git-remote-testpy.py

   1 #!/usr/bin/env python
   2
   3 # This command is a simple remote-helper, that is used both as a
   4 # testcase for the remote-helper functionality, and as an example to
   5 # show remote-helper authors one possible implementation.
   6 #
   7 # This is a Git <-> Git importer/exporter, that simply uses git
   8 # fast-import and git fast-export to consume and produce fast-import
   9 # streams.
  10 #
  11 # To understand better the way things work, one can activate debug
  12 # traces by setting (to any value) the environment variables
  13 # GIT_TRANSPORT_HELPER_DEBUG and GIT_DEBUG_TESTGIT, to see messages
  14 # from the transport-helper side, or from this example remote-helper.
  15
  16 # hashlib is only available in python >= 2.5
  17 try:
  18     import hashlib
  19     _digest = hashlib.sha1
  20 except ImportError:
  21     import sha
  22     _digest = sha.new
  23 import sys
  24 import os
  25 import time
  26 sys.path.insert(0, os.getenv("GITPYTHONLIB","."))
  27
  28 from git_remote_helpers.util import die, debug, warn
  29 from git_remote_helpers.git.repo import GitRepo
  30 from git_remote_helpers.git.exporter import GitExporter
  31 from git_remote_helpers.git.importer import GitImporter
  32 from git_remote_helpers.git.non_local import NonLocalGit
  33
  34 if sys.hexversion < 0x01050200:
  35     # os.makedirs() is the limiter
  36     sys.stderr.write("git-remote-testgit: requires Python 1.5.2 or later.\n")
  37     sys.exit(1)
  38
  39 def get_repo(alias, url):
  40     """Returns a git repository object initialized for usage.
  41     """
  42
  43     repo = GitRepo(url)
  44     repo.get_revs()
  45     repo.get_head()
  46
  47     hasher = _digest()
  48     hasher.update(repo.path)
  49     repo.hash = hasher.hexdigest()
  50
  51     repo.get_base_path = lambda base: os.path.join(
  52         base, 'info', 'fast-import', repo.hash)
  53
  54     prefix = 'refs/testgit/%s/' % alias
  55     debug("prefix: '%s'", prefix)
  56
  57     repo.gitdir = os.environ["GIT_DIR"]
  58     repo.alias = alias
  59     repo.prefix = prefix
  60
  61     repo.exporter = GitExporter(repo)
  62     repo.importer = GitImporter(repo)
  63     repo.non_local = NonLocalGit(repo)
  64
  65     return repo
  66
  67
  68 def local_repo(repo, path):
  69     """Returns a git repository object initalized for usage.
  70     """
  71
  72     local = GitRepo(path)
  73
  74     local.non_local = None
  75     local.gitdir = repo.gitdir
  76     local.alias = repo.alias
  77     local.prefix = repo.prefix
  78     local.hash = repo.hash
  79     local.get_base_path = repo.get_base_path
  80     local.exporter = GitExporter(local)
  81     local.importer = GitImporter(local)
  82
  83     return local
  84
  85
  86 def do_capabilities(repo, args):
  87     """Prints the supported capabilities.
  88     """
  89
  90     print "import"
  91     print "export"
  92     print "refspec refs/heads/*:%s*" % repo.prefix
  93
  94     dirname = repo.get_base_path(repo.gitdir)
  95
  96     if not os.path.exists(dirname):
  97         os.makedirs(dirname)
  98
  99     path = os.path.join(dirname, 'git.marks')
 100
 101     print "*export-marks %s" % path
 102     if os.path.exists(path):
 103         print "*import-marks %s" % path
 104
 105     print # end capabilities
 106
 107
 108 def do_list(repo, args):
 109     """Lists all known references.
 110
 111     Bug: This will always set the remote head to master for non-local
 112     repositories, since we have no way of determining what the remote
 113     head is at clone time.
 114     """
 115
 116     for ref in repo.revs:
 117         debug("? refs/heads/%s", ref)
 118         print "? refs/heads/%s" % ref
 119
 120     if repo.head:
 121         debug("@refs/heads/%s HEAD" % repo.head)
 122         print "@refs/heads/%s HEAD" % repo.head
 123     else:
 124         debug("@refs/heads/master HEAD")
 125         print "@refs/heads/master HEAD"
 126
 127     print # end list
 128
 129
 130 def update_local_repo(repo):
 131     """Updates (or clones) a local repo.
