From a18a94c8f70868bf18167366f8318fe122c2affc Mon Sep 17 00:00:00 2001
From: Virantha Ekanayake <virantha@gmail.com>
Date: Thu, 18 Feb 2016 13:41:27 -0500
Subject: [PATCH] Fix for win32 multiprocessing with pyinstaller

---
 pypdfocr/pypdfocr.py                 |  7 ++++
 pypdfocr/pypdfocr_multiprocessing.py | 56 ++++++++++++++++++++++++++++
 pypdfocr/pypdfocr_pdffiler.py        |  6 +++
 pypdfocr/pypdfocr_tesseract.py       |  4 +-
 4 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 pypdfocr/pypdfocr_multiprocessing.py

diff --git a/pypdfocr/pypdfocr.py b/pypdfocr/pypdfocr.py
index 4ef136b..9b68250 100644
--- a/pypdfocr/pypdfocr.py
+++ b/pypdfocr/pypdfocr.py
@@ -25,6 +25,12 @@
 from PIL import Image
 import yaml
 
+import multiprocessing
+# Replace the Popen routine to allow win32 pyinstaller to build
+from multiprocessing import forking
+from pypdfocr_multiprocessing import _Popen
+forking.Popen = _Popen
+
 from pypdfocr_pdf import PyPdf
 from pypdfocr_tesseract import PyTesseract
 from pypdfocr_gs import PyGs
@@ -452,6 +458,7 @@ def _convert_and_file_email(self, pdf_filename):
             self._send_email(pdf_filename, ocr_pdffilename, filing)
 
 def main(): # pragma: no cover 
+    multiprocessing.freeze_support()
     script = PyPDFOCR()
     script.go(sys.argv[1:])
 
diff --git a/pypdfocr/pypdfocr_multiprocessing.py b/pypdfocr/pypdfocr_multiprocessing.py
new file mode 100644
index 0000000..3666268
--- /dev/null
+++ b/pypdfocr/pypdfocr_multiprocessing.py
@@ -0,0 +1,56 @@
+#!/usr/bin/env python2.7
+# Copyright 2013 Virantha Ekanayake 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.
+
+import sys, os, multiprocessing.forking
+import logging
+
+""" Special work-around to support multiprocessing and pyinstaller --onefile on windows systms
+
+    https://github.com/pyinstaller/pyinstaller/wiki/Recipe-Multiprocessing
+"""
+
+import multiprocessing.forking as forking
+import os
+import sys
+
+class _Popen(multiprocessing.forking.Popen):
+    def __init__(self, *args, **kw):
+        if hasattr(sys, 'frozen'):
+            # We have to set original _MEIPASS2 value from sys._MEIPASS
+            # to get --onefile mode working.
+            os.putenv('_MEIPASS2', sys._MEIPASS)
+        try:
+            super(_Popen, self).__init__(*args, **kw)
+        finally:
+            if hasattr(sys, 'frozen'):
+                # On some platforms (e.g. AIX) 'os.unsetenv()' is not
+                # available. In those cases we cannot delete the variable
+                # but only set it to the empty string. The bootloader
+                # can handle this case.
+                if hasattr(os, 'unsetenv'):
+                    os.unsetenv('_MEIPASS2')
+                else:
+                    os.putenv('_MEIPASS2', '')
+
+forking.Popen = _Popen
+
+#class Process(multiprocessing.Process):
+    #_Popen = _Popen
+
+# ...
+
+if __name__ == '__main__':
+    # On Windows calling this function is necessary.
+    multiprocessing.freeze_support()
diff --git a/pypdfocr/pypdfocr_pdffiler.py b/pypdfocr/pypdfocr_pdffiler.py
index 6f26b88..1bb23f5 100644
--- a/pypdfocr/pypdfocr_pdffiler.py
+++ b/pypdfocr/pypdfocr_pdffiler.py
@@ -26,6 +26,7 @@
 
 from PyPDF2 import PdfFileReader
 from pypdfocr_filer import PyFiler
+from pypdfocr_filer_dirs import PyFilerDirs
 
 class PyPdfFiler(object):
     def __init__(self, filer):
@@ -72,3 +73,8 @@ def move_to_matching_folder(self, filename):
         tgt_file = self.filer.move_to_matching_folder(filename, tgt_folder)
         return tgt_file
         
+if __name__ == '__main__':
+    p = PyPdfFiler(PyFilerDirs())
+    for page_text in p.iter_pdf_page_text("scan_ocr.pdf"):
+        print (page_text)
+
diff --git a/pypdfocr/pypdfocr_tesseract.py b/pypdfocr/pypdfocr_tesseract.py
index 476d5cd..d1411a3 100644
--- a/pypdfocr/pypdfocr_tesseract.py
+++ b/pypdfocr/pypdfocr_tesseract.py
@@ -24,8 +24,10 @@
 import subprocess
 import glob
 from subprocess import CalledProcessError
+
 from multiprocessing import Pool
 
+
 def error(text):
     print("ERROR: %s" % text)
     sys.exit(-1)
@@ -129,8 +131,8 @@ def make_hocr_from_pnms(self, fns):
 
         # Glob it
         #fns = glob.glob(img_filename)
+        logging.debug("Making pool for tesseract")
         pool = Pool(processes=self.threads)
-        print("Making pool")
         hocr_filenames = pool.map(unwrap_self, zip([self]*len(fns), fns))
         pool.close()
         pool.join()