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dupeguru/core/engine.py
Virgil Dupras b1ef3dc8fe Simplify progress report during scanning
We now get less progress feedback, but in exchange, our progress job is
simpler. Previously, our progress bar would often get wonky towards the
end of the scan and I didn't have the energy to debug that.

Besides, people don't care about that level of progress feedback.
2016-06-08 12:29:28 -04:00

502 lines
18 KiB
Python

# Created By: Virgil Dupras
# Created On: 2006/01/29
# Copyright 2015 Hardcoded Software (http://www.hardcoded.net)
#
# This software is licensed under the "GPLv3" License as described in the "LICENSE" file,
# which should be included with this package. The terms are also available at
# http://www.gnu.org/licenses/gpl-3.0.html
import difflib
import itertools
import logging
import string
from collections import defaultdict, namedtuple
from unicodedata import normalize
from hscommon.util import flatten, multi_replace
from hscommon.trans import tr
from hscommon.jobprogress import job
(
WEIGHT_WORDS,
MATCH_SIMILAR_WORDS,
NO_FIELD_ORDER,
) = range(3)
JOB_REFRESH_RATE = 100
def getwords(s):
# We decompose the string so that ascii letters with accents can be part of the word.
s = normalize('NFD', s)
s = multi_replace(s, "-_&+():;\\[]{}.,<>/?~!@#$*", ' ').lower()
s = ''.join(c for c in s if c in string.ascii_letters + string.digits + string.whitespace)
return [_f for _f in s.split(' ') if _f] # remove empty elements
def getfields(s):
fields = [getwords(field) for field in s.split(' - ')]
return [_f for _f in fields if _f]
def unpack_fields(fields):
result = []
for field in fields:
if isinstance(field, list):
result += field
else:
result.append(field)
return result
def compare(first, second, flags=()):
"""Returns the % of words that match between ``first`` and ``second``
The result is a ``int`` in the range 0..100.
``first`` and ``second`` can be either a string or a list (of words).
"""
if not (first and second):
return 0
if any(isinstance(element, list) for element in first):
return compare_fields(first, second, flags)
second = second[:] #We must use a copy of second because we remove items from it
match_similar = MATCH_SIMILAR_WORDS in flags
weight_words = WEIGHT_WORDS in flags
joined = first + second
total_count = (sum(len(word) for word in joined) if weight_words else len(joined))
match_count = 0
in_order = True
for word in first:
if match_similar and (word not in second):
similar = difflib.get_close_matches(word, second, 1, 0.8)
if similar:
word = similar[0]
if word in second:
if second[0] != word:
in_order = False
second.remove(word)
match_count += (len(word) if weight_words else 1)
result = round(((match_count * 2) / total_count) * 100)
if (result == 100) and (not in_order):
result = 99 # We cannot consider a match exact unless the ordering is the same
return result
def compare_fields(first, second, flags=()):
"""Returns the score for the lowest matching :ref:`fields`.
``first`` and ``second`` must be lists of lists of string. Each sub-list is then compared with
:func:`compare`.
"""
if len(first) != len(second):
return 0
if NO_FIELD_ORDER in flags:
results = []
#We don't want to remove field directly in the list. We must work on a copy.
second = second[:]
for field1 in first:
max = 0
matched_field = None
for field2 in second:
r = compare(field1, field2, flags)
if r > max:
max = r
matched_field = field2
results.append(max)
if matched_field:
second.remove(matched_field)
else:
results = [compare(field1, field2, flags) for field1, field2 in zip(first, second)]
return min(results) if results else 0
def build_word_dict(objects, j=job.nulljob):
"""Returns a dict of objects mapped by their words.
objects must have a ``words`` attribute being a list of strings or a list of lists of strings
(:ref:`fields`).
The result will be a dict with words as keys, lists of objects as values.
"""
result = defaultdict(set)
for object in j.iter_with_progress(objects, 'Prepared %d/%d files', JOB_REFRESH_RATE):
for word in unpack_fields(object.words):
result[word].add(object)
return result
def merge_similar_words(word_dict):
"""Take all keys in ``word_dict`` that are similar, and merge them together.
``word_dict`` has been built with :func:`build_word_dict`. Similarity is computed with Python's
``difflib.get_close_matches()``, which computes the number of edits that are necessary to make
a word equal to the other.
"""
keys = list(word_dict.keys())
keys.sort(key=len)# we want the shortest word to stay
while keys:
key = keys.pop(0)
similars = difflib.get_close_matches(key, keys, 100, 0.8)
if not similars:
continue
objects = word_dict[key]
for similar in similars:
objects |= word_dict[similar]
del word_dict[similar]
keys.remove(similar)
def reduce_common_words(word_dict, threshold):
"""Remove all objects from ``word_dict`` values where the object count >= ``threshold``
``word_dict`` has been built with :func:`build_word_dict`.
The exception to this removal are the objects where all the words of the object are common.
Because if we remove them, we will miss some duplicates!
