tests/test-subrepo-svn.out

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)

% create subversion repo
Checked out revision 0.
A         src
A         src/alpha
A         externals
A         externals/other
Adding         externals
Adding         externals/other
Adding         src
Adding         src/alpha
Transmitting file data ..
Committed revision 1.
At revision 1.
property 'svn:externals' set on 'src'
Sending        src

Committed revision 2.
% create hg repo
% first revision, no sub
adding a
% add first svn sub with leading whitespaces
committing subrepository s
% debugsub
path s
 source   file:///root/svn-repo/src
 revision 2

% change file in svn and hg, commit
committing subrepository s
Sending        s/alpha
Transmitting file data .
Committed revision 3.

Fetching external item into 's/externals'
External at revision 1.

At revision 3.
path s
 source   file:///root/svn-repo/src
 revision 3

% should be empty despite change to s/a

% add a commit from svn
U    alpha

Fetching external item into 'externals'
A    externals/other
Updated external to revision 1.

Updated to revision 3.
property 'svn:mime-type' set on 'alpha'
Sending        src/alpha
Transmitting file data .
Committed revision 4.
% this commit from hg will fail
committing subrepository s
abort: svn: Commit failed (details follow):
svn: File '/src/alpha' is out of date
% this commit fails because of meta changes
property 'svn:mime-type' set on 's/alpha'
committing subrepository s
abort: svn: Commit failed (details follow):
svn: File '/src/alpha' is out of date
% this commit fails because of externals changes
committing subrepository s
abort: cannot commit svn externals
% this commit fails because of externals meta changes
property 'svn:mime-type' set on 's/externals/other'
committing subrepository s
abort: cannot commit svn externals

% clone
updating to branch default
A    tc/s/alpha
 U   tc/s

Fetching external item into 'tc/s/externals'
A    tc/s/externals/other
Checked out external at revision 1.

Checked out revision 3.
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
% debugsub in clone
path s
 source   file:///root/svn-repo/src
 revision 3
% verify subrepo is contained within the repo directory
True