blob: 007a1bfdf37d231470f69d9d0cffa46e80127f34 [file] [log] [blame]
#!/usr/bin/env python
"""Functionality for interacting with Git repositories.
This module provides classes for interfacing with a Git repository.
"""
import os
import re
import time
from binascii import hexlify
from cStringIO import StringIO
import unittest
from git_remote_helpers.util import debug, error, die, start_command, run_command
def get_git_dir ():
"""Return the path to the GIT_DIR for this repo."""
args = ("git", "rev-parse", "--git-dir")
exit_code, output, errors = run_command(args)
if exit_code:
die("Failed to retrieve git dir")
assert not errors
return output.strip()
def parse_git_config ():
"""Return a dict containing the parsed version of 'git config -l'."""
exit_code, output, errors = run_command(("git", "config", "-z", "-l"))
if exit_code:
die("Failed to retrieve git configuration")
assert not errors
return dict([e.split('\n', 1) for e in output.split("\0") if e])
def git_config_bool (value):
"""Convert the given git config string value to True or False.
Raise ValueError if the given string was not recognized as a
boolean value.
"""
norm_value = str(value).strip().lower()
if norm_value in ("true", "1", "yes", "on", ""):
return True
if norm_value in ("false", "0", "no", "off", "none"):
return False
raise ValueError("Failed to parse '%s' into a boolean value" % (value))
def valid_git_ref (ref_name):
"""Return True iff the given ref name is a valid git ref name."""
# The following is a reimplementation of the git check-ref-format
# command. The rules were derived from the git check-ref-format(1)
# manual page. This code should be replaced by a call to
# check_refname_format() in the git library, when such is available.
if ref_name.endswith('/') or \
ref_name.startswith('.') or \
ref_name.count('/.') or \
ref_name.count('..') or \
ref_name.endswith('.lock'):
return False
for c in ref_name:
if ord(c) < 0x20 or ord(c) == 0x7f or c in " ~^:?*[":
return False
return True
class GitObjectFetcher(object):
"""Provide parsed access to 'git cat-file --batch'.
This provides a read-only interface to the Git object database.
"""
def __init__ (self):
"""Initiate a 'git cat-file --batch' session."""
self.queue = [] # List of object names to be submitted
self.in_transit = None # Object name currently in transit
# 'git cat-file --batch' produces binary output which is likely
# to be corrupted by the default "rU"-mode pipe opened by
# start_command. (Mode == "rU" does universal new-line
# conversion, which mangles carriage returns.) Therefore, we
# open an explicitly binary-safe pipe for transferring the
# output from 'git cat-file --batch'.
pipe_r_fd, pipe_w_fd = os.pipe()
pipe_r = os.fdopen(pipe_r_fd, "rb")
pipe_w = os.fdopen(pipe_w_fd, "wb")
self.proc = start_command(("git", "cat-file", "--batch"),
stdout = pipe_w)
self.f = pipe_r
def __del__ (self):
"""Verify completed communication with 'git cat-file --batch'."""
assert not self.queue
assert self.in_transit is None
self.proc.stdin.close()
assert self.proc.wait() == 0 # Zero exit code
assert self.f.read() == "" # No remaining output
def _submit_next_object (self):
"""Submit queue items to the 'git cat-file --batch' process.
If there are items in the queue, and there is currently no item
currently in 'transit', then pop the first item off the queue,
and submit it.
"""
if self.queue and self.in_transit is None:
self.in_transit = self.queue.pop(0)
print >> self.proc.stdin, self.in_transit[0]
def push (self, obj, callback):
"""Push the given object name onto the queue.
