Merge branches 'bf/doc' and 'db/tartree'
This commit is contained in:
commit
1a5c3a01aa
@ -1623,123 +1623,7 @@ suggested in the previous section may be new to you. You do not
|
||||
have to worry. git supports "shared public repository" style of
|
||||
cooperation you are probably more familiar with as well.
|
||||
|
||||
For this, set up a public repository on a machine that is
|
||||
reachable via SSH by people with "commit privileges". Put the
|
||||
committers in the same user group and make the repository
|
||||
writable by that group. Make sure their umasks are set up to
|
||||
allow group members to write into directories other members
|
||||
have created.
|
||||
|
||||
You, as an individual committer, then:
|
||||
|
||||
- First clone the shared repository to a local repository:
|
||||
------------------------------------------------
|
||||
$ git clone repo.shared.xz:/pub/scm/project.git/ my-project
|
||||
$ cd my-project
|
||||
$ hack away
|
||||
------------------------------------------------
|
||||
|
||||
- Merge the work others might have done while you were hacking
|
||||
away:
|
||||
------------------------------------------------
|
||||
$ git pull origin
|
||||
$ test the merge result
|
||||
------------------------------------------------
|
||||
[NOTE]
|
||||
================================
|
||||
The first `git clone` would have placed the following in
|
||||
`my-project/.git/remotes/origin` file, and that's why this and
|
||||
the next step work.
|
||||
------------
|
||||
URL: repo.shared.xz:/pub/scm/project.git/ my-project
|
||||
Pull: master:origin
|
||||
------------
|
||||
================================
|
||||
|
||||
- push your work as the new head of the shared
|
||||
repository.
|
||||
------------------------------------------------
|
||||
$ git push origin master
|
||||
------------------------------------------------
|
||||
If somebody else pushed into the same shared repository while
|
||||
you were working locally, `git push` in the last step would
|
||||
complain, telling you that the remote `master` head does not
|
||||
fast forward. You need to pull and merge those other changes
|
||||
back before you push your work when it happens.
|
||||
|
||||
The `git push` command without any explicit refspec parameter
|
||||
pushes the refs that exist both in the local repository and the
|
||||
remote repository. So the last `push` can be done with either
|
||||
one of these:
|
||||
------------
|
||||
$ git push origin
|
||||
$ git push repo.shared.xz:/pub/scm/project.git/
|
||||
------------
|
||||
as long as the shared repository does not have any branches
|
||||
other than `master`.
|
||||
[NOTE]
|
||||
============
|
||||
If you created your shared repository by cloning from somewhere
|
||||
else, you may have the `origin` branch. Your developers
|
||||
typically do not use that branch; remove it. Otherwise, that
|
||||
would be pushed back by the `git push origin` because your
|
||||
developers' repository would surely have `origin` branch to keep
|
||||
track of the shared repository, and would be counted as "exist
|
||||
on both ends".
|
||||
============
|
||||
|
||||
Advanced Shared Repository Management
|
||||
-------------------------------------
|
||||
|
||||
Being able to push into a shared repository means being able to
|
||||
write into it. If your developers are coming over the network,
|
||||
this means you, as the repository administrator, need to give
|
||||
each of them an SSH access to the shared repository machine.
|
||||
|
||||
In some cases, though, you may not want to give a normal shell
|
||||
account to them, but want to restrict them to be able to only
|
||||
do `git push` into the repository and nothing else.
|
||||
|
||||
You can achieve this by setting the login shell of your
|
||||
developers on the shared repository host to `git-shell` program.
|
||||
|
||||
[NOTE]
|
||||
Most likely you would also need to list `git-shell` program in
|
||||
`/etc/shells` file.
|
||||
|
||||
This restricts the set of commands that can be run from incoming
|
||||
SSH connection for these users to only `receive-pack` and
|
||||
`upload-pack`, so the only thing they can do are `git fetch` and
|
||||
`git push`.
|
||||
|
||||
You still need to create UNIX user accounts for each developer,
|
||||
and put them in the same group. Make sure that the repository
|
||||
shared among these developers is writable by that group.
