diff options
Diffstat (limited to 'contrib/fast-import')
| -rwxr-xr-x | contrib/fast-import/git-p4 | 420 | ||||
| -rw-r--r-- | contrib/fast-import/git-p4.txt | 289 |
2 files changed, 325 insertions, 384 deletions
diff --git a/contrib/fast-import/git-p4 b/contrib/fast-import/git-p4 index b975d67fca..3e1aa276cf 100755 --- a/contrib/fast-import/git-p4 +++ b/contrib/fast-import/git-p4 @@ -53,9 +53,10 @@ def p4_build_cmd(cmd): def chdir(dir): # P4 uses the PWD environment variable rather than getcwd(). Since we're - # not using the shell, we have to set it ourselves. - os.environ['PWD']=dir + # not using the shell, we have to set it ourselves. This path could + # be relative, so go there first, then figure out where we ended up. os.chdir(dir) + os.environ['PWD'] = os.getcwd() def die(msg): if verbose: @@ -361,6 +362,11 @@ def isValidGitDir(path): def parseRevision(ref): return read_pipe("git rev-parse %s" % ref).strip() +def branchExists(ref): + rev = read_pipe(["git", "rev-parse", "-q", "--verify", ref], + ignore_error=True) + return len(rev) > 0 + def extractLogMessageFromGitCommit(commit): logMessage = "" @@ -847,6 +853,41 @@ class P4Submit(Command, P4UserMap): return template + def edit_template(self, template_file): + """Invoke the editor to let the user change the submission + message. Return true if okay to continue with the submit.""" + + # if configured to skip the editing part, just submit + if gitConfig("git-p4.skipSubmitEdit") == "true": + return True + + # look at the modification time, to check later if the user saved + # the file + mtime = os.stat(template_file).st_mtime + + # invoke the editor + if os.environ.has_key("P4EDITOR"): + editor = os.environ.get("P4EDITOR") + else: + editor = read_pipe("git var GIT_EDITOR").strip() + system(editor + " " + template_file) + + # If the file was not saved, prompt to see if this patch should + # be skipped. But skip this verification step if configured so. + if gitConfig("git-p4.skipSubmitEditCheck") == "true": + return True + + # modification time updated means user saved the file + if os.stat(template_file).st_mtime > mtime: + return True + + while True: + response = raw_input("Submit template unchanged. Submit anyway? [y]es, [n]o (skip this patch) ") + if response == 'y': + return True + if response == 'n': + return False + def applyCommit(self, id): print "Applying %s" % (read_pipe("git log --max-count=1 --pretty=oneline %s" % id)) @@ -1001,7 +1042,7 @@ class P4Submit(Command, P4UserMap): separatorLine = "######## everything below this line is just the diff #######\n" - [handle, fileName] = tempfile.mkstemp() + (handle, fileName) = tempfile.mkstemp() tmpFile = os.fdopen(handle, "w+") if self.isWindows: submitTemplate = submitTemplate.replace("\n", "\r\n") @@ -1009,25 +1050,9 @@ class P4Submit(Command, P4UserMap): newdiff = newdiff.replace("\n", "\r\n") tmpFile.write(submitTemplate + separatorLine + diff + newdiff) tmpFile.close() - mtime = os.stat(fileName).st_mtime - if os.environ.has_key("P4EDITOR"): - editor = os.environ.get("P4EDITOR") - else: - editor = read_pipe("git var GIT_EDITOR").strip() - system(editor + " " + fileName) - - if gitConfig("git-p4.skipSubmitEditCheck") == "true": - checkModTime = False - else: - checkModTime = True - response = "y" - if checkModTime and (os.stat(fileName).st_mtime <= mtime): - response = "x" - while response != "y" and response != "n": - response = raw_input("Submit template unchanged. Submit anyway? [y]es, [n]o (skip this patch) ") - - if response == "y": + if self.edit_template(fileName): + # read the edited message and submit tmpFile = open(fileName, "rb") message = tmpFile.read() tmpFile.close() @@ -1039,11 +1064,13 @@ class P4Submit(Command, P4UserMap): if self.preserveUser: if p4User: # Get last changelist number. Cannot easily get it from - # the submit command output as the output is unmarshalled. + # the submit command output as the output is + # unmarshalled. changelist = self.lastP4Changelist() self.modifyChangelistUser(changelist, p4User) - else: + # skip this patch + print "Submission cancelled, undoing p4 changes." for f in editedFiles: p4_revert(f) for f in filesToAdd: @@ -1067,6 +1094,8 @@ class P4Submit(Command, P4UserMap): die("Detecting current git branch failed!") elif len(args) == 1: self.master = args[0] + if not branchExists(self.master): + die("Branch %s does not exist" % self.master) else: return False @@ -1099,6 +1128,10 @@ class P4Submit(Command, P4UserMap): print "Perforce checkout for depot path %s located at %s" % (self.depotPath, self.clientPath) self.oldWorkingDirectory = os.getcwd() + # ensure the clientPath exists + if not os.path.exists(self.clientPath): + os.makedirs(self.clientPath) + chdir(self.clientPath) print "Synchronizing p4 checkout..." p4_sync("...") @@ -1136,6 +1169,218 @@ class P4Submit(Command, P4UserMap): return True +class View(object): + """Represent a p4 view ("p4 help views"), and map files in a + repo according to the view.""" + + class Path(object): + """A depot or client path, possibly containing wildcards. + The only one supported is ... at the end, currently. + Initialize with the full path, with //depot or //client.""" + + def __init__(self, path, is_depot): + self.path = path + self.is_depot = is_depot + self.find_wildcards() + # remember the prefix bit, useful for relative mappings + m = re.match("(//[^/]+/)", self.path) + if not m: + die("Path %s does not start with //prefix/" % self.path) + prefix = m.group(1) + if not self.is_depot: + # strip //client/ on client paths + self.path = self.path[len(prefix):] + + def find_wildcards(self): + """Make sure wildcards are valid, and set up internal + variables.""" + + self.ends_triple_dot = False + # There are three wildcards allowed in p4 views + # (see "p4 help views"). This code knows how to + # handle "..." (only at the end), but cannot deal with + # "%%n" or "*". Only check the depot_side, as p4 should + # validate that the client_side matches too. + if re.search(r'%%[1-9]', self.path): + die("Can't handle %%n wildcards in view: %s" % self.path) + if self.path.find("*") >= 0: + die("Can't handle * wildcards in view: %s" % self.path) + triple_dot_index = self.path.find("...") + if triple_dot_index >= 0: + if not self.path.endswith("..."): + die("Can handle ... wildcard only at end of path: %s" % + self.path) + self.ends_triple_dot = True + + def ensure_compatible(self, other_path): + """Make sure the wildcards agree.""" + if self.ends_triple_dot != other_path.ends_triple_dot: + die("Both paths must end with ... if either does;\n" + + "paths: %s %s" % (self.path, other_path.path)) + + def match_wildcards(self, test_path): + """See if this test_path matches us, and fill in the value + of the wildcards if so. Returns a tuple of + (True|False, wildcards[]). For now, only the ... at end + is supported, so at most one wildcard.""" + if self.ends_triple_dot: + dotless = self.path[:-3] + if test_path.startswith(dotless): + wildcard = test_path[len(dotless):] + return (True, [ wildcard ]) + else: + if test_path == self.path: + return (True, []) + return (False, []) + + def match(self, test_path): + """Just return if it matches; don't bother with the wildcards.""" + b, _ = self.match_wildcards(test_path) + return b + + def fill_in_wildcards(self, wildcards): + """Return the relative path, with the wildcards filled in + if there are any.""" + if self.ends_triple_dot: + return self.path[:-3] + wildcards[0] + else: + return self.path + + class Mapping(object): + def __init__(self, depot_side, client_side, overlay, exclude): + # depot_side is without the trailing /... if it had one + self.depot_side = View.Path(depot_side, is_depot=True) + self.client_side = View.Path(client_side, is_depot=False) + self.overlay = overlay # started with "+" + self.exclude = exclude # started with "-" + assert not (self.overlay and self.exclude) + self.depot_side.ensure_compatible(self.client_side) + + def __str__(self): + c = " " + if self.overlay: + c = "+" + if self.exclude: + c = "-" + return "View.Mapping: %s%s -> %s" % \ + (c, self.depot_side, self.client_side) + + def map_depot_to_client(self, depot_path): + """Calculate the client path if using this mapping on the + given depot path; does not consider the effect of other + mappings in a view. Even excluded mappings are returned.""" + matches, wildcards = self.depot_side.match_wildcards(depot_path) + if not matches: + return "" + client_path = self.client_side.fill_in_wildcards(wildcards) + return client_path + + # + # View methods + # + def __init__(self): + self.mappings = [] + + def append(self, view_line): + """Parse a view line, splitting it into depot and client + sides. Append to self.mappings, preserving order.""" + + # Split the view line into exactly two words. P4 enforces + # structure on these lines that simplifies this quite a bit. + # + # Either or both words may be double-quoted. + # Single quotes do not matter. + # Double-quote marks cannot occur inside the words. + # A + or - prefix is also inside the quotes. + # There are no quotes unless they contain a