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PyGIT.py
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PyGIT.py
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# -*- coding: iso-8859-1 -*-
#
# Copyright (C) 2006,2008 Herbert Valerio Riedel <hvr@gnu.org>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
from __future__ import with_statement
import os, re, sys, time, weakref
from collections import deque
from functools import partial
from threading import Lock
from subprocess import Popen, PIPE
import cStringIO
__all__ = ["git_version", "GitError", "GitErrorSha", "Storage", "StorageFactory"]
class GitError(Exception):
pass
class GitErrorSha(GitError):
pass
class GitCore:
def __init__(self, git_dir=None, git_bin="git"):
self.__git_bin = git_bin
self.__git_dir = git_dir
def __build_git_cmd(self, gitcmd, *args):
"construct command tuple for git call suitable for Popen()"
cmd = [self.__git_bin]
if self.__git_dir:
cmd.append('--git-dir=%s' % self.__git_dir)
cmd.append(gitcmd)
cmd.extend(args)
return cmd
def __execute(self, git_cmd, *cmd_args):
"execute git command and return file-like object of stdout"
#print >>sys.stderr, "DEBUG:", git_cmd, cmd_args
p = Popen(self.__build_git_cmd(git_cmd, *cmd_args),
stdin=None, stdout=PIPE, stderr=PIPE, close_fds=True)
stdout_data, stderr_data = p.communicate()
#TODO, do something with p.returncode, e.g. raise exception
return cStringIO.StringIO(stdout_data)
def __getattr__(self, name):
return partial(self.__execute, name.replace('_','-'))
__is_sha_pat = re.compile(r'[0-9A-Fa-f]*$')
@classmethod
def is_sha(cls,sha):
"""returns whether sha is a potential sha id
(i.e. proper hexstring between 4 and 40 characters"""
if not (4 <= len(sha) <= 40):
return False
return bool(cls.__is_sha_pat.match(sha))
# helper class for caching...
class SizedDict(dict):
def __init__(self, max_size=0):
dict.__init__(self)
self.__max_size = max_size
self.__key_fifo = deque()
self.__lock = Lock()
def __setitem__(self, name, value):
with self.__lock:
assert len(self) == len(self.__key_fifo) # invariant
if not self.__contains__(name):
self.__key_fifo.append(name)
rc = dict.__setitem__(self, name, value)
while len(self.__key_fifo) > self.__max_size:
self.__delitem__(self.__key_fifo.popleft())
assert len(self) == len(self.__key_fifo) # invariant
return rc
def setdefault(k,d=None):
# TODO
raise AttributeError("SizedDict has no setdefault() method")
class StorageFactory:
__dict = weakref.WeakValueDictionary()
__dict_nonweak = dict()
__dict_lock = Lock()
def __init__(self, repo, log, weak=True, git_bin='git'):
self.logger = log
with StorageFactory.__dict_lock:
try:
i = StorageFactory.__dict[repo]
except KeyError:
i = Storage(repo, log, git_bin)
StorageFactory.__dict[repo] = i
# create or remove additional reference depending on 'weak' argument
if weak:
try:
del StorageFactory.__dict_nonweak[repo]
except KeyError:
pass
else:
StorageFactory.__dict_nonweak[repo] = i
self.__inst = i
self.__repo = repo
def getInstance(self):
is_weak = self.__repo not in StorageFactory.__dict_nonweak
self.logger.debug("requested %sPyGIT.Storage instance %d for '%s'"
% (("","weak ")[is_weak], id(self.__inst), self.__repo))
return self.__inst
class Storage:
__SREV_MIN = 4 # minimum short-rev length
@staticmethod
def __rev_key(rev):
assert len(rev) >= 4
#assert GitCore.is_sha(rev)
srev_key = int(rev[:4], 16)
assert srev_key >= 0 and srev_key <= 0xffff
return srev_key
@staticmethod
def git_version(git_bin="git"):
GIT_VERSION_MIN_REQUIRED = (1,5,6)
try:
g = GitCore(git_bin=git_bin)
output = g.version()
[v] = output.readlines()
_,_,version = v.strip().split()
# 'version' has usually at least 3 numeric version components, e.g.::
# 1.5.4.2
# 1.5.4.3.230.g2db511
# 1.5.4.GIT
def try_int(s):
try:
return int(s)
except ValueError:
return s
split_version = tuple(map(try_int, version.split('.')))