 132     """
 133
 134     if repo.local:
 135         return repo
 136
 137     path = repo.non_local.clone(repo.gitdir)
 138     repo.non_local.update(repo.gitdir)
 139     repo = local_repo(repo, path)
 140     return repo
 141
 142
 143 def do_import(repo, args):
 144     """Exports a fast-import stream from testgit for git to import.
 145     """
 146
 147     if len(args) != 1:
 148         die("Import needs exactly one ref")
 149
 150     if not repo.gitdir:
 151         die("Need gitdir to import")
 152
 153     ref = args[0]
 154     refs = [ref]
 155
 156     while True:
 157         line = sys.stdin.readline()
 158         if line == '\n':
 159             break
 160         if not line.startswith('import '):
 161             die("Expected import line.")
 162
 163         # strip of leading 'import '
 164         ref = line[7:].strip()
 165         refs.append(ref)
 166
 167     repo = update_local_repo(repo)
 168     repo.exporter.export_repo(repo.gitdir, refs)
 169
 170     print "done"
 171
 172
 173 def do_export(repo, args):
 174     """Imports a fast-import stream from git to testgit.
 175     """
 176
 177     if not repo.gitdir:
 178         die("Need gitdir to export")
 179
 180     update_local_repo(repo)
 181     changed = repo.importer.do_import(repo.gitdir)
 182
 183     if not repo.local:
 184         repo.non_local.push(repo.gitdir)
 185
 186     for ref in changed:
 187         print "ok %s" % ref
 188     print
 189
 190
 191 COMMANDS = {
 192     'capabilities': do_capabilities,
 193     'list': do_list,
 194     'import': do_import,
 195     'export': do_export,
 196 }
 197
 198
 199 def sanitize(value):
 200     """Cleans up the url.
 201     """
 202
 203     if value.startswith('testgit::'):
 204         value = value[9:]
 205
 206     return value
 207
 208
 209 def read_one_line(repo):
 210     """Reads and processes one command.
 211     """
 212
 213     sleepy = os.environ.get("GIT_REMOTE_TESTGIT_SLEEPY")
 214     if sleepy:
 215         debug("Sleeping %d sec before readline" % int(sleepy))
 216         time.sleep(int(sleepy))
 217
 218     line = sys.stdin.readline()
 219
 220     cmdline = line
 221
 222     if not cmdline:
 223         warn("Unexpected EOF")
 224         return False
 225
 226     cmdline = cmdline.strip().split()
 227     if not cmdline:
 228         # Blank line means we're about to quit
 229         return False
 230
 231     cmd = cmdline.pop(0)
 232     debug("Got command '%s' with args '%s'", cmd, ' '.join(cmdline))
 233
 234     if cmd not in COMMANDS:
 235         die("Unknown command, %s", cmd)
 236
 237     func = COMMANDS[cmd]
 238     func(repo, cmdline)
 239     sys.stdout.flush()
 240
 241     return True
 242
 243
 244 def main(args):
 245     """Starts a new remote helper for the specified repository.
 246     """
 247
 248     if len(args) != 3:
 249         die("Expecting exactly three arguments.")
 250         sys.exit(1)
 251
 252     if os.getenv("GIT_DEBUG_TESTGIT"):
 253         import git_remote_helpers.util
 254         git_remote_helpers.util.DEBUG = True
 255
 256     alias = sanitize(args[1])
 257     url = sanitize(args[2])
 258
 259     if not alias.isalnum():
 260         warn("non-alnum alias '%s'", alias)
 261         alias = "tmp"
 262
 263     args[1] = alias
 264     args[2] = url
 265
 266     repo = get_repo(alias, url)
 267
 268     debug("Got arguments %s", args[1:])
 269
 270     more = True
 271
 272     sys.stdin = os.fdopen(sys.stdin.fileno(), 'r', 0)
 273     while (more):
 274         more = read_one_line(repo)
 275
 276 if __name__ == '__main__':
 277     sys.exit(main(sys.argv))