From 7aeaa2fc0abbf439534769e15b3a59a5814cc3d1 Mon Sep 17 00:00:00 2001 From: Sverre Rabbelier Date: Mon, 29 Mar 2010 11:48:28 -0500 Subject: remote-helpers: add testgit helper Currently the remote helper infrastructure is only used by the curl helper, which does not give a good impression of how remote helpers can be used to interact with foreign repositories. Since implementing such a helper is non-trivial it would be good to have at least one easy-to-follow example demonstrating how to implement a helper that interacts with a foreign vcs using fast-import/fast-export. The testgit helper can be used to interact with remote git repositories by prefixing the url with "testgit::". Signed-off-by: Junio C Hamano diff --git a/.gitignore b/.gitignore index 7b3acb7..7aebd6b 100644 --- a/.gitignore +++ b/.gitignore @@ -112,6 +112,7 @@ /git-remote-https /git-remote-ftp /git-remote-ftps +/git-remote-testgit /git-repack /git-replace /git-repo-config diff --git a/Makefile b/Makefile index 3a6c6ea..b1e5f61 100644 --- a/Makefile +++ b/Makefile @@ -366,6 +366,8 @@ SCRIPT_PERL += git-relink.perl SCRIPT_PERL += git-send-email.perl SCRIPT_PERL += git-svn.perl +SCRIPT_PYTHON += git-remote-testgit.py + SCRIPTS = $(patsubst %.sh,%,$(SCRIPT_SH)) \ $(patsubst %.perl,%,$(SCRIPT_PERL)) \ $(patsubst %.py,%,$(SCRIPT_PYTHON)) \ diff --git a/git-remote-testgit.py b/git-remote-testgit.py new file mode 100644 index 0000000..f61624e --- /dev/null +++ b/git-remote-testgit.py @@ -0,0 +1,233 @@ +#!/usr/bin/env python + +import hashlib +import sys + +from git_remote_helpers.util import die, debug, warn +from git_remote_helpers.git.repo import GitRepo +from git_remote_helpers.git.exporter import GitExporter +from git_remote_helpers.git.importer import GitImporter +from git_remote_helpers.git.non_local import NonLocalGit + +def get_repo(alias, url): + """Returns a git repository object initialized for usage. + """ + + repo = GitRepo(url) + repo.get_revs() + repo.get_head() + + hasher = hashlib.sha1() + hasher.update(repo.path) + repo.hash = hasher.hexdigest() + + repo.get_base_path = lambda base: os.path.join( + base, 'info', 'fast-import', repo.hash) + + prefix = 'refs/testgit/%s/' % alias + debug("prefix: '%s'", prefix) + + repo.gitdir = "" + repo.alias = alias + repo.prefix = prefix + + repo.exporter = GitExporter(repo) + repo.importer = GitImporter(repo) + repo.non_local = NonLocalGit(repo) + + return repo + + +def local_repo(repo, path): + """Returns a git repository object initalized for usage. + """ + + local = GitRepo(path) + + local.non_local = None + local.gitdir = repo.gitdir + local.alias = repo.alias + local.prefix = repo.prefix + local.hash = repo.hash + local.get_base_path = repo.get_base_path + local.exporter = GitExporter(local) + local.importer = GitImporter(local) + + return local + + +def do_capabilities(repo, args): + """Prints the supported capabilities. + """ + + print "import" + print "export" + print "gitdir" + print "refspec refs/heads/*:%s*" % repo.prefix + + print # end capabilities + + +def do_list(repo, args): + """Lists all known references. + + Bug: This will always set the remote head to master for non-local + repositories, since we have no way of determining what the remote + head is at clone time. + """ + + for ref in repo.revs: + debug("? refs/heads/%s", ref) + print "? refs/heads/%s" % ref + + if repo.head: + debug("@refs/heads/%s HEAD" % repo.head) + print "@refs/heads/%s HEAD" % repo.head + else: + debug("@refs/heads/master HEAD") + print "@refs/heads/master HEAD" + + print # end list + + +def update_local_repo(repo): + """Updates (or clones) a local repo. + """ + + if repo.local: + return repo + + path = repo.non_local.clone(repo.gitdir) + repo.non_local.update(repo.gitdir) + repo = local_repo(repo, path) + return repo + + +def do_import(repo, args): + """Exports a fast-import stream from testgit for git to import. + """ + + if len(args) != 1: + die("Import needs exactly one ref") + + if not repo.gitdir: + die("Need gitdir to import") + + repo = update_local_repo(repo) + repo.exporter.export_repo(repo.gitdir) + + +def