changeset 30774:eaa5607132a2

debugcommands: stub for debugupgraderepo command Currently, if Mercurial introduces a new repository/store feature or changes behavior of an existing feature, users must perform an `hg clone` to create a new repository with hopefully the correct/optimal settings. Unfortunately, even `hg clone` may not give the correct results. For example, if you do a local `hg clone`, you may get hardlinks to revlog files that inherit the old state. If you `hg clone` from a remote or `hg clone --pull`, changegroup application may bypass some optimization, such as converting to generaldelta. Optimizing a repository is harder than it seems and requires more than a simple `hg` command invocation. This commit starts the process of changing that. We introduce `hg debugupgraderepo`, a command that performs an in-place upgrade of a repository to use new, optimal features. The command is just a stub right now. Features will be added in subsequent commits. This commit does foreshadow some of the behavior of the new command, notably that it doesn't do anything by default and that it takes arguments that influence what actions it performs. These will be explained more in subsequent commits.
author Gregory Szorc <gregory.szorc@gmail.com>
date Thu, 24 Nov 2016 16:24:09 -0800
parents c390b40fe1d7
children 513d68a90398
files mercurial/debugcommands.py tests/test-completion.t tests/test-help.t tests/test-upgrade-repo.t
diffstat 4 files changed, 34 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/debugcommands.py	Wed Jan 11 21:47:19 2017 -0500
+++ b/mercurial/debugcommands.py	Thu Nov 24 16:24:09 2016 -0800
@@ -849,3 +849,28 @@
         if pp[1] != nullid:
             ui.write("\t%d -> %d\n" % (r.rev(pp[1]), i))
     ui.write("}\n")
+
+@command('debugupgraderepo', [
+    ('o', 'optimize', [], _('extra optimization to perform'), _('NAME')),
+    ('', 'run', False, _('performs an upgrade')),
+])
+def debugupgraderepo(ui, repo, run=False, optimize=None):
+    """upgrade a repository to use different features
+
+    If no arguments are specified, the repository is evaluated for upgrade
+    and a list of problems and potential optimizations is printed.
+
+    With ``--run``, a repository upgrade is performed. Behavior of the upgrade
+    can be influenced via additional arguments. More details will be provided
+    by the command output when run without ``--run``.
+
+    During the upgrade, the repository will be locked and no writes will be
+    allowed.
+
+    At the end of the upgrade, the repository may not be readable while new
+    repository data is swapped in. This window will be as long as it takes to
+    rename some directories inside the ``.hg`` directory. On most machines, this
+    should complete almost instantaneously and the chances of a consumer being
+    unable to access the repository should be low.
+    """
+    raise error.Abort(_('not yet implemented'))
--- a/tests/test-completion.t	Wed Jan 11 21:47:19 2017 -0500
+++ b/tests/test-completion.t	Thu Nov 24 16:24:09 2016 -0800
@@ -109,6 +109,7 @@
   debugsub
   debugsuccessorssets
   debugtemplate
+  debugupgraderepo
   debugwalk
   debugwireargs
 
@@ -274,6 +275,7 @@
   debugsub: rev
   debugsuccessorssets: 
   debugtemplate: rev, define
+  debugupgraderepo: optimize, run
   debugwalk: include, exclude
   debugwireargs: three, four, five, ssh, remotecmd, insecure
   files: rev, print0, include, exclude, template, subrepos
--- a/tests/test-help.t	Wed Jan 11 21:47:19 2017 -0500
+++ b/tests/test-help.t	Thu Nov 24 16:24:09 2016 -0800
@@ -910,6 +910,8 @@
                  show set of successors for revision
    debugtemplate
                  parse and apply a template
+   debugupgraderepo
+                 upgrade a repository to use different features
    debugwalk     show how files match on given patterns
    debugwireargs
                  (no help text available)
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/test-upgrade-repo.t	Thu Nov 24 16:24:09 2016 -0800
@@ -0,0 +1,5 @@
+  $ hg init empty
+  $ cd empty
+  $ hg debugupgraderepo
+  abort: not yet implemented
+  [255]