|
||||
|
||||
. Initializing the shared repository with `git-init-db --shared`
|
||||
helps somewhat.
|
||||
|
||||
. Run the following in the shared repository:
|
||||
+
|
||||
------------
|
||||
$ chgrp -R $group repo.git
|
||||
$ find repo.git -type d -print | xargs chmod ug+rwx,g+s
|
||||
$ GIT_DIR=repo.git git repo-config core.sharedrepository true
|
||||
------------
|
||||
|
||||
The above measures make sure that directories lazily created in
|
||||
`$GIT_DIR` are writable by group members. You, as the
|
||||
repository administrator, are still responsible to make sure
|
||||
your developers belong to that shared repository group and set
|
||||
their umask to a value no stricter than 027 (i.e. at least allow
|
||||
reading and searching by group members).
|
||||
|
||||
You can implement finer grained branch policies using update
|
||||
hooks. There is a document ("control access to branches") in
|
||||
Documentation/howto by Carl Baldwin and JC outlining how to (1)
|
||||
limit access to branch per user, (2) forbid overwriting existing
|
||||
tags.
|
||||
|
||||
See link:cvs-migration.txt[git for CVS users] for the details.
|
||||
|
||||
Bundling your work together
|
||||
---------------------------
|
||||
|
@ -1,126 +1,182 @@
|
||||
git for CVS users
|
||||
=================
|
||||
|
||||
Ok, so you're a CVS user. That's ok, it's a treatable condition, and the
|
||||
first step to recovery is admitting you have a problem. The fact that
|
||||
you are reading this file means that you may be well on that path
|
||||
already.
|
||||
So you're a CVS user. That's ok, it's a treatable condition. The job of
|
||||
this document is to put you on the road to recovery, by helping you
|
||||
convert an existing cvs repository to git, and by showing you how to use a
|
||||
git repository in a cvs-like fashion.
|
||||
|
||||
The thing about CVS is that it absolutely sucks as a source control
|
||||
manager, and you'll thus be happy with almost anything else. git,
|
||||
however, may be a bit 'too' different (read: "good") for your taste, and
|
||||
does a lot of things differently.
|
||||
Some basic familiarity with git is required. This
|
||||
link:tutorial.html[tutorial introduction to git] should be sufficient.
|
||||
|
||||
One particular suckage of CVS is very hard to work around: CVS is
|
||||
basically a tool for tracking 'file' history, while git is a tool for
|
||||
tracking 'project' history. This sometimes causes problems if you are
|
||||
used to doing very strange things in CVS, in particular if you're doing
|
||||
things like making branches of just a subset of the project. git can't
|
||||
track that, since git never tracks things on the level of an individual
|
||||
file, only on the whole project level.
|
||||
First, note some ways that git differs from CVS:
|
||||
|
||||
The good news is that most people don't do that, and in fact most sane
|
||||
people think it's a bug in CVS that makes it tag (and check in changes)
|
||||
one file at a time. So most projects you'll ever see will use CVS
|
||||
'as if' it was sane. In which case you'll find it very easy indeed to
|
||||
move over to git.
|
||||
* Commits are atomic and project-wide, not per-file as in CVS.
|
||||
|
||||
First off: this is not a git tutorial. See
|
||||
link:tutorial.html[Documentation/tutorial.txt] for how git
|
||||
actually works. This is more of a random collection of gotcha's
|
||||
and notes on converting from CVS to git.
|
||||
* Offline work is supported: you can make multiple commits locally,
|
||||
then submit them when you're ready.
|
||||
|
||||
Second: CVS has the notion of a "repository" as opposed to the thing
|
||||
that you're actually working in (your working directory, or your
|
||||
"checked out tree"). git does not have that notion at all, and all git
|
||||
working directories 'are' the repositories. However, you can easily
|
||||
emulate the CVS model by having one special "global repository", which
|
||||
people can synchronize with. See details later, but in the meantime
|
||||
just keep in mind that with git, every checked out working tree will
|
||||
have a full revision control history of its own.
|
||||
* Branching is fast and easy.