result = {}
result['v_str'] = version
result['v_tuple'] = split_version
result['v_min_tuple'] = GIT_VERSION_MIN_REQUIRED
result['v_min_str'] = ".".join(map(str, GIT_VERSION_MIN_REQUIRED))
result['v_compatible'] = split_version >= GIT_VERSION_MIN_REQUIRED
return result
except:
raise GitError("Could not retrieve GIT version")
def __init__(self, git_dir, log, git_bin='git'):
self.logger = log
# simple sanity checking
__git_file_path = partial(os.path.join, git_dir)
if not all(map(os.path.exists,
map(__git_file_path,
['HEAD','objects','refs']))):
self.logger.error("GIT control files missing in '%s'" % git_dir)
if os.path.exists(__git_file_path('.git')):
self.logger.error("entry '.git' found in '%s'"
" -- maybe use that folder instead..." % git_dir)
raise GitError("GIT control files not found, maybe wrong directory?")
self.logger.debug("PyGIT.Storage instance %d constructed" % id(self))
self.repo = GitCore(git_dir, git_bin=git_bin)
self.commit_encoding = None
# caches
self.__rev_cache = None
self.__rev_cache_lock = Lock()
# cache the last 200 commit messages
self.__commit_msg_cache = SizedDict(200)
self.__commit_msg_lock = Lock()
def __del__(self):
self.logger.debug("PyGIT.Storage instance %d destructed" % id(self))
#
# cache handling
#
# called by Storage.sync()
def __rev_cache_sync(self, youngest_rev=None):
"invalidates revision db cache if necessary"
with self.__rev_cache_lock:
need_update = False
if self.__rev_cache:
last_youngest_rev = self.__rev_cache[0]
if last_youngest_rev != youngest_rev:
self.logger.debug("invalidated caches (%s != %s)" % (last_youngest_rev, youngest_rev))
need_update = True
else:
need_update = True # almost NOOP
if need_update:
self.__rev_cache = None
return need_update
def get_rev_cache(self):
with self.__rev_cache_lock:
if self.__rev_cache is None: # can be cleared by Storage.__rev_cache_sync()
self.logger.debug("triggered rebuild of commit tree db for %d" % id(self))
new_db = {}
new_sdb = {}
new_tags = set([])
youngest = None
oldest = None
for revs in self.repo.rev_parse("--tags"):
new_tags.add(revs.strip())
# helper for reusing strings
__rev_seen = {}
def __rev_reuse(rev):
rev = str(rev)
return __rev_seen.setdefault(rev, rev)
rev = ord_rev = 0
for revs in self.repo.rev_list("--parents", "--all"):
revs = revs.strip().split()
revs = map(__rev_reuse, revs)
rev = revs[0]
# shortrev "hash" map
srev_key = self.__rev_key(rev)
new_sdb.setdefault(srev_key, []).append(rev)
parents = tuple(revs[1:])
ord_rev += 1
# first rev seen is assumed to be the youngest one (and has ord_rev=1)
if not youngest:
youngest = rev
# new_db[rev] = (children(rev), parents(rev), ordinal_id(rev))
if new_db.has_key(rev):
_children,_parents,_ord_rev = new_db[rev]
assert _children
assert not _parents
assert _ord_rev == 0
else:
_children = []
# create/update entry
new_db[rev] = _children, parents, ord_rev
# update all parents(rev)'s children
for parent in parents:
# by default, a dummy ordinal_id is used for the mean-time
_children, _parents, _ord_rev = new_db.setdefault(parent, ([], [], 0))
if rev not in _children:
_children.append(rev)
# last rev seen is assumed to be the oldest one (with highest ord_rev)
oldest = rev
__rev_seen = None
assert len(new_db) == ord_rev
# convert children lists to tuples
tmp = {}
try:
while True:
k,v = new_db.popitem()
assert v[2] > 0
tmp[k] = tuple(v[0]),v[1],v[2]
except KeyError:
pass
assert len(new_db) == 0
new_db = tmp
# convert sdb either to dict or array depending on size
tmp = [()]*(max(new_sdb.keys())+1) if len(new_sdb) > 5000 else {}
try:
while True:
k,v = new_sdb.popitem()
tmp[k] = tuple(v)
except KeyError:
pass
assert len(new_sdb) == 0
new_sdb = tmp
