_damo_fs: Support dryrun

Add dryrun mode from _damo_fs, for debugging and testing purpose.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>

1 files changed, 26 insertions, 5 deletions

diff --git a/_damo_fs.py b/_damo_fs.py
index 075449a6..50289917 100644
--- a/_damo_fs.py
+++ b/_damo_fs.py
@@ -3,18 +3,35 @@
 import os
 
 debug_do_print = False
+debug_dryrun_logs = None
+debug_dryrun_read_outputs = None
 
 def debug_print_ops(do_print):
     global debug_do_print
     debug_do_print = do_print
 
+def debug_dryrun(read_outputs):
+    '''Set damo_fs to not do the real io, but just log the ops in a buffer'''
+    global debug_dryrun_logs
+    global debug_dryrun_read_outputs
+    debug_dryrun_logs = []
+    debug_dryrun_read_outputs = read_outputs
+
+def debug_get_dryrun_logs():
+    return debug_dryrun_logs
+
 '''Returns content and error'''
 def read_file(filepath):
-    try:
-        with open(filepath, 'r') as f:
-            content = f.read()
-    except Exception as e:
-        return None, 'reading %s failed (%s)' % (filepath, e)
+    if debug_dryrun_logs is not None:
+        content = debug_dryrun_read_outputs[filepath]
+        debug_dryrun_logs.append('read \'%s\': \'%s\'' %
+                                 (filepath, content.strip()))
+    else:
+        try:
+            with open(filepath, 'r') as f:
+                content = f.read()
+        except Exception as e:
+            return None, 'reading %s failed (%s)' % (filepath, e)
     if debug_do_print:
         print('read \'%s\': \'%s\'' % (filepath, content.strip()))
     return content, None
@@ -37,6 +54,10 @@ Returns None if success error string otherwise
 def write_file(filepath, content):
     if debug_do_print:
         print('write \'%s\' to \'%s\'' % (content.strip(), filepath))
+    if debug_dryrun_logs is not None:
+        debug_dryrun_logs.append(
+                'write \'%s\' to \'%s\'' % (content.strip(), filepath))
+        return None
     try:
         with open(filepath, 'w') as f:
             f.write(content)