes.

We speed up 'findrenames' for the usecase when a user specifies they
want a similarity of 100% by matching files by their exact SHA1 hash
value. This reduces the number of comparisons required to find exact
matches from O(n^2) to O(n).

While it would be nice if we could just use mercurial's pre-calculated
SHA1 hash for existing files, this hash includes the file's ancestor
information making it unsuitable for our purposes. Instead, we calculate
the hash of old content from scratch.

The following benchmarks were taken on the current head of crew:

addremove 100% similarity:
  rm -rf *; hg up -C; mv tests tests.new
  hg --time addremove -s100 --dry-run

  before:  real 176.350 secs (user 128.890+0.000 sys 47.430+0.000)
  after:   real   2.130 secs (user   1.890+0.000 sys  0.240+0.000)

addremove 75% similarity:
  rm -rf *; hg up -C; mv tests tests.new; \
      for i in tests.new/*; do echo x >> $i; done
  hg --time addremove -s75  --dry-run

  before: real 264.560 secs (user 215.130+0.000 sys 49.410+0.000)
  after:  real 218.710 secs (user 172.790+0.000 sys 45.870+0.000)

#!/bin/sh

echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
echo "[diff]" >> $HGRCPATH
echo "nodates=true" >> $HGRCPATH


catlog() {
    cat .hg/patches/$1.patch | sed -e "s/^diff \-r [0-9a-f]* /diff -r ... /" \
                                   -e "s/^\(# Parent \).*/\1/"
    hg log --template "{rev}: {desc} - {author}\n"
}

runtest() {
    echo ==== init
    hg init a
    cd a
    hg qinit


    echo ==== qnew -U
    hg qnew -U 1.patch
    catlog 1

    echo ==== qref
    echo "1" >1
    hg add
    hg qref
    catlog 1

    echo ==== qref -u
    hg qref -u mary
    catlog 1

    echo ==== qnew
    hg qnew 2.patch
    echo "2" >2
    hg add
    hg qref
    catlog 2

    echo ==== qref -u
    hg qref -u jane
    catlog 2


    echo ==== qnew -U -m
    hg qnew -U -m "Three" 3.patch
    catlog 3

    echo ==== qref
    echo "3" >3
    hg add
    hg qref
    catlog 3

    echo ==== qref -m
    hg qref -m "Drei"
    catlog 3

    echo ==== qref -u
    hg qref -u mary
    catlog 3

    echo ==== qref -u -m
    hg qref -u maria -m "Three (again)"
    catlog 3

    echo ==== qnew -m
    hg qnew -m "Four" 4.patch
    echo "4" >4of t
    hg add
    hg qref
    catlog 4

    echo ==== qref -u
    hg qref -u jane
    catlog 4


    echo ==== qnew with HG header
    hg qnew --config 'mq.plain=true' 5.patch
    hg qpop
    echo "# HG changeset patch" >>.hg/patches/5.patch
    echo "# User johndoe" >>.hg/patches/5.patch
    hg qpush 2>&1 | grep 'now at'
    catlog 5

    echo ==== hg qref
    echo "5" >5
    hg add
    hg qref
    catlog 5

    echo ==== hg qref -U
    hg qref -U
    catlog 5

    echo ==== hg qref -u
    hg qref -u johndeere
    catlog 5


    echo ==== qnew with plain header
    hg qnew --config 'mq.plain=true' -U 6.patch
    hg qpop
    hg qpush 2>&1 | grep 'now at'
    catlog 6

    echo ==== hg qref
    echo "6" >6
    hg add
    hg qref
    catlog 6

    echo ==== hg qref -U
    hg qref -U
    catlog 6

    echo ==== hg qref -u
    hg qref -u johndeere
    catlog 6


    echo ==== "qpop -a / qpush -a"
    hg qpop -a
    hg qpush -a
    hg log --template "{rev}: {desc} - {author}\n"
}


echo ======= plain headers

echo "[mq]" >> $HGRCPATH
echo "plain=true" >> $HGRCPATH

mkdir sandbox
(cd sandbox ; runtest)
rm -r sandbox


echo ======= hg headers

echo "plain=false" >> $HGRCPATH

mkdir sandbox
(cd sandbox ; runtest)
rm -r sandbox

runtest