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diff --git a/Documentation/git-p4.txt b/Documentation/git-p4.txt new file mode 100644 index 0000000000..8b92cc0f8d --- /dev/null +++ b/Documentation/git-p4.txt @@ -0,0 +1,498 @@ +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. + See the "CLIENT SPEC" section below. + +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. + + +CLIENT SPEC +----------- +The p4 client specification is maintained with the 'p4 client' command +and contains among other fields, a View that specifies how the depot +is mapped into the client repository. Git-p4 can consult the client +spec when given the '--use-client-spec' option or useClientSpec +variable. + +The full syntax for a p4 view is documented in 'p4 help views'. Git-p4 +knows only a subset of the view syntax. It understands multi-line +mappings, overlays with '+', exclusions with '-' and double-quotes +around whitespace. Of the possible wildcards, git-p4 only handles +'...', and only when it is at the end of the path. Git-p4 will complain +if it encounters an unhandled wildcard. + +Bugs in the implementation of overlap mappings exist. If multiple depot +paths map through overlays to the same location in the repository, +git-p4 can choose the wrong one. This is hard to solve without +dedicating a client spec just for git-p4. + +The name of the client can be given to git-p4 in multiple ways. The +variable 'git-p4.client' takes precedence if it exists. Otherwise, +normal p4 mechanisms of determining the client are used: environment +variable P4CLIENT, a file referenced by P4CONFIG, or the local host name. + + +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>', including the client spec. + +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 should be used to identify p4 + depot paths of interest. This is equivalent to specifying the + option '--use-client-spec'. See the "CLIENT SPEC" section above. + This variable is a boolean, not the name of a p4 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. |