File size: 56,984 Bytes
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
2c5a28b
68f6bad
16517d8
 
68f6bad
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
16517d8
 
2c5a28b
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
68f6bad
 
 
b1c34ff
68f6bad
 
 
 
b1c34ff
68f6bad
16517d8
68f6bad
 
 
16517d8
68f6bad
 
 
b1c34ff
68f6bad
 
 
 
b1c34ff
16517d8
 
68f6bad
 
2c5a28b
15ecbe8
 
 
16517d8
68f6bad
 
 
f2e4555
 
68f6bad
 
 
 
 
ddad56c
 
 
 
 
bbf2c33
ddad56c
7834fdb
bbf2c33
ddad56c
bcae421
ddad56c
 
16517d8
 
 
2c5a28b
 
16517d8
dbe1403
 
 
 
 
 
 
 
 
16517d8
 
 
 
 
dbe1403
 
 
 
 
 
 
 
 
ddad56c
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
ddad56c
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
f2e4555
 
 
16517d8
 
 
2c5a28b
 
 
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
 
 
 
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
 
 
 
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
 
 
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
 
16517d8
 
2c5a28b
 
 
 
16517d8
 
 
 
 
2c5a28b
 
16517d8
 
 
2c5a28b
 
 
 
 
16517d8
 
 
2c5a28b
16517d8
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ca97cde
 
 
 
 
16517d8
 
2c5a28b
 
16517d8
 
 
2c5a28b
 
 
 
 
 
 
16517d8
 
 
2c5a28b
 
 
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
2c5a28b
 
16517d8
 
 
2c5a28b
 
 
16517d8
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
#!/usr/bin/env python
# coding=utf-8
# Copyright 2021 The HuggingFace Team All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# 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.
"""
Fine-tuning the library vision-encoder-decoder models for image captioning.
"""

import json
import logging
import os
import sys
import time
from dataclasses import asdict, dataclass, field
from enum import Enum
from functools import partial
from pathlib import Path
from typing import Callable, Optional

import datasets
import nltk  # Here to have a nice missing dependency error message early on
import numpy as np
from datasets import Dataset, load_dataset, load_metric
from PIL import Image
from tqdm import tqdm

import jax
import jax.numpy as jnp
import optax
import transformers
from filelock import FileLock
from flax import jax_utils, traverse_util
from flax.jax_utils import unreplicate
from flax.training import train_state
from flax.training.common_utils import get_metrics, onehot, shard, shard_prng_key
from huggingface_hub import Repository
from transformers import (
    CONFIG_MAPPING,
    FLAX_MODEL_FOR_CAUSAL_LM_MAPPING,
    FLAX_MODEL_FOR_VISION_2_SEQ_MAPPING,
    AutoConfig,
    AutoFeatureExtractor,
    AutoTokenizer,
    FlaxAutoModelForVision2Seq,
    FlaxVisionEncoderDecoderModel,
    HfArgumentParser,
    is_tensorboard_available,
    VisionEncoderDecoderConfig,
)
from transformers.file_utils import get_full_repo_name, is_offline_mode


logger = logging.getLogger(__name__)

try:
    nltk.data.find("tokenizers/punkt")
except (LookupError, OSError):
    if is_offline_mode():
        raise LookupError(
            "Offline mode: run this script without TRANSFORMERS_OFFLINE first to download nltk data files"
        )
    with FileLock(".lock") as lock:
        nltk.download("punkt", quiet=True)


MODEL_CONFIG_CLASSES = list(FLAX_MODEL_FOR_VISION_2_SEQ_MAPPING.keys())
MODEL_TYPES = tuple(conf.model_type for conf in MODEL_CONFIG_CLASSES)
DECODER_MODEL_TYPES = tuple(conf.model_type for conf in list(FLAX_MODEL_FOR_CAUSAL_LM_MAPPING.keys()))


# Copied from transformers.models.bart.modeling_flax_bart.shift_tokens_right
def shift_tokens_right(input_ids: np.ndarray, pad_token_id: int, decoder_start_token_id: int) -> np.ndarray:
    """
    Shift input ids one token to the right.
    """
    shifted_input_ids = np.zeros_like(input_ids)
    shifted_input_ids[:, 1:] = input_ids[:, :-1]
    shifted_input_ids[:, 0] = decoder_start_token_id

    shifted_input_ids = np.where(shifted_input_ids == -100, pad_token_id, shifted_input_ids)
    return shifted_input_ids


@dataclass
class TrainingArguments:
    output_dir: str = field(
        metadata={"help": "The output directory where the model predictions and checkpoints will be written."},
    )
    overwrite_output_dir: bool = field(
        default=False,
        metadata={
            "help": (
                "Overwrite the content of the output directory. "
                "Use this to continue training if output_dir points to a checkpoint directory."
            )
        },
    )
    do_train: bool = field(default=False, metadata={"help": "Whether to run training."})
    do_eval: bool = field(default=False, metadata={"help": "Whether to run eval on the dev set."})
    do_predict: bool = field(default=False, metadata={"help": "Whether to run predictions on the test set."})
    per_device_train_batch_size: int = field(
        default=8, metadata={"help": "Batch size per GPU/TPU core/CPU for training."}
    )
    per_device_eval_batch_size: int = field(
        default=8, metadata={"help": "Batch size per GPU/TPU core/CPU for evaluation."}
    )
    _block_size_doc = """
        The default value `0` will preprocess (tokenization + feature extraction) the whole dataset before training and
        cache the results. This uses more disk space, but avoids (repeated) processing time during training. This is a
        good option if your disk space is large enough to store the whole processed dataset.
        If a positive value is given, the captions in the dataset will be tokenized before training and the results are
        cached. During training, it iterates the dataset in chunks of size `block_size`. On each block, images are
        transformed by the feature extractor with the results being kept in memory (no cache), and batches of size
        `batch_size` are yielded before processing the next block. This could avoid the heavy disk usage when the
        dataset is large.
        """
    block_size: int = field(default=0, metadata={"help": _block_size_doc})
    learning_rate: float = field(default=5e-5, metadata={"help": "The initial learning rate for AdamW."})
    weight_decay: float = field(default=0.0, metadata={"help": "Weight decay for AdamW if we apply some."})
    adam_beta1: float = field(default=0.9, metadata={"help": "Beta1 for AdamW optimizer"})
    adam_beta2: float = field(default=0.999, metadata={"help": "Beta2 for AdamW optimizer"})
    adam_epsilon: float = field(default=1e-8, metadata={"help": "Epsilon for AdamW optimizer."})
    label_smoothing_factor: float = field(
        default=0.0, metadata={"help": "The label smoothing epsilon to apply (zero means no label smoothing)."}
    )
    num_train_epochs: float = field(default=3.0, metadata={"help": "Total number of training epochs to perform."})
    warmup_steps: int = field(default=0, metadata={"help": "Linear warmup over warmup_steps."})
    logging_steps: int = field(default=500, metadata={"help": "Log every X updates steps."})
    eval_steps: int = field(default=None, metadata={"help": "Run an evaluation every X steps."})
    seed: int = field(default=42, metadata={"help": "Random seed that will be set at the beginning of training."})
    push_to_hub: bool = field(
        default=False, metadata={"help": "Whether or not to upload the trained model to the model hub after training."}
    )
    hub_model_id: str = field(
        default=None, metadata={"help": "The name of the repository to keep in sync with the local `output_dir`."}
    )
    hub_token: str = field(default=None, metadata={"help": "The token to use to push to the Model Hub."})

