view tests/test-eol-add.t @ 27430:e240e914d226 stable

revlog: seek to end of file before writing (issue4943)

Revlogs were recently refactored to open file handles in "a+" and use a
persistent file handle for reading and writing. This drastically
reduced the number of file handles being opened.

Unfortunately, it appears that some versions of Solaris lose the file
offset when performing a write after the handle has been seeked.

The simplest workaround is to seek to EOF on files opened in a+ mode
before writing to them, which is what this patch does.

Ideally, this code would exist in the vfs layer. However, this would
require creating a proxy class for file objects in order to provide a
custom implementation of write(). This would add overhead. Since
revlogs are the only files we open in a+ mode, the one-off workaround
in revlog.py should be sufficient.

This patch appears to have little to no impact on performance on my
Linux machine.

Test adding .hgeol

  $ cat >> $HGRCPATH <<EOF
  > [diff]
  > git = 1
  > EOF
  $ seteol () {
  >     if [ $1 = "LF" ]; then
  >         EOL='\n'
  >     else
  >         EOL='\r\n'
  >     fi
  > }
  $ makerepo () {
  >     echo
  >     echo "# ==== setup repository ===="
  >     echo '% hg init'
  >     hg init repo
  >     cd repo
  >     printf "first\nsecond\nthird\n" > a.txt
  >     hg commit -d '100 0' --addremove -m 'LF commit'
  >     cd ..
  > }
  $ dotest () {
  >     seteol $1
  >     echo
  >     echo "% hg clone repo repo-$1"
  >     hg clone repo repo-$1
  >     cd repo-$1
  >     cat > .hg/hgrc <<EOF
  > [extensions]
  > eol =
  > [eol]
  > native = LF
  > EOF
  >     cat > .hgeol <<EOF
  > [patterns]
  > **.txt = native
  > [repository]
  > native = $1
  > EOF
  >     echo '% hg add .hgeol'
  >     hg add .hgeol
  >     echo '% hg status'
  >     hg status
  >     echo '% hg commit'
  >     hg commit -d '200 0' -m 'Added .hgeol file'
  >     echo '% hg status'
  >     hg status
  >     echo '% hg tip -p'
  >     hg tip -p
  >     cd ..
  >     rm -r repo-$1
  > }
  $ makerepo
  
  # ==== setup repository ====
  % hg init
  adding a.txt
  $ dotest LF
  
  % hg clone repo repo-LF
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg add .hgeol
  % hg status
  A .hgeol
  % hg commit
  % hg status
  % hg tip -p
  changeset:   1:33503edb53b0
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:03:20 1970 +0000
  summary:     Added .hgeol file
  
  diff --git a/.hgeol b/.hgeol
  new file mode 100644
  --- /dev/null
  +++ b/.hgeol
  @@ -0,0 +1,4 @@
  +[patterns]
  +**.txt = native
  +[repository]
  +native = LF
  
  $ dotest CRLF
  
  % hg clone repo repo-CRLF
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  % hg add .hgeol
  % hg status
  M a.txt
  A .hgeol
  % hg commit
  % hg status
  % hg tip -p
  changeset:   1:6e64eaa9eb23
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:03:20 1970 +0000
  summary:     Added .hgeol file
  
  diff --git a/.hgeol b/.hgeol
  new file mode 100644
  --- /dev/null
  +++ b/.hgeol
  @@ -0,0 +1,4 @@
  +[patterns]
  +**.txt = native
  +[repository]
  +native = CRLF
  diff --git a/a.txt b/a.txt
  --- a/a.txt
  +++ b/a.txt
  @@ -1,3 +1,3 @@
  -first
  -second
  -third
  +first\r (esc)
  +second\r (esc)
  +third\r (esc)
  
  $ rm -r repo