"""
uncommon_words = set(word for word, objects in word_dict.items() if len(objects) < threshold)
for word, objects in list(word_dict.items()):
if len(objects) < threshold:
continue
reduced = set()
for o in objects:
if not any(w in uncommon_words for w in unpack_fields(o.words)):
reduced.add(o)
if reduced:
word_dict[word] = reduced
else:
del word_dict[word]
# Writing docstrings in a namedtuple is tricky. From Python 3.3, it's possible to set __doc__, but
# some research allowed me to find a more elegant solution, which is what is done here. See
# http://stackoverflow.com/questions/1606436/adding-docstrings-to-namedtuples-in-python
class Match(namedtuple('Match', 'first second percentage')):
"""Represents a match between two :class:`~core.fs.File`.
Regarless of the matching method, when two files are determined to match, a Match pair is created,
which holds, of course, the two matched files, but also their match "level".
.. attribute:: first
first file of the pair.
.. attribute:: second
second file of the pair.
.. attribute:: percentage
their match level according to the scan method which found the match. int from 1 to 100. For
exact scan methods, such as Contents scans, this will always be 100.
"""
__slots__ = ()
def get_match(first, second, flags=()):
#it is assumed here that first and second both have a "words" attribute
percentage = compare(first.words, second.words, flags)
return Match(first, second, percentage)
def getmatches(
objects, min_match_percentage=0, match_similar_words=False, weight_words=False,
no_field_order=False, j=job.nulljob):
"""Returns a list of :class:`Match` within ``objects`` after fuzzily matching their words.
:param objects: List of :class:`~core.fs.File` to match.
:param int min_match_percentage: minimum % of words that have to match.
:param bool match_similar_words: make similar words (see :func:`merge_similar_words`) match.
:param bool weight_words: longer words are worth more in match % computations.
:param bool no_field_order: match :ref:`fields` regardless of their order.
:param j: A :ref:`job progress instance <jobs>`.
"""
COMMON_WORD_THRESHOLD = 50
LIMIT = 5000000
j = j.start_subjob(2)
sj = j.start_subjob(2)
for o in objects:
if not hasattr(o, 'words'):
o.words = getwords(o.name)
word_dict = build_word_dict(objects, sj)
reduce_common_words(word_dict, COMMON_WORD_THRESHOLD)
if match_similar_words:
merge_similar_words(word_dict)
match_flags = []
if weight_words:
match_flags.append(WEIGHT_WORDS)
if match_similar_words:
match_flags.append(MATCH_SIMILAR_WORDS)
if no_field_order:
match_flags.append(NO_FIELD_ORDER)
j.start_job(len(word_dict), tr("0 matches found"))
compared = defaultdict(set)
result = []
try:
# This whole 'popping' thing is there to avoid taking too much memory at the same time.
while word_dict:
items = word_dict.popitem()[1]
while items:
ref = items.pop()
compared_already = compared[ref]
to_compare = items - compared_already
compared_already |= to_compare
for other in to_compare:
m = get_match(ref, other, match_flags)
if m.percentage >= min_match_percentage:
result.append(m)
if len(result) >= LIMIT:
return result
j.add_progress(desc=tr("%d matches found") % len(result))
except MemoryError:
# This is the place where the memory usage is at its peak during the scan.
# Just continue the process with an incomplete list of matches.
del compared # This should give us enough room to call logging.
logging.warning('Memory Overflow. Matches: %d. Word dict: %d' % (len(result), len(word_dict)))
return result
return result
def getmatches_by_contents(files, j=job.nulljob):
"""Returns a list of :class:`Match` within ``files`` if their contents is the same.
:param j: A :ref:`job progress instance <jobs>`.
"""
size2files = defaultdict(set)
for f in files:
if f.size:
size2files[f.size].add(f)
del files
possible_matches = [files for files in size2files.values() if len(files) > 1]
del size2files
result = []
j.start_job(len(possible_matches), tr("0 matches found"))
for group in possible_matches:
for first, second in itertools.combinations(group, 2):
if first.is_ref and second.is_ref:
continue # Don't spend time comparing two ref pics together.
if first.md5partial == second.md5partial:
if first.md5 == second.md5:
result.append(Match(first, second, 100))
j.add_progress(desc=tr("%d matches found") % len(result))
return result
class Group:
"""A group of :class:`~core.fs.File` that match together.
This manages match pairs into groups and ensures that all files in the group match to each
other.
.. attribute:: ref
The "reference" file, which is the file among the group that isn't going to be deleted.
.. attribute:: ordered
Ordered list of duplicates in the group (including the :attr:`ref`).
.. attribute:: unordered
Set duplicates in the group (including the :attr:`ref`).
.. attribute:: dupes
An ordered list of the group's duplicate, without :attr:`ref`. Equivalent to
``ordered[1:]``
.. attribute:: percentage
Average match percentage of match pairs containing :attr:`ref`.