    def __post_init__(self):
        if self.output_dir is not None:
            self.output_dir = os.path.expanduser(self.output_dir)

    def to_dict(self):
        """
        Serializes this instance while replace `Enum` by their values (for JSON serialization support). It obfuscates
        the token values by removing their value.
        """
        d = asdict(self)
        for k, v in d.items():
            if isinstance(v, Enum):
                d[k] = v.value
            if isinstance(v, list) and len(v) > 0 and isinstance(v[0], Enum):
                d[k] = [x.value for x in v]
            if k.endswith("_token"):
                d[k] = f"<{k.upper()}>"
        return d


@dataclass
class ModelArguments:
    """
    Arguments pertaining to which model/config/tokenizer we are going to fine-tune, or train from scratch.
    """

    encoder_model_name_or_path: Optional[str] = field(
        default=None,
        metadata={
            "help": "The encoder model checkpoint for weights initialization."
            "Don't set if you want to train an encoder model from scratch."
        },
    )
    decoder_model_name_or_path: Optional[str] = field(
        default=None,
        metadata={
            "help": "The decoder model checkpoint for weights initialization."
            "Don't set if you want to train a decoder model from scratch."
        },
    )
    encoder_config_name: Optional[str] = field(
        default=None, metadata={"help": "Pretrained encoder config name or path if not the same as encoder_model_name"}
    )
    decoder_config_name: Optional[str] = field(
        default=None, metadata={"help": "Pretrained decoder config name or path if not the same as decoder_model_name"}
    )
    feature_extractor_name: Optional[str] = field(
        default=None,
        metadata={"help": "Pretrained encoder feature extractor_name or path if not the same as encoder_model_name"},
    )
    tokenizer_name: Optional[str] = field(
        default=None,
        metadata={"help": "Pretrained decoder tokenizer name or path if not the same as decoder_model_name"},
    )
    cache_dir: Optional[str] = field(
        default=None, metadata={"help": "Where do you want to store the pretrained models downloaded from s3"}
    )
    use_fast_tokenizer: bool = field(
        default=True,
        metadata={"help": "Whether to use one of the fast tokenizer (backed by the tokenizers library) or not."},
    )
    dtype: Optional[str] = field(
        default="float32",
        metadata={
            "help": "Floating-point format in which the model weights should be initialized and trained. Choose one of `[float32, float16, bfloat16]`."
        },
    )


@dataclass
class DataTrainingArguments:
    """
    Arguments pertaining to what data we are going to input our model for training and eval.
    """

    dataset_name: Optional[str] = field(
        default=None, metadata={"help": "The name of the dataset to use (via the datasets library)."}
    )
    dataset_config_name: Optional[str] = field(
        default=None, metadata={"help": "The configuration name of the dataset to use (via the datasets library)."}
    )
    data_dir: Optional[str] = field(
        default=None, metadata={"help": "The data directory of the dataset to use (via the datasets library)."}
    )
    image_column: Optional[str] = field(
        default=None,
        metadata={"help": "The name of the column in the datasets containing the full image file paths."},
    )
    caption_column: Optional[str] = field(
        default=None,
        metadata={"help": "The name of the column in the datasets containing the image captions."},
    )
    train_file: Optional[str] = field(default=None, metadata={"help": "The input training data file (a text file)."})
    validation_file: Optional[str] = field(
        default=None,
        metadata={"help": "An optional input evaluation data file to evaluate the perplexity on (a text file)."},
    )
    test_file: Optional[str] = field(
        default=None,
        metadata={"help": "An optional input predict data file to do prediction on (a text file)."},
    )
    max_target_length: Optional[int] = field(
        default=128,
        metadata={
            "help": "The maximum total sequence length for target text after tokenization. Sequences longer "
            "than this will be truncated, sequences shorter will be padded."
        },
    )
    val_max_target_length: Optional[int] = field(
        default=None,
        metadata={
            "help": "The maximum total sequence length for validation target text after tokenization. Sequences longer "
            "than this will be truncated, sequences shorter will be padded. Will default to `max_target_length`."
            "This argument is also used to override the `max_length` param of `model.generate`, which is used "
            "during evaluation."
        },
    )
    max_train_samples: Optional[int] = field(
        default=None,
        metadata={
            "help": "For debugging purposes or quicker training, truncate the number of training examples to this "
            "value if set."
        },
    )
    max_eval_samples: Optional[int] = field(
        default=None,
        metadata={
            "help": "For debugging purposes or quicker training, truncate the number of evaluation examples to this "
            "value if set."
        },
    )
    max_predict_samples: Optional[int] = field(
        default=None,
        metadata={
            "help": "For debugging purposes or quicker training, truncate the number of prediction examples to this "
            "value if set."
        },
    )
    preprocessing_num_workers: Optional[int] = field(
        default=None,
        metadata={"help": "The number of processes to use for the preprocessing."},
    )
    predict_with_generate: bool = field(
        default=False, metadata={"help": "Whether to use generate to calculate generative metrics (ROUGE, BLEU)."}
    )
    num_beams: Optional[int] = field(
        default=None,
        metadata={
            "help": "Number of beams to use for evaluation. This argument will be passed to `model.generate`, "
            "which is used during evaluation."
        },
    )
    overwrite_cache: bool = field(
        default=False, metadata={"help": "Overwrite the cached training and evaluation sets"}
    )