space. + # The line is already white-space stripped. + # The two words are separated by a single space. + # + if view_line[0] == '"': + # First word is double quoted. Find its end. + close_quote_index = view_line.find('"', 1) + if close_quote_index <= 0: + die("No first-word closing quote found: %s" % view_line) + depot_side = view_line[1:close_quote_index] + # skip closing quote and space + rhs_index = close_quote_index + 1 + 1 + else: + space_index = view_line.find(" ") + if space_index <= 0: + die("No word-splitting space found: %s" % view_line) + depot_side = view_line[0:space_index] + rhs_index = space_index + 1 + + if view_line[rhs_index] == '"': + # Second word is double quoted. Make sure there is a + # double quote at the end too. + if not view_line.endswith('"'): + die("View line with rhs quote should end with one: %s" % + view_line) + # skip the quotes + client_side = view_line[rhs_index+1:-1] + else: + client_side = view_line[rhs_index:] + + # prefix + means overlay on previous mapping + overlay = False + if depot_side.startswith("+"): + overlay = True + depot_side = depot_side[1:] + + # prefix - means exclude this path + exclude = False + if depot_side.startswith("-"): + exclude = True + depot_side = depot_side[1:] + + m = View.Mapping(depot_side, client_side, overlay, exclude) + self.mappings.append(m) + + def map_in_client(self, depot_path): + """Return the relative location in the client where this + depot file should live. Returns "" if the file should + not be mapped in the client.""" + + paths_filled = [] + client_path = "" + + # look at later entries first + for m in self.mappings[::-1]: + + # see where will this path end up in the client + p = m.map_depot_to_client(depot_path) + + if p == "": + # Depot path does not belong in client. Must remember + # this, as previous items should not cause files to + # exist in this path either. Remember that the list is + # being walked from the end, which has higher precedence. + # Overlap mappings do not exclude previous mappings. + if not m.overlay: + paths_filled.append(m.client_side) + + else: + # This mapping matched; no need to search any further. + # But, the mapping could be rejected if the client path + # has already been claimed by an earlier mapping. + already_mapped_in_client = False + for f in paths_filled: + # this is View.Path.match + if f.match(p): + already_mapped_in_client = True + break + if not already_mapped_in_client: + # Include this file, unless it is from a line that + # explicitly said to exclude it. + if not m.exclude: + client_path = p + + # a match, even if rejected, always stops the search + break + + return client_path + class P4Sync(Command, P4UserMap): delete_actions = ( "delete", "move/delete", "purge" ) @@ -1183,7 +1428,7 @@ class P4Sync(Command, P4UserMap): self.p4BranchesInGit = [] self.cloneExclude = [] self.useClientSpec = False - self.clientSpecDirs = [] + self.clientSpecDirs = None if gitConfig("git-p4.syncFromOrigin") == "false": self.syncWithOrigin = False @@ -1234,20 +1479,7 @@ class P4Sync(Command, P4UserMap): def stripRepoPath(self, path, prefixes): if self.useClientSpec: - - # if using the client spec, we use the output directory - # specified in the client. For example, a view - # //depot/foo/branch/... //client/branch/foo/... - # will end up putting all foo/branch files into - # branch/foo/ - for val in self.clientSpecDirs: - if path.startswith(val[0]): - # replace the depot path with the client path - path = path.replace(val[0], val[1][1]) - # now strip out the client (//client/...) - path = re.sub("^(//[^/]+/)", '', path) - # the rest is all path - return path + return self.clientSpecDirs.map_in_client(path) if self.keepRepoPath: prefixes = [re.sub("^(//[^/]+/).*", r'\1', prefixes[0])] @@ -1397,19 +1629,17 @@ class P4Sync(Command, P4UserMap): filesToDelete = [] for f in files: - includeFile = True - for val in self.clientSpecDirs: - if f['path'].startswith(val[0]): - if val[1][0] <= 0: - includeFile = False - break + # if using a client spec, only add the files that have + # a path in the client + if self.clientSpecDirs: + if self.clientSpecDirs.map_in_client(f['path']) == "": + continue - if includeFile: - filesForCommit.append(f) - if f['action'] in self.delete_actions: - filesToDelete.append(f) - else: - filesToRead.append(f) + filesForCommit.append(f) + if f['action'] in self.delete_actions: + filesToDelete.append(f) + else: + filesToRead.append(f) # deleted files... for f in filesToDelete: @@ -1848,50 +2078,31 @@ class P4Sync(Command, P4UserMap): def