wireproto: define and implement HTTP handshake to upgrade protocol
When clients connect to repositories over HTTP, they issue a request
to the well-known URL "?cmd=capabilities" to fetch the repository
capabilities. This is the handshake portion of the HTTP protocol.
This commit defines a mechanism to use that HTTP request to return
information about modern server features.
If a client sends an X-HgUpgrade-* header containing a list of
client-supported API names, the server responds with a response
containing information about available services. This includes
the normal capabilities string. So if the server doesn't support
any newer services, the client can easily fall back.
By advertising supported services from clients, server operators
can see and log what client support exists in the wild. This will
also help with debugging.
The response contains the base path to API services. We know there
are potential issues with the <repo>/api/ URL space conflicting with
hgwebdir and subrepos. By making the API URL dynamic from the
perspective of the client, the URL for APIs is not subject to backwards
compatibility concerns - at least as long as a ?cmd=capabilities request
is made.
We've also defined the ``cbor`` client capability for the X-HgProto-*
header. This MUST be sent in order to get the modern response from
"?cmd=capabilities". During implementation, I initially always sent
an application/mercurial-cbor response. However, the handshake
mechanism will be more future compatible if the client is in charge
of which formats to request. We already perform content negotiation
from X-HgProto-*, so keying off this for the capabilities response
feels appropriate.
In addition, I initially used application/cbor. However, it is
conceivable that a non-Mercurial server could serve application/cbor.
To rule out this possibility, I've invented a new media type that
is Mercurial specific and can't be confused for generic CBOR.
Differential Revision: https://phab.mercurial-scm.org/D3242
$ cat <<EOF >> $HGRCPATH
> [extensions]
> purge =
> EOF
init
$ hg init t
$ cd t
setup
$ echo r1 > r1
$ hg ci -qAmr1 -d'0 0'
$ mkdir directory
$ echo r2 > directory/r2
$ hg ci -qAmr2 -d'1 0'
$ echo 'ignored' > .hgignore
$ hg ci -qAmr3 -d'2 0'
delete an empty directory
$ mkdir empty_dir
$ hg purge -p -v
empty_dir
$ hg purge -v
removing directory empty_dir
$ ls
directory
r1
delete an untracked directory
$ mkdir untracked_dir
$ touch untracked_dir/untracked_file1
$ touch untracked_dir/untracked_file2
$ hg purge -p
untracked_dir/untracked_file1
untracked_dir/untracked_file2
$ hg purge -v
removing file untracked_dir/untracked_file1
removing file untracked_dir/untracked_file2
removing directory untracked_dir
$ ls
directory
r1
delete an untracked file
$ touch untracked_file
$ touch untracked_file_readonly
$ $PYTHON <<EOF
> import os, stat
> f= 'untracked_file_readonly'
> os.chmod(f, stat.S_IMODE(os.stat(f).st_mode) & ~stat.S_IWRITE)
> EOF
$ hg purge -p
untracked_file
untracked_file_readonly
$ hg purge -v
removing file untracked_file
removing file untracked_file_readonly
$ ls
directory
r1
delete an untracked file in a tracked directory
$ touch directory/untracked_file
$ hg purge -p
directory/untracked_file
$ hg purge -v
removing file directory/untracked_file
$ ls
directory
r1
delete nested directories
$ mkdir -p untracked_directory/nested_directory
$ hg purge -p
untracked_directory/nested_directory
$ hg purge -v
removing directory untracked_directory/nested_directory
removing directory untracked_directory
$ ls
directory
r1
delete nested directories from a subdir
$ mkdir -p untracked_directory/nested_directory
$ cd directory
$ hg purge -p
untracked_directory/nested_directory
$ hg purge -v
removing directory untracked_directory/nested_directory
removing directory untracked_directory
$ cd ..
$ ls
directory
r1
delete only part of the tree
$ mkdir -p untracked_directory/nested_directory
$ touch directory/untracked_file
$ cd directory
$ hg purge -p ../untracked_directory
untracked_directory/nested_directory
$ hg purge -v ../untracked_directory
removing directory untracked_directory/nested_directory
removing directory untracked_directory
$ cd ..
$ ls
directory
r1
$ ls directory/untracked_file
directory/untracked_file
$ rm directory/untracked_file
skip ignored files if --all not specified
$ touch ignored
$ hg purge -p
$ hg purge -v
$ ls
directory
ignored
r1
$ hg purge -p --all
ignored
$ hg purge -v --all
removing file ignored
$ ls
directory
r1
abort with missing files until we support name mangling filesystems
$ touch untracked_file
$ rm r1
hide error messages to avoid changing the output when the text changes
$ hg purge -p 2> /dev/null
untracked_file
$ hg st
! r1
? untracked_file
$ hg purge -p
untracked_file
$ hg purge -v 2> /dev/null
removing file untracked_file
$ hg st
! r1
$ hg purge -v
$ hg revert --all --quiet
$ hg st -a
tracked file in ignored directory (issue621)
$ echo directory >> .hgignore
$ hg ci -m 'ignore directory'
$ touch untracked_file
$ hg purge -p
untracked_file
$ hg purge -v
removing file untracked_file
skip excluded files
$ touch excluded_file
$ hg purge -p -X excluded_file
$ hg purge -v -X excluded_file
$ ls
directory
excluded_file
r1
$ rm excluded_file
skip files in excluded dirs
$ mkdir excluded_dir
$ touch excluded_dir/file
$ hg purge -p -X excluded_dir
$ hg purge -v -X excluded_dir
$ ls
directory
excluded_dir
r1
$ ls excluded_dir
file
$ rm -R excluded_dir
skip excluded empty dirs
$ mkdir excluded_dir
$ hg purge -p -X excluded_dir
$ hg purge -v -X excluded_dir
$ ls
directory
excluded_dir
r1
$ rmdir excluded_dir
skip patterns
$ mkdir .svn
$ touch .svn/foo
$ mkdir directory/.svn
$ touch directory/.svn/foo
$ hg purge -p -X .svn -X '*/.svn'
$ hg purge -p -X re:.*.svn
$ rm -R .svn directory r1
only remove files
$ mkdir -p empty_dir dir
$ touch untracked_file dir/untracked_file
$ hg purge -p --files
dir/untracked_file
untracked_file
$ hg purge -v --files
removing file dir/untracked_file
removing file untracked_file
$ ls
dir
empty_dir
$ ls dir
only remove dirs
$ mkdir -p empty_dir dir
$ touch untracked_file dir/untracked_file
$ hg purge -p --dirs
empty_dir
$ hg purge -v --dirs
removing directory empty_dir
$ ls
dir
untracked_file
$ ls dir
untracked_file
remove both files and dirs
$ mkdir -p empty_dir dir
$ touch untracked_file dir/untracked_file
$ hg purge -p --files --dirs
dir/untracked_file
untracked_file
empty_dir
$ hg purge -v --files --dirs
removing file dir/untracked_file
removing file untracked_file
removing directory empty_dir
removing directory dir
$ ls
$ cd ..