    def __post_init__(self):
        if self.dataset_name is None and self.train_file is None and self.validation_file is None:
            raise ValueError("Need either a dataset name or a training/validation file.")
        else:
            if self.train_file is not None:
                extension = self.train_file.split(".")[-1]
                assert extension in ["csv", "json"], "`train_file` should be a csv or a json file."
            if self.validation_file is not None:
                extension = self.validation_file.split(".")[-1]
                assert extension in ["csv", "json"], "`validation_file` should be a csv or a json file."
        if self.val_max_target_length is None:
            self.val_max_target_length = self.max_target_length


image_captioning_name_mapping = {
    "image_caption_dataset.py": ("image_path", "caption"),
}


class TrainState(train_state.TrainState):
    dropout_rng: jnp.ndarray

    def replicate(self):
        return jax_utils.replicate(self).replace(dropout_rng=shard_prng_key(self.dropout_rng))


def data_loader(rng: jax.random.PRNGKey, dataset: Dataset, batch_size: int, shuffle: bool = False):
    """
    Returns batches of size `batch_size` from truncated `dataset`, sharded over all local devices.
    Shuffle batches if `shuffle` is `True`.
    """
    steps = len(dataset) // batch_size  # Skip incomplete batch.

    if shuffle:
        batch_idx = jax.random.permutation(rng, len(dataset))
        batch_idx = np.asarray(batch_idx)
    else:
        batch_idx = np.arange(len(dataset))

    for idx in range(steps):

        start_idx = batch_size * idx
        end_idx = batch_size * (idx + 1)

        selected_indices = batch_idx[start_idx:end_idx]
        batch = dataset[selected_indices]
        batch = shard(batch)

        yield batch


def write_metric(summary_writer, metrics, train_time, step, metric_key_prefix="train"):

    if train_time:
        summary_writer.scalar("train_time", train_time, step)

        metrics = get_metrics(metrics)
        for key, vals in metrics.items():
            tag = f"{metric_key_prefix}_{key}"
            for i, val in enumerate(vals):
                summary_writer.scalar(tag, val, step - len(vals) + i + 1)

    else:
        for metric_name, value in metrics.items():
            summary_writer.scalar(f"{metric_key_prefix}_{metric_name}", value, step)


def create_learning_rate_fn(
    train_ds_size: int, train_batch_size: int, num_train_epochs: int, num_warmup_steps: int, learning_rate: float
) -> Callable[[int], jnp.array]:
    """Returns a linear warmup, linear_decay learning rate function."""
    steps_per_epoch = train_ds_size // train_batch_size
    num_train_steps = steps_per_epoch * num_train_epochs
    warmup_fn = optax.linear_schedule(init_value=0.0, end_value=learning_rate, transition_steps=num_warmup_steps)
    decay_fn = optax.linear_schedule(
        init_value=learning_rate, end_value=0, transition_steps=num_train_steps - num_warmup_steps
    )
    schedule_fn = optax.join_schedules(schedules=[warmup_fn, decay_fn], boundaries=[num_warmup_steps])
    return schedule_fn


def main():
    # See all possible arguments in src/transformers/training_args.py
    # or by passing the --help flag to this script.
    # We now keep distinct sets of args, for a cleaner separation of concerns.

    parser = HfArgumentParser((ModelArguments, DataTrainingArguments, TrainingArguments))
    if len(sys.argv) == 2 and sys.argv[1].endswith(".json"):
        # If we pass only one argument to the script and it's the path to a json file,
        # let's parse it to get our arguments.
        model_args, data_args, training_args = parser.parse_json_file(json_file=os.path.abspath(sys.argv[1]))
    else:
        model_args, data_args, training_args = parser.parse_args_into_dataclasses()

    if (
        os.path.exists(training_args.output_dir)
        and os.listdir(training_args.output_dir)
        and training_args.do_train
        and not training_args.overwrite_output_dir
    ):
        raise ValueError(
            f"Output directory ({training_args.output_dir}) already exists and is not empty."
            "Use --overwrite_output_dir to overcome."
        )

    # Make one log on every process with the configuration for debugging.
    logging.basicConfig(
        format="%(asctime)s - %(levelname)s - %(name)s - %(message)s",
        datefmt="%m/%d/%Y %H:%M:%S",
        level=logging.INFO,
    )
    # Setup logging, we only want one process per machine to log things on the screen.
    logger.setLevel(logging.INFO if jax.process_index() == 0 else logging.ERROR)
    if jax.process_index() == 0:
        datasets.utils.logging.set_verbosity_warning()
        transformers.utils.logging.set_verbosity_info()
    else:
        datasets.utils.logging.set_verbosity_error()
        transformers.utils.logging.set_verbosity_error()

    # Set the verbosity to info of the Transformers logger (on main process only):
    logger.info(f"Training/evaluation parameters {training_args}")

    # Handle the repository creation
    if training_args.push_to_hub:
        if training_args.hub_model_id is None:
            repo_name = get_full_repo_name(
                Path(training_args.output_dir).absolute().name, token=training_args.hub_token
            )
        else:
            repo_name = training_args.hub_model_id
        repo = Repository(training_args.output_dir, clone_from=repo_name)

    # Get the datasets: you can either provide your own CSV/JSON training and evaluation files (see below)
    # or just provide the name of one of the public datasets available on the hub at https://huggingface.co/datasets/
    # (the dataset will be downloaded automatically from the datasets Hub).
    #
    # For CSV/JSON files this script will use the first column for the full image path and the second column for the
    # captions (unless you specify column names for this with the `image_column` and `caption_column` arguments).
    #
    if data_args.dataset_name is not None:
        # Downloading and loading a dataset from the hub.
        dataset = load_dataset(
            data_args.dataset_name,
            data_args.dataset_config_name,
            cache_dir=model_args.cache_dir,
            keep_in_memory=False,
            data_dir=data_args.data_dir,
        )
    else:
        data_files = {}
        if data_args.train_file is not None:
            data_files["train"] = data_args.train_file
            extension = data_args.train_file.split(".")[-1]
        if data_args.validation_file is not None:
            data_files["validation"] = data_args.validation_file
            extension = data_args.validation_file.split(".")[-1]
        if data_args.test_file is not None:
            data_files["test"] = data_args.test_file
            extension = data_args.test_file.split(".")[-1]
        dataset = load_dataset(extension, data_files=data_files, cache_dir=model_args.cache_dir)
    # See more about loading any type of standard or custom dataset (from files, python dict, pandas DataFrame, etc) at
    # https://huggingface.co/docs/datasets/loading_datasets.html.

