Adding parallel execution using subprocesses

wani.py

@@ -7,6 +7,9 @@ import logging
 import argparse
 import pickle
 import time
+import subprocess
+import concurrent.futures
+import tempfile
 
 from msd_translate import MSD_TRANSLATE
 
@@ -968,9 +971,44 @@ def main(input_file, structures_file, args):
     colocation_ids = ColocationIds()
     matches = {s.id: [] for s in structures}
 
-    for words in load_files(args):
-        new_matches = match_file(words, structures)
-        matches = colocation_ids.merge_matches(matches, new_matches)
+    if args.parallel:
+        num_parallel = int(args.parallel)
+
+        # make temporary directory to hold temporary files
+        with tempfile.TemporaryDirectory() as tmpdirname:
+            cmd = sys.argv 
+            for inpt in args.input:
+                if inpt in cmd:
+                    cmd.remove(inpt)
+
+            # remove "--parallel X"
+            pidx = cmd.index('--parallel')
+            del cmd[pidx]
+            del cmd[pidx]
+
+            def func(n): 
+                cmdn = [sys.executable] + cmd + [args.input[n], "--match-to-file", "{}/{}.p".format(tmpdirname, n)]
+                subprocess.check_call(cmdn)
+                return n
+
+            # use ThreadPoolExecuter to run subprocesses in parallel using py threads
+            with concurrent.futures.ThreadPoolExecutor(max_workers=num_parallel) as executor:
+                # fancy interface to wait for threads to finish
+                for id_input in executor.map(func, [i for i, _ in enumerate(args.input)]):
+                    with open("{}/{}.p".format(tmpdirname, id_input), "rb") as fp:
+                        new_matches = pickle.load(fp)
+                    matches = colocation_ids.merge_matches(matches, new_matches)
+
+    else:
+        for words in load_files(args):
+            new_matches = match_file(words, structures)
+            # just save to temporary file, used for children of a parallel process
+            if args.match_to_file is not None:
+                with open(args.match_to_file, "wb") as fp:
+                    pickle.dump(new_matches, fp)
+                    return
+            else:
+                matches = colocation_ids.merge_matches(matches, new_matches)
 
     writer.write_out(matches, structures, colocation_ids)
 
@@ -993,6 +1031,8 @@ if __name__ == '__main__':
     parser.add_argument('--multiple-output', help='Generate one output for each syntactic structure', action='store_true')
 
     parser.add_argument('--pc-tag', help='Tag for separators, usually pc or c', default="pc")
+    parser.add_argument('--parallel', help='Run in multiple processes, should speed things up')
+    parser.add_argument('--match-to-file', help='Do not use!')
 
     args = parser.parse_args()
     logging.basicConfig(stream=sys.stderr, level=args.verbose.upper())