tests/test-diff-hashes.t
author Gregory Szorc <gregory.szorc@gmail.com>
Sun, 16 Oct 2016 10:38:52 -0700
changeset 30187 3e86261bf110
parent 16913 f2719b387380
child 41784 251332dbf33d
permissions -rw-r--r--
exchange: refactor APIs to obtain bundle data (API) Currently, exchange.getbundle() returns either a cg1unpacker or a util.chunkbuffer (in the case of bundle2). This is kinda OK, as both expose a .read() to consumers. However, localpeer.getbundle() has code inferring what the response type is based on arguments and converts the util.chunkbuffer returned in the bundle2 case to a bundle2.unbundle20 instance. This is a sign that the API for exchange.getbundle() is not ideal because it doesn't consistently return an "unbundler" instance. In addition, unbundlers mask the fact that there is an underlying generator of changegroup data. In both cg1 and bundle2, this generator is being fed into a util.chunkbuffer so it can be re-exposed as a file object. util.chunkbuffer is a nice abstraction. However, it should only be used "at the edges." This is because keeping data as a generator is more efficient than converting it to a chunkbuffer, especially if we convert that chunkbuffer back to a generator (as is the case in some code paths currently). This patch refactors exchange.getbundle() into exchange.getbundlechunks(). The new API returns an iterator of chunks instead of a file-like object. Callers of exchange.getbundle() have been updated to use the new API. There is a minor change of behavior in test-getbundle.t. This is because `hg debuggetbundle` isn't defining bundlecaps. As a result, a cg1 data stream and unpacker is being produced. This is getting fed into a new bundle20 instance via bundle2.writebundle(), which uses a backchannel mechanism between changegroup generation to add the "nbchanges" part parameter. I never liked this backchannel mechanism and I plan to remove it someday. `hg bundle` still produces the "nbchanges" part parameter, so there should be no user-visible change of behavior. I consider this "regression" a bug in `hg debuggetbundle`. And that bug is captured by an existing "TODO" in the code to use bundle2 capabilities.

  $ hg init a
  $ cd a

  $ hg diff inexistent1 inexistent2
  inexistent1: * (glob)
  inexistent2: * (glob)

  $ echo bar > foo
  $ hg add foo
  $ hg ci -m 'add foo'

  $ echo foobar > foo
  $ hg ci -m 'change foo'

  $ hg --quiet diff -r 0 -r 1
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar

  $ hg diff -r 0 -r 1
  diff -r a99fb63adac3 -r 9b8568d3af2f foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar

  $ hg --verbose diff -r 0 -r 1
  diff -r a99fb63adac3 -r 9b8568d3af2f foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar

  $ hg --debug diff -r 0 -r 1
  diff -r a99fb63adac3f31816a22f665bc3b7a7655b30f4 -r 9b8568d3af2f1749445eef03aede868a6f39f210 foo
  --- a/foo	Thu Jan 01 00:00:00 1970 +0000
  +++ b/foo	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,1 +1,1 @@
  -bar
  +foobar

  $ cd ..