    # Load pretrained model and tokenizer

    # Use explicit specified encoder config
    if model_args.encoder_config_name:
        encoder_config = AutoConfig.from_pretrained(
            model_args.encoder_config_name, cache_dir=model_args.cache_dir
        )
    # Use pretrained encoder model's config
    elif model_args.encoder_model_name_or_path:
        encoder_config = AutoConfig.from_pretrained(
            model_args.encoder_model_name_or_path, cache_dir=model_args.cache_dir
        )
    else:
        raise ValueError(
            "Encoder Config: Either a pretrained config or a model location for encoder is required."
        )

    # Use explicit specified decoder config
    if model_args.decoder_config_name:
        decoder_config = AutoConfig.from_pretrained(
            model_args.decoder_config_name, cache_dir=model_args.cache_dir
        )
    # Use pretrained decoder model's config
    elif model_args.decoder_model_name_or_path:
        decoder_config = AutoConfig.from_pretrained(
            model_args.decoder_model_name_or_path, cache_dir=model_args.cache_dir
        )
    else:
        raise ValueError(
            "Decoder Config: Either a pretrained config or a model location for decoder is required."
        )
    # necessary for `from_encoder_decoder_pretrained` when `decoder_config` is passed
    decoder_config.is_decoder = True
    decoder_config.add_cross_attention = True

    model = FlaxVisionEncoderDecoderModel.from_encoder_decoder_pretrained(
        encoder_pretrained_model_name_or_path=model_args.encoder_model_name_or_path,
        decoder_pretrained_model_name_or_path=model_args.decoder_model_name_or_path,
        encoder_config=encoder_config,
        decoder_config=decoder_config,
        encoder_seed=training_args.seed,
        decoder_seed=training_args.seed,
        encoder_dtype=getattr(jnp, model_args.dtype),
        decoder_dtype=getattr(jnp, model_args.dtype),
    )

    # GPT2 only has bos/eos tokens but not decoder_start/pad tokens
    decoder_start_token_id = decoder_config.decoder_start_token_id
    pad_token_id = decoder_config.pad_token_id
    if decoder_start_token_id is None:
        decoder_start_token_id = decoder_config.bos_token_id
    if pad_token_id is None:
        pad_token_id = decoder_config.eos_token_id

    # This is necessary to make Flax's generate() work
    model.config.eos_token_id = decoder_config.eos_token_id
    model.config.decoder_start_token_id = decoder_start_token_id
    model.config.pad_token_id = pad_token_id

    if model_args.feature_extractor_name:
        feature_extractor = AutoFeatureExtractor.from_pretrained(
            model_args.feature_extractor_name,
            cache_dir=model_args.cache_dir,
        )
    elif model_args.encoder_model_name_or_path:
        feature_extractor = AutoFeatureExtractor.from_pretrained(
            model_args.encoder_model_name_or_path, cache_dir=model_args.cache_dir
        )
    else:
        raise ValueError(
            "You are instantiating a new feature extractor from scratch. This is not supported by this script."
            "You can do it from another script, save it, and load it from here, using --feature_extractor_name."
        )

    if model_args.tokenizer_name:
        tokenizer = AutoTokenizer.from_pretrained(
            model_args.tokenizer_name, cache_dir=model_args.cache_dir, use_fast=model_args.use_fast_tokenizer
        )
    elif model_args.decoder_model_name_or_path:
        tokenizer = AutoTokenizer.from_pretrained(
            model_args.decoder_model_name_or_path, cache_dir=model_args.cache_dir, use_fast=model_args.use_fast_tokenizer
        )
    else:
        raise ValueError(
            "You are instantiating a new tokenizer from scratch. This is not supported by this script."
            "You can do it from another script, save it, and load it from here, using --tokenizer_name."
        )
    tokenizer.pad_token = tokenizer.convert_ids_to_tokens(model.config.pad_token_id)

    # Preprocessing the datasets.
    # We need to tokenize inputs and targets.
    if training_args.do_train:
        column_names = dataset["train"].column_names
    elif training_args.do_eval:
        column_names = dataset["validation"].column_names
    elif training_args.do_predict:
        column_names = dataset["test"].column_names
    else:
        logger.info("There is nothing to do. Please pass `do_train`, `do_eval` and/or `do_predict`.")
        return

    # Get the column names for input/target.
    dataset_columns = image_captioning_name_mapping.get(data_args.dataset_name, None)
    if data_args.image_column is None:
        assert dataset_columns is not None
        image_column = dataset_columns[0]
    else:
        image_column = data_args.image_column
        if image_column not in column_names:
            raise ValueError(
                f"--image_column' value '{data_args.image_column}' needs to be one of: {', '.join(column_names)}"
            )
    if data_args.caption_column is None:
        assert dataset_columns is not None
        caption_column = dataset_columns[1]
    else:
        caption_column = data_args.caption_column
        if caption_column not in column_names:
            raise ValueError(
                f"--caption_column' value '{data_args.caption_column}' needs to be one of: {', '.join(column_names)}"
            )

    # In Flax, for seq2seq models we need to pass `decoder_input_ids`
    # as the Flax models don't accept `labels`, we need to prepare the decoder_input_ids here
    # for that dynamically import the `shift_tokens_right` function from the model file
    model_module = __import__(model.__module__, fromlist=["shift_tokens_right"])
    shift_tokens_right_fn = getattr(model_module, "shift_tokens_right", shift_tokens_right)

    def filter_fn(examples):
        """remove problematic images"""

        bools = []
        for image_file in examples[image_column]:
            try:
                image = Image.open(image_file)
                feature_extractor(images=image, return_tensors="np")
                bools.append(True)
            except Exception:
                bools.append(False)

        return bools

    # Setting padding="max_length" as we need fixed length inputs for jitted functions
    def tokenization_fn(examples, max_target_length):
        """Run tokenization on captions."""

        captions = []
        for caption in examples[caption_column]:
            captions.append(caption.lower() + " " + tokenizer.eos_token)

        targets = captions

        model_inputs = {}

        # Setup the tokenizer for targets
        with tokenizer.as_target_tokenizer():
            labels = tokenizer(
                targets, max_length=max_target_length, padding="max_length", truncation=True, return_tensors="np"
            )

        model_inputs["labels"] = labels["input_ids"]
        decoder_input_ids = shift_tokens_right_fn(
            labels["input_ids"], model.config.pad_token_id, model.config.decoder_start_token_id
        )
        model_inputs["decoder_input_ids"] = np.asarray(decoder_input_ids)

        # We need decoder_attention_mask so we can ignore pad tokens from loss
        model_inputs["decoder_attention_mask"] = labels["attention_mask"]

        model_inputs[image_column] = examples[image_column]

        return model_inputs

    def feature_extraction_fn(examples, check_image=True):
        """
        Run feature extraction on images

