view tests/test-revset-outgoing.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
  > [alias]
  > tlog = log --template "{rev}:{node|short}: '{desc}' {branches}\n"
  > tglog = tlog -G
  > tout = out --template "{rev}:{node|short}: '{desc}' {branches}\n"
  > EOF

  $ hg init a
  $ cd a

  $ echo a > a
  $ hg ci -Aqm0

  $ echo foo >> a
  $ hg ci -Aqm1

  $ hg up -q 0

  $ hg branch stable
  marked working directory as branch stable
  (branches are permanent and global, did you want a bookmark?)
  $ echo bar >> a
  $ hg ci -qm2

  $ hg tglog
  @  2:7bee6c3bea3a: '2' stable
  |
  | o  1:3560197d8331: '1'
  |/
  o  0:f7b1eb17ad24: '0'
  

  $ cd ..

  $ hg clone -q a#stable b

  $ cd b
  $ cat .hg/hgrc
  # example repository config (see "hg help config" for more info)
  [paths]
  default = $TESTTMP/a#stable (glob)
  
  # path aliases to other clones of this repo in URLs or filesystem paths
  # (see "hg help config.paths" for more info)
  #
  # default-push = ssh://[e-mail]/hg/jdoes-fork
  # my-fork      = ssh://[e-mail]/hg/jdoes-fork
  # my-clone     = /home/jdoe/jdoes-clone
  
  [ui]
  # name and email (local to this repository, optional), e.g.
  # username = Jane Doe <[e-mail]>

  $ echo red >> a
  $ hg ci -qm3

  $ hg up -q default

  $ echo blue >> a
  $ hg ci -qm4

  $ hg tglog
  @  3:f0461977a3db: '4'
  |
  | o  2:1d4099801a4e: '3' stable
  | |
  | o  1:7bee6c3bea3a: '2' stable
  |/
  o  0:f7b1eb17ad24: '0'
  

  $ hg tout
  comparing with $TESTTMP/a (glob)
  searching for changes
  2:1d4099801a4e: '3' stable

  $ hg tlog -r 'outgoing()'
  2:1d4099801a4e: '3' stable

  $ hg tout ../a#default
  comparing with ../a
  searching for changes
  3:f0461977a3db: '4' 

  $ hg tlog -r 'outgoing("../a#default")'
  3:f0461977a3db: '4' 

  $ echo "green = ../a#default" >> .hg/hgrc

  $ cat .hg/hgrc
  # example repository config (see "hg help config" for more info)
  [paths]
  default = $TESTTMP/a#stable (glob)
  
  # path aliases to other clones of this repo in URLs or filesystem paths
  # (see "hg help config.paths" for more info)
  #
  # default-push = ssh://[e-mail]/hg/jdoes-fork
  # my-fork      = ssh://[e-mail]/hg/jdoes-fork
  # my-clone     = /home/jdoe/jdoes-clone
  
  [ui]
  # name and email (local to this repository, optional), e.g.
  # username = Jane Doe <[e-mail]>
  green = ../a#default

  $ hg tout green
  comparing with green
  abort: repository green not found!
  [255]

  $ hg tlog -r 'outgoing("green")'
  abort: repository green not found!
  [255]

  $ cd ..