The given callback function will at some point in the future
be called exactly once with the following arguments:
- self - this GitObjectFetcher instance
- obj - the object name provided to push()
- sha1 - the SHA1 of the object, if 'None' obj is missing
- t - the type of the object (tag/commit/tree/blob)
- size - the size of the object in bytes
- data - the object contents
"""
self.queue.append((obj, callback))
self._submit_next_object() # (Re)start queue processing
def process_next_entry (self):
"""Read the next entry off the queue and invoke callback."""
obj, cb = self.in_transit
self.in_transit = None
header = self.f.readline()
if header == "%s missing\n" % (obj):
cb(self, obj, None, None, None, None)
return
sha1, t, size = header.split(" ")
assert len(sha1) == 40
assert t in ("tag", "commit", "tree", "blob")
assert size.endswith("\n")
size = int(size.strip())
data = self.f.read(size)
assert self.f.read(1) == "\n"
cb(self, obj, sha1, t, size, data)
self._submit_next_object()
def process (self):
"""Process the current queue until empty."""
while self.in_transit is not None:
self.process_next_entry()
# High-level convenience methods:
def get_sha1 (self, objspec):
"""Return the SHA1 of the object specified by 'objspec'.
Return None if 'objspec' does not specify an existing object.
"""
class _ObjHandler(object):
"""Helper class for getting the returned SHA1."""
def __init__ (self, parser):
self.parser = parser
self.sha1 = None
def __call__ (self, parser, obj, sha1, t, size, data):
# FIXME: Many unused arguments. Could this be cheaper?
assert parser == self.parser
self.sha1 = sha1
handler = _ObjHandler(self)
self.push(objspec, handler)
self.process()
return handler.sha1
def open_obj (self, objspec):
"""Return a file object wrapping the contents of a named object.
The caller is responsible for calling .close() on the returned
file object.
Raise KeyError if 'objspec' does not exist in the repo.
"""
class _ObjHandler(object):
"""Helper class for parsing the returned git object."""
def __init__ (self, parser):
"""Set up helper."""
self.parser = parser
self.contents = StringIO()
self.err = None
def __call__ (self, parser, obj, sha1, t, size, data):
"""Git object callback (see GitObjectFetcher documentation)."""
assert parser == self.parser
if not sha1: # Missing object
self.err = "Missing object '%s'" % obj
else:
assert size == len(data)
self.contents.write(data)
handler = _ObjHandler(self)
self.push(objspec, handler)
self.process()
if handler.err:
raise KeyError(handler.err)
handler.contents.seek(0)
return handler.contents
def walk_tree (self, tree_objspec, callback, prefix = ""):
"""Recursively walk the given Git tree object.
Recursively walk all subtrees of the given tree object, and
invoke the given callback passing three arguments:
(path, mode, data) with the path, permission bits, and contents
of all the blobs found in the entire tree structure.
"""
class _ObjHandler(object):
"""Helper class for walking a git tree structure."""
def __init__ (self, parser, cb, path, mode = None):
"""Set up helper."""
self.parser = parser
self.cb = cb
self.path = path
self.mode = mode
self.err = None
def parse_tree (self, treedata):
"""Parse tree object data, yield tree entries.
Each tree entry is a 3-tuple (mode, sha1, path)
self.path is prepended to all paths yielded
from this method.
"""
while treedata:
mode = int(treedata[:6], 10)
# Turn 100xxx into xxx
if mode > 100000:
mode -= 100000
assert treedata[6] == " "
i = treedata.find("\0", 7)
assert i > 0
path = treedata[7:i]
sha1 = hexlify(treedata[i + 1: i + 21])
yield (mode, sha1, self.path + path)
treedata = treedata[i + 21:]
def __call__ (self, parser, obj, sha1, t, size, data):
"""Git object callback (see GitObjectFetcher documentation)."""
assert parser == self.parser
if not sha1: # Missing object
self.err = "Missing object '%s'" % (obj)
return
assert size == len(data)
if t == "tree":
if self.path:
self.path += "/"
# Recurse into all blobs and subtrees
for m, s, p in self.parse_tree(data):
parser.push(s,
self.__class__(self.parser, self.cb, p, m))
elif t == "blob":
self.cb(self.path, self.mode, data)
else:
raise ValueError("Unknown object type '%s'" % (t))
self.push(tree_objspec, _ObjHandler(self, callback, prefix))
self.process()
class GitRefMap(object):
"""Map Git ref names to the Git object names they currently point to.
Behaves like a dictionary of Git ref names -> Git object names.
