fleshed out the NodeDirMonitor's on_modified method + wrote tests for it.

	modified:   combox/events.py
	modified:   tests/events_test.py

2 files changed, 64 insertions, 2 deletions

diff --git a/combox/events.py b/combox/events.py
index 779b6f6..3692adc 100644
--- a/combox/events.py
+++ b/combox/events.py
@@ -26,7 +26,7 @@ from watchdog.events import LoggingEventHandler
 from combox.crypto import split_and_encrypt, decrypt_and_glue
 from combox.file import (mk_nodedir, rm_nodedir, rm_shards,
                          relative_path, move_shards, move_nodedir,
-                         cb_path, node_path)
+                         cb_path, node_path, hash_file)
 from combox.silo import ComboxSilo
 
 
@@ -179,6 +179,13 @@ class NodeDirMonitor(LoggingEventHandler):
         self.silo = ComboxSilo(self.config)
 
 
+    def silo_update(self):
+        """
+        Re-reads the silo from disk.
+        """
+        self.silo = ComboxSilo(self.config)
+
+
     def housekeep(self):
         """Recursively traverses node directory, discovers changes and updates silo and combox directory.
 
@@ -230,4 +237,25 @@ class NodeDirMonitor(LoggingEventHandler):
 
     def on_modified(self, event):
         super(NodeDirMonitor, self).on_modified(event)
-        pass
+        self.silo_update()
+
+        file_cb_path = cb_path(event.src_path, self.config)
+
+        if event.is_directory:
+            # do nothing
+            pass
+        elif (not event.is_directory):
+            file_content = decrypt_and_glue(file_cb_path,
+                                            self.config,
+                                            write=False)
+            file_content_hash = hash_file(file_cb_path, file_content)
+
+            if self.silo.stale(file_cb_path, file_content_hash):
+                # shard modified
+
+                # means, file was modified on another computer (also
+                # running combox). so, reconstruct the file and put it
+                # in the combox directory.
+                decrypt_and_glue(file_cb_path, self.config)
+                # update db.
+                self.silo.update(file_cb_path)
diff --git a/tests/events_test.py b/tests/events_test.py
index c62d3f2..f645e75 100644
--- a/tests/events_test.py
+++ b/tests/events_test.py
@@ -266,6 +266,40 @@ class TestEvents(object):
         self.purge_list.append(self.TEST_FILE_MUTANT)
         self.purge_list.append(self.FOO_DIR)
 
+        # Test - shard modification
+        self.lorem_file = path.join(self.FILES_DIR, 'lorem.txt')
+        lorem_content = read_file(self.lorem_file)
+        self.lorem_file_copy = "%s.copy" % self.lorem_file
+
+        copyfile(self.lorem_file, self.lorem_file_copy)
+        split_and_encrypt(self.lorem_file_copy, self.config,
+                          lorem_content)
+
+        silo = ComboxSilo(self.config)
+        silo.update(self.lorem_file_copy)
+        shardedp(self.lorem_file_copy)
+
+        silo = ComboxSilo(self.config)
+        lorem_file_copy_hash = silo.db.get(self.lorem_file_copy)
+
+        self.ipsum_file = path.join(self.FILES_DIR, 'ipsum.txt')
+        ipsum_content = read_file(self.ipsum_file)
+        lorem_copy_content = "%s\n%s" % (lorem_content, ipsum_content)
+
+        split_and_encrypt(self.lorem_file_copy, self.config,
+                          lorem_copy_content)
+        time.sleep(1)
+        ## check if the lorem_file_copy's info is updated in silo
+        silo = ComboxSilo(self.config)
+
+        assert lorem_copy_content == read_file(self.lorem_file_copy)
+        assert lorem_file_copy_hash != silo.db.get(self.lorem_file_copy)
+
+        self.purge_list.append(self.lorem_file_copy)
+
+        observer.stop()
+        observer.join()
+
 
     def teardown(self):
         """Cleans up things after each test in this class"""