        If `check_image` is `True`, the examples that fails during `Image.open()` will be caught and discarded.
        Otherwise, an exception will be thrown.
        """

        model_inputs = {}

        if check_image:
            images = []
            to_keep = []
            for image_file in examples[image_column]:
                try:
                    img = Image.open(image_file)
                    images.append(img)
                    to_keep.append(True)
                except Exception:
                    to_keep.append(False)

            for k, v in examples.items():
                if k != image_column:
                    model_inputs[k] = v[to_keep]
        else:
            images = [Image.open(image_file) for image_file in examples[image_column]]

        encoder_inputs = feature_extractor(images=images, return_tensors="np")
        model_inputs["pixel_values"] = encoder_inputs.pixel_values

        return model_inputs

    def preprocess_fn(examples, max_target_length, check_image=True):
        """Run tokenization + image feature extraction"""

        model_inputs = {}
        # This contains image path column
        model_inputs.update(tokenization_fn(examples, max_target_length))
        model_inputs.update(feature_extraction_fn(model_inputs, check_image=check_image))
        # Remove image path column
        model_inputs.pop(image_column)

        return model_inputs

    features = datasets.Features(
        {
            "pixel_values": datasets.Array3D(
                shape=(
                    getattr(model.config.encoder, "num_channels", 3),
                    model.config.encoder.image_size,
                    model.config.encoder.image_size,
                ),
                dtype="float32",
            ),
            "labels": datasets.Sequence(feature=datasets.Value(dtype="int32", id=None), length=-1, id=None),
            "decoder_input_ids": datasets.Sequence(feature=datasets.Value(dtype="int32", id=None), length=-1, id=None),
            "decoder_attention_mask": datasets.Sequence(
                feature=datasets.Value(dtype="int32", id=None), length=-1, id=None
            ),
        }
    )

    # If `block_size` is `0`, tokenization & image feature extraction is done at the beginning
    run_feat_ext_at_beginning = training_args.block_size == 0
    # Used in .map() below
    function_kwarg = preprocess_fn if run_feat_ext_at_beginning else tokenization_fn
    # `features` is used only for the final preprocessed dataset (for the performance purpose).
    features_kwarg = features if run_feat_ext_at_beginning else None
    # Keep `image_column` if the feature extraction is done during training
    remove_columns_kwarg = [x for x in column_names if x != image_column or run_feat_ext_at_beginning]
    processor_names = "tokenizer and feature extractor" if run_feat_ext_at_beginning else "tokenizer"

    if training_args.do_train:
        if "train" not in dataset:
            raise ValueError("--do_train requires a train dataset")
        train_dataset = dataset["train"]
        if data_args.max_train_samples is not None:
            train_dataset = train_dataset.select(range(data_args.max_train_samples))
        # remove problematic examples
        # (if feature extraction is performed at the beginning, the filtering is done during preprocessing below
        # instead here.)
        if not run_feat_ext_at_beginning:
            train_dataset = train_dataset.filter(filter_fn, batched=True, num_proc=data_args.preprocessing_num_workers)
        train_dataset = train_dataset.map(
            function=function_kwarg,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            # kept image paths
            remove_columns=remove_columns_kwarg,
            load_from_cache_file=not data_args.overwrite_cache,
            desc=f"Running {processor_names} on train dataset",
            fn_kwargs={"max_target_length": data_args.max_target_length},
            features=features_kwarg,
        )
        if run_feat_ext_at_beginning:
            # set format (for performance) since the dataset is ready to be used
            train_dataset = train_dataset.with_format("numpy")

    if training_args.do_eval:
        if "validation" not in dataset:
            raise ValueError("--do_eval requires a validation dataset")
        eval_dataset = dataset["validation"]
        if data_args.max_eval_samples is not None:
            eval_dataset = eval_dataset.select(range(data_args.max_eval_samples))
        # remove problematic examples
        # (if feature extraction is performed at the beginning, the filtering is done during preprocessing below
        # instead here.)
        if not run_feat_ext_at_beginning:
            eval_dataset = eval_dataset.filter(filter_fn, batched=True, num_proc=data_args.preprocessing_num_workers)
        eval_dataset = eval_dataset.map(
            function=function_kwarg,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            # kept image paths
            remove_columns=remove_columns_kwarg,
            load_from_cache_file=not data_args.overwrite_cache,
            desc=f"Running {processor_names} on validation dataset",
            fn_kwargs={"max_target_length": data_args.val_max_target_length},
            features=features_kwarg,
        )
        if run_feat_ext_at_beginning:
            # set format (for performance) since the dataset is ready to be used
            eval_dataset = eval_dataset.with_format("numpy")

    if training_args.do_predict:
        if "test" not in dataset:
            raise ValueError("--do_predict requires a test dataset")
        predict_dataset = dataset["test"]
        if data_args.max_predict_samples is not None:
            predict_dataset = predict_dataset.select(range(data_args.max_predict_samples))
        # remove problematic examples
        # (if feature extraction is performed at the beginning, the filtering is done during preprocessing below
        # instead here.)
        if not run_feat_ext_at_beginning:
            predict_dataset = predict_dataset.filter(
                filter_fn, batched=True, num_proc=data_args.preprocessing_num_workers
            )
        predict_dataset = predict_dataset.map(
            function=function_kwarg,
            batched=True,
            num_proc=data_args.preprocessing_num_workers,
            # kept image paths
            remove_columns=remove_columns_kwarg,
            load_from_cache_file=not data_args.overwrite_cache,
            desc=f"Running {processor_names} on prediction dataset",
            fn_kwargs={"max_target_length": data_args.val_max_target_length},
            features=features_kwarg,
        )
        if run_feat_ext_at_beginning:
            # set format (for performance) since the dataset is ready to be used
            predict_dataset = predict_dataset.with_format("numpy")

    # Store some constant

    train_batch_size = int(training_args.per_device_train_batch_size) * jax.device_count()

    if training_args.block_size % train_batch_size > 0:
        raise ValueError(
            f"`training_args.block_size` needs to be a multiple of the global batch size. Got {training_args.block_size} and {train_batch_size} instead."
        )

    if training_args.do_train:
        steps_per_epoch = len(train_dataset) // train_batch_size
        num_train_examples_per_epoch = steps_per_epoch * train_batch_size
        num_epochs = int(training_args.num_train_epochs)
        total_train_steps = steps_per_epoch * num_epochs
    else:
        num_train_examples_per_epoch = 0

    eval_batch_size = int(training_args.per_device_eval_batch_size) * jax.device_count()

    if training_args.do_eval:
        num_eval_examples = len(eval_dataset)
        eval_steps = num_eval_examples // eval_batch_size

    if training_args.do_predict:
        num_test_examples = len(predict_dataset)
        test_steps = num_test_examples // eval_batch_size

    def blockwise_data_loader(
        rng: jax.random.PRNGKey,
        ds: Dataset,
        block_size: int,
        batch_size: int,
        shuffle: bool = False,
        keep_in_memory: bool = False,
        split: str = "",
    ):
        """
        Wrap the simple `data_loader` in a block-wise way if `block_size` > 0, else it's the same as `data_loader`.

