From 5babd24450fa839bbc9163d9711d2f233f2724c2 Mon Sep 17 00:00:00 2001
From: Andrey Golovizin <ag@sologoc.com>
Date: Thu, 21 Aug 2014 21:19:57 +0200
Subject: [PATCH] Save glyph database on exit, load on startup.

---
 pixelocr/gui/__init__.py  |  1 +
 pixelocr/gui/ocrengine.py | 21 ++++++++++++++++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/pixelocr/gui/__init__.py b/pixelocr/gui/__init__.py
index 8855975..f4994b5 100644
--- a/pixelocr/gui/__init__.py
+++ b/pixelocr/gui/__init__.py
@@ -46,6 +46,7 @@ def main():
     ocr.pageChanged.connect(win.pageScene.setPage)
     ocr.unknownGlyph.connect(win.unknownGlyph)
     win.glyphEntered.connect(ocr.give_help)
+    app.aboutToQuit.connect(ocr.save_glyphdb)
     ocr.start()
 
     signal.signal(signal.SIGINT, signal.SIG_DFL)
diff --git a/pixelocr/gui/ocrengine.py b/pixelocr/gui/ocrengine.py
index 409d045..b78e22b 100644
--- a/pixelocr/gui/ocrengine.py
+++ b/pixelocr/gui/ocrengine.py
@@ -14,6 +14,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 
+import pickle
 from glob import glob
 from os import path
 from queue import Queue
@@ -34,10 +35,24 @@ class OCREngine(QThread):
 
     def __init__(self, dirname):
         super().__init__()
+        self.dirname = dirname
         self.filenames = glob(path.join(dirname, '*.png'))
-        self.chardb = {}
+        self.glyphdb_filename = path.join(self.dirname, 'glyphdb.pickle')
+        self.glyphdb = self.load_glyphdb()
         self.help_queue = Queue()
 
+    def load_glyphdb(self):
+        if path.isfile(self.glyphdb_filename):
+            with open(self.glyphdb_filename, 'rb') as glyphdb_file:
+                glyphdb = pickle.load(glyphdb_file)
+        else:
+            glyphdb = {}
+        return glyphdb
+
+    def save_glyphdb(self):
+        with open(self.glyphdb_filename, 'wb') as glyphdb_file:
+            pickle.dump(self.glyphdb, glyphdb_file)
+
     def load_page(self, filename):
         return Page(Image.fromfile(filename).unframe(10))
 
@@ -63,10 +78,10 @@ class OCREngine(QThread):
         if isinstance(glyph, Space):
             return ' '
         try:
-            return self.chardb[glyph.key]
+            return self.glyphdb[glyph.key]
         except KeyError:
             text = self.ask_for_help(glyph)
-            self.chardb[glyph.key] = text
+            self.glyphdb[glyph.key] = text
             return text
 
     def ask_for_help(self, unknown_glyph):