repository: define new interface for running commands
Today, the peer interface exposes methods for each command that can
be executed. In addition, there is an iterbatch() API that allows
commands to be issued in batches and provides an iterator over the
results. This is a glorified wrapper around the "batch" wire command.
Wire protocol version 2 supports nicer things (such as batching
any command and out-of-order replies). It will require a more
flexible API for executing commands.
This commit introduces a new peer interface for making command
requests. In the new world, you can't simply call a method on the
peer to execute a command: you need to obtain an object to be used
for executing commands. That object can be used to issue a single
command or it can batch multiple requests. In the case of full duplex
peers, the command may even be sent out over the wire immediately.
There are no per-command methods. Instead, there is a generic
method to call a command. The implementation can then perform domain
specific processing for specific commands. This includes passing
data via a specially named argument.
Arguments are also passed as a dictionary instead of using **kwargs.
While **kwargs is nicer to use, we've historically gotten into
trouble using it because there will inevitably be a conflict between
the name of an argument to a wire protocol command and an argument
we want to pass into a function.
Instead of a command returning a value, it returns a future which
will resolve to a value. This opens the door for out-of-order
response handling and concurrent response handling in the version
2 protocol.
Differential Revision: https://phab.mercurial-scm.org/D3267
https://bz.mercurial-scm.org/1502
Initialize repository
$ hg init foo
$ touch foo/a && hg -R foo commit -A -m "added a"
adding a
$ hg clone foo foo1
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo "bar" > foo1/a && hg -R foo1 commit -m "edit a in foo1"
$ echo "hi" > foo/a && hg -R foo commit -m "edited a foo"
$ hg -R foo1 pull
pulling from $TESTTMP/foo
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 273d008d6e8e
(run 'hg heads' to see heads, 'hg merge' to merge)
$ hg -R foo1 book branchy
$ hg -R foo1 book
* branchy 1:e3e522925eff
Pull. Bookmark should not jump to new head.
$ echo "there" >> foo/a && hg -R foo commit -m "edited a again"
$ hg -R foo1 pull
pulling from $TESTTMP/foo
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 84a798d48b17
(run 'hg update' to get a working copy)
$ hg -R foo1 book
* branchy 1:e3e522925eff