do_export(repo, args): + """Imports a fast-import stream from git to testgit. + """ + + if not repo.gitdir: + die("Need gitdir to export") + + dirname = repo.get_base_path(repo.gitdir) + + if not os.path.exists(dirname): + os.makedirs(dirname) + + path = os.path.join(dirname, 'testgit.marks') + print path + print path if os.path.exists(path) else "" + sys.stdout.flush() + + update_local_repo(repo) + repo.importer.do_import(repo.gitdir) + repo.non_local.push(repo.gitdir) + + +def do_gitdir(repo, args): + """Stores the location of the gitdir. + """ + + if not args: + die("gitdir needs an argument") + + repo.gitdir = ' '.join(args) + + +COMMANDS = { + 'capabilities': do_capabilities, + 'list': do_list, + 'import': do_import, + 'export': do_export, + 'gitdir': do_gitdir, +} + + +def sanitize(value): + """Cleans up the url. + """ + + if value.startswith('testgit::'): + value = value[9:] + + return value + + +def read_one_line(repo): + """Reads and processes one command. + """ + + line = sys.stdin.readline() + + cmdline = line + + if not cmdline: + warn("Unexpected EOF") + return False + + cmdline = cmdline.strip().split() + if not cmdline: + # Blank line means we're about to quit + return False + + cmd = cmdline.pop(0) + debug("Got command '%s' with args '%s'", cmd, ' '.join(cmdline)) + + if cmd not in COMMANDS: + die("Unknown command, %s", cmd) + + func = COMMANDS[cmd] + func(repo, cmdline) + sys.stdout.flush() + + return True + + +def main(args): + """Starts a new remote helper for the specified repository. + """ + + if len(args) != 3: + die("Expecting exactly three arguments.") + sys.exit(1) + + if os.getenv("GIT_DEBUG_TESTGIT"): + import git_remote_helpers.util + git_remote_helpers.util.DEBUG = True + + alias = sanitize(args[1]) + url = sanitize(args[2]) + + if not alias.isalnum(): + warn("non-alnum alias '%s'", alias) + alias = "tmp" + + args[1] = alias + args[2] = url + + repo = get_repo(alias, url) + + debug("Got arguments %s", args[1:]) + + more = True + + while (more): + more = read_one_line(repo) + +if __name__ == '__main__': + sys.exit(main(sys.argv)) diff --git a/git_remote_helpers/git/exporter.py b/git_remote_helpers/git/exporter.py new file mode 100644 index 0000000..dfaab00 --- /dev/null +++ b/git_remote_helpers/git/exporter.py @@ -0,0 +1,51 @@ +import os +import subprocess +import sys + + +class GitExporter(object): + """An exporter for testgit repositories. + + The exporter simply delegates to git fast-export. + """ + + def __init__(self, repo): + """Creates a new exporter for the specified repo. + """ + + self.repo = repo + + def export_repo(self, base): + """Exports a fast-export stream for the given directory. + + Simply delegates to git fast-epxort and pipes it through sed + to make the refs show up under the prefix rather than the + default refs/heads. This is to demonstrate how the export + data can be stored under it's own ref (using the refspec + capability). + """ + + dirname = self.repo.get_base_path(base) + path = os.path.abspath(os.path.join(dirname, 'testgit.marks')) + + if not os.path.exists(dirname): + os.makedirs(dirname) + + print "feature relative-marks" + if os.path.exists(os.path.join(dirname, 'git.marks')): + print "feature import-marks=%s/git.marks" % self.repo.hash + print "feature export-marks=%s/git.marks" % self.repo.hash + sys.stdout.flush() + + args = ["git", "--git-dir=" + self.repo.gitpath, "fast-export", "--export-marks=" + path] + + if os.path.exists(path): + args.append("--import-marks=" + path) + + args.append("HEAD") + + p1 = subprocess.Popen(args, stdout=subprocess.PIPE) + + args = ["sed", "s_refs/heads/_" + self.repo.prefix + "_g"] + + subprocess.check_call(args, stdin=p1.stdout) diff --git a/git_remote_helpers/git/importer.py b/git_remote_helpers/git/importer.py new file mode 100644 index 0000000..af2919d --- /dev/null +++ b/git_remote_helpers/git/importer.py @@ -0,0 +1,38 @@ +import os +import subprocess + + +class GitImporter(object): + """An importer for testgit repositories. + + This importer simply delegates to git fast-import. + """ + + def __init__(self, repo): + """Creates a