|
||||
|
||||
* Every working tree contains a repository with a full copy of the
|
||||
project history, and no repository is inherently more important than
|
||||
any other. However, you can emulate the CVS model by designating a
|
||||
single shared repository which people can synchronize with; see below
|
||||
for details.
|
||||
|
||||
Importing a CVS archive
|
||||
-----------------------
|
||||
|
||||
Ok, you have an old project, and you want to at least give git a chance
|
||||
to see how it performs. The first thing you want to do (after you've
|
||||
gone through the git tutorial, and generally familiarized yourself with
|
||||
how to commit stuff etc in git) is to create a git'ified version of your
|
||||
CVS archive.
|
||||
First, install version 2.1 or higher of cvsps from
|
||||
link:http://www.cobite.com/cvsps/[http://www.cobite.com/cvsps/] and make
|
||||
sure it is in your path. The magic command line is then
|
||||
|
||||
Happily, that's very easy indeed. git will do it for you, although git
|
||||
will need the help of a program called "cvsps":
|
||||
-------------------------------------------
|
||||
$ git cvsimport -v -d <cvsroot> -C <destination> <module>
|
||||
-------------------------------------------
|
||||
|
||||
http://www.cobite.com/cvsps/
|
||||
This puts a git archive of the named CVS module in the directory
|
||||
<destination>, which will be created if necessary. The -v option makes
|
||||
the conversion script very chatty.
|
||||
|
||||
which is not actually related to git at all, but which makes CVS usage
|
||||
look almost sane (ie you almost certainly want to have it even if you
|
||||
decide to stay with CVS). However, git will want 'at least' version 2.1
|
||||
of cvsps (available at the address above), and in fact will currently
|
||||
refuse to work with anything else.
|
||||
The import checks out from CVS every revision of every file. Reportedly
|
||||
cvsimport can average some twenty revisions per second, so for a
|
||||
medium-sized project this should not take more than a couple of minutes.
|
||||
Larger projects or remote repositories may take longer.
|
||||
|
||||
Once you've gotten (and installed) cvsps, you may or may not want to get
|
||||
any more familiar with it, but make sure it is in your path. After that,
|
||||
the magic command line is
|
||||
The main trunk is stored in the git branch named `origin`, and additional
|
||||
CVS branches are stored in git branches with the same names. The most
|
||||
recent version of the main trunk is also left checked out on the `master`
|
||||
branch, so you can start adding your own changes right away.
|
||||
|
||||
git cvsimport -v -d <cvsroot> -C <destination> <module>
|
||||
The import is incremental, so if you call it again next month it will
|
||||
fetch any CVS updates that have been made in the meantime. For this to
|
||||
work, you must not modify the imported branches; instead, create new
|
||||
branches for your own changes, and merge in the imported branches as
|
||||
necessary.
|
||||
|
||||
which will do exactly what you'd think it does: it will create a git
|
||||
archive of the named CVS module. The new archive will be created in the
|
||||
subdirectory named <destination>; it'll be created if it doesn't exist.
|
||||
Default is the local directory.
|
||||
Development Models
|
||||
------------------
|
||||
|
||||
It can take some time to actually do the conversion for a large archive
|
||||
since it involves checking out from CVS every revision of every file,
|
||||
and the conversion script is reasonably chatty unless you omit the '-v'
|
||||
option, but on some not very scientific tests it averaged about twenty
|
||||
revisions per second, so a medium-sized project should not take more
|
||||
than a couple of minutes. For larger projects or remote repositories,
|
||||
the process may take longer.
|
||||
CVS users are accustomed to giving a group of developers commit access to
|
||||
a common repository. In the next section we'll explain how to do this
|
||||
with git. However, the distributed nature of git allows other development
|
||||
models, and you may want to first consider whether one of them might be a
|
||||
better fit for your project.
|
||||
|
||||
After the (initial) import is done, the CVS archive's current head
|
||||
revision will be checked out -- thus, you can start adding your own
|
||||
changes right away.