        If `block_size` > 0, it requires `ds` to have a column that gives image paths in order to perform image feature
        extraction (with the column name being specified by `image_column`). The tokenization should be done before
        training in this case.
        """

        if shuffle:
            indices = jax.random.permutation(rng, len(ds))
            indices = np.asarray(indices)
        else:
            indices = np.arange(len(ds))

        _block_size = len(ds) if not block_size else block_size

        steps_per_block = _block_size // batch_size
        num_examples = len(ds)
        steps = num_examples // batch_size
        num_splits = steps // steps_per_block + int(steps % steps_per_block > 0)

        for idx in range(num_splits):

            if not block_size:
                _ds = ds
            else:

                start_idx = block_size * idx
                end_idx = block_size * (idx + 1)

                selected_indices = indices[start_idx:end_idx]

                _ds = ds.select(selected_indices)

                _ds = _ds.map(
                    feature_extraction_fn,
                    batched=True,
                    num_proc=data_args.preprocessing_num_workers,
                    remove_columns=[image_column],
                    load_from_cache_file=not data_args.overwrite_cache,
                    features=features,
                    keep_in_memory=keep_in_memory,
                    # The images are already checked either in `.filter()` or in `preprocess_fn()`
                    fn_kwargs={"check_image": False},
                    desc=f"Running feature extraction on {split} dataset".replace("  ", " "),
                )
                _ds = _ds.with_format("numpy")

            # No need to shuffle here
            loader = data_loader(rng, _ds, batch_size=batch_size, shuffle=False)

            for batch in loader:
                yield batch

    # Metric
    metric = load_metric("rouge")

    def postprocess_text(preds, labels):
        preds = [pred.strip() for pred in preds]
        labels = [label.strip() for label in labels]

        # rougeLSum expects newline after each sentence
        preds = ["\n".join(nltk.sent_tokenize(pred)) for pred in preds]
        labels = ["\n".join(nltk.sent_tokenize(label)) for label in labels]

        return preds, labels

    def compute_metrics(preds, labels):
        decoded_preds = tokenizer.batch_decode(preds, skip_special_tokens=True)
        decoded_labels = tokenizer.batch_decode(labels, skip_special_tokens=True)

        # Some simple post-processing
        decoded_preds, decoded_labels = postprocess_text(decoded_preds, decoded_labels)

        result = metric.compute(predictions=decoded_preds, references=decoded_labels, use_stemmer=True)
        # Extract a few results from ROUGE
        result = {key: value.mid.fmeasure * 100 for key, value in result.items()}

        prediction_lens = [np.count_nonzero(pred != tokenizer.pad_token_id) for pred in preds]
        result["gen_len"] = np.mean(prediction_lens)
        result = {k: round(v, 6) for k, v in result.items()}

        return result, decoded_preds, decoded_labels

    # Enable tensorboard only on the master node
    has_tensorboard = is_tensorboard_available()
    if has_tensorboard and jax.process_index() == 0:
        try:
            from flax.metrics.tensorboard import SummaryWriter

            summary_writer = SummaryWriter(log_dir=Path(training_args.output_dir))
        except ImportError as ie:
            has_tensorboard = False
            logger.warning(
                f"Unable to display metrics through TensorBoard because some package are not installed: {ie}"
            )
    else:
        logger.warning(
            "Unable to display metrics through TensorBoard because the package is not installed: "
            "Please run pip install tensorboard to enable."
        )

    # Initialize our training
    rng = jax.random.PRNGKey(training_args.seed)
    rng, dropout_rng = jax.random.split(rng)

    # Create learning rate schedule
    linear_decay_lr_schedule_fn = create_learning_rate_fn(
        num_train_examples_per_epoch,
        train_batch_size,
        training_args.num_train_epochs,
        training_args.warmup_steps,
        training_args.learning_rate,
    )

    # We use Optax's "masking" functionality to not apply weight decay
    # to bias and LayerNorm scale parameters. decay_mask_fn returns a
    # mask boolean with the same structure as the parameters.
    # The mask is True for parameters that should be decayed.
    # Note that this mask is specifically adapted for FlaxBart.
    # For FlaxT5, one should correct the layer norm parameter naming
    # accordingly - see `run_t5_mlm_flax.py` e.g.
    def decay_mask_fn(params):
        flat_params = traverse_util.flatten_dict(params)
        layer_norm_params = [
            (name, "scale") for name in ["self_attn_layer_norm", "layernorm_embedding", "final_layer_norm"]
        ]
        flat_mask = {path: (path[-1] != "bias" and path[-2:] not in layer_norm_params) for path in flat_params}
        return traverse_util.unflatten_dict(flat_mask)

    # create adam optimizer
    adamw = optax.adamw(
        learning_rate=linear_decay_lr_schedule_fn,
        b1=training_args.adam_beta1,
        b2=training_args.adam_beta2,
        eps=training_args.adam_epsilon,
        weight_decay=training_args.weight_decay,
        mask=decay_mask_fn,
    )

    # Setup train state
    state = TrainState.create(apply_fn=model.__call__, params=model.params, tx=adamw, dropout_rng=dropout_rng)

    # label smoothed cross entropy
    def loss_fn(logits, labels, padding_mask, label_smoothing_factor=0.0):
        """
        The label smoothing implementation is adapted from Flax's official example:
        https://github.com/google/flax/blob/87a211135c6a377c8f29048a1cac3840e38b9da4/examples/wmt/train.py#L104
        """
        vocab_size = logits.shape[-1]
        confidence = 1.0 - label_smoothing_factor
        low_confidence = (1.0 - confidence) / (vocab_size - 1)
        normalizing_constant = -(
            confidence * jnp.log(confidence) + (vocab_size - 1) * low_confidence * jnp.log(low_confidence + 1e-20)
        )
        soft_labels = onehot(labels, vocab_size, on_value=confidence, off_value=low_confidence)

        loss = optax.softmax_cross_entropy(logits, soft_labels)
        loss = loss - normalizing_constant