"""
#---Override
def __init__(self):
self._clear()
def __contains__(self, item):
return item in self.unordered
def __getitem__(self, key):
return self.ordered.__getitem__(key)
def __iter__(self):
return iter(self.ordered)
def __len__(self):
return len(self.ordered)
#---Private
def _clear(self):
self._percentage = None
self._matches_for_ref = None
self.matches = set()
self.candidates = defaultdict(set)
self.ordered = []
self.unordered = set()
def _get_matches_for_ref(self):
if self._matches_for_ref is None:
ref = self.ref
self._matches_for_ref = [match for match in self.matches if ref in match]
return self._matches_for_ref
#---Public
def add_match(self, match):
"""Adds ``match`` to internal match list and possibly add duplicates to the group.
A duplicate can only be considered as such if it matches all other duplicates in the group.
This method registers that pair (A, B) represented in ``match`` as possible candidates and,
if A and/or B end up matching every other duplicates in the group, add these duplicates to
the group.
:param tuple match: pair of :class:`~core.fs.File` to add
"""
def add_candidate(item, match):
matches = self.candidates[item]
matches.add(match)
if self.unordered <= matches:
self.ordered.append(item)
self.unordered.add(item)
if match in self.matches:
return
self.matches.add(match)
first, second, _ = match
if first not in self.unordered:
add_candidate(first, second)
if second not in self.unordered:
add_candidate(second, first)
self._percentage = None
self._matches_for_ref = None
def discard_matches(self):
"""Remove all recorded matches that didn't result in a duplicate being added to the group.
You can call this after the duplicate scanning process to free a bit of memory.
"""
discarded = set(m for m in self.matches if not all(obj in self.unordered for obj in [m.first, m.second]))
self.matches -= discarded
self.candidates = defaultdict(set)
return discarded
def get_match_of(self, item):
"""Returns the match pair between ``item`` and :attr:`ref`.
"""
if item is self.ref:
return
for m in self._get_matches_for_ref():
if item in m:
return m
def prioritize(self, key_func, tie_breaker=None):
"""Reorders :attr:`ordered` according to ``key_func``.
:param key_func: Key (f(x)) to be used for sorting
:param tie_breaker: function to be used to select the reference position in case the top
duplicates have the same key_func() result.
"""
# tie_breaker(ref, dupe) --> True if dupe should be ref
# Returns True if anything changed during prioritization.
master_key_func = lambda x: (-x.is_ref, key_func(x))
new_order = sorted(self.ordered, key=master_key_func)
changed = new_order != self.ordered
self.ordered = new_order
if tie_breaker is None:
return changed
ref = self.ref
key_value = key_func(ref)
for dupe in self.dupes:
if key_func(dupe) != key_value:
break
if tie_breaker(ref, dupe):
ref = dupe
if ref is not self.ref:
self.switch_ref(ref)
return True
return changed
def remove_dupe(self, item, discard_matches=True):
try:
self.ordered.remove(item)
self.unordered.remove(item)
self._percentage = None
self._matches_for_ref = None
if (len(self) > 1) and any(not getattr(item, 'is_ref', False) for item in self):
if discard_matches:
self.matches = set(m for m in self.matches if item not in m)
else:
self._clear()
except ValueError:
pass
def switch_ref(self, with_dupe):
"""Make the :attr:`ref` dupe of the group switch position with ``with_dupe``.
"""
if self.ref.is_ref:
return False
try:
self.ordered.remove(with_dupe)
self.ordered.insert(0, with_dupe)
self._percentage = None
self._matches_for_ref = None
return True
except ValueError:
return False
dupes = property(lambda self: self[1:])
@property
def percentage(self):
if self._percentage is None:
if self.dupes:
matches = self._get_matches_for_ref()
self._percentage = sum(match.percentage for match in matches) // len(matches)
else:
self._percentage = 0
return self._percentage
@property
def ref(self):
if self:
return self[0]
def get_groups(matches):
"""Returns a list of :class:`Group` from ``matches``.
Create groups out of match pairs in the smartest way possible.
"""
matches.sort(key=lambda match: -match.percentage)
dupe2group = {}
groups = []
try:
for match in matches:
first, second, _ = match
first_group = dupe2group.get(first)
second_group = dupe2group.get(second)
if first_group:
if second_group:
if first_group is second_group:
target_group = first_group
else:
continue
else:
target_group = first_group
dupe2group[second] = target_group
else:
if second_group:
target_group = second_group
dupe2group[first] = target_group
else:
target_group = Group()
groups.append(target_group)
dupe2group[first] = target_group
dupe2group[second] = target_group
target_group.add_match(match)
except MemoryError:
del dupe2group
del matches
# should free enough memory to continue
logging.warning('Memory Overflow. Groups: {0}'.format(len(groups)))
# Now that we have a group, we have to discard groups' matches and see if there're any "orphan"
# matches, that is, matches that were candidate in a group but that none of their 2 files were
# accepted in the group. With these orphan groups, it's safe to build additional groups
matched_files = set(flatten(groups))
orphan_matches = []
for group in groups:
orphan_matches += {
m for m in group.discard_matches()
if not any(obj in matched_files for obj in [m.first, m.second])
}
if groups and orphan_matches:
groups += get_groups(orphan_matches) # no job, as it isn't supposed to take a long time
return groups