new importer for the specified repo. + """ + + self.repo = repo + + def do_import(self, base): + """Imports a fast-import stream to the given directory. + + Simply delegates to git fast-import. + """ + + dirname = self.repo.get_base_path(base) + if self.repo.local: + gitdir = self.repo.gitpath + else: + gitdir = os.path.abspath(os.path.join(dirname, '.git')) + path = os.path.abspath(os.path.join(dirname, 'git.marks')) + + if not os.path.exists(dirname): + os.makedirs(dirname) + + args = ["git", "--git-dir=" + gitdir, "fast-import", "--quiet", "--export-marks=" + path] + + if os.path.exists(path): + args.append("--import-marks=" + path) + + subprocess.check_call(args) diff --git a/git_remote_helpers/git/non_local.py b/git_remote_helpers/git/non_local.py new file mode 100644 index 0000000..d75ef8f --- /dev/null +++ b/git_remote_helpers/git/non_local.py @@ -0,0 +1,61 @@ +import os +import subprocess + +from git_remote_helpers.util import die, warn + + +class NonLocalGit(object): + """Handler to interact with non-local repos. + """ + + def __init__(self, repo): + """Creates a new non-local handler for the specified repo. + """ + + self.repo = repo + + def clone(self, base): + """Clones the non-local repo to base. + + Does nothing if a clone already exists. + """ + + path = os.path.join(self.repo.get_base_path(base), '.git') + + # already cloned + if os.path.exists(path): + return path + + os.makedirs(path) + args = ["git", "clone", "--bare", "--quiet", self.repo.gitpath, path] + + subprocess.check_call(args) + + return path + + def update(self, base): + """Updates checkout of the non-local repo in base. + """ + + path = os.path.join(self.repo.get_base_path(base), '.git') + + if not os.path.exists(path): + die("could not find repo at %s", path) + + args = ["git", "--git-dir=" + path, "fetch", "--quiet", self.repo.gitpath] + subprocess.check_call(args) + + args = ["git", "--git-dir=" + path, "update-ref", "refs/heads/master", "FETCH_HEAD"] + subprocess.check_call(args) + + def push(self, base): + """Pushes from the non-local repo to base. + """ + + path = os.path.join(self.repo.get_base_path(base), '.git') + + if not os.path.exists(path): + die("could not find repo at %s", path) + + args = ["git", "--git-dir=" + path, "push", "--quiet", self.repo.gitpath] + subprocess.check_call(args) diff --git a/git_remote_helpers/git/repo.py b/git_remote_helpers/git/repo.py new file mode 100644 index 0000000..82d5f78 --- /dev/null +++ b/git_remote_helpers/git/repo.py @@ -0,0 +1,70 @@ +import os +import subprocess + +def sanitize(rev, sep='\t'): + """Converts a for-each-ref line to a name/value pair. + """ + + splitrev = rev.split(sep) + branchval = splitrev[0] + branchname = splitrev[1].strip() + if branchname.startswith("refs/heads/"): + branchname = branchname[11:] + + return branchname, branchval + +def is_remote(url): + """Checks whether the specified value is a remote url. + """ + + prefixes = ["http", "file", "git"] + + return any(url.startswith(i) for i in prefixes) + +class GitRepo(object): + """Repo object representing a repo. + """ + + def __init__(self, path): + """Initializes a new repo at the given path. + """ + + self.path = path + self.head = None + self.revmap = {} + self.local = not is_remote(self.path) + + if(self.path.endswith('.git')): + self.gitpath = self.path + else: + self.gitpath = os.path.join(self.path, '.git') + + if self.local and not os.path.exists(self.gitpath): + os.makedirs(self.gitpath) + + def get_revs(self): + """Fetches all revs from the remote. + """ + + args = ["git", "ls-remote", self.gitpath] + path = ".cached_revs" + ofile = open(path, "w") + + subprocess.check_call(args, stdout=ofile) + output = open(path).readlines() + self.revmap = dict(sanitize(i) for i in output) + if "HEAD" in self.revmap: + del self.revmap["HEAD"] + self.revs = self.revmap.keys() + ofile.close() + + def get_head(self): + """Determines the head of a local repo. + """ + + if not self.local: + return + + path = os.path.join(self.gitpath, "HEAD") + head = open(path).readline() + self.head, _ = sanitize(head, ' ') -- cgit v0.10.2-6-g49f6