backup: Improving the algorithm

create_backup.py

@@ -50,30 +50,32 @@ if len(sys.argv) > 1:
 
 os.makedirs(fn_dir, exist_ok = True)
 
-if pid is None and a_part != 'a':
-  for p, part in enumerate(dev.partlist):
-    if part['addr'] == 0 and part['size'] > 0x00800000:  # 8MiB
-      pid = p
-      name = dev.partlist[p]['name']  # "ALL"
-      name = ''.join(e for e in name if e.isalnum())
-      addr = dev.partlist[p]['addr']
-      size = dev.partlist[p]['size']
-      break
 
-def backup_and_download(pid, filename, die_on_error = True):
+def backup_and_download(pid, filename, chunk_size = 0, die_on_error = True):
     global fn_dir
     os.remove(filename) if os.path.exists(filename) else None
     with open(filename, 'wb') as file:
         pass
     part_size = dev.partlist[pid]["size"]
-    fn_remote = f'/tmp/dump_mtd.bin'
-    blk_size = 20*1024*1024
+    blk_size = 128*1024
+    if not chunk_size:
+        chunk_size = 20*1024*1024
+    if chunk_size % blk_size != 0:
+        die(f'Incorrect value of chunk_size = {chunk_size}')
+    max_blocks = chunk_size // blk_size
     dump_size = 0
     while dump_size < part_size:
+        if dump_size % blk_size != 0:
+            die(f'Internal error on backup_and_download (dump_size = {dump_size})')
         skip = dump_size // blk_size
         fn_local = fn_dir + f'dump_mtd{pid}_{skip}.bin'
         os.remove(fn_local) if os.path.exists(fn_local) else None
-        cmd = f"rm -f {fn_remote} ; dd if=/dev/mtd{pid} of={fn_remote} bs={blk_size} count=1 skip={skip}"
+        count = (part_size - dump_size) // blk_size
+        if count == 0:
+            count = 1
+        if count > max_blocks:
+            count = max_blocks
+        cmd = f"rm -f {fn_remote} ; dd if=/dev/mtd{pid} of={fn_remote} bs={blk_size} skip={skip} count={count}"
         ret = gw.run_cmd(cmd, timeout = 25, die_on_error = False)
         if not ret:
             print(f'ERROR on execute command: "{cmd}"')
@@ -88,10 +90,11 @@ def backup_and_download(pid, filename, die_on_error = True):
             if die_on_error:
                 sys.exit(1)
             return False
-        if not os.path.exists(fn_local):
+        if not os.path.exists(fn_local) or os.path.getsize(fn_local) == 0:
             print(f'ERROR: File "{fn_local}" not found!')
             if die_on_error:
                 sys.exit(1)
+            gw.run_cmd("rm -f " + fn_remote)
             return False
         chunk_size = os.path.getsize(fn_local)
         if chunk_size:
@@ -106,48 +109,34 @@ def backup_and_download(pid, filename, die_on_error = True):
     print(f'File "{filename}" created!"')
     return True
 
+
 if pid is not None:
   if os.path.exists(fn_dir): 
     if os.path.exists(fn_local): 
       if os.path.exists(fn_old):
         os.remove(fn_old)
       os.rename(fn_local, fn_old)
-  if a_part is None:
-    print("Full backup creating...")
   backup_and_download(pid, fn_local)
   print(" ")
-  if a_part is None:
-    print('Full backup saved to file "./{}"'.format(fn_local))
-  else:
-    print('Backup of "{}" saved to file "./{}"'.format(name, fn_local))
+  print('Backup of "{}" saved to file "./{}"'.format(name, fn_local))
 else:
   print("Full backup creating...")
   for p, part in enumerate(dev.partlist):
     if part['addr'] == 0 and part['size'] > 0x00800000:  # 8MiB
-      continue  # skip "ALL" part
-    name = dev.partlist[p]['name']
-    name = ''.join(e for e in name if e.isalnum())
+      name = "FULL_DUMP"
+    else:
+      name = dev.partlist[p]['name']
+      name = ''.join(e for e in name if e.isalnum())
     addr = dev.partlist[p]['addr']
     size = dev.partlist[p]['size']
     fn_old    = fn_dir + 'mtd{id}_{name}.old'.format(id=p, name=name)
-    fn_local  = fn_dir + 'mtd{id}_{name}.bin'.format(id=p, name=name)    
+    fn_local  = fn_dir + 'mtd{id}_{name}.bin'.format(id=p, name=name)
     if os.path.exists(fn_dir): 
       if os.path.exists(fn_local): 
         if os.path.exists(fn_old):
           os.remove(fn_old)
         os.rename(fn_local, fn_old)
-    cmd = "dd if=/dev/mtd{id} of={o}".format(id=p, o=fn_remote)
-    ret = gw.run_cmd(cmd, timeout=30, die_on_error = False)
-    if not ret:
-      print('ERROR on execute command: "{}"'.format(cmd))
-    else:
-      print('Download dump to file "./{}"...'.format(fn_local))
-      try:
-        gw.download(fn_remote, fn_local, verbose = 0)
-      except Exception:
-        print('Remote file "{}" not found!'.format(fn_remote))
-        continue
-    gw.run_cmd("rm -f " + fn_remote)
+    ret = backup_and_download(p, fn_local, die_on_error = False)
     if ret:
       print('Backup of "{}" saved to file "./{}"'.format(name, fn_local))
   print(" ")