src/base/utils_unittest.cc

/*
 * Copyright (C) 2017 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 "perfetto/ext/base/utils.h"
#include <cstdint>
#include <limits>

#include "perfetto/base/build_config.h"

#if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
#include <windows.h>
#else
#include <fcntl.h>
#include <signal.h>
#include <unistd.h>
#endif

#include <stdint.h>

#include <algorithm>
#include <random>
#include <thread>

#include "perfetto/ext/base/file_utils.h"
#include "perfetto/ext/base/pipe.h"
#include "perfetto/ext/base/temp_file.h"
#include "test/gtest_and_gmock.h"
#include "test/status_matchers.h"

using testing::StartsWith;

namespace perfetto {
namespace base {
namespace {

TEST(UtilsTest, ArraySize) {
  char char_arr_1[1];
  char char_arr_4[4];
  EXPECT_EQ(1u, ArraySize(char_arr_1));
  EXPECT_EQ(4u, ArraySize(char_arr_4));

  int32_t int32_arr_1[1];
  int32_t int32_arr_4[4];
  EXPECT_EQ(1u, ArraySize(int32_arr_1));
  EXPECT_EQ(4u, ArraySize(int32_arr_4));

  uint64_t int64_arr_1[1];
  uint64_t int64_arr_4[4];
  EXPECT_EQ(1u, ArraySize(int64_arr_1));
  EXPECT_EQ(4u, ArraySize(int64_arr_4));

  char kString[] = "foo";
  EXPECT_EQ(4u, ArraySize(kString));

  struct Bar {
    int32_t a;
    int32_t b;
  };
  Bar bar_1[1];
  Bar bar_4[4];
  EXPECT_EQ(1u, ArraySize(bar_1));
  EXPECT_EQ(4u, ArraySize(bar_4));
}

TEST(UtilsTest, PipeBlockingRW) {
  Pipe pipe = Pipe::Create();
  std::string expected;
  expected.resize(1024 * 512u);
  for (size_t i = 0; i < expected.size(); i++)
    expected[i] = '!' + static_cast<char>(i % 64);

  std::thread writer([&] {
    std::string tx = expected;
    std::minstd_rand0 rnd_engine(0);

    while (!tx.empty()) {
      size_t wsize = static_cast<size_t>(rnd_engine() % 4096) + 1;
      wsize = std::min(wsize, tx.size());
      WriteAllHandle(*pipe.wr, &tx[0], wsize);
      tx.erase(0, wsize);
    }
    pipe.wr.reset();
  });

  std::string actual;
  ASSERT_TRUE(ReadPlatformHandle(*pipe.rd, &actual));
  ASSERT_EQ(actual, expected);
  writer.join();
}

// Tests that WriteAllHandle and ReadPlatformHandle work as advertised.
// TODO(primiano): normalize File handling on Windows. Right now some places
// use POSIX-compat APIs that use "int" file descriptors (_open, _read, _write),
// some other places use WINAPI files (CreateFile(), ReadFile()), where the file
// is a HANDLE.
TEST(UtilsTest, ReadWritePlatformHandle) {
  auto tmp = TempDir::Create();
  // Explicitly set the string size, we want to write all data to the file.
  std::string payload("foo\nbar\0baz\r\nqux", 16);
  ASSERT_EQ(payload.size(), static_cast<size_t>(16));
  std::string tmp_path = tmp.path() + "/temp.txt";

  // Write a file using PlatformHandle. Note: the {} blocks are to make sure
  // that the file is automatically closed via RAII before being reopened.
  {
    ScopedPlatformHandle handle{
#if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
        ::CreateFileA(tmp_path.c_str(), GENERIC_WRITE, 0, nullptr,
                      CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, nullptr)
#else
        OpenFile(tmp_path, O_WRONLY | O_CREAT | O_TRUNC, 0644)
#endif
    };
    ASSERT_TRUE(handle);
    ASSERT_EQ(WriteAllHandle(*handle, payload.data(), payload.size()),
              static_cast<ssize_t>(payload.size()));
  }

  // Read it back.
  {
    ScopedPlatformHandle handle{
#if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
        ::CreateFileA(tmp_path.c_str(), GENERIC_READ, 0, nullptr, OPEN_EXISTING,
                      FILE_ATTRIBUTE_NORMAL, nullptr)
#else
        OpenFile(tmp_path, O_RDONLY)
#endif
    };
    ASSERT_TRUE(handle);
    std::string actual = "preserve_existing:";
    ASSERT_TRUE(ReadPlatformHandle(*handle, &actual));
    ASSERT_EQ(actual, "preserve_existing:" + payload);
  }

  ASSERT_EQ(remove(tmp_path.c_str()), 0);
}

// Fuchsia doesn't currently support sigaction(), see
// https://fxbug.dev/42105390 .
#if PERFETTO_BUILDFLAG(PERFETTO_OS_LINUX) ||   \
    PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID) || \
    PERFETTO_BUILDFLAG(PERFETTO_OS_APPLE)
TEST(UtilsTest, EintrWrapper) {
  Pipe pipe = Pipe::Create();

  struct sigaction sa = {};
  struct sigaction old_sa = {};

