""" Copyright [2022] Victor C Hall Licensed under the GNU Affero General Public License; You may not use this code except in compliance with the License. You may obtain a copy of the License at https://www.gnu.org/licenses/agpl-3.0.en.html Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. """ import bisect import logging import math import copy import random from typing import List, Dict from data.image_train_item import ImageTrainItem, DEFAULT_BATCH_ID import PIL.Image from utils.first_fit_decreasing import first_fit_decreasing PIL.Image.MAX_IMAGE_PIXELS = 715827880*4 # increase decompression bomb error limit to 4x default class DataLoaderMultiAspect(): """ Data loader for multi-aspect-ratio training and bucketing image_train_items: list of `ImageTrainItem` objects seed: random seed batch_size: number of images per batch """ def __init__(self, image_train_items: list[ImageTrainItem], seed=555, batch_size=1, grad_accum=1): self.seed = seed self.batch_size = batch_size self.grad_accum = grad_accum self.prepared_train_data = image_train_items random.Random(self.seed).shuffle(self.prepared_train_data) self.prepared_train_data = sorted(self.prepared_train_data, key=lambda img: img.caption.rating()) self.expected_epoch_size = math.floor(sum([i.multiplier for i in self.prepared_train_data])) if self.expected_epoch_size != len(self.prepared_train_data): logging.info(f" * DLMA initialized with {len(image_train_items)} source images. After applying multipliers, each epoch will train on at least {self.expected_epoch_size} images.") else: logging.info(f" * DLMA initialized with {len(image_train_items)} images.") self.rating_overall_sum: float = 0.0 self.ratings_summed: list[float] = [] self.__update_rating_sums() def __pick_multiplied_set(self, randomizer: random.Random): """ Deals with multiply.txt whole and fractional numbers """ picked_images = [] data_copy = copy.deepcopy(self.prepared_train_data) # deep copy to avoid modifying original multiplier property for iti in data_copy: while iti.multiplier >= 1: picked_images.append(iti) iti.multiplier -= 1 remaining = self.expected_epoch_size - len(picked_images) assert remaining >= 0, "Something went wrong with the multiplier calculation" # resolve fractional parts, ensure each is only added max once while remaining > 0: for iti in data_copy: if randomizer.random() < iti.multiplier: picked_images.append(iti) iti.multiplier = 0 remaining -= 1 if remaining <= 0: break return picked_images def get_shuffled_image_buckets(self, dropout_fraction: float = 1.0) -> list[ImageTrainItem]: """ Returns the current list of `ImageTrainItem` in randomized order, sorted into buckets with same sized images. If dropout_fraction < 1.0, only a subset of the images will be returned. If dropout_fraction >= 1.0, repicks fractional multipliers based on folder/multiply.txt values swept at prescan. :param dropout_fraction: must be between 0.0 and 1.0. :return: Randomized list of `ImageTrainItem` objects """ self.seed += 1 randomizer = random.Random(self.seed) if dropout_fraction < 1.0: picked_images = self.__pick_random_subset(dropout_fraction, randomizer) else: picked_images = self.__pick_multiplied_set(randomizer) randomizer.shuffle(picked_images) buckets = {} batch_size = self.batch_size grad_accum = self.grad_accum for image_caption_pair in picked_images: image_caption_pair.runt_size = 0 bucket_key = (image_caption_pair.batch_id, image_caption_pair.target_wh[0], image_caption_pair.target_wh[1]) if bucket_key not in buckets: buckets[bucket_key] = [] buckets[bucket_key].append(image_caption_pair) # handle runts by randomly duplicating items for bucket in buckets: truncate_count = len(buckets[bucket]) % batch_size if truncate_count > 0: runt_bucket = buckets[bucket][-truncate_count:] for item in runt_bucket: item.runt_size = truncate_count while len(runt_bucket) < batch_size: runt_bucket.append(random.choice(runt_bucket)) current_bucket_size = len(buckets[bucket]) buckets[bucket] = buckets[bucket][:current_bucket_size - truncate_count] buckets[bucket].extend(runt_bucket) # handle