|
||||
For example, you can choose a single person to maintain the project's
|
||||
primary public repository. Other developers then clone this repository
|
||||
and each work in their own clone. When they have a series of changes that
|
||||
they're happy with, they ask the maintainer to pull from the branch
|
||||
containing the changes. The maintainer reviews their changes and pulls
|
||||
them into the primary repository, which other developers pull from as
|
||||
necessary to stay coordinated. The Linux kernel and other projects use
|
||||
variants of this model.
|
||||
|
||||
The import is incremental, i.e. if you call it again next month it'll
|
||||
fetch any CVS updates that have been happening in the meantime. The
|
||||
cut-off is date-based, so don't change the branches that were imported
|
||||
from CVS.
|
||||
With a small group, developers may just pull changes from each other's
|
||||
repositories without the need for a central maintainer.
|
||||
|
||||
You can merge those updates (or, in fact, a different CVS branch) into
|
||||
your main branch:
|
||||
Emulating the CVS Development Model
|
||||
-----------------------------------
|
||||
|
||||
git resolve HEAD origin "merge with current CVS HEAD"
|
||||
Start with an ordinary git working directory containing the project, and
|
||||
remove the checked-out files, keeping just the bare .git directory:
|
||||
|
||||
The HEAD revision from CVS is named "origin", not "HEAD", because git
|
||||
already uses "HEAD". (If you don't like 'origin', use cvsimport's
|
||||
'-o' option to change it.)
|
||||
------------------------------------------------
|
||||
$ mv project/.git /pub/repo.git
|
||||
$ rm -r project/
|
||||
------------------------------------------------
|
||||
|
||||
Next, give every team member read/write access to this repository. One
|
||||
easy way to do this is to give all the team members ssh access to the
|
||||
machine where the repository is hosted. If you don't want to give them a
|
||||
full shell on the machine, there is a restricted shell which only allows
|
||||
users to do git pushes and pulls; see gitlink:git-shell[1].
|
||||
|
||||
Emulating CVS behaviour
|
||||
-----------------------
|
||||
Put all the committers should in the same group, and make the repository
|
||||
writable by that group:
|
||||
|
||||
------------------------------------------------
|
||||
$ chgrp -R $group repo.git
|
||||
$ find repo.git -mindepth 1 -type d |xargs chmod ug+rwx,g+s
|
||||
$ GIT_DIR=repo.git git repo-config core.sharedrepository true
|
||||
------------------------------------------------
|
||||
|
||||
So, by now you are convinced you absolutely want to work with git, but
|
||||
at the same time you absolutely have to have a central repository.
|
||||
Step back and think again. Okay, you still need a single central
|
||||
repository? There are several ways to go about that:
|
||||
Make sure committers have a umask of at most 027, so that the directories
|
||||
they create are writable and searchable by other group members.
|
||||
|
||||
1. Designate a person responsible to pull all branches. Make the
|
||||
repository of this person public, and make every team member
|
||||
pull regularly from it.
|
||||
Suppose this repository is now set up in /pub/repo.git on the host
|
||||
foo.com. Then as an individual commiter you can clone the shared
|
||||
repository:
|
||||
|
||||
2. Set up a public repository with read/write access for every team
|
||||
member. Use "git pull/push" as you used "cvs update/commit". Be
|
||||
sure that your repository is up to date before pushing, just
|
||||
like you used to do with "cvs commit"; your push will fail if
|
||||
what you are pushing is not up to date.
|
||||
------------------------------------------------
|
||||
$ git clone foo.com:/pub/repo.git/ my-project
|
||||
$ cd my-project
|
||||
------------------------------------------------
|
||||
|
||||
3. Make the repository of every team member public. It is the
|
||||
responsibility of each single member to pull from every other
|
||||
team member.
|
||||
and hack away. The equivalent of `cvs update` is
|
||||
|
||||
------------------------------------------------
|
||||
$ git pull origin
|
||||
------------------------------------------------
|
||||
|
||||
which merges in any work that others might have done since the clone
|
||||
operation.
