Multi-processing grammar extraction

+ various surface fixes

1 files changed, 34 insertions, 11 deletions

diff --git a/python/pkg/cdec/sa/extract.py b/python/pkg/cdec/sa/extract.py
index 875bf42e..39eac824 100644
--- a/python/pkg/cdec/sa/extract.py
+++ b/python/pkg/cdec/sa/extract.py
@@ -3,29 +3,52 @@ import sys
 import os
 import argparse
 import logging
+import multiprocessing as mp
+import signal
 import cdec.sa
 
+extractor, prefix = None, None
+def make_extractor(config, grammars):
+    global extractor, prefix
+    signal.signal(signal.SIGINT, signal.SIG_IGN) # Let parent process catch Ctrl+C
+    extractor = cdec.sa.GrammarExtractor(config)
+    prefix = grammars
+
+def extract(inp):
+    global extractor, prefix
+    i, sentence = inp
+    sentence = sentence[:-1]
+    grammar_file = os.path.join(prefix, 'grammar.{0}'.format(i))
+    with open(grammar_file, 'w') as output:
+        for rule in extractor.grammar(sentence):
+            output.write(str(rule)+'\n')
+    grammar_file = os.path.abspath(grammar_file)
+    return '<seg grammar="{0}" id="{1}">{2}</seg>'.format(grammar_file, i, sentence)
+
+
 def main():
     logging.basicConfig(level=logging.INFO)
     parser = argparse.ArgumentParser(description='Extract grammars from a compiled corpus.')
     parser.add_argument('-c', '--config', required=True,
-                        help='Extractor configuration')
+                        help='extractor configuration')
     parser.add_argument('-g', '--grammars', required=True,
-                        help='Grammar output path')
+                        help='grammar output path')
+    parser.add_argument('-j', '--jobs', type=int, default=1,
+                        help='number of parallel extractors')
+    parser.add_argument('-s', '--chunksize', type=int, default=10,
+                        help='number of sentences / chunk')
     args = parser.parse_args()
 
     if not os.path.exists(args.grammars):
         os.mkdir(args.grammars)
 
-    extractor = cdec.sa.GrammarExtractor(args.config)
-    for i, sentence in enumerate(sys.stdin):
-        sentence = sentence[:-1]
-        grammar_file = os.path.join(args.grammars, 'grammar.{0}'.format(i))
-        with open(grammar_file, 'w') as output:
-            for rule in extractor.grammar(sentence):
-                output.write(str(rule)+'\n')
-        grammar_file = os.path.abspath(grammar_file)
-        print('<seg grammar="{0}" id="{1}">{2}</seg>'.format(grammar_file, i, sentence))
+    logging.info('Starting %d workers; chunk size: %d', args.jobs, args.chunksize)
+    pool = mp.Pool(args.jobs, make_extractor, (args.config, args.grammars))
+    try:
+        for output in pool.imap(extract, enumerate(sys.stdin), args.chunksize):
+            print(output)
+    except KeyboardInterrupt:
+        pool.terminate()
 
 if __name__ == '__main__':
     main()