# atomically update self.__rev_cache
self.__rev_cache = youngest, oldest, new_db, new_tags, new_sdb
self.logger.debug("rebuilt commit tree db for %d with %d entries" % (id(self),len(new_db)))
assert all(e is not None for e in self.__rev_cache) or not any(self.__rev_cache)
return self.__rev_cache
# with self.__rev_cache_lock
# tuple: youngest_rev, oldest_rev, rev_dict, tag_dict, short_rev_dict
rev_cache = property(get_rev_cache)
def get_commits(self):
return self.rev_cache[2]
def oldest_rev(self):
return self.rev_cache[1]
def youngest_rev(self):
return self.rev_cache[0]
def history_relative_rev(self, sha, rel_pos):
db = self.get_commits()
if sha not in db:
raise GitErrorSha
if rel_pos == 0:
return sha
lin_rev = db[sha][2] + rel_pos
if lin_rev < 1 or lin_rev > len(db):
return None
for k,v in db.iteritems():
if v[2] == lin_rev:
return k
# should never be reached if db is consistent
raise GitError("internal inconsistency detected")
def hist_next_revision(self, sha):
return self.history_relative_rev(sha, -1)
def hist_prev_revision(self, sha):
return self.history_relative_rev(sha, +1)
def get_commit_encoding(self):
if self.commit_encoding is None:
self.commit_encoding = \
self.repo.repo_config("--get", "i18n.commitEncoding").read().strip() or 'utf-8'
return self.commit_encoding
def head(self):
"get current HEAD commit id"
return self.verifyrev("HEAD")
def verifyrev(self, rev):
"verify/lookup given revision object and return a sha id or None if lookup failed"
rev = str(rev)
db, tag_db = self.rev_cache[2:4]
if GitCore.is_sha(rev):
# maybe it's a short or full rev
fullrev = self.fullrev(rev)
if fullrev:
return fullrev
# fall back to external git calls
rc = self.repo.rev_parse("--verify", rev).read().strip()
if not rc:
return None
if db.has_key(rc):
return rc
if rc in tag_db:
sha=self.repo.cat_file("tag", rc).read().split(None, 2)[:2]
if sha[0] != 'object':
self.logger.debug("unexpected result from 'git-cat-file tag %s'" % rc)
return None
return sha[1]
return None
def shortrev(self, rev, min_len=7):
"try to shorten sha id"
#try to emulate the following:
#return self.repo.rev_parse("--short", str(rev)).read().strip()
rev = str(rev)
if min_len < self.__SREV_MIN:
min_len = self.__SREV_MIN
db, tag_db, sdb = self.rev_cache[2:5]
if rev not in db:
return None
srev = rev[:min_len]
srevs = set(sdb[self.__rev_key(rev)])
if len(srevs) == 1:
return srev # we already got a unique id
# find a shortened id for which rev doesn't conflict with
# the other ones from srevs
crevs = srevs - set([rev])
for l in range(min_len+1, 40):
srev = rev[:l]
if srev not in [ r[:l] for r in crevs ]:
return srev
return rev # worst-case, all except the last character match
def fullrev(self, srev):
"try to reverse shortrev()"
srev = str(srev)
db, tag_db, sdb = self.rev_cache[2:5]
# short-cut
if len(srev) == 40 and srev in db:
return srev
if not GitCore.is_sha(srev):
return None
try:
srevs = sdb[self.__rev_key(srev)]
except KeyError:
return None
srevs = filter(lambda s: s.startswith(srev), srevs)
if len(srevs) == 1:
return srevs[0]
return None
def get_branches(self):
"returns list of (local) branches, with active (= HEAD) one being the first item"
result=[]
for e in self.repo.branch("-v", "--no-abbrev"):
(bname,bsha)=e[1:].strip().split()[:2]
if e.startswith('*'):
result.insert(0,(bname,bsha))
else:
result.append((bname,bsha))
return result
def get_tags(self):
return [e.strip() for e in self.repo.tag("-l")]
def ls_tree(self, rev, path=""):
rev = str(rev) # paranoia
if path.startswith('/'):
path = path[1:]
tree = self.repo.ls_tree("-z", "-l", rev, "--", path).read().split('\0')
def split_ls_tree_line(l):
"split according to '<mode> <type> <sha> <size>\t<fname>'"
