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5 commits

Author SHA1 Message Date
Derrick Stolee 8628a842bd bundle-uri: suppress stderr from remote-https
When downloading bundles from a git-remote-https subprocess, the bundle
URI logic wants to be opportunistic and download as much as possible and
work with what did succeed. This is particularly important in the "any"
mode, where any single bundle success will work.

If the URI is not available, the git-remote-https process will die()
with a "fatal:" error message, even though that error is not actually
fatal to the super process. Since stderr is passed through, it looks
like a fatal error to the user.

Suppress stderr to avoid these errors from bubbling to the surface. The
bundle URI API adds its own warning() messages on these failures.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-12 09:13:25 -07:00
Derrick Stolee 70334fc3eb bundle-uri: quiet failed unbundlings
When downloading a list of bundles in "all" mode, Git has no
understanding of the dependencies between the bundles. Git attempts to
unbundle the bundles in some order, but some may not pass the
verify_bundle() step because of missing prerequisites. This is passed as
error messages to the user, even when they eventually succeed in later
attempts after their dependent bundles are unbundled.

Add a new VERIFY_BUNDLE_QUIET flag to verify_bundle() that avoids the
error messages from the missing prerequisite commits. The method still
returns the number of missing prerequisit commits, allowing callers to
unbundle() to notice that the bundle failed to apply.

Use this flag in bundle-uri.c and test that the messages go away for
'git clone --bundle-uri' commands.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-12 09:13:25 -07:00
Derrick Stolee c23f592117 bundle-uri: fetch a list of bundles
When the content at a given bundle URI is not understood as a bundle
(based on inspecting the initial content), then Git currently gives up
and ignores that content. Independent bundle providers may want to split
up the bundle content into multiple bundles, but still make them
available from a single URI.

Teach Git to attempt parsing the bundle URI content as a Git config file
providing the key=value pairs for a bundle list. Git then looks at the
mode of the list to see if ANY single bundle is sufficient or if ALL
bundles are required. The content at the selected URIs are downloaded
and the content is inspected again, creating a recursive process.

To guard the recursion against malformed or malicious content, limit the
recursion depth to a reasonable four for now. This can be converted to a
configured value in the future if necessary. The value of four is twice
as high as expected to be useful (a bundle list is unlikely to point to
more bundle lists).

To test this scenario, create an interesting bundle topology where three
incremental bundles are built on top of a single full bundle. By using a
merge commit, the two middle bundles are "independent" in that they do
not require each other in order to unbundle themselves. They each only
need the base bundle. The bundle containing the merge commit requires
both of the middle bundles, though. This leads to some interesting
decisions when unbundling, especially when we later implement heuristics
that promote downloading bundles until the prerequisite commits are
satisfied.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-10-12 09:13:25 -07:00
Derrick Stolee 59c1752ab6 bundle-uri: add support for http(s):// and file://
The previous change created the 'git clone --bundle-uri=<uri>' option.
Currently, <uri> must be a filename.

Update copy_uri_to_file() to first inspect the URI for an HTTP(S) prefix
and use git-remote-https as the way to download the data at that URI.
Otherwise, check to see if file:// is present and modify the prefix
accordingly.

Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-10 14:07:37 -07:00
Derrick Stolee 5556891961 clone: add --bundle-uri option
Cloning a remote repository is one of the most expensive operations in
Git. The server can spend a lot of CPU time generating a pack-file for
the client's request. The amount of data can clog the network for a long
time, and the Git protocol is not resumable. For users with poor network
connections or are located far away from the origin server, this can be
especially painful.

Add a new '--bundle-uri' option to 'git clone' to bootstrap a clone from
a bundle. If the user is aware of a bundle server, then they can tell
Git to bootstrap the new repository with these bundles before fetching
the remaining objects from the origin server.

Reviewed-by: Josh Steadmon <steadmon@google.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-10 14:07:37 -07:00