This is a small style update for clarity. The previous situation was:
if foo:
50 lines
else:
2 lines
In such case I tend to invert these to get the simpler branch out of the way
earlier:
if not foo:
2 lines
else:
50 lines
This makes the conditional and various alternatives fit on the same screen,
simpler to read overall.
Bundle2 has its own mechanisms to check for heads (and other) changes, so push
using bundle2 is relying on the "check:heads" bundle part of unbundle and the
'check_heads' call is not checking anything. We add a small comment to make
this clearer.
Python 3 removed the "cmp" argument from sorted(). Custom sorting in
Python 3 must be implemented with the dunder comparison methods on
types and/or with a "key" function.
This patch converts our custom "cmp" function to a custom type.
The implementation is very similar to functools.cmp_to_key(). However,
cmp_to_key() doesn't exist in Python 2, so we can't use it.
This was the only use of the "cmp" argument to sorted() in the code
base.
Binary bookmark format should be used internally. It doesn't make sense to have
optional parameters `srchex` and `dsthex`. This patch removes them. It will
also be useful for `bookmarks` bundle2 part because unnecessary conversions
between hex and bin nodes will be avoided.
Next commit will remove optional parameters from `compare()` function.
Let's rename `compare()` to `comparebookmarks()` to avoid ambiguity from
callers from external extensions.
This function will be used to generate bookmarks bundle2 part.
It is a separate function in order to make it easy to overwrite it
in extensions. Passing `kwargs` to the function makes it easy to
add new parameters in extensions.
util.compengines has knowledge of all registered compression engines
and the metadata that associates them with various bundle types.
This patch removes the now redundant declaration of this metadata from
exchange.py and obtains it from the new source.
The effect of this patch is that once a new compression engine is
registered with util.compengines, `hg bundle -t <engine>` will just
work.
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.
because pull might move bookmarks and bookmark are protected by wlock, we have
to grab wlock for pull :-(
This required a small upgrade of the 'lockdelay' extension used by
'test-clone.t' because the delay must apply to a single lock only.
Now that all users are in exchange, we can safely move the code in the
'exchange' module. This function is really about processing the argument of a
'getbundle' call, so it even makes senses to do so.
There is various version of this function that differ mostly by the way they
define the bundled set. The flexibility is now available in the outgoing object
itself so we move the complexity into the caller themself. This will allow use
to remove a good share of the similar function to obtains a changegroup in the
'changegroup.py' module.
An important side effect is that we stop calling 'computeoutgoing' in
'getchangegroup'. This is fine as code that needs such argument processing
is actually going through the 'exchange' module which already all this function
itself.
This parameter is slightly confusingly named in wireproto, so it got
mis-specified from the start as 'push' instead of the URL to which we
are pushing. Sigh. I've got a patch for that which I'll mail
separately since it's not really appropriate for stable.
Fixes a regression in bundle2 from bundle1.
All versions of Python we support or hope to support make the hash
functions available in the same way under the same name, so we may as
well drop the util forwards.
getbundle was requesting the "phase" namespace instead of the "phases"
namespace, which led to the client still requesting the phases
separately after getbundle finished.
All users are migrated to 'devel.legacy.exchange', we can clean up the
experimental namespace.
Marking as (BC) because I know some large installation have bundle2 off and I
want to make sure they notice the change.
We need an official way to force bundle1 to be used in test. We introduce a new
option 'devel.legacy.exchange' to control this. When specified, this option
will control the list of bundle version Mercurial consider when exchanging with
a peer. Current valid value are 'bundle1' and 'bundle2'.
Using this option in all tests will allow us to remove the
'experimental.bundle2-exp' option. We will simplify the code once the
experimental option is dropped.
We rename and invert the logic of the _canusebundle2 utility. The idea here is
that we need to have a way to enforce the use of bundle1 in the tests. The
Mercurial philosophy is to try to use the best method available. Currently that
best method is bundle2, but this might change in the future. Therefore expressing
"do not use bundle2" is a loosy way to say "use bundle 1" and will likely create
issue in the future. As the config option will be explicitly about bundle1, we
rename the function beforehand to align with this. This will make the life of a
future developer working on bundle3 easier.
prepushoutgoinghook was introduced in 8dfcd476a7f7 and largefiles is the only
in-tree use of it. Refactor it to be more useful for other use cases in
largefiles.
In b89de5ee5b31 (changegroup: don't support versions 01 and 02 with
treemanifests, 2016-01-19), I stopped supporting use of cg1 and cg2
with treemanifest repos. What I had not considered was that it's
perfectly safe to pull *to* a treemanifest repo using any changegroup
version. As reported in issue5066, I therefore broke pull from old
repos into a treemanifest repo. It was not covered by the test case,
because that pulled from a local repo while enabling treemanifests,
which enabled treemanifests on the source repo as well. After
switching to pulling via HTTP, it breaks.
Fix by splitting up changegroup.supportedversions() into
supportedincomingversions() and supportedoutgoingversions().
In 7a1ccfe03f74 (treemanifests: set bundle2 part parameter indicating
treemanifest, 2016-01-08), I didn't realize I had to set the parameter
separately for getbundle and unbundle. Having the parameter there on
push allows us to push to an empty repo and have the requirements
updated correctly.
We don't currently have a mechanism for inferring bundle spec strings
from bundle files. This patch adds one.