        # ignore padded tokens from loss
        loss = loss * padding_mask
        loss = loss.sum() / padding_mask.sum()
        return loss

    # Define gradient update step fn
    def train_step(state, batch, label_smoothing_factor=0.0):
        dropout_rng, new_dropout_rng = jax.random.split(state.dropout_rng)

        def compute_loss(params):
            labels = batch.pop("labels")
            logits = state.apply_fn(**batch, params=params, dropout_rng=dropout_rng, train=True)[0]
            loss = loss_fn(logits, labels, batch["decoder_attention_mask"], label_smoothing_factor)
            return loss

        grad_fn = jax.value_and_grad(compute_loss)
        loss, grad = grad_fn(state.params)
        grad = jax.lax.pmean(grad, "batch")

        new_state = state.apply_gradients(grads=grad, dropout_rng=new_dropout_rng)

        metrics = {"loss": loss, "learning_rate": linear_decay_lr_schedule_fn(state.step)}
        metrics = jax.lax.pmean(metrics, axis_name="batch")

        return new_state, metrics

    # Define eval fn
    def eval_step(params, batch, label_smoothing_factor=0.0):
        labels = batch.pop("labels")
        logits = model(**batch, params=params, train=False)[0]
        loss = loss_fn(logits, labels, batch["decoder_attention_mask"], label_smoothing_factor)

        # summarize metrics
        metrics = {"loss": loss}
        metrics = jax.lax.pmean(metrics, axis_name="batch")
        return metrics

    # Define generation function
    max_length = (
        data_args.val_max_target_length if data_args.val_max_target_length is not None else model.config.max_length
    )
    num_beams = data_args.num_beams if data_args.num_beams is not None else model.config.num_beams
    gen_kwargs = {"max_length": max_length, "num_beams": num_beams}

    def generate_step(params, batch):
        model.params = params
        output_ids = model.generate(batch["pixel_values"], **gen_kwargs)
        return output_ids.sequences

    # Create parallel version of the train and eval step
    p_train_step = jax.pmap(
        partial(train_step, label_smoothing_factor=training_args.label_smoothing_factor), "batch", donate_argnums=(0,)
    )
    p_eval_step = jax.pmap(partial(eval_step, label_smoothing_factor=training_args.label_smoothing_factor), "batch")
    p_generate_step = jax.pmap(generate_step, "batch")

    # Replicate the train state on each device
    state = state.replicate()

    if training_args.do_train:
        logger.info("***** Running training *****")
        logger.info(f"  Num train examples = {num_train_examples_per_epoch}")
        logger.info(f"  Num Epochs = {num_epochs}")
        logger.info(f"  Instantaneous train batch size per device = {training_args.per_device_train_batch_size}")
        logger.info(f"  Total train batch size (w. parallel & distributed) = {train_batch_size}")
        logger.info(f"  Optimization steps per epoch = {steps_per_epoch}")
        logger.info(f"  Total optimization steps = {total_train_steps}")
    if training_args.do_eval:
        logger.info(f"  Num evaluation examples = {num_eval_examples}")
        logger.info(f"  Instantaneous evaluation batch size per device = {training_args.per_device_eval_batch_size}")
        logger.info(f"  Total evaluation batch size (w. parallel & distributed) = {eval_batch_size}")
        logger.info(f"  Evaluation steps = {eval_steps}")
    if training_args.do_predict:
        logger.info(f"  Num test examples = {num_test_examples}")
        logger.info(f"  Instantaneous test batch size per device = {training_args.per_device_eval_batch_size}")
        logger.info(f"  Total test batch size (w. parallel & distributed) = {eval_batch_size}")
        logger.info(f"  Test steps = {test_steps}")

    # create output directory
    if not os.path.isdir(os.path.join(training_args.output_dir)):
        os.makedirs(os.path.join(training_args.output_dir), exist_ok=True)

    def save_ckpt(ckpt_dir: str, commit_msg: str = ""):
        """save checkpoints and push to Hugging Face Hub if specified"""

        # save checkpoint after each epoch and push checkpoint to the hub
        if jax.process_index() == 0:
            params = jax.device_get(jax.tree_map(lambda x: x[0], state.params))
            model.save_pretrained(os.path.join(training_args.output_dir, ckpt_dir), params=params)
            tokenizer.save_pretrained(os.path.join(training_args.output_dir, ckpt_dir))
            if training_args.push_to_hub:
                repo.push_to_hub(commit_message=commit_msg, blocking=False)

    def evaluation_loop(
        rng: jax.random.PRNGKey,
        dataset: Dataset,
        metric_key_prefix: str = "eval",
        ckpt_dir: str = "",
        is_prediction=False,
    ):

        logger.info(f"*** {'Predict' if is_prediction else 'Evaluate'} ***")

        metrics = []
        preds = []
        labels = []

        batches = blockwise_data_loader(
            rng,
            dataset,
            block_size=training_args.block_size,
            batch_size=eval_batch_size,
            keep_in_memory=False,
            shuffle=False,
            split="prediction" if is_prediction else "validation",
        )
        steps = len(dataset) // eval_batch_size
        for _ in tqdm(
            range(steps), desc=f"{'Predicting' if is_prediction else 'Evaluating'}...", position=2, leave=False
        ):
            # Model forward
            batch = next(batches)
            _labels = batch.get("labels", None)
            if not is_prediction and _labels is None:
                raise ValueError("Evaluation requires the validation dataset to have `labels`")

            if _labels is not None:
                _metrics = p_eval_step(state.params, batch)
                metrics.append(_metrics)

            # generation
            if data_args.predict_with_generate:
                generated_ids = p_generate_step(state.params, batch)
                preds.extend(jax.device_get(generated_ids.reshape(-1, gen_kwargs["max_length"])))
                if _labels is not None:
                    labels.extend(jax.device_get(_labels.reshape(-1, _labels.shape[-1])))

        if metrics:
            # normalize metrics
            metrics = get_metrics(metrics)
            metrics = jax.tree_map(jnp.mean, metrics)

