dupeguru/core_pe/matchbase.py

130 lines
5.4 KiB
Python

# Created By: Virgil Dupras
# Created On: 2007/02/25
# Copyright 2010 Hardcoded Software (http://www.hardcoded.net)
#
# This software is licensed under the "BSD" License as described in the "LICENSE" file,
# which should be included with this package. The terms are also available at
# http://www.hardcoded.net/licenses/bsd_license
import logging
import multiprocessing
from collections import defaultdict, deque
from jobprogress import job
from core.engine import Match
from .block import avgdiff, DifferentBlockCountError, NoBlocksError
from .cache import Cache
MIN_ITERATIONS = 3
BLOCK_COUNT_PER_SIDE = 15
# Enough so that we're sure that the main thread will not wait after a result.get() call
# cpucount*2 should be enough to be sure that the spawned process will not wait after the results
# collection made by the main process.
RESULTS_QUEUE_LIMIT = multiprocessing.cpu_count() * 2
def prepare_pictures(pictures, cache_path, j=job.nulljob):
# The MemoryError handlers in there use logging without first caring about whether or not
# there is enough memory left to carry on the operation because it is assumed that the
# MemoryError happens when trying to read an image file, which is freed from memory by the
# time that MemoryError is raised.
cache = Cache(cache_path)
prepared = [] # only pictures for which there was no error getting blocks
try:
for picture in j.iter_with_progress(pictures, 'Analyzed %d/%d pictures'):
picture.dimensions
picture.unicode_path = str(picture.path)
try:
if picture.unicode_path not in cache:
blocks = picture.get_blocks(BLOCK_COUNT_PER_SIDE)
cache[picture.unicode_path] = blocks
prepared.append(picture)
except (IOError, ValueError) as e:
logging.warning(str(e))
except MemoryError:
logging.warning('Ran out of memory while reading %s of size %d' % (picture.unicode_path, picture.size))
if picture.size < 10 * 1024 * 1024: # We're really running out of memory
raise
except MemoryError:
logging.warning('Ran out of memory while preparing pictures')
cache.close()
return prepared
def get_match(first, second, percentage):
if percentage < 0:
percentage = 0
return Match(first, second, percentage)
def async_compare(ref_id, other_ids, dbname, threshold):
cache = Cache(dbname)
limit = 100 - threshold
ref_blocks = cache[ref_id]
pairs = cache.get_multiple(other_ids)
results = []
for other_id, other_blocks in pairs:
try:
diff = avgdiff(ref_blocks, other_blocks, limit, MIN_ITERATIONS)
percentage = 100 - diff
except (DifferentBlockCountError, NoBlocksError):
percentage = 0
if percentage >= threshold:
results.append((ref_id, other_id, percentage))
cache.close()
return results
def getmatches(pictures, cache_path, threshold=75, match_scaled=False, j=job.nulljob):
j = j.start_subjob([3, 7])
pictures = prepare_pictures(pictures, cache_path, j)
j = j.start_subjob([9, 1], 'Preparing for matching')
cache = Cache(cache_path)
id2picture = {}
dimensions2pictures = defaultdict(set)
for picture in pictures:
try:
picture.cache_id = cache.get_id(picture.unicode_path)
id2picture[picture.cache_id] = picture
if not match_scaled:
dimensions2pictures[picture.dimensions].add(picture)
except ValueError:
pass
cache.close()
pictures = [p for p in pictures if hasattr(p, 'cache_id')]
pool = multiprocessing.Pool()
async_results = deque()
matches = []
pictures_copy = set(pictures)
for ref in j.iter_with_progress(pictures, 'Matched %d/%d pictures'):
others = pictures_copy if match_scaled else dimensions2pictures[ref.dimensions]
others.remove(ref)
if ref.is_ref:
# Don't spend time comparing two ref pics together.
others = [pic for pic in others if not pic.is_ref]
if others:
cache_ids = [f.cache_id for f in others]
# We limit the number of cache_ids we send for multi-processing because otherwise, we
# might get an error saying "String or BLOB exceeded size limit"
ARG_LIMIT = 1000
while cache_ids:
args = (ref.cache_id, cache_ids[:ARG_LIMIT], cache_path, threshold)
async_results.append(pool.apply_async(async_compare, args))
cache_ids = cache_ids[ARG_LIMIT:]
# We use a while here because it's possible that more than one result has been added if
# ARG_LIMIT has been reached.
while len(async_results) > RESULTS_QUEUE_LIMIT:
result = async_results.popleft()
matches.extend(result.get())
for result in async_results: # process the rest of the results
matches.extend(result.get())
result = []
for ref_id, other_id, percentage in j.iter_with_progress(matches, 'Verified %d/%d matches', every=10):
ref = id2picture[ref_id]
other = id2picture[other_id]
if percentage == 100 and ref.md5 != other.md5:
percentage = 99
if percentage >= threshold:
result.append(get_match(ref, other, percentage))
return result
multiprocessing.freeze_support()