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Diffstat (limited to 'sharedstate.git/sharedstate/sharedpython.py')
| -rw-r--r-- | sharedstate.git/sharedstate/sharedpython.py | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/sharedstate.git/sharedstate/sharedpython.py b/sharedstate.git/sharedstate/sharedpython.py deleted file mode 100644 index 78a622a..0000000 --- a/sharedstate.git/sharedstate/sharedpython.py +++ /dev/null @@ -1,234 +0,0 @@ -# sharedpython.py, classes to aid activities in sharing a state -# @author: Miguel Angel Alvarez, miguel@laptop.org -# @author: Reinier Heeres -# -# 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. -# -# You should have received a copy of the GNU General Public License -# along with this program; if not, write to the Free Software -# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA -# -# Change log: -# - -import pickle -import difflib -import logging -from sharedobject import DiffRec -_logger = logging.getLogger('sharedpython') - -from sharedobject import SharedObject - -class SharedPython(SharedObject): - - def __init__(self, name, helper, opt={}): - SharedObject.__init__(self, name, helper, opt=opt) - self._value = None - self._picklestr = '' - - def _divide_change(self, c): - """Separate the index and the string parts of the chage string""" - if ' ' in c: - i = c.index(' ') - return (c[:i], c[i+1:]) - else: - print c - return None - - def inverse_diff(self, diff): - """Return the inverse diff object""" - d = SharedObject.inverse_diff(self, diff) - if d == None: - obj = self._generate_inverse_diffobj(diff.obj) - return DiffRec(diff.version_id, diff.sender, True, obj) - - def _generate_inverse_diffobj(self, changes): - ret = [] - delta = 0 - last_num = -1 - last_n_in = -1 - - for c in changes: - n, s = self._divide_change(c) - l = len(s) - num = abs(int(n)) - if num == last_num: - n_in = last_n_in - else: - n_in = num + delta - last_num = num - last_n_in = n_in - - if c[0] == '+': - ret.append('-'+str(n_in)+' '+s) - delta += l - elif c[0] == '-': - ret.append('+'+str(n_in)+' '+s) - delta -= l - else: - print "Unknown line type:", c - ret = self._format_changes(ret) - return ret - - def _update_interval(self, i, cs): - """Get an 'exclusion interval' (where no other different edits are accepted) for the change cs[i]""" - c = cs[i] - n, d = self._divide_change(c) - n = int(n) - if n >= 0: - return (n+1, n+1) - else: - return (abs(n), abs(n) + len(d)) - - def _intersect(self, ia, ib): - """function that takes 2 intervals (2 element ordered int lists) and returns whether they - intersect and, if not, which one is bigger: - ret > 0 => ia bigger - ret < 0 => ib bigger - ret = 0 => intersection""" - assert ia[1] >= ia[0] and len(ia) == 2 - assert ib[1] >= ib[0] and len(ib) == 2 - if ia[0] > ib[1]: - return 1 #No _intersect, ia bigger - if ia[1] < ib[0]: - return -1 #No _intersect, ia smaller - return 0 #Intersect - - def _compatible_diffs(self, diff_a, diff_b): - """ It returns whether two change arrays act upon the same positions, and - cannot therefore be automatically merged without risking conflict""" - _logger.debug("_compatible_diffs(): a=%s, b=%s", diff_a, diff_b) - index_a = index_b = 0 - while index_a < len(diff_a) and index_b < len(diff_b): - interval_a = self._update_interval(index_a, diff_a) - interval_b = self._update_interval(index_b, diff_b) - d = self._intersect(interval_a, interval_b) - if d == 0 : -## if diff_a[index_a] not in diff_b and diff_b[index_b] not in diff_a: -## print "change a:'%s'\tchange_b:'%s'" % (diff_a[index_a], diff_b[index_b]) -## return False -## elif interval_a[1] > interval_b[1]: -## index_b += 1 -## else: -## index_a += 1 -## ATT: More restrictive version of compatible_diffs used right now - return False - elif d == 1: - index_b += 1 - elif d == -1: - index_a += 1 - else: - index_a += 1 - index_b += 1 - return True - - def _format_changes(self, changes): - last_sign = None - last_num = -1 - foreseen_index = -1 - res=[] - for c in changes: - sign = c[0] - n, s = self._divide_change(c) - number = abs(int(n)) - if sign == "+" and last_sign == "-" and (number == foreseen_index or number == last_num) : - res = res[:-1]+[sign +str(last_num)+" "+s, res[-1]] - last_sign = sign - foreseen_index = number + len(s) - last_num = number - else: - res.append(c) - last_sign = sign - foreseen_index = number + len(s) - last_num = number - return res - - def diff(self, new_object, old_object): - """Generate a change array from two python objects""" - _logger.debug("Diffing old:%s (type: %s), new: %s (type: %s)", old_object, type(old_object), - new_object, type(new_object)) - differ = difflib.Differ() - old = pickle.dumps(old_object) - new = pickle.dumps(new_object) -## _logger.debug('Old text: %s', old) -## _logger.debug(' New text:%s', new) - ret = [] - raw_delta = list(differ.compare(old, new)) -## _logger.debug('raw delta: %s', raw_delta) - pos = 0 - continuous = False - for r in raw_delta: - if r[:2] == "+ ": - if len(ret) > 0 and ret[-1][0] == "+" and continuous: - ret[-1] += r[2:] - #if 2 continuous additions occur, append at the end - else: - string = "+"+str(pos)+" "+r[2:] - ret.append(string) - continuous = True - elif r[:2] == "- ": - if len(ret) > 0 and ret[-1][0] == "-" and continuous: - ret[-1] += r[2:] #append at the end - else: - string = "-"+str(pos)+" "+r[2:] - ret.append(string) - continuous = True - pos += 1 # TODO: important change; verify - elif r[:2] == "? ": - pass - else: - continuous = False - pos += len(r) - 2 -## _logger.debug('Ret before format changes: %s', ret) - return self._format_changes(ret) - - def _apply_diff_to(self, object, diffobj): - """ Apply a diff to a given object and return the new version - In this case, the provided object gets modified, too.""" - old = pickle.dumps(object) - _logger.debug("_apply_diff_to(): old=%r, diffobj=%s", old, diffobj) - new = "" - pos = old_pos = 0 - for c in diffobj: - id, st = self._divide_change(c) - pos = abs(int(id)) - new += old[old_pos:pos] - if id[0] == "+": -## _logger.debug("_apply_diff_to(): adding %r", st) - new += st - elif id[0] == "-": -## _logger.debug("_apply_diff_to(): deleting %r", st) - if old[pos:pos+len(st)] != st: - exc = "Bad delete at %d, expected %s, got %r" % (pos, - st, old[pos:pos+len(st)]) - raise Exception(exc) - pos += len(st) - old_pos = pos - if pos < len(old): - new += old[pos:] - res = pickle.loads(new) - _logger.debug("_apply_diff_to(): new=%r, res=%s", new, res) - idiff = self._generate_inverse_diffobj(diffobj) - return (res, idiff) - - def get_version(self, versionid): - _logger.debug("get_version(): called with versionid = %d", versionid) - if versionid == self._version_id: - return self._value - ret = self._value - if versionid > self._version_id: - return None - for i in range(len(self._received_diffs)-1, self._get_diff_index(versionid), -1): - d = self._received_diffs[i] - idobj = self._generate_inverse_diffobj(d.obj) - ret = self._apply_diff_to(ret, idobj)[0] - _logger.debug("get_version(): return value: %s", ret) - return ret |