view tests/test-convert-datesort.t @ 27475:a2e2a8fa5fd1

revlog: avoid string slice when decompressing u* chunks

Revlog chunks can be stored uncompressed. If the first byte of the
raw data is \0, we store the data as is. Else we prefix it with 'u'.

Before, we performed a string slice to strip out the 'u' prefix.
With this patch, we use a buffer to avoid an extra memory copy and
associated garbage collection overhead.

I was unable to verify any performance impact of this patch. For both
mozilla-central and the hg repos, the number of manifest revisions
with 'u' prefixes is very small - under 1%. So this change likely
isn't called enough to have an impact on manifest reading. However,
the reasoning behind this change is solid, so it should be safe.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > convert=
  > EOF
  $ hg init t
  $ cd t
  $ echo a >> a
  $ hg ci -Am a0 -d '1 0'
  adding a
  $ hg branch brancha
  marked working directory as branch brancha
  (branches are permanent and global, did you want a bookmark?)
  $ echo a >> a
  $ hg ci -m a1 -d '2 0'
  $ echo a >> a
  $ hg ci -m a2 -d '3 0'
  $ echo a >> a
  $ hg ci -m a3 -d '4 0'
  $ hg up -C 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg branch branchb
  marked working directory as branch branchb
  $ echo b >> b
  $ hg ci -Am b0 -d '6 0'
  adding b
  $ hg up -C brancha
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo a >> a
  $ hg ci -m a4 -d '5 0'
  $ echo a >> a
  $ hg ci -m a5 -d '7 0'
  $ echo a >> a
  $ hg ci -m a6 -d '8 0'
  $ hg up -C branchb
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo b >> b
  $ hg ci -m b1 -d '9 0'
  $ hg up -C 0
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo c >> c
  $ hg branch branchc
  marked working directory as branch branchc
  $ hg ci -Am c0 -d '10 0'
  adding c
  $ hg up -C brancha
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg ci --close-branch -m a7x -d '11 0'
  $ hg up -C branchb
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg ci --close-branch -m b2x -d '12 0'
  $ hg up -C branchc
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge branchb
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg ci -m c1 -d '13 0'
  $ cd ..

convert with datesort

  $ hg convert --datesort t t-datesort
  initializing destination t-datesort repository
  scanning source...
  sorting...
  converting...
  12 a0
  11 a1
  10 a2
  9 a3
  8 a4
  7 b0
  6 a5
  5 a6
  4 b1
  3 c0
  2 a7x
  1 b2x
  0 c1

graph converted repo

  $ hg -R t-datesort log -G --template '{rev} "{desc}"\n'
  o    12 "c1"
  |\
  | _  11 "b2x"
  | |
  | | _  10 "a7x"
  | | |
  o | |  9 "c0"
  | | |
  | o |  8 "b1"
  | | |
  | | o  7 "a6"
  | | |
  | | o  6 "a5"
  | | |
  | o |  5 "b0"
  |/ /
  | o  4 "a4"
  | |
  | o  3 "a3"
  | |
  | o  2 "a2"
  | |
  | o  1 "a1"
  |/
  o  0 "a0"
  

convert with datesort (default mode)

  $ hg convert t t-sourcesort
  initializing destination t-sourcesort repository
  scanning source...
  sorting...
  converting...
  12 a0
  11 a1
  10 a2
  9 a3
  8 b0
  7 a4
  6 a5
  5 a6
  4 b1
  3 c0
  2 a7x
  1 b2x
  0 c1

graph converted repo

  $ hg -R t-sourcesort log -G --template '{rev} "{desc}"\n'
  o    12 "c1"
  |\
  | _  11 "b2x"
  | |
  | | _  10 "a7x"
  | | |
  o | |  9 "c0"
  | | |
  | o |  8 "b1"
  | | |
  | | o  7 "a6"
  | | |
  | | o  6 "a5"
  | | |
  | | o  5 "a4"
  | | |
  | o |  4 "b0"
  |/ /
  | o  3 "a3"
  | |
  | o  2 "a2"
  | |
  | o  1 "a1"
  |/
  o  0 "a0"
  

convert with closesort

  $ hg convert --closesort t t-closesort
  initializing destination t-closesort repository
  scanning source...
  sorting...
  converting...
  12 a0
  11 a1
  10 a2
  9 a3
  8 b0
  7 a4
  6 a5
  5 a6
  4 a7x
  3 b1
  2 b2x
  1 c0
  0 c1

graph converted repo

  $ hg -R t-closesort log -G --template '{rev} "{desc}"\n'
  o    12 "c1"
  |\
  | o  11 "c0"
  | |
  _ |  10 "b2x"
  | |
  o |  9 "b1"
  | |
  | | _  8 "a7x"
  | | |
  | | o  7 "a6"
  | | |
  | | o  6 "a5"
  | | |
  | | o  5 "a4"
  | | |
  o | |  4 "b0"
  |/ /
  | o  3 "a3"
  | |
  | o  2 "a2"
  | |
  | o  1 "a1"
  |/
  o  0 "a0"