|
||||
|
||||
[NOTE]
|
||||
================================
|
||||
The first `git clone` places the following in the
|
||||
`my-project/.git/remotes/origin` file, and that's why the previous step
|
||||
and the next step both work.
|
||||
------------
|
||||
URL: foo.com:/pub/project.git/ my-project
|
||||
Pull: master:origin
|
||||
------------
|
||||
================================
|
||||
|
||||
You can update the shared repository with your changes using:
|
||||
|
||||
------------------------------------------------
|
||||
$ git push origin master
|
||||
------------------------------------------------
|
||||
|
||||
If someone else has updated the repository more recently, `git push`, like
|
||||
`cvs commit`, will complain, in which case you must pull any changes
|
||||
before attempting the push again.
|
||||
|
||||
In the `git push` command above we specify the name of the remote branch
|
||||
to update (`master`). If we leave that out, `git push` tries to update
|
||||
any branches in the remote repository that have the same name as a branch
|
||||
in the local repository. So the last `push` can be done with either of:
|
||||
|
||||
------------
|
||||
$ git push origin
|
||||
$ git push repo.shared.xz:/pub/scm/project.git/
|
||||
------------
|
||||
|
||||
as long as the shared repository does not have any branches
|
||||
other than `master`.
|
||||
|
||||
[NOTE]
|
||||
============
|
||||
Because of this behaviour, if the shared repository and the developer's
|
||||
repository both have branches named `origin`, then a push like the above
|
||||
attempts to update the `origin` branch in the shared repository from the
|
||||
developer's `origin` branch. The results may be unexpected, so it's
|
||||
usually best to remove any branch named `origin` from the shared
|
||||
repository.
|
||||
============
|
||||
|
||||
Advanced Shared Repository Management
|
||||
-------------------------------------
|
||||
|
||||
Git allows you to specify scripts called "hooks" to be run at certain
|
||||
points. You can use these, for example, to send all commits to the shared
|
||||
repository to a mailing list. See link:hooks.txt[Hooks used by git].
|
||||
|
||||
You can enforce finer grained permissions using update hooks. See
|
||||
link:howto/update-hook-example.txt[Controlling access to branches using
|
||||
update hooks].
|
||||
|
||||
CVS annotate
|
||||
------------
|
||||
|
89
tar-tree.c
89
tar-tree.c
@ -3,6 +3,8 @@
|
||||
*/
|
||||
#include <time.h>
|
||||
#include "cache.h"
|
||||
#include "tree.h"
|
||||
#include "commit.h"
|
||||
|
||||
#define RECORDSIZE (512)
|
||||
#define BLOCKSIZE (RECORDSIZE * 20)
|
||||
@ -334,76 +336,45 @@ static void write_header(const unsigned char *sha1, char typeflag, const char *b
|
||||
write_if_needed();
|
||||
}
|
||||
|
||||
static void traverse_tree(void *buffer, unsigned long size,
|
||||
static void traverse_tree(struct tree *tree,
|
||||
struct path_prefix *prefix)
|
||||
{
|
||||
struct path_prefix this_prefix;
|
||||
struct tree_entry_list *item;
|
||||
this_prefix.prev = prefix;
|
||||
|
||||
while (size) {
|
||||
int namelen = strlen(buffer)+1;
|
||||
parse_tree(tree);
|
||||
item = tree->entries;
|
||||
|
||||
while (item) {
|
||||
void *eltbuf;
|
||||
char elttype[20];
|
||||
unsigned long eltsize;
|
||||
unsigned char *sha1 = buffer + namelen;
|
||||