This will eventually be used to make the producing of clone bundles
manifests easier.
The clone bundles feature was introduced in Mercurial 3.6 behind an
experimental and disabled by default flag. The feature has been enabled
on hg.mozilla.org for a few months and has served many terabytes of
clones. Users have been encouraged to use the feature and reception
has been very positive (mainly due to faster clones as a result of
connecting to a CDN). I have heard no feedback about changing the
feature other than inquiries about when it will be enabled by default.
So, I think the feature is ready to be enabled by default.
This patch renames experimental.clonebundles to ui.clonebundles,
documents the option, and enables it by default. References to the
experimental state of clone bundles have been removed. The remaining
config option docs in clonebundles.py have been removed because they
are redudant with `hg help config`.
There are some oddities with behavior of clone bundles. Because clones
with clone bundles are effectively 2 `hg pull` operations, there may be
2 transactions. This could result in hooks running twice. If the
subsequent pull is aborted, it could result in partial rollback and an
incomplete clone. This behavior is a bit wonky and should probably
be documented. If this patch is accepted, I'll send a follow-up to
document it. I don't think this behavior should prevent the feature
being enabled by default. Reworking the clone mechanism to support
interrupted or multi-part clones feels like a major new feature and
something that when implemented can change the hook and rollback
semantics of clone bundles. Besides, partial clone is better than
full rollback and hooks running on initial clone are likely rare, so I
think the impact is minimal.
By adding a mandatory 'treemanifest' parameter in the bundle2 part, we
make it possible for the recipient to set repo requirements before the
manifest revlog is accessed.
Prior to this, a pull of 90k markers (already known locally!) was
making about 2000 calls to obsstore.add, which was repeatedly building
a full set of known markers (in addition to other transaction
overhead). This quadratic behavior accounted for about 50 seconds of a
70 second no-op pull. After this change, we're down to 20 seconds.
While it would seem simplest to just cache the known set for
obsstore.add, this would also introduce issues of correct cache invalidation.
The extra pointless transaction overhead would also remain.
Previously, we passed a bunch of parameters to discovery.checkheads, but all
of the arguments can be fetched out of pushop, which may contain a lot more
useful information for extensions now that pushop is extensible.
Before bundle2, hook output from hook failures was prefixed with
"remote: ". Up to this point with bundle2, the output was converted to
the message to print in an Abort exception. This had 2 implications:
1) It was unclear whether an error message came from the local repo
or the remote
2) The exit code changed from 1 to 255
This patch changes the handling of error:abort bundle2 parts during push
to prefix the error message with "remote: ". This restores the old
behavior.
We still preserve the behavior of raising an Abort during bundle2
application failure. This is a regression from pre-bundle2 because the
exit code changed.
Because we no longer raise an Abort with the remote's message, we needed
to insert a message for the new Abort. So, I invented a new error
message for that. This is another change from pre-bundle2. However, I
like the new error message because it states unambiguously who aborted
the push failed, which I think is important for users so they can decide
what's next.
Now that we have support for detecting compatible stream clone bundles
in bundle specifications, we can safely add support for applying stream
clone bundles to the clone bundles feature.
Stream clone bundles can only be consumed if the consumer supports the
exact format requirements that were present on the producer.
This patch adds support for encoding and verifying the format
requirements on the bundle specification string for a stream clone
bundle are supported by the local repository. If they aren't, we raise
an UnsupportedBundleSpecification, just like we do when an unknown
compression or bundle type is encountered.
The impetus for this patch is so the clone bundles manifest can
advertise stream clone bundles and so clients can filter out stream
clones with unsupported format requirements. e.g. a stream clone
produced with the not-yet-invented "revlogv2" format will be ignored by
clients that only support "revlogv1."
Sometimes a basic type string is not sufficient for representing the
contents of a bundle. Take bundle2 for example: future bundle2 files may
contain parts that today's bundle2 parser can't read. Another example is
stream clone data. These require clients to support specific
repository formats or they won't be able to read the written files. In
both scenarios, we need to describe additional metadata beyond the outer
container type. Furthermore, this metadata behaves more like an
unordered set, so an order-based declaration format (such as static
strings) is not sufficient.
We introduce support for "parameters" into the bundle specification
string. These are essentially key-value pairs that can be used to encode
additional metadata about the bundle.
Semicolons are used as the delimiter partially to increase similarity to
MIME parameter values (see RFC 2231) and because they are relatively
safe from the command line (although values will need quotes to avoid
interpretation as multiple shell commands). Alternatives considered were
spaces (a bit annoying to encode) and '&' (similar to URL query strings)
(which will do bad things in a shell if unquoted).
The parsing function now returns a dict of parsed parameters and
consumers have been updated accordingly.
Now that we have a mechanism to produce and consume streaming clone
bundles, we need to teach the human-facing bundle specification parser
and the internal bundle file header reading code to be aware of this new
format. This patch does so.
For the human-facing bundle specification, we choose the name "packed"
to describe "streaming clone bundles" because the bundle is essentially
a "pack" of raw revlog files that are "packed" together. There should
probably be a bikeshed over the name, especially since it is human
facing.
We don't appear to print error codes elsewhere. The error codes are
inconsistent between at least Linux and OS X and are more trouble than
they are worth. Humans care about the error string more than the code
anyway.
A glob was also added to pave over differences in error strings between
Linux and OS X.
