Fixed a bug in RamFileSystem::FileExists

PiperOrigin-RevId: 329022084
Change-Id: Iaff54394db78fc3818cacf28f12971fcbc9d8529

tensorflow/core/platform/ram_file_system.h

@@ -177,7 +177,7 @@ class RamFileSystem : public FileSystem {
               FileStatistics* stat) override {
     mutex_lock m(mu_);
     auto it = fs_.lower_bound(fname);
-    if (it == fs_.end()) {
+    if (it == fs_.end() || !absl::StartsWith(it->first, fname)) {
       return errors::NotFound("");
     }
 

tensorflow/core/platform/ram_file_system_test.py

@@ -21,6 +21,7 @@ from __future__ import print_function
 
 import numpy as np
 
+from tensorflow.python.eager import def_function
 from tensorflow.python.estimator.estimator import Estimator
 from tensorflow.python.estimator.model_fn import EstimatorSpec
 from tensorflow.python.estimator.run_config import RunConfig
@@ -28,9 +29,11 @@ from tensorflow.python.framework import constant_op
 from tensorflow.python.framework import dtypes
 from tensorflow.python.framework import test_util
 from tensorflow.python.layers import core as core_layers
+from tensorflow.python.module import module
 from tensorflow.python.ops.losses import losses
 from tensorflow.python.platform import gfile
 from tensorflow.python.platform import test
+from tensorflow.python.saved_model import saved_model
 from tensorflow.python.training import adam
 from tensorflow.python.training import training_util
 
@@ -82,6 +85,17 @@ class RamFilesystemTest(test_util.TensorFlowTestCase):
     matches = ['ram://c/b/%d.txt' % i for i in range(10)]
     self.assertEqual(gfile.Glob('ram://c/b/*'), matches)
 
+  def test_file_exists(self):
+    with gfile.GFile('ram://exists/a/b/c.txt', 'w') as f:
+      f.write('')
+    self.assertTrue(gfile.Exists('ram://exists/a'))
+    self.assertTrue(gfile.Exists('ram://exists/a/b'))
+    self.assertTrue(gfile.Exists('ram://exists/a/b/c.txt'))
+
+    self.assertFalse(gfile.Exists('ram://exists/b'))
+    self.assertFalse(gfile.Exists('ram://exists/a/c'))
+    self.assertFalse(gfile.Exists('ram://exists/a/b/k'))
+
   def test_estimator(self):
 
     def model_fn(features, labels, mode, params):
@@ -114,6 +128,18 @@ class RamFilesystemTest(test_util.TensorFlowTestCase):
     estimator.train(input_fn=input_fn, steps=10)
     estimator.train(input_fn=input_fn, steps=10)
 
+  def test_savedmodel(self):
+    class MyModule(module.Module):
+
+      @def_function.function(input_signature=[])
+      def foo(self):
+        return constant_op.constant([1])
+
+    saved_model.save(MyModule(), 'ram://my_module')
+
+    loaded = saved_model.load('ram://my_module')
+    self.assertAllEqual(loaded.foo(), [1])
+
 
 if __name__ == '__main__':
   test.main()