getClientSpec(self): - specList = p4CmdList( "client -o" ) - temp = {} - for entry in specList: - for k,v in entry.iteritems(): - if k.startswith("View"): - - # p4 has these %%1 to %%9 arguments in specs to - # reorder paths; which we can't handle (yet :) - if re.match('%%\d', v) != None: - print "Sorry, can't handle %%n arguments in client specs" - sys.exit(1) - - if v.startswith('"'): - start = 1 - else: - start = 0 - index = v.find("...") - - # save the "client view"; i.e the RHS of the view - # line that tells the client where to put the - # files for this view. - cv = v[index+3:].strip() # +3 to remove previous '...' - - # if the client view doesn't end with a - # ... wildcard, then we're going to mess up the - # output directory, so fail gracefully. - if not cv.endswith('...'): - print 'Sorry, client view in "%s" needs to end with wildcard' % (k) - sys.exit(1) - cv=cv[:-3] - - # now save the view; +index means included, -index - # means it should be filtered out. - v = v[start:index] - if v.startswith("-"): - v = v[1:] - include = -len(v) - else: - include = len(v) + specList = p4CmdList("client -o") + if len(specList) != 1: + die('Output from "client -o" is %d lines, expecting 1' % + len(specList)) + + # dictionary of all client parameters + entry = specList[0] + + # just the keys that start with "View" + view_keys = [ k for k in entry.keys() if k.startswith("View") ] - temp[v] = (include, cv) + # hold this new View + view = View() - self.clientSpecDirs = temp.items() - self.clientSpecDirs.sort( lambda x, y: abs( y[1][0] ) - abs( x[1][0] ) ) + # append the lines, in order, to the view + for view_num in range(len(view_keys)): + k = "View%d" % view_num + if k not in view_keys: + die("Expected view key %s missing" % k) + view.append(entry[k]) + + self.clientSpecDirs = view + if self.verbose: + for i, m in enumerate(self.clientSpecDirs.mappings): + print "clientSpecDirs %d: %s" % (i, str(m)) def run(self, args): self.depotPaths = [] @@ -1925,7 +2136,10 @@ class P4Sync(Command, P4UserMap): if not gitBranchExists(self.refPrefix + "HEAD") and self.importIntoRemotes and gitBranchExists(self.branch): system("git symbolic-ref %sHEAD %s" % (self.refPrefix, self.branch)) - if self.useClientSpec or gitConfig("git-p4.useclientspec") == "true": + if not self.useClientSpec: + if gitConfig("git-p4.useclientspec", "--bool") == "true": + self.useClientSpec = True + if self.useClientSpec: self.getClientSpec() # TODO: should always look at previous commits, @@ -1998,6 +2212,17 @@ class P4Sync(Command, P4UserMap): revision = "" self.users = {} + # Make sure no revision specifiers are used when --changesfile + # is specified. + bad_changesfile = False + if len(self.changesFile) > 0: + for p in self.depotPaths: + if p.find("@") >= 0 or p.find("#") >= 0: + bad_changesfile = True + break + if bad_changesfile: + die("Option --changesfile is incompatible with revision specifiers") + newPaths = [] for p in self.depotPaths: if p.find("@") != -1: @@ -2014,7 +2239,10 @@ class P4Sync(Command, P4UserMap): revision = p[hashIdx:] p = p[:hashIdx] elif self.previousDepotPaths == []: - revision = "#head" + # pay attention to changesfile, if given, else import + # the entire p4 tree at the head revision + if len(self.changesFile) == 0: + revision = "#head" p = re.sub ("\.\.\.$", "", p) if not p.endswith("/"): @@ -2309,7 +2537,8 @@ def main(): args = sys.argv[2:] if len(options) > 0: - options.append(optparse.make_option("--git-dir", dest="gitdir")) + if cmd.needsGit: + options.append(optparse.make_option("--git-dir", dest="gitdir")) parser = optparse.OptionParser(cmd.usage.replace("%prog", "%prog " + cmdName), options, @@ -2339,6 +2568,7 @@ def main(): if not cmd.run(args): parser.print_help() + sys.exit(2) if __name__ == '__main__': diff --git a/contrib/fast-import/git-p4.txt b/contrib/fast-import/git-p4.txt deleted file mode 100644 index 52003ae904..0000000000 --- a/contrib/fast-import/git-p4.txt +++ /dev/null @@ -1,289 +0,0 @@ -git-p4 - Perforce <-> Git converter using git-fast-import - -Usage -===== - -git-p4 can be used in two different ways: - -1) To import changes from Perforce to a Git repository, using "git-p4 sync". - -2) To submit changes from Git back to Perforce, using "git-p4 submit". - -Importing -========= - -Simply start with - - git-p4 clone //depot/path/project - -or - - git-p4 clone //depot/path/project myproject - -This will: - -1) Create an empty git repository in a subdirectory called "project" (or -"myproject" with the second command) - -2) Import