FM / technical

/usr/share/doc/git/technical

Name	Size	Mode	Actions
api-error-handling.html	22259	0644	edit dl rm
api-error-handling.txt	3818	0644	edit dl rm
api-index-skel.txt	432	0644	edit dl rm
api-index.html	17183	0644	edit dl rm
api-index.sh	611	0644	edit dl rm
api-index.txt	648	0644	edit dl rm
api-merge.html	18305	0644	edit dl rm
api-merge.txt	1090	0644	edit dl rm
api-parse-options.html	36657	0644	edit dl rm
api-parse-options.txt	13157	0644	edit dl rm
api-simple-ipc.html	22388	0644	edit dl rm
api-simple-ipc.txt	4852	0644	edit dl rm
api-trace2.html	77619	0644	edit dl rm
api-trace2.txt	44255	0644	edit dl rm
bitmap-format.html	30403	0644	edit dl rm
bitmap-format.txt	8871	0644	edit dl rm
bundle-uri.html	51387	0644	edit dl rm
bundle-uri.txt	26787	0644	edit dl rm
commit-graph.txt	17957	0644	edit dl rm
directory-rename-detection.txt	5199	0644	edit dl rm
hash-function-transition.html	64539	0644	edit dl rm
hash-function-transition.txt	35894	0644	edit dl rm
long-running-process-protocol.html	18995	0644	edit dl rm
long-running-process-protocol.txt	1929	0644	edit dl rm
multi-pack-index.html	22462	0644	edit dl rm
multi-pack-index.txt	4459	0644	edit dl rm
pack-heuristics.html	43594	0644	edit dl rm
pack-heuristics.txt	18040	0644	edit dl rm
packfile-uri.txt	3748	0644	edit dl rm
parallel-checkout.html	31715	0644	edit dl rm
parallel-checkout.txt	12301	0644	edit dl rm
partial-clone.html	36496	0644	edit dl rm
partial-clone.txt	14968	0644	edit dl rm
racy-git.html	27995	0644	edit dl rm
racy-git.txt	9121	0644	edit dl rm
reftable.html	73792	0644	edit dl rm
reftable.txt	37525	0644	edit dl rm
remembering-renames.txt	30360	0644	edit dl rm
repository-version.txt	4311	0644	edit dl rm
rerere.txt	6510	0644	edit dl rm
scalar.html	20458	0644	edit dl rm
scalar.txt	2935	0644	edit dl rm
send-pack-pipeline.html	19315	0644	edit dl rm
send-pack-pipeline.txt	1969	0644	edit dl rm
shallow.html	19685	0644	edit dl rm
shallow.txt	2548	0644	edit dl rm
sparse-checkout.txt	47499	0644	edit dl rm
sparse-index.txt	9501	0644	edit dl rm
trivial-merge.html	22273	0644	edit dl rm
trivial-merge.txt	4264	0644	edit dl rm

Edit: /usr/share/doc/git/technical/shallow.txt (2548B)

Shallow commits
===============

.Definition
*********************************************************
Shallow commits do have parents, but not in the shallow
repo, and therefore grafts are introduced pretending that
these commits have no parents.
*********************************************************

$GIT_DIR/shallow lists commit object names and tells Git to
pretend as if they are root commits (e.g. "git log" traversal
stops after showing them; "git fsck" does not complain saying
the commits listed on their "parent" lines do not exist).

Each line contains exactly one object name. When read, a commit_graft
will be constructed, which has nr_parent < 0 to make it easier
to discern from user provided grafts.

Note that the shallow feature could not be changed easily to
use replace refs: a commit containing a `mergetag` is not allowed
to be replaced, not even by a root commit. Such a commit can be
made shallow, though. Also, having a `shallow` file explicitly
listing all the commits made shallow makes it a *lot* easier to
do shallow-specific things such as to deepen the history.

Since fsck-objects relies on the library to read the objects,
it honours shallow commits automatically.

There are some unfinished ends of the whole shallow business:

- maybe we have to force non-thin packs when fetching into a
  shallow repo (ATM they are forced non-thin).

- A special handling of a shallow upstream is needed. At some
  stage, upload-pack has to check if it sends a shallow commit,
  and it should send that information early (or fail, if the
  client does not support shallow repositories). There is no
  support at all for this in this patch series.

- Instead of locking $GIT_DIR/shallow at the start, just
  the timestamp of it is noted, and when it comes to writing it,
  a check is performed if the mtime is still the same, dying if
  it is not.

- It is unclear how "push into/from a shallow repo" should behave.

- If you deepen a history, you'd want to get the tags of the
  newly stored (but older!) commits. This does not work right now.

To make a shallow clone, you can call "git-clone --depth 20 repo".
The result contains only commit chains with a length of at most 20.
It also writes an appropriate $GIT_DIR/shallow.

You can deepen a shallow repository with "git-fetch --depth 20
repo branch", which will fetch branch from repo, but stop at depth
20, updating $GIT_DIR/shallow.

The special depth 2147483647 (or 0x7fffffff, the largest positive
number a signed 32-bit integer can contain) means infinite depth.

cmd: