Add cached reader.

paddleslim/common/__init__.py

@@ -23,6 +23,8 @@ import controller_client
 from controller_client import *
 import lock_utils
 from lock_utils import *
+import cached_reader
+from cached_reader import *
 
 __all__ = []
 __all__ += controller.__all__
@@ -30,3 +32,4 @@ __all__ += sa_controller.__all__
 __all__ += controller_server.__all__
 __all__ += controller_client.__all__
 __all__ += lock_utils.__all__
+__all__ += cached_reader.__all__

paddleslim/common/cached_reader.py

+# Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+import logging
+import numpy as np
+from .log_helper import get_logger
+
+__all__ = ['cached_reader']
+
+_logger = get_logger(__name__, level=logging.INFO)
+
+
+def cached_reader(reader, sampled_rate, cache_path, cached_id):
+    """
+    Sample partial data from reader and cache them into local file system.
+    Args:
+        reader: Iterative data source.
+        sampled_rate(float): The sampled rate used to sample partial data for evaluation. None means using all data in eval_reader. default: None.
+        cache_path(str): The path to cache the sampled data.
+        cached_id(int): The id of dataset sampled. Evaluations with same cached_id use the same sampled dataset. default: 0.
+    """
+    np.random.seed(cached_id)
+    cache_path = os.path.join(cache_path, str(cached_id))
+    _logger.debug('read data from: {}'.format(cache_path))
+
+    def s_reader():
+        if os.path.isdir(cache_path):
+            for file_name in open(os.path.join(cache_path, "list")):
+                yield np.load(
+                    os.path.join(cache_path, file_name.strip()),
+                    allow_pickle=True)
+        else:
+            os.makedirs(cache_path)
+            list_file = open(os.path.join(cache_path, "list"), 'w')
+            batch = 0
+            dtype = None
+            for data in reader():
+                if batch == 0 or (np.random.uniform() < sampled_rate):
+                    np.save(
+                        os.path.join(cache_path, 'batch' + str(batch)), data)
+                    list_file.write('batch' + str(batch) + '.npy\n')
+                    batch += 1
+                    yield data
+
+    return s_reader