char *path = strchr(buffer, ' ') + 1;
|
||||
unsigned int mode;
|
||||
|
||||
if (size < namelen + 20 || sscanf(buffer, "%o", &mode) != 1)
|
||||
die("corrupt 'tree' file");
|
||||
if (S_ISDIR(mode) || S_ISREG(mode))
|
||||
mode |= (mode & 0100) ? 0777 : 0666;
|
||||
buffer = sha1 + 20;
|
||||
size -= namelen + 20;
|
||||
|
||||
eltbuf = read_sha1_file(sha1, elttype, &eltsize);
|
||||
eltbuf = read_sha1_file(item->item.any->sha1,
|
||||
elttype, &eltsize);
|
||||
if (!eltbuf)
|
||||
die("cannot read %s", sha1_to_hex(sha1));
|
||||
write_header(sha1, TYPEFLAG_AUTO, basedir, prefix, path,
|
||||
mode, eltbuf, eltsize);
|
||||
if (!strcmp(elttype, "tree")) {
|
||||
this_prefix.name = path;
|
||||
traverse_tree(eltbuf, eltsize, &this_prefix);
|
||||
} else if (!strcmp(elttype, "blob") && !S_ISLNK(mode)) {
|
||||
die("cannot read %s",
|
||||
sha1_to_hex(item->item.any->sha1));
|
||||
write_header(item->item.any->sha1, TYPEFLAG_AUTO, basedir,
|
||||
prefix, item->name,
|
||||
item->mode, eltbuf, eltsize);
|
||||
if (item->directory) {
|
||||
this_prefix.name = item->name;
|
||||
traverse_tree(item->item.tree, &this_prefix);
|
||||
} else if (!item->symlink) {
|
||||
write_blocked(eltbuf, eltsize);
|
||||
}
|
||||
free(eltbuf);
|
||||
item = item->next;
|
||||
}
|
||||
}
|
||||
|
||||
/* get commit time from committer line of commit object */
|
||||
static time_t commit_time(void * buffer, unsigned long size)
|
||||
{
|
||||
time_t result = 0;
|
||||
char *p = buffer;
|
||||
|
||||
while (size > 0) {
|
||||
char *endp = memchr(p, '\n', size);
|
||||
if (!endp || endp == p)
|
||||
break;
|
||||
*endp = '\0';
|
||||
if (endp - p > 10 && !memcmp(p, "committer ", 10)) {
|
||||
char *nump = strrchr(p, '>');
|
||||
if (!nump)
|
||||
break;
|
||||
nump++;
|
||||
result = strtoul(nump, &endp, 10);
|
||||
if (*endp != ' ')
|
||||
result = 0;
|
||||
break;
|
||||
}
|
||||
size -= endp - p - 1;
|
||||
p = endp + 1;
|
||||
}
|
||||
return result;
|
||||
}
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
unsigned char sha1[20];
|
||||
unsigned char commit_sha1[20];
|
||||
void *buffer;
|
||||
unsigned long size;
|
||||
struct commit *commit;
|
||||
struct tree *tree;
|
||||
|
||||
setup_git_directory();
|
||||
|
||||
@ -419,14 +390,13 @@ int main(int argc, char **argv)
|
||||
usage(tar_tree_usage);
|
||||
}
|
||||
|
||||
buffer = read_object_with_reference(sha1, "commit", &size, commit_sha1);
|
||||
if (buffer) {
|
||||
write_global_extended_header(commit_sha1);
|
||||
archive_time = commit_time(buffer, size);
|
||||
free(buffer);
|
||||
commit = lookup_commit_reference(sha1);
|
||||
if (commit) {
|
||||
write_global_extended_header(commit->object.sha1);
|
||||
archive_time = commit->date;
|
||||
}
|
||||
buffer = read_object_with_reference(sha1, "tree", &size, NULL);
|
||||
if (!buffer)
|
||||
tree = parse_tree_indirect(sha1);
|
||||
if (!tree)
|
||||
die("not a reference to a tag, commit or tree object: %s",
|
||||
sha1_to_hex(sha1));
|
||||
if (!archive_time)
|
||||
@ -434,8 +404,7 @@ int main(int argc, char **argv)
|
||||
if (basedir)
|
||||
write_header((unsigned char *)"0", TYPEFLAG_DIR, NULL, NULL,
|
||||
basedir, 040777, NULL, 0);
|
||||
traverse_tree(buffer, size, NULL);
|
||||
free(buffer);
|
||||
traverse_tree(tree, NULL);
|
||||
write_trailer();
|
||||
return 0;
|
||||
}
|
||||
|
Loading…
Reference in New Issue
Block a user