summaryrefslogtreecommitdiff
path: root/Documentation/git-p4.txt
blob: d7f5a51feaeaf1acd804510ddc910f11fcfdbe50 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
git-p4(1)
=========

NAME
----
git-p4 - Import from and submit to Perforce repositories


SYNOPSIS
--------
[verse]
'git p4 clone' [<sync options>] [<clone options>] <p4 depot path>...
'git p4 sync' [<sync options>] [<p4 depot path>...]
'git p4 rebase'
'git p4 submit' [<submit options>] [<master branch name>]


DESCRIPTION
-----------
This command provides a way to interact with p4 repositories
using git.

Create a new git repository from an existing p4 repository using
'git p4 clone', giving it one or more p4 depot paths.  Incorporate
new commits from p4 changes with 'git p4 sync'.  The 'sync' command
is also used to include new branches from other p4 depot paths.
Submit git changes back to p4 using 'git p4 submit'.  The command
'git p4 rebase' does a sync plus rebases the current branch onto
the updated p4 remote branch.


EXAMPLE
-------
* Create an alias for 'git p4', using the full path to the 'git-p4'
  script if needed:
+
------------
$ git config --global alias.p4 '!git-p4'
------------

* Clone a repository:
+
------------
$ git p4 clone //depot/path/project
------------

* Do some work in the newly created git repository:
+
------------
$ cd project
$ vi foo.h
$ git commit -a -m "edited foo.h"
------------

* Update the git repository with recent changes from p4, rebasing your
  work on top:
+
------------
$ git p4 rebase
------------

* Submit your commits back to p4:
+
------------
$ git p4 submit
------------


COMMANDS
--------

Clone
~~~~~
Generally, 'git p4 clone' is used to create a new git directory
from an existing p4 repository:
------------
$ git p4 clone //depot/path/project
------------
This:

1.   Creates an empty git repository in a subdirectory called 'project'.
+
2.   Imports the full contents of the head revision from the given p4
depot path into a single commit in the git branch 'refs/remotes/p4/master'.
+
3.   Creates a local branch, 'master' from this remote and checks it out.

To reproduce the entire p4 history in git, use the '@all' modifier on
the depot path:
------------
$ git p4 clone //depot/path/project@all
------------


Sync
~~~~
As development continues in the p4 repository, those changes can
be included in the git repository using:
------------
$ git p4 sync
------------
This command finds new changes in p4 and imports them as git commits.

P4 repositories can be added to an existing git repository using
'git p4 sync' too:
------------
$ mkdir repo-git
$ cd repo-git
$ git init
$ git p4 sync //path/in/your/perforce/depot
------------
This imports the specified depot into
'refs/remotes/p4/master' in an existing git repository.  The
'--branch' option can be used to specify a different branch to
be used for the p4 content.

If a git repository includes branches 'refs/remotes/origin/p4', these
will be fetched and consulted first during a 'git p4 sync'.  Since
importing directly from p4 is considerably slower than pulling changes
from a git remote, this can be useful in a multi-developer environment.


Rebase
~~~~~~
A common working pattern is to fetch the latest changes from the p4 depot
and merge them with local uncommitted changes.  Often, the p4 repository
is the ultimate location for all code, thus a rebase workflow makes
sense.  This command does 'git p4 sync' followed by 'git rebase' to move
local commits on top of updated p4 changes.
------------
$ git p4 rebase
------------


Submit
~~~~~~
Submitting changes from a git repository back to the p4 repository
requires a separate p4 client workspace.  This should be specified
using the 'P4CLIENT' environment variable or the git configuration
variable 'git-p4.client'.  The p4 client must exist, but the client root
will be created and populated if it does not already exist.

To submit all changes that are in the current git branch but not in
the 'p4/master' branch, use:
------------
$ git p4 submit
------------

To specify a branch other than the current one, use:
------------
$ git p4 submit topicbranch
------------

The upstream reference is generally 'refs/remotes/p4/master', but can
be overridden using the '--origin=' command-line option.

The p4 changes will be created as the user invoking 'git p4 submit'. The
'--preserve-user' option will cause ownership to be modified
according to the author of the git commit.  This option requires admin
privileges in p4, which can be granted using 'p4 protect'.


OPTIONS
-------

General options
~~~~~~~~~~~~~~~
All commands except clone accept this option.

--git-dir <dir>::
	Set the 'GIT_DIR' environment variable.  See linkgit:git[1].

Sync options
~~~~~~~~~~~~
These options can be used in the initial 'clone' as well as in
subsequent 'sync' operations.

--branch <branch>::
	Import changes into given branch.  If the branch starts with
	'refs/', it will be used as is, otherwise the path 'refs/heads/'
	will be prepended.  The default branch is 'master'.  If used
	with an initial clone, no HEAD will be checked out.
+
This example imports a new remote "p4/proj2" into an existing
git repository:
----
    $ git init
    $ git p4 sync --branch=refs/remotes/p4/proj2 //depot/proj2
----

--detect-branches::
	Use the branch detection algorithm to find new paths in p4.  It is
	documented below in "BRANCH DETECTION".