the head revision from the given Perforce path into a git branch -called "p4" (remotes/p4 actually) - -3) Create a master branch based on it and check it out. - -If you want the entire history (not just the head revision) then you can simply -append a "@all" to the depot path: - - git-p4 clone //depot/project/main@all myproject - - - -If you want more control you can also use the git-p4 sync command directly: - - mkdir repo-git - cd repo-git - git init - git-p4 sync //path/in/your/perforce/depot - -This will import the current head revision of the specified depot path into a -"remotes/p4/master" branch of your git repository. You can use the ---branch=mybranch option to import into a different branch. - -If you want to import the entire history of a given depot path simply use: - - git-p4 sync //path/in/depot@all - - -Note: - -To achieve optimal compression you may want to run 'git repack -a -d -f' after -a big import. This may take a while. - -Incremental Imports -=================== - -After an initial import you can continue to synchronize your git repository -with newer changes from the Perforce depot by just calling - - git-p4 sync - -in your git repository. By default the "remotes/p4/master" branch is updated. - -Advanced Setup -============== - -Suppose you have a periodically updated git repository somewhere, containing a -complete import of a Perforce project. This repository can be cloned and used -with git-p4. When updating the cloned repository with the "sync" command, -git-p4 will try to fetch changes from the original repository first. The git -protocol used with this is usually faster than importing from Perforce -directly. - -This behaviour can be disabled by setting the "git-p4.syncFromOrigin" git -configuration variable to "false". - -Updating -======== - -A common working pattern is to fetch the latest changes from the Perforce depot -and merge them with local uncommitted changes. The recommended way is to use -git's rebase mechanism to preserve linear history. git-p4 provides a convenient - - git-p4 rebase - -command that calls git-p4 sync followed by git rebase to rebase the current -working branch. - -Submitting -========== - -git-p4 has support for submitting changes from a git repository back to the -Perforce depot. This requires a Perforce checkout separate from your git -repository. To submit all changes that are in the current git branch but not in -the "p4" branch (or "origin" if "p4" doesn't exist) simply call - - git-p4 submit - -in your git repository. If you want to submit changes in a specific branch that -is not your current git branch you can also pass that as an argument: - - git-p4 submit mytopicbranch - -You can override the reference branch with the --origin=mysourcebranch option. - -The Perforce changelists will be created with the user who ran git-p4. If you -use --preserve-user then git-p4 will attempt to create Perforce changelists -with the Perforce user corresponding to the git commit author. You need to -have sufficient permissions within Perforce, and the git users need to have -Perforce accounts. Permissions can be granted using 'p4 protect'. - -If a submit fails you may have to "p4 resolve" and submit manually. You can -continue importing the remaining changes with - - git-p4 submit --continue - -Example -======= - -# Clone a repository - git-p4 clone //depot/path/project -# Enter the newly cloned directory - cd project -# Do some work... - vi foo.h -# ... and commit locally to gi - git commit foo.h -# In the meantime somebody submitted changes to the Perforce depot. Rebase your latest -# changes against the latest changes in Perforce: - git-p4 rebase -# Submit your locally committed changes back to Perforce - git-p4 submit -# ... and synchronize with Perforce - git-p4 rebase - - -Configuration parameters -======================== - -git-p4.user ($P4USER) - -Allows you to specify the username to use to connect to the Perforce repository. - - git config [--global] git-p4.user public - -git-p4.password ($P4PASS) - -Allows you to specify the password to use to connect to the Perforce repository. -Warning this password will be visible on the command-line invocation of the p4 binary. - - git config [--global] git-p4.password public1234 - -git-p4.port ($P4PORT) - -Specify the port to be used to contact the Perforce server. As this will be passed -directly to the p4 binary, it may be in the format host:port as well. - - git config [--global] git-p4.port codes.zimbra.com:2666 - -git-p4.host ($P4HOST) - -Specify