        # compute ROUGE metrics
        generations = []
        rouge_desc = ""
        if data_args.predict_with_generate:
            if labels:
                rouge_metrics, decoded_preds, decoded_labels = compute_metrics(preds, labels)
                metrics.update(rouge_metrics)
                rouge_desc = " ".join(
                    [
                        f"{'Predict' if is_prediction else 'Eval'} {key}: {value} |"
                        for key, value in rouge_metrics.items()
                    ]
                )
                for pred, label in zip(decoded_preds, decoded_labels):
                    pred = pred.replace("\n", " ")
                    label = label.replace("\n", " ")
                    generations.append({"label": label, "pred": pred})
            else:
                decoded_preds = tokenizer.batch_decode(preds, skip_special_tokens=True)
                # Some simple post-processing
                decoded_preds = [pred.strip() for pred in decoded_preds]
                # rougeLSum expects newline after each sentence
                decoded_preds = ["\n".join(nltk.sent_tokenize(pred)) for pred in decoded_preds]
                for pred in decoded_preds:
                    pred = pred.replace("\n", " ")
                    generations.append({"pred": pred})

        if metrics:
            # Print metrics and update progress bar
            desc = f"{'Predict' if is_prediction else 'Eval'} Loss: {metrics['loss']} | {rouge_desc})"
            if training_args.do_train and not is_prediction:
                desc = f"Epoch... ({epoch + 1}/{num_epochs} | Step: {cur_step} | " + desc
                epochs.write(desc)
                epochs.desc = desc
            logger.info(desc)

        if jax.process_index() == 0:

            if not os.path.isdir(os.path.join(training_args.output_dir, ckpt_dir)):
                os.makedirs(os.path.join(training_args.output_dir, ckpt_dir), exist_ok=True)

            if metrics:

                # Save metrics (only for the evaluation/prediction being done along with training)
                if has_tensorboard and training_args.do_train:
                    write_metric(
                        summary_writer, metrics, train_time=None, step=cur_step, metric_key_prefix=metric_key_prefix
                    )

                # save final metrics in json
                metrics = {
                    f"{metric_key_prefix}_{metric_name}": round(value.item(), 6)
                    for metric_name, value in metrics.items()
                }
                _path = os.path.join(training_args.output_dir, ckpt_dir, f"{metric_key_prefix}_results.json")
                with open(_path, "w") as f:
                    json.dump(metrics, f, indent=4, sort_keys=True)

                # Update report
                with open(os.path.join(training_args.output_dir, "log"), "a", encoding="UTF-8") as fp:
                    fp.write(desc + "\n")

            # Save generations
            if generations:
                with open(
                    os.path.join(training_args.output_dir, ckpt_dir, f"{metric_key_prefix}_generation.json"),
                    "w",
                    encoding="UTF-8",
                ) as fp:
                    json.dump(generations, fp, ensure_ascii=False, indent=4)

    def evaluate(rng: jax.random.PRNGKey, dataset: Dataset, ckpt_dir: str = ""):
        evaluation_loop(rng, dataset, metric_key_prefix="eval", ckpt_dir=ckpt_dir)

    def predict(rng: jax.random.PRNGKey, dataset: Dataset):
        evaluation_loop(rng, dataset, metric_key_prefix="test", is_prediction=True)

    input_rng = None

    if training_args.do_train:

        cur_step = 0
        train_time = 0
        epochs = tqdm(range(num_epochs), desc=f"Epoch ... (1/{num_epochs})", position=0)

        for epoch in epochs:

            # ======================== Training ================================

            # Create sampling rng
            rng, input_rng = jax.random.split(rng)

            train_metrics = []

            train_batches = blockwise_data_loader(
                input_rng,
                train_dataset,
                block_size=training_args.block_size,
                batch_size=train_batch_size,
                keep_in_memory=True,
                shuffle=True,
                split="train",
            )

            # train
            for (batch_idx, _) in enumerate(tqdm(range(steps_per_epoch), desc="Training...", position=1, leave=False)):

                cur_step += 1
                batch = next(train_batches)
                batch_start = time.time()
                state, train_metric = p_train_step(state, batch)
                train_metrics.append(train_metric)
                train_time += time.time() - batch_start
                time_per_step = train_time / cur_step

                # log and save info
                if training_args.logging_steps > 0 and cur_step % training_args.logging_steps == 0:

                    _train_metric = unreplicate(train_metric)
                    desc = f"Epoch... ({epoch + 1}/{num_epochs} | Step: {cur_step} | Loss: {_train_metric['loss']} | Learning Rate: {_train_metric['learning_rate']} | Time per step: {time_per_step})"
                    epochs.desc = desc
                    epochs.write(desc)

                    logger.info(desc)

                    with open(os.path.join(training_args.output_dir, "log"), "a", encoding="UTF-8") as fp:
                        fp.write(desc + "\n")

                    # Save metrics
                    if has_tensorboard and jax.process_index() == 0:
                        write_metric(
                            summary_writer,
                            train_metrics,
                            train_time=train_time,
                            step=cur_step,
                            metric_key_prefix="train",
                        )

                # ======================== Evaluating (inside an epoch) ==============================

                if (
                    training_args.do_eval
                    and (training_args.eval_steps is not None and training_args.eval_steps > 0)
                    and cur_step % training_args.eval_steps == 0
                ):
                    ckpt_dir = f"ckpt_epoch_{epoch + 1}_step_{cur_step}"
                    commit_msg = f"Saving weights and logs of epoch {epoch + 1} - step {cur_step}"
                    evaluate(input_rng, eval_dataset, ckpt_dir)
                    save_ckpt(ckpt_dir=ckpt_dir, commit_msg=commit_msg)

            # ======================== Epoch End ==============================

            # log and save info
            if training_args.logging_steps <= 0:

                logger.info(desc)

                with open(os.path.join(training_args.output_dir, "log"), "a", encoding="UTF-8") as fp:
                    fp.write(desc + "\n")

                # Save metrics
                if has_tensorboard and jax.process_index() == 0:
                    write_metric(
                        summary_writer, train_metrics, train_time=train_time, step=cur_step, metric_key_prefix="train"
                    )

            # ======================== Evaluating (after each epoch) ==============================

            if training_args.do_eval and (training_args.eval_steps is None or training_args.eval_steps <= 0):
                ckpt_dir = f"ckpt_epoch_{epoch + 1}_step_{cur_step}"
                commit_msg = f"Saving weights and logs of epoch {epoch + 1} - step {cur_step}"
                evaluate(input_rng, eval_dataset, ckpt_dir)
                save_ckpt(ckpt_dir=ckpt_dir, commit_msg=commit_msg)

    # ======================== Evaluating | Predicting ==============================

    # Create sampling rng
    if input_rng is None:
        rng, input_rng = jax.random.split(rng)

    # run evaluation without training
    if training_args.do_eval and not training_args.do_train:
        evaluate(input_rng, eval_dataset)

    # run prediction after (or without) training
    if training_args.do_predict:
        predict(input_rng, predict_dataset)


if __name__ == "__main__":

    main()