Merge pull request #733 from ceremonious/parallel-generation

Added option to use multiple workers to create training data

examples/lm_finetuning/pregenerate_training_data.py

@@ -3,6 +3,7 @@ from pathlib import Path
 from tqdm import tqdm, trange
 from tempfile import TemporaryDirectory
 import shelve
+from multiprocessing import Pool
 
 from random import random, randrange, randint, shuffle, choice
 from pytorch_pretrained_bert.tokenization import BertTokenizer
@@ -264,6 +265,28 @@ def create_instances_from_document(
     return instances
 
 
+def create_training_file(docs, vocab_list, args, epoch_num):
+    epoch_filename = args.output_dir / "epoch_{}.json".format(epoch_num)
+    num_instances = 0
+    with epoch_filename.open('w') as epoch_file:
+        for doc_idx in trange(len(docs), desc="Document"):
+            doc_instances = create_instances_from_document(
+                docs, doc_idx, max_seq_length=args.max_seq_len, short_seq_prob=args.short_seq_prob,
+                masked_lm_prob=args.masked_lm_prob, max_predictions_per_seq=args.max_predictions_per_seq,
+                whole_word_mask=args.do_whole_word_mask, vocab_list=vocab_list)
+            doc_instances = [json.dumps(instance) for instance in doc_instances]
+            for instance in doc_instances:
+                epoch_file.write(instance + '\n')
+                num_instances += 1
+    metrics_file = args.output_dir / "epoch_{}_metrics.json".format(epoch_num)
+    with metrics_file.open('w') as metrics_file:
+        metrics = {
+            "num_training_examples": num_instances,
+            "max_seq_len": args.max_seq_len
+        }
+        metrics_file.write(json.dumps(metrics))
+
+
 def main():
     parser = ArgumentParser()
     parser.add_argument('--train_corpus', type=Path, required=True)
@@ -277,6 +300,8 @@ def main():
     parser.add_argument("--reduce_memory", action="store_true",
                         help="Reduce memory usage for large datasets by keeping data on disc rather than in memory")
 
+    parser.add_argument("--num_workers", type=int, default=1,
+                        help="The number of workers to use to write the files")
     parser.add_argument("--epochs_to_generate", type=int, default=3,
                         help="Number of epochs of data to pregenerate")
     parser.add_argument("--max_seq_len", type=int, default=128)
@@ -289,6 +314,9 @@ def main():
 
     args = parser.parse_args()
 
+    if args.num_workers > 1 and args.reduce_memory:
+        raise ValueError("Cannot use multiple workers while reducing memory")
+
     tokenizer = BertTokenizer.from_pretrained(args.bert_model, do_lower_case=args.do_lower_case)
     vocab_list = list(tokenizer.vocab.keys())
     with DocumentDatabase(reduce_memory=args.reduce_memory) as docs:
@@ -312,26 +340,14 @@ def main():
                  "sections or paragraphs.")
 
         args.output_dir.mkdir(exist_ok=True)
+
+        if args.num_workers > 1:
+            writer_workers = Pool(min(args.num_workers, args.epochs_to_generate))
+            arguments = [(docs, vocab_list, args, idx) for idx in range(args.epochs_to_generate)]
+            writer_workers.starmap(create_training_file, arguments)
+        else:
             for epoch in trange(args.epochs_to_generate, desc="Epoch"):
-            epoch_filename = args.output_dir / f"epoch_{epoch}.json"
-            num_instances = 0
-            with epoch_filename.open('w') as epoch_file:
-                for doc_idx in trange(len(docs), desc="Document"):
-                    doc_instances = create_instances_from_document(
-                        docs, doc_idx, max_seq_length=args.max_seq_len, short_seq_prob=args.short_seq_prob,
-                        masked_lm_prob=args.masked_lm_prob, max_predictions_per_seq=args.max_predictions_per_seq,
-                        whole_word_mask=args.do_whole_word_mask, vocab_list=vocab_list)
-                    doc_instances = [json.dumps(instance) for instance in doc_instances]
-                    for instance in doc_instances:
-                        epoch_file.write(instance + '\n')
-                        num_instances += 1
-            metrics_file = args.output_dir / f"epoch_{epoch}_metrics.json"
-            with metrics_file.open('w') as metrics_file:
-                metrics = {
-                    "num_training_examples": num_instances,
-                    "max_seq_len": args.max_seq_len
-                }
-                metrics_file.write(json.dumps(metrics))
+                create_training_file(docs, vocab_list, args, epoch)
 
 
 if __name__ == '__main__':