meta,fname = l.split('\t')
_mode,_type,_sha,_size = meta.split()
if _size == '-':
_size = None
else:
_size = int(_size)
return _mode,_type,_sha,_size,fname
return [ split_ls_tree_line(e) for e in tree if e ]
def read_commit(self, commit_id):
if not commit_id:
raise GitError("read_commit called with empty commit_id")
commit_id = str(commit_id)
db = self.get_commits()
if commit_id not in db:
self.logger.info("read_commit failed for '%s'" % commit_id)
raise GitErrorSha
with self.__commit_msg_lock:
if self.__commit_msg_cache.has_key(commit_id):
# cache hit
result = self.__commit_msg_cache[commit_id]
return result[0], dict(result[1])
# cache miss
raw = self.repo.cat_file("commit", commit_id).read()
raw = unicode(raw, self.get_commit_encoding(), 'replace')
lines = raw.splitlines()
if not lines:
raise GitErrorSha
line = lines.pop(0)
props = {}
while line:
(key,value) = line.split(None, 1)
props.setdefault(key,[]).append(value.strip())
line = lines.pop(0)
result = ("\n".join(lines), props)
self.__commit_msg_cache[commit_id] = result
return result[0], dict(result[1])
def get_file(self, sha):
return self.repo.cat_file("blob", str(sha))
def get_obj_size(self, sha):
sha = str(sha)
try:
obj_size = int(self.repo.cat_file("-s", sha).read().strip())
except ValueError:
raise GitErrorSha("object '%s' not found" % sha)
return obj_size
def children(self, sha):
db = self.get_commits()
try:
return list(db[sha][0])
except KeyError:
return []
def children_recursive(self, sha):
db = self.get_commits()
work_list = deque()
seen = set()
seen.update(db[sha][0])
work_list.extend(db[sha][0])
while work_list:
p = work_list.popleft()
yield p
_children = set(db[p][0]) - seen
seen.update(_children)
work_list.extend(_children)
assert len(work_list) == 0
def parents(self, sha):
db = self.get_commits()
try:
return list(db[sha][1])
except KeyError:
return []
def all_revs(self):
return self.get_commits().iterkeys()
def sync(self):
rev = self.repo.rev_list("--max-count=1", "--all").read().strip()
return self.__rev_cache_sync(rev)
def last_change(self, sha, path):
return self.repo.rev_list("--max-count=1",
sha, "--", path).read().strip() or None
def history(self, sha, path, limit=None):
if limit is None:
limit = -1
for rev in self.repo.rev_list("--max-count=%d" % limit,
str(sha), "--", path):
yield rev.strip()
def history_timerange(self, start, stop):
for rev in self.repo.rev_list("--reverse",
"--max-age=%d" % start,
"--min-age=%d" % stop,
"--all"):
yield rev.strip()
def rev_is_anchestor_of(self, rev1, rev2):
"""return True if rev2 is successor of rev1"""
rev1 = rev1.strip()
rev2 = rev2.strip()
return rev2 in self.children_recursive(rev1)
def blame(self, commit_sha, path):
in_metadata = False
for line in self.repo.blame("-p", "--", path, str(commit_sha)):
assert line
if in_metadata:
in_metadata = not line.startswith('\t')
else:
split_line = line.split()
if len(split_line) == 4:
(sha, orig_lineno, lineno, group_size) = split_line
else:
(sha, orig_lineno, lineno) = split_line
assert len(sha) == 40
yield (sha, lineno)
in_metadata = True
assert not in_metadata
def diff_tree(self, tree1, tree2, path="", find_renames=False):
"""calls `git diff-tree` and returns tuples of the kind
(mode1,mode2,obj1,obj2,action,path1,path2)"""
# diff-tree returns records with the following structure:
# :<old-mode> <new-mode> <old-sha> <new-sha> <change> NUL <old-path> NUL [ <new-path> NUL ]
diff_tree_args = ["-z", "-r"]
if find_renames:
diff_tree_args.append("-M")
diff_tree_args.extend([str(tree1) if tree1 else "--root",
str(tree2),
"--", path])
lines = self.repo.diff_tree(*diff_tree_args).read().split('\0')
assert lines[-1] == ""
del lines[-1]
if tree1 is None and lines:
