add checkpoint in io

python/paddle/fluid/io.py

@@ -13,21 +13,17 @@
 # limitations under the License.
 
 import os
+import time
+import shutil
 
 from paddle.fluid.evaluator import Evaluator
 from paddle.fluid.framework import Program, Parameter, default_main_program, Variable
 from . import core
 
 __all__ = [
-    'save_vars',
-    'save_params',
-    'save_persistables',
-    'load_vars',
-    'load_params',
-    'load_persistables',
-    'save_inference_model',
-    'load_inference_model',
-    'get_inference_program',
+    'save_vars', 'save_params', 'save_persistables', 'load_vars', 'load_params',
+    'load_persistables', 'save_inference_model', 'load_inference_model',
+    'get_inference_program', 'save_checkpoint', 'restore_checkpoint'
 ]
 
 
@@ -195,6 +191,8 @@ def load_vars(executor,
         load_var_map = {}
         for each_var in vars:
             assert isinstance(each_var, Variable)
+            if each_var.type == core.VarDesc.VarType.RAW:
+                continue
             new_var = _clone_var_in_block_(load_block, each_var)
             if filename is None:
                 load_block.append_op(
@@ -457,11 +455,12 @@ def get_parameter_value_by_name(name, executor, program=None):
 
 
 SUCCESS = "_SUCCESS"
+BEGIN_SECS = time.time()
 
 
 def save_checkpoint(executor,
                     dirname,
-                    keep_max=10,
+                    keep_max=3,
                     save_secs=600,
                     main_program=None):
     """
@@ -470,38 +469,70 @@ def save_checkpoint(executor,
     :param dirname
     :param keep_max
     :param save_secs
+    :param main_program
     """
     if dirname is None:
         raise Exception("save checkpoint dir can not be none")
 
     if not os.path.isdir(dirname):
         os.makedirs(dirname)
-    serial = _get_lastest_checkpoint_dir(dirname) + 1
 
-    cur_dir = os.path.join(dirname, serial)
+    global BEGIN_SECS
+    if time.time() - BEGIN_SECS < save_secs:
+        return
+    BEGIN_SECS = time.time()
+
+    serial = _get_lastest_checkpoint_dir(dirname) + 1
+    cur_dir = os.path.join(dirname, str(serial))
     save_persistables(executor, cur_dir, main_program)
     _write_success(cur_dir)
+    _lru_delete(dirname, keep_max)
 
 
 def restore_checkpoint(dirname, executor, main_program=None):
     """
     Load Variables from Checkpint Dir
 
-    :param dir
+    :param dirname
+    :param executor
+    :param main_program
     """
     if dirname is None and os.path.isdir(dirname):
         raise Exception("restore checkpoint can not load variables from %s" %
                         dirname)
-    serial = _get_lastest_checkpoint_dir(dirname) + 1
+    serial = _get_lastest_checkpoint_dir(dirname)
 
-    if serial < -1:
+    if serial < 0:
         return
-    cur_dir = os.path.join(dirname, serial)
+    cur_dir = os.path.join(dirname, str(serial))
     load_persistables(executor, cur_dir, main_program)
 
 
+def _lru_delete(dirname, keep_max=3):
+    """
+    retain checkpoint nums with keep_max
+    """
+    dirs = os.listdir(dirname)
+    serials = []
+    for serial in dirs:
+        try:
+            serials.append(int(serial))
+        except ValueError:
+            continue
+
+    if len(serials) <= keep_max:
+        return
+
+    serials.sort(reverse=True)
+    serials = serials[keep_max:]
+    for serial in serials:
+        cur_dir = os.path.join(dirname, str(serial))
+        shutil.rmtree(cur_dir)
+
+
 def _write_success(dirname):
     """
+    write _SUCCESS to checkpoint dir
     """
     success_file = os.path.join(dirname, SUCCESS)
     with open(success_file, 'a'):
@@ -513,7 +544,7 @@ def _get_lastest_checkpoint_dir(checkpoint_dir):
     get the biggest number in checkpoint_dir, which has _SUCCESS
     """
     if not checkpoint_dir.strip():
-        return ""
+        return -1
 
     def has_success(checkpoint_dir, cur_dir):
         """