--changesfile <file>::
	Import exactly the p4 change numbers listed in 'file', one per
	line.  Normally, 'git p4' inspects the current p4 repository
	state and detects the changes it should import.

--silent::
	Do not print any progress information.

--verbose::
	Provide more progress information.

--detect-labels::
	Query p4 for labels associated with the depot paths, and add
	them as tags in git.

--import-local::
	By default, p4 branches are stored in 'refs/remotes/p4/',
	where they will be treated as remote-tracking branches by
	linkgit:git-branch[1] and other commands.  This option instead
	puts p4 branches in 'refs/heads/p4/'.  Note that future
	sync operations must specify '--import-local' as well so that
	they can find the p4 branches in refs/heads.

--max-changes <n>::
	Limit the number of imported changes to 'n'.  Useful to
	limit the amount of history when using the '@all' p4 revision
	specifier.

--keep-path::
	The mapping of file names from the p4 depot path to git, by
	default, involves removing the entire depot path.  With this
	option, the full p4 depot path is retained in git.  For example,
	path '//depot/main/foo/bar.c', when imported from
	'//depot/main/', becomes 'foo/bar.c'.  With '--keep-path', the
	git path is instead 'depot/main/foo/bar.c'.

--use-client-spec::
	Use a client spec to find the list of interesting files in p4.
	The client spec is discovered using 'p4 client -o' which checks
	the 'P4CLIENT' environment variable and returns a mapping of
	depot files to workspace files.  Note that a depot path is
	still required, but files found in the path that match in
	the client spec view will be laid out according to the client
	spec.

Clone options
~~~~~~~~~~~~~
These options can be used in an initial 'clone', along with the 'sync'
options described above.

--destination <directory>::
	Where to create the git repository.  If not provided, the last
	component in the p4 depot path is used to create a new
	directory.

--bare::
	Perform a bare clone.  See linkgit:git-clone[1].

-/ <path>::
	Exclude selected depot paths when cloning.

Submit options
~~~~~~~~~~~~~~
These options can be used to modify 'git p4 submit' behavior.

--verbose::
	Provide more progress information.

--origin <commit>::
	Upstream location from which commits are identified to submit to
	p4.  By default, this is the most recent p4 commit reachable
	from 'HEAD'.

-M[<n>]::
	Detect renames.  See linkgit:git-diff[1].  Renames will be
	represented in p4 using explicit 'move' operations.  There
	is no corresponding option to detect copies, but there are
	variables for both moves and copies.

--preserve-user::
	Re-author p4 changes before submitting to p4.  This option
	requires p4 admin privileges.


DEPOT PATH SYNTAX
-----------------
The p4 depot path argument to 'git p4 sync' and 'git p4 clone' can
be one or more space-separated p4 depot paths, with an optional
p4 revision specifier on the end:

"//depot/my/project"::
    Import one commit with all files in the '#head' change under that tree.

"//depot/my/project@all"::
    Import one commit for each change in the history of that depot path.

"//depot/my/project@1,6"::
    Import only changes 1 through 6.

"//depot/proj1@all //depot/proj2@all"::
    Import all changes from both named depot paths into a single
    repository.  Only files below these directories are included.
    There is not a subdirectory in git for each "proj1" and "proj2".
    You must use the '--destination' option when specifying more
    than one depot path.  The revision specifier must be specified
    identically on each depot path.  If there are files in the
    depot paths with the same name, the path with the most recently
    updated version of the file is the one that appears in git.

See 'p4 help revisions' for the full syntax of p4 revision specifiers.


BRANCH DETECTION
----------------
P4 does not have the same concept of a branch as git.  Instead,
p4 organizes its content as a directory tree, where by convention
different logical branches are in different locations in the tree.
The 'p4 branch' command is used to maintain mappings between
different areas in the tree, and indicate related content.  'git p4'
can use these mappings to determine branch relationships.

If you have a repository where all the branches of interest exist as
subdirectories of a single depot path, you can use '--detect-branches'
when cloning or syncing to have 'git p4' automatically find
subdirectories in p4, and to generate these as branches in git.

For example, if the P4 repository structure is:
----
//depot/main/...
//depot/branch1/...
----

And "p4 branch -o branch1" shows a View line that looks like:
----
//depot/main/... //depot/branch1/...
----

Then this 'git p4 clone' command:
----
git p4 clone --detect-branches //depot@all
----
produces a separate branch in 'refs/remotes/p4/' for //depot/main,
called 'master', and one for //depot/branch1 called 'depot/branch1'.

