text: /*
   * Copyright (C) 2018 The Android Open Source Project
   *
   * 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.
   */
  
  #include "android-base/mapped_file.h"
  
  #include <gtest/gtest.h>
  
  #include <errno.h>
  #include <fcntl.h>
  #include <unistd.h>
  
  #include <string>
  
  #include "android-base/file.h"
  
  TEST(mapped_file, smoke) {
    TemporaryFile tf;
    ASSERT_TRUE(tf.fd != -1);
    ASSERT_TRUE(android::base::WriteStringToFd("hello world", tf.fd));
  
    auto m = android::base::MappedFile::FromFd(tf.fd, 3, 2, PROT_READ);
    ASSERT_EQ(2u, m->size());
    ASSERT_EQ('l', m->data()[0]);
    ASSERT_EQ('o', m->data()[1]);
  }
  
  TEST(mapped_file, zero_length_mapping) {
    // http://b/119818070 "app crashes when reading asset of zero length".
    // mmap fails with EINVAL for a zero length region.
    TemporaryFile tf;
    ASSERT_TRUE(tf.fd != -1);
  
    auto m = android::base::MappedFile::FromFd(tf.fd, 4096, 0, PROT_READ);
    EXPECT_EQ(0u, m->size());
    EXPECT_NE(nullptr, m->data());
  }
  