"""
def __init__ (self, obj_fetcher):
"""Create a new Git ref -> object map."""
self.obj_fetcher = obj_fetcher
self._cache = {} # dict: refname -> objname
def _load (self, ref):
"""Retrieve the object currently bound to the given ref.
The name of the object pointed to by the given ref is stored
into this mapping, and also returned.
"""
if ref not in self._cache:
self._cache[ref] = self.obj_fetcher.get_sha1(ref)
return self._cache[ref]
def __contains__ (self, refname):
"""Return True if the given refname is present in this cache."""
return bool(self._load(refname))
def __getitem__ (self, refname):
"""Return the git object name pointed to by the given refname."""
commit = self._load(refname)
if commit is None:
raise KeyError("Unknown ref '%s'" % (refname))
return commit
def get (self, refname, default = None):
"""Return the git object name pointed to by the given refname."""
commit = self._load(refname)
if commit is None:
return default
return commit
class GitFICommit(object):
"""Encapsulate the data in a Git fast-import commit command."""
SHA1RE = re.compile(r'^[0-9a-f]{40}$')
@classmethod
def parse_mode (cls, mode):
"""Verify the given git file mode, and return it as a string."""
assert mode in (644, 755, 100644, 100755, 120000)
return "%i" % (mode)
@classmethod
def parse_objname (cls, objname):
"""Return the given object name (or mark number) as a string."""
if isinstance(objname, int): # Object name is a mark number
assert objname > 0
return ":%i" % (objname)
# No existence check is done, only checks for valid format
assert cls.SHA1RE.match(objname) # Object name is valid SHA1
return objname
@classmethod
def quote_path (cls, path):
"""Return a quoted version of the given path."""
path = path.replace("\\", "\\\\")
path = path.replace("\n", "\\n")
path = path.replace('"', '\\"')
return '"%s"' % (path)
@classmethod
def parse_path (cls, path):
"""Verify that the given path is valid, and quote it, if needed."""
assert not isinstance(path, int) # Cannot be a mark number
# These checks verify the rules on the fast-import man page
assert not path.count("//")
assert not path.endswith("/")
assert not path.startswith("/")
assert not path.count("/./")
assert not path.count("/../")
assert not path.endswith("/.")
assert not path.endswith("/..")
assert not path.startswith("./")
assert not path.startswith("../")
if path.count('"') + path.count('\n') + path.count('\\'):
return cls.quote_path(path)
return path
def __init__ (self, name, email, timestamp, timezone, message):
"""Create a new Git fast-import commit, with the given metadata."""
self.name = name
self.email = email
self.timestamp = timestamp
self.timezone = timezone
self.message = message
self.pathops = [] # List of path operations in this commit
def modify (self, mode, blobname, path):
"""Add a file modification to this Git fast-import commit."""
self.pathops.append(("M",
self.parse_mode(mode),
self.parse_objname(blobname),
self.parse_path(path)))
def delete (self, path):
"""Add a file deletion to this Git fast-import commit."""
self.pathops.append(("D", self.parse_path(path)))
def copy (self, path, newpath):
"""Add a file copy to this Git fast-import commit."""
self.pathops.append(("C",
self.parse_path(path),
self.parse_path(newpath)))
def rename (self, path, newpath):
"""Add a file rename to this Git fast-import commit."""
self.pathops.append(("R",
self.parse_path(path),
self.parse_path(newpath)))
def note (self, blobname, commit):
"""Add a note object to this Git fast-import commit."""
self.pathops.append(("N",
self.parse_objname(blobname),
self.parse_objname(commit)))
def deleteall (self):
"""Delete all files in this Git fast-import commit."""
self.pathops.append("deleteall")
class TestGitFICommit(unittest.TestCase):
"""GitFICommit selftests."""
def test_basic (self):
"""GitFICommit basic selftests."""
def expect_fail (method, data):
"""Verify that the method(data) raises an AssertionError."""
try:
method(data)
except AssertionError:
return
raise AssertionError("Failed test for invalid data '%s(%s)'" %
(method.__name__, repr(data)))
def test_parse_mode (self):
"""GitFICommit.parse_mode() selftests."""