# if only one tree-sha is given on commandline,
# the first line is just the redundant tree-sha itself...
assert not lines[0].startswith(':')
del lines[0]
chg = None
def __chg_tuple():
if len(chg) == 6:
chg.append(None)
assert len(chg) == 7
return tuple(chg)
for line in lines:
if line.startswith(':'):
if chg:
yield __chg_tuple()
chg = line[1:].split()
assert len(chg) == 5
else:
chg.append(line)
if chg:
yield __chg_tuple()
############################################################################
############################################################################
############################################################################
if __name__ == '__main__':
import sys, logging, timeit
assert not GitCore.is_sha("123")
assert GitCore.is_sha("1a3f")
assert GitCore.is_sha("f"*40)
assert not GitCore.is_sha("x"+"f"*39)
assert not GitCore.is_sha("f"*41)
print "git version [%s]" % str(Storage.git_version())
# custom linux hack reading `/proc/<PID>/statm`
if sys.platform == "linux2":
__pagesize = os.sysconf('SC_PAGESIZE')
def proc_statm(pid = os.getpid()):
__proc_statm = '/proc/%d/statm' % pid
try:
t = open(__proc_statm)
result = t.read().split()
t.close()
assert len(result) == 7
return tuple([ __pagesize*int(p) for p in result ])
except:
raise RuntimeError("failed to get memory stats")
else: # not linux2
print "WARNING - meminfo.proc_statm() not available"
def proc_statm():
return (0,)*7
print "statm =", proc_statm()
__data_size = proc_statm()[5]
__data_size_last = __data_size
def print_data_usage():
global __data_size_last
__tmp = proc_statm()[5]
print "DATA: %6d %+6d" % (__tmp - __data_size, __tmp - __data_size_last)
__data_size_last = __tmp
print_data_usage()
g = Storage(sys.argv[1], logging)
print_data_usage()
print "[%s]" % g.head()
print g.ls_tree(g.head())
print "--------------"
print_data_usage()
print g.read_commit(g.head())
print "--------------"
print_data_usage()
p = g.parents(g.head())
print list(p)
print "--------------"
print list(g.children(list(p)[0]))
print list(g.children(list(p)[0]))
print "--------------"
print g.get_commit_encoding()
print "--------------"
print g.get_branches()
print "--------------"
print g.hist_prev_revision(g.oldest_rev()), g.oldest_rev(), g.hist_next_revision(g.oldest_rev())
print_data_usage()
print "--------------"
p = g.youngest_rev()
print g.hist_prev_revision(p), p, g.hist_next_revision(p)
print "--------------"
p = g.head()
for i in range(-5,5):
print i, g.history_relative_rev(p, i)
# check for loops
def check4loops(head):
print "check4loops", head
seen = set([head])
for sha in g.children_recursive(head):
if sha in seen:
print "dupe detected :-/", sha, len(seen)
seen.add(sha)
return seen
print len(check4loops(g.parents(g.head())[0]))
#p = g.head()
#revs = [ g.history_relative_rev(p, i) for i in range(0,10) ]
print_data_usage()
revs = g.get_commits().keys()
print_data_usage()
def shortrev_test():
for i in revs:
i = str(i)
s = g.shortrev(i, min_len=4)
assert i.startswith(s)
assert g.fullrev(s) == i
iters = 1
print "timing %d*shortrev_test()..." % len(revs)
t = timeit.Timer("shortrev_test()", "from __main__ import shortrev_test")
print "%.2f usec/rev" % (1000000 * t.timeit(number=iters)/len(revs))
#print len(check4loops(g.oldest_rev()))
#print len(list(g.children_recursive(g.oldest_rev())))
print_data_usage()
# perform typical trac operations:
if 1:
print "--------------"
rev = g.head()
for mode,type,sha,_size,name in g.ls_tree(rev):
[last_rev] = g.history(rev, name, limit=1)
s = g.get_obj_size(sha) if type == "blob" else 0
msg = g.read_commit(last_rev)
print "%s %s %10d [%s]" % (type, last_rev, s, name)
print "allocating 2nd instance"
print_data_usage()
g2 = Storage(sys.argv[1], logging)
g2.head()
print_data_usage()
print "allocating 3rd instance"
g3 = Storage(sys.argv[1], logging)
g3.head()
print_data_usage()