the host to contact for a Perforce repository. - - git config [--global] git-p4.host perforce.example.com - -git-p4.client ($P4CLIENT) - -Specify the client name to use - - git config [--global] git-p4.client public-view - -git-p4.allowSubmit - - git config [--global] git-p4.allowSubmit false - -git-p4.syncFromOrigin - -A useful setup may be that you have a periodically updated git repository -somewhere that contains a complete import of a Perforce project. That git -repository can be used to clone the working repository from and one would -import from Perforce directly after cloning using git-p4. If the connection to -the Perforce server is slow and the working repository hasn't been synced for a -while it may be desirable to fetch changes from the origin git repository using -the efficient git protocol. git-p4 supports this setup by calling "git fetch origin" -by default if there is an origin branch. You can disable this using: - - git config [--global] git-p4.syncFromOrigin false - -git-p4.useclientspec - - git config [--global] git-p4.useclientspec false - -The P4CLIENT environment variable should be correctly set for p4 to be -able to find the relevant client. This client spec will be used to -both filter the files cloned by git and set the directory layout as -specified in the client (this implies --keep-path style semantics). - -git-p4.skipSubmitModTimeCheck - - git config [--global] git-p4.skipSubmitModTimeCheck false - -If true, submit will not check if the p4 change template has been modified. - -git-p4.preserveUser - - git config [--global] git-p4.preserveUser false - -If true, attempt to preserve user names by modifying the p4 changelists. See -the "--preserve-user" submit option. - -git-p4.allowMissingPerforceUsers - - git config [--global] git-p4.allowMissingP4Users false - -If git-p4 is setting the perforce user for a commit (--preserve-user) then -if there is no perforce user corresponding to the git author, git-p4 will -stop. With allowMissingPerforceUsers set to true, git-p4 will use the -current user (i.e. the behavior without --preserve-user) and carry on with -the perforce commit. - -git-p4.skipUserNameCheck - - git config [--global] git-p4.skipUserNameCheck false - -When submitting, git-p4 checks that the git commits are authored by the current -p4 user, and warns if they are not. This disables the check. - -git-p4.detectRenames - -Detect renames when submitting changes to Perforce server. Will enable -M git -argument. Can be optionally set to a number representing the threshold -percentage value of the rename detection. - - git config [--global] git-p4.detectRenames true - git config [--global] git-p4.detectRenames 50 - -git-p4.detectCopies - -Detect copies when submitting changes to Perforce server. Will enable -C git -argument. Can be optionally set to a number representing the threshold -percentage value of the copy detection. - - git config [--global] git-p4.detectCopies true - git config [--global] git-p4.detectCopies 80 - -git-p4.detectCopiesHarder - -Detect copies even between files that did not change when submitting changes to -Perforce server. Will enable --find-copies-harder git argument. - - git config [--global] git-p4.detectCopies true - -git-p4.branchUser - -Only use branch specifications defined by the selected username. - - git config [--global] git-p4.branchUser username - -git-p4.branchList - -List of branches to be imported when branch detection is enabled. - - git config [--global] git-p4.branchList main:branchA - git config [--global] --add git-p4.branchList main:branchB - -Implementation Details... -========================= - -* Changesets from Perforce are imported using git fast-import. -* The import does not require anything from the Perforce client view as it just uses - "p4 print //depot/path/file#revision" to get the actual file contents. -* Every imported changeset has a special [git-p4...] line at the - end of the log message that gives information about the corresponding - Perforce change number and is also used by git-p4 itself to find out - where to continue importing when doing incremental imports. - Basically when syncing it extracts the perforce change number of the - latest commit in the "p4" branch and uses "p4 changes //depot/path/...@changenum,#head" - to find out which changes need to be imported. -* git-p4 submit uses "git rev-list" to pick the commits between the "p4" branch - and the current branch. - The commits themselves are applied using git diff/format-patch ... | git apply - |