self.assertEqual(GitFICommit.parse_mode(644), "644")
self.assertEqual(GitFICommit.parse_mode(755), "755")
self.assertEqual(GitFICommit.parse_mode(100644), "100644")
self.assertEqual(GitFICommit.parse_mode(100755), "100755")
self.assertEqual(GitFICommit.parse_mode(120000), "120000")
self.assertRaises(AssertionError, GitFICommit.parse_mode, 0)
self.assertRaises(AssertionError, GitFICommit.parse_mode, 123)
self.assertRaises(AssertionError, GitFICommit.parse_mode, 600)
self.assertRaises(AssertionError, GitFICommit.parse_mode, "644")
self.assertRaises(AssertionError, GitFICommit.parse_mode, "abc")
def test_parse_objname (self):
"""GitFICommit.parse_objname() selftests."""
self.assertEqual(GitFICommit.parse_objname(1), ":1")
self.assertRaises(AssertionError, GitFICommit.parse_objname, 0)
self.assertRaises(AssertionError, GitFICommit.parse_objname, -1)
self.assertEqual(GitFICommit.parse_objname("0123456789" * 4),
"0123456789" * 4)
self.assertEqual(GitFICommit.parse_objname("2468abcdef" * 4),
"2468abcdef" * 4)
self.assertRaises(AssertionError, GitFICommit.parse_objname,
"abcdefghij" * 4)
def test_parse_path (self):
"""GitFICommit.parse_path() selftests."""
self.assertEqual(GitFICommit.parse_path("foo/bar"), "foo/bar")
self.assertEqual(GitFICommit.parse_path("path/with\n and \" in it"),
'"path/with\\n and \\" in it"')
self.assertRaises(AssertionError, GitFICommit.parse_path, 1)
self.assertRaises(AssertionError, GitFICommit.parse_path, 0)
self.assertRaises(AssertionError, GitFICommit.parse_path, -1)
self.assertRaises(AssertionError, GitFICommit.parse_path, "foo//bar")
self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/bar/")
self.assertRaises(AssertionError, GitFICommit.parse_path, "/foo/bar")
self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/./bar")
self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/../bar")
self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/bar/.")
self.assertRaises(AssertionError, GitFICommit.parse_path, "foo/bar/..")
self.assertRaises(AssertionError, GitFICommit.parse_path, "./foo/bar")
self.assertRaises(AssertionError, GitFICommit.parse_path, "../foo/bar")
class GitFastImport(object):
"""Encapsulate communication with git fast-import."""
def __init__ (self, f, obj_fetcher, last_mark = 0):
"""Set up self to communicate with a fast-import process through f."""
self.f = f # File object where fast-import stream is written
self.obj_fetcher = obj_fetcher # GitObjectFetcher instance
self.next_mark = last_mark + 1 # Next mark number
self.refs = set() # Keep track of the refnames we've seen
def comment (self, s):
"""Write the given comment in the fast-import stream."""
assert "\n" not in s, "Malformed comment: '%s'" % (s)
self.f.write("# %s\n" % (s))
def commit (self, ref, commitdata):
"""Make a commit on the given ref, with the given GitFICommit.
Return the mark number identifying this commit.
"""
self.f.write("""\
commit %(ref)s
mark :%(mark)i
committer %(name)s <%(email)s> %(timestamp)i %(timezone)s
data %(msgLength)i
%(msg)s
""" % {
'ref': ref,
'mark': self.next_mark,
'name': commitdata.name,
'email': commitdata.email,
'timestamp': commitdata.timestamp,
'timezone': commitdata.timezone,
'msgLength': len(commitdata.message),
'msg': commitdata.message,
})
if ref not in self.refs:
self.refs.add(ref)
parent = ref + "^0"
if self.obj_fetcher.get_sha1(parent):
self.f.write("from %s\n" % (parent))
for op in commitdata.pathops:
self.f.write(" ".join(op))
self.f.write("\n")
self.f.write("\n")
retval = self.next_mark
self.next_mark += 1
return retval
def blob (self, data):
"""Import the given blob.
