rename checkpoint folder to checkpoint_serial

Author: seiriosPlus

python/paddle/fluid/io.py

@@ -455,37 +455,40 @@ def get_parameter_value_by_name(name, executor, program=None):
 
 
 SUCCESS_MARK_FILENAME = "_SUCCESS"
+CHECKPOINT_PREFIX = "checkpoint"
+CHECKPOINT_SEPARATOR = "_"
 
 
 def save_checkpoint(executor,
-                    dirname=None,
+                    checkpoint_dir=None,
                     max_num_checkpoints=3,
                     save_interval_secs=600,
                     main_program=None):
     """
     Save Checkpoint will save persistable LodTensor variables from main_program in checkpoint directory,
     the directory named by serial number from 0 to (n -1), save_checkpoint use LRU strategy
     to keep numbers of checkpoint directory,  the numbers of checkpoint directory are max_num_checkpoints at most,
-    The interval time between two save_checkpoint must great than or equal to save_interval_secs.
+    The interval between two saved checkpoints must greater than save_interval_secs.
 
-    :param dirname
+    :param executor
+    :param checkpoint_dir
     :param max_num_checkpoints
-    :param save_secs
+    :param save_interval_secs
     :param main_program
     """
-    if dirname is None:
-        dirname = os.getcwd()
+    if checkpoint_dir is None:
+        checkpoint_dir = os.getcwd()
 
-    if not os.path.isdir(dirname):
-        os.makedirs(dirname)
+    if not os.path.isdir(checkpoint_dir):
+        os.makedirs(checkpoint_dir)
 
-    serial = _get_lastest_checkpoint_dir(dirname)
+    serial = _get_lastest_checkpoint_dir(checkpoint_dir)
     if serial >= 0 and not _interval_secs_exceed(
-            os.path.join(dirname, str(serial)), save_interval_secs):
+            _get_serial_dir(serial, checkpoint_dir), save_interval_secs):
         return
 
-    serial = serial + 1
-    cur_dir = os.path.join(dirname, str(serial))
+    serial += 1
+    cur_dir = _get_serial_dir(serial, checkpoint_dir)
 
     save_vars(
         executor,
@@ -495,27 +498,28 @@ def save_checkpoint(executor,
         predicate=_is_checkpoint_var,
         filename=None)
     _write_success(cur_dir)
-    _lru_delete(dirname, max_num_checkpoints)
+    _lru_delete(checkpoint_dir, max_num_checkpoints)
 
 
-def load_checkpoint(executor, dirname=None, main_program=None):
+def load_checkpoint(executor, checkpoint_dir=None, main_program=None):
     """
     Load checkpoint from a directory by executor,
-    it will find latest checkpoint file and load it auto.
+    it will find  the most recent saved checkpoint file and load it auto.
 
     :param executor
-    :param dirname
+    :param checkpoint_dir
     :param main_program
     """
 
-    if dirname is None:
-        dirname = os.getcwd()
+    if checkpoint_dir is None:
+        checkpoint_dir = os.getcwd()
 
-    serial = _get_lastest_checkpoint_dir(dirname)
+    serial = _get_lastest_checkpoint_dir(checkpoint_dir)
 
     if serial < 0:
         return
-    cur_dir = os.path.join(dirname, str(serial))
+
+    cur_dir = _get_serial_dir(serial, checkpoint_dir)
 
     load_vars(
         executor,
@@ -525,6 +529,11 @@ def load_checkpoint(executor, dirname=None, main_program=None):
         filename=None)
 
 
+def _get_serial_dir(serial, checkpoint_dir):
+    serial_folder = CHECKPOINT_PREFIX + CHECKPOINT_SEPARATOR + str(serial)
+    return os.path.join(checkpoint_dir, serial_folder)
+
+
 def _is_checkpoint_var(var):
     """
     the checkpoint will not save or load all the variables.
@@ -577,7 +586,8 @@ def _write_success(dirname):
     """
     success_file = os.path.join(dirname, SUCCESS_MARK_FILENAME)
     with open(success_file, 'a'):
-        pass
+        now = time.ctime()
+        success_file.write(now)
 
 
 def _get_lastest_checkpoint_dir(checkpoint_dir):
@@ -593,18 +603,20 @@ def has_success(checkpoint_dir, cur_dir):
         """
         is _SUCCESS in this dir
         """
-        if not os.path.isdir(os.path.join(checkpoint_dir, cur_dir)):
-            return -1
+        _, serial = cur_dir.split(CHECKPOINT_SEPARATOR)
 
         try:
-            int(cur_dir)
+            int(serial)
         except ValueError:
             return -1
 
-        success_path = os.path.join(checkpoint_dir, cur_dir,
-                                    SUCCESS_MARK_FILENAME)
+        if not os.path.isdir(os.path.join(checkpoint_dir, cur_dir)):
+            return -1
+
+        success_path = os.path.join(
+            _get_serial_dir(serial, checkpoint_dir), SUCCESS_MARK_FILENAME)
         if os.path.isfile(success_path):
-            return int(cur_dir)
+            return int(serial)
 
     if not os.path.isdir(checkpoint_dir):
         return -1