batch_id # unlabelled data (no batch_id) is in batches labelled DEFAULT_BATCH_ID. items_by_batch_id = collapse_buckets_by_batch_id(buckets) items = flatten_buckets_preserving_named_batch_adjacency(items_by_batch_id, batch_size=batch_size, grad_accum=grad_accum) effective_batch_size = batch_size * grad_accum items = chunked_shuffle(items, chunk_size=effective_batch_size, randomizer=randomizer) return items def __pick_random_subset(self, dropout_fraction: float, picker: random.Random) -> list[ImageTrainItem]: """ Picks a random subset of all images - The size of the subset is limited by dropout_faction - The chance of an image to be picked is influenced by its rating. Double that rating -> double the chance :param dropout_fraction: must be between 0.0 and 1.0 :param picker: seeded random picker :return: list of picked ImageTrainItem """ prepared_train_data = self.prepared_train_data.copy() ratings_summed = self.ratings_summed.copy() rating_overall_sum = self.rating_overall_sum num_images = len(prepared_train_data) num_images_to_pick = math.ceil(num_images * dropout_fraction) num_images_to_pick = max(min(num_images_to_pick, num_images), 0) # logging.info(f"Picking {num_images_to_pick} images out of the {num_images} in the dataset for drop_fraction {dropout_fraction}") picked_images: list[ImageTrainItem] = [] while num_images_to_pick > len(picked_images): # find random sample in dataset point = picker.uniform(0.0, rating_overall_sum) pos = min(bisect.bisect_left(ratings_summed, point), len(prepared_train_data) -1 ) # pick random sample picked_image = prepared_train_data[pos] picked_images.append(picked_image) # kick picked item out of data set to not pick it again rating_overall_sum = max(rating_overall_sum - picked_image.caption.rating(), 0.0) ratings_summed.pop(pos) prepared_train_data.pop(pos) return picked_images def __update_rating_sums(self): self.rating_overall_sum: float = 0.0 self.ratings_summed: list[float] = [] for item in self.prepared_train_data: self.rating_overall_sum += item.caption.rating() self.ratings_summed.append(self.rating_overall_sum) def chunk(l: List, chunk_size) -> List: num_chunks = int(math.ceil(float(len(l)) / chunk_size)) return [l[i * chunk_size:(i + 1) * chunk_size] for i in range(num_chunks)] def unchunk(chunked_list: List): return [i for c in chunked_list for i in c] def collapse_buckets_by_batch_id(buckets: Dict) -> Dict: batch_ids = [k[0] for k in buckets.keys()] items_by_batch_id = {} for batch_id in batch_ids: items_by_batch_id[batch_id] = unchunk([b for bucket_key,b in buckets.items() if bucket_key[0] == batch_id]) return items_by_batch_id def flatten_buckets_preserving_named_batch_adjacency(items_by_batch_id: Dict[str, List[ImageTrainItem]], batch_size: int, grad_accum: int) -> List[ImageTrainItem]: # precondition: items_by_batch_id has no incomplete batches assert(all((len(v) % batch_size)==0 for v in items_by_batch_id.values())) # ensure we don't mix up aspect ratios by treating each chunk of batch_size images as # a single unit to pass to first_fit_decreasing() filler_items = chunk(items_by_batch_id.get(DEFAULT_BATCH_ID, []), batch_size) custom_batched_items = [chunk(v, batch_size) for k, v in items_by_batch_id.items() if k != DEFAULT_BATCH_ID] neighbourly_chunked_items = first_fit_decreasing(custom_batched_items, batch_size=grad_accum, filler_items=filler_items) items: List[ImageTrainItem] = unchunk(neighbourly_chunked_items) return items def chunked_shuffle(l: List, chunk_size: int, randomizer: random.Random) -> List: """ Shuffles l in chunks, preserving the chunk boundaries and the order of items within each chunk. If the last chunk is incomplete, it is not shuffled (i.e. preserved as the last chunk) """ # chunk by effective batch size chunks = chunk(l, chunk_size) # preserve last chunk as last if it is incomplete last_chunk = None if len(chunks[-1]) < chunk_size: last_chunk = chunks.pop(-1) randomizer.shuffle(chunks) if last_chunk is not None: chunks.append(last_chunk) l = unchunk(chunks) return l