Return the mark number identifying this blob.
"""
self.f.write("blob\nmark :%i\ndata %i\n%s\n" %
(self.next_mark, len(data), data))
retval = self.next_mark
self.next_mark += 1
return retval
def reset (self, ref, objname):
"""Reset the given ref to point at the given Git object."""
self.f.write("reset %s\nfrom %s\n\n" %
(ref, GitFICommit.parse_objname(objname)))
if ref not in self.refs:
self.refs.add(ref)
class GitNotes(object):
"""Encapsulate access to Git notes.
Simulates a dictionary of object name (SHA1) -> Git note mappings.
"""
def __init__ (self, notes_ref, obj_fetcher):
"""Create a new Git notes interface, bound to the given notes ref."""
self.notes_ref = notes_ref
self.obj_fetcher = obj_fetcher # Used to get objects from repo
self.imports = [] # list: (objname, note data blob name) tuples
def __del__ (self):
"""Verify that self.commit_notes() was called before destruction."""
if self.imports:
error("Missing call to self.commit_notes().")
error("%i notes are not committed!", len(self.imports))
def _load (self, objname):
"""Return the note data associated with the given git object.
The note data is returned in string form. If no note is found
for the given object, None is returned.
"""
try:
f = self.obj_fetcher.open_obj("%s:%s" % (self.notes_ref, objname))
ret = f.read()
f.close()
except KeyError:
ret = None
return ret
def __getitem__ (self, objname):
"""Return the note contents associated with the given object.
Raise KeyError if given object has no associated note.
"""
blobdata = self._load(objname)
if blobdata is None:
raise KeyError("Object '%s' has no note" % (objname))
return blobdata
def get (self, objname, default = None):
"""Return the note contents associated with the given object.
Return given default if given object has no associated note.
"""
blobdata = self._load(objname)
if blobdata is None:
return default
return blobdata
def import_note (self, objname, data, gfi):
"""Tell git fast-import to store data as a note for objname.
This method uses the given GitFastImport object to create a
blob containing the given note data. Also an entry mapping the
given object name to the created blob is stored until
commit_notes() is called.
Note that this method only works if it is later followed by a
call to self.commit_notes() (which produces the note commit
that refers to the blob produced here).
"""
if not data.endswith("\n"):
data += "\n"
gfi.comment("Importing note for object %s" % (objname))
mark = gfi.blob(data)
self.imports.append((objname, mark))
def commit_notes (self, gfi, author, message):
"""Produce a git fast-import note commit for the imported notes.
This method uses the given GitFastImport object to create a
commit on the notes ref, introducing the notes previously
submitted to import_note().
"""
if not self.imports:
return
commitdata = GitFICommit(author[0], author[1],
time.time(), "0000", message)
for objname, blobname in self.imports:
assert isinstance(objname, int) and objname > 0
assert isinstance(blobname, int) and blobname > 0
commitdata.note(blobname, objname)
gfi.commit(self.notes_ref, commitdata)
self.imports = []
class GitCachedNotes(GitNotes):
"""Encapsulate access to Git notes (cached version).
Only use this class if no caching is done at a higher level.
Simulates a dictionary of object name (SHA1) -> Git note mappings.
"""
def __init__ (self, notes_ref, obj_fetcher):
"""Set up a caching wrapper around GitNotes."""
GitNotes.__init__(self, notes_ref, obj_fetcher)
self._cache = {} # Cache: object name -> note data
def __del__ (self):
"""Verify that GitNotes' destructor is called."""
GitNotes.__del__(self)
def _load (self, objname):
"""Extend GitNotes._load() with a local objname -> note cache."""
if objname not in self._cache:
self._cache[objname] = GitNotes._load(self, objname)
return self._cache[objname]
def import_note (self, objname, data, gfi):
"""Extend GitNotes.import_note() with a local objname -> note cache."""
if not data.endswith("\n"):
data += "\n"
assert objname not in self._cache
self._cache[objname] = data
GitNotes.import_note(self, objname, data, gfi)
if __name__ == '__main__':
unittest.main()