However, it is not necessary to create branches in p4 to be able to use
them like branches.  Because it is difficult to infer branch
relationships automatically, a git configuration setting
'git-p4.branchList' can be used to explicitly identify branch
relationships.  It is a list of "source:destination" pairs, like a
simple p4 branch specification, where the "source" and "destination" are
the path elements in the p4 repository.  The example above relied on the
presence of the p4 branch.  Without p4 branches, the same result will
occur with:
----
git config git-p4.branchList main:branch1
git p4 clone --detect-branches //depot@all
----


PERFORMANCE
-----------
The fast-import mechanism used by 'git p4' creates one pack file for
each invocation of 'git p4 sync'.  Normally, git garbage compression
(linkgit:git-gc[1]) automatically compresses these to fewer pack files,
but explicit invocation of 'git repack -adf' may improve performance.


CONFIGURATION VARIABLES
-----------------------
The following config settings can be used to modify 'git p4' behavior.
They all are in the 'git-p4' section.

General variables
~~~~~~~~~~~~~~~~~
git-p4.user::
	User specified as an option to all p4 commands, with '-u <user>'.
	The environment variable 'P4USER' can be used instead.

git-p4.password::
	Password specified as an option to all p4 commands, with
	'-P <password>'.
	The environment variable 'P4PASS' can be used instead.

git-p4.port::
	Port specified as an option to all p4 commands, with
	'-p <port>'.
	The environment variable 'P4PORT' can be used instead.

git-p4.host::
	Host specified as an option to all p4 commands, with
	'-h <host>'.
	The environment variable 'P4HOST' can be used instead.

git-p4.client::
	Client specified as an option to all p4 commands, with
	'-c <client>'.  This can also be used as a way to find
	the client spec for the 'useClientSpec' option.
	The environment variable 'P4CLIENT' can be used instead.

Clone and sync variables
~~~~~~~~~~~~~~~~~~~~~~~~
git-p4.syncFromOrigin::
	Because importing commits from other git repositories is much faster
	than importing them from p4, a mechanism exists to find p4 changes
	first in git remotes.  If branches exist under 'refs/remote/origin/p4',
	those will be fetched and used when syncing from p4.  This
	variable can be set to 'false' to disable this behavior.

git-p4.branchUser::
	One phase in branch detection involves looking at p4 branches
	to find new ones to import.  By default, all branches are
	inspected.  This option limits the search to just those owned
	by the single user named in the variable.

git-p4.branchList::
	List of branches to be imported when branch detection is
	enabled.  Each entry should be a pair of branch names separated
	by a colon (:).  This example declares that both branchA and
	branchB were created from main:
-------------
git config       git-p4.branchList main:branchA
git config --add git-p4.branchList main:branchB
-------------

git-p4.useClientSpec::
	Specify that the p4 client spec to be used to identify p4 depot
	paths of interest.  This is equivalent to specifying the option
	'--use-client-spec'.  The variable 'git-p4.client' can be used
	to specify the name of the client.

Submit variables
~~~~~~~~~~~~~~~~
git-p4.detectRenames::
	Detect renames.  See linkgit:git-diff[1].

git-p4.detectCopies::
	Detect copies.  See linkgit:git-diff[1].

git-p4.detectCopiesHarder::
	Detect copies harder.  See linkgit:git-diff[1].

git-p4.preserveUser::
	On submit, re-author changes to reflect the git author,
	regardless of who invokes 'git p4 submit'.

git-p4.allowMissingP4Users::
	When 'preserveUser' is true, 'git p4' normally dies if it
	cannot find an author in the p4 user map.  This setting
	submits the change regardless.

git-p4.skipSubmitEdit::
	The submit process invokes the editor before each p4 change
	is submitted.  If this setting is true, though, the editing
	step is skipped.

git-p4.skipSubmitEditCheck::
	After editing the p4 change message, 'git p4' makes sure that
	the description really was changed by looking at the file
	modification time.  This option disables that test.

git-p4.allowSubmit::
	By default, any branch can be used as the source for a 'git p4
	submit' operation.  This configuration variable, if set, permits only
	the named branches to be used as submit sources.  Branch names
	must be the short names (no "refs/heads/"), and should be
	separated by commas (","), with no spaces.

git-p4.skipUserNameCheck::
	If the user running 'git p4 submit' does not exist in the p4
	user map, 'git p4' exits.  This option can be used to force
	submission regardless.


IMPLEMENTATION DETAILS
----------------------
* Changesets from p4 are imported using git fast-import.
* Cloning or syncing does not require a p4 client; file contents are
  collected using 'p4 print'.
* Submitting requires a p4 client, which is not in the same location
  as the git repository.  Patches are applied, one at a time, to
  this p4 client and submitted from there.
* Each commit imported by 'git p4' has a line at the end of the log
  message indicating the p4 depot location and change number.  This
  line is used by later 'git p4 sync' operations to know which p4
  changes are new.