// Glibc headers for sa_sigaction trigger this.
#pragma GCC diagnostic push
#if defined(__clang__)
#pragma GCC diagnostic ignored "-Wdisabled-macro-expansion"
#endif
  sa.sa_sigaction = [](int, siginfo_t*, void*) {};
#pragma GCC diagnostic pop

  ASSERT_EQ(0, sigaction(SIGUSR2, &sa, &old_sa));
  int parent_pid = getpid();
  pid_t pid = fork();
  ASSERT_NE(-1, pid);
  if (pid == 0 /* child */) {
    usleep(5000);
    kill(parent_pid, SIGUSR2);
    ignore_result(WriteAll(*pipe.wr, "foo\0", 4));
    _exit(0);
  }

  char buf[6] = {};
  EXPECT_EQ(4, PERFETTO_EINTR(read(*pipe.rd, buf, sizeof(buf))));
  EXPECT_TRUE(close(*pipe.rd) == 0 || errno == EINTR);
  pipe.wr.reset();

  // A 2nd close should fail with the proper errno.
  int res = close(*pipe.rd);
  auto err = errno;
  EXPECT_EQ(-1, res);
  EXPECT_EQ(EBADF, err);
  pipe.rd.release();

  // Restore the old handler.
  sigaction(SIGUSR2, &old_sa, nullptr);
}
#endif  // LINUX | ANDROID | APPLE

TEST(UtilsTest, IsPowerOfTwo) {
  EXPECT_FALSE(IsPowerOfTwo(0u));
  EXPECT_TRUE(IsPowerOfTwo(1u));
  EXPECT_TRUE(IsPowerOfTwo(2u));
  EXPECT_FALSE(IsPowerOfTwo(3u));
  EXPECT_TRUE(IsPowerOfTwo(4u));

  constexpr uint64_t max_pow2 = static_cast<uint64_t>(1) << 63;
  EXPECT_FALSE(IsPowerOfTwo(max_pow2 - 1));
  EXPECT_TRUE(IsPowerOfTwo(max_pow2));
  EXPECT_FALSE(IsPowerOfTwo(max_pow2 + 1));
}

TEST(UtilsTest, RoundUpToPowerOfTwo) {
  EXPECT_EQ(RoundUpToPowerOfTwo(0u), 0u);
  EXPECT_EQ(RoundUpToPowerOfTwo(1u), 1u);
  EXPECT_EQ(RoundUpToPowerOfTwo(2u), 2u);
  EXPECT_EQ(RoundUpToPowerOfTwo(3u), 4u);
  EXPECT_EQ(RoundUpToPowerOfTwo(5u), 8u);
  EXPECT_EQ(RoundUpToPowerOfTwo(uint32_t{1} << 31), uint32_t{1} << 31);
  EXPECT_EQ(RoundUpToPowerOfTwo((uint32_t{1} << 31) + 1), 0u);
}

TEST(UtilsTest, AlignUp) {
  EXPECT_EQ(0u, AlignUp<4>(0));
  EXPECT_EQ(4u, AlignUp<4>(1));
  EXPECT_EQ(4u, AlignUp<4>(3));
  EXPECT_EQ(4u, AlignUp<4>(4));
  EXPECT_EQ(8u, AlignUp<4>(5));
  EXPECT_EQ(0u, AlignUp<16>(0));
  EXPECT_EQ(16u, AlignUp<16>(1));
  EXPECT_EQ(16u, AlignUp<16>(15));
  EXPECT_EQ(16u, AlignUp<16>(16));
  EXPECT_EQ(32u, AlignUp<16>(17));
  EXPECT_EQ(0xffffff00u, AlignUp<16>(0xffffff00 - 1));
}

TEST(UtilsTest, AlignDown) {
  EXPECT_EQ(0u, AlignDown(0, 4));
  EXPECT_EQ(0u, AlignDown(1, 4));
  EXPECT_EQ(0u, AlignDown(3, 4));
  EXPECT_EQ(4u, AlignDown(4, 4));
  EXPECT_EQ(4u, AlignDown(5, 4));

  EXPECT_EQ(12345u, AlignDown(12345, 1));
}

TEST(UtilsTest, HexDump) {
  char input[] = {0x00, 0x00, 'a', 'b', 'c', 'd', 'e', 'f', 'g',
                  'h',  'i',  'j', 'k', 'l', 'm', 'n', 'o', 'p'};

  std::string output = HexDump(input, sizeof(input));

  EXPECT_EQ(
      output,
      R"(00000000: 00 00 61 62 63 64 65 66 67 68 69 6A 6B 6C 6D 6E   ..abcdefghijklmn
00000010: 6F 70                                             op
)");
}

TEST(UtilsTest, CopyFileContents) {
  auto assert_file_content_fn = [&](TempFile& file,
                                    const std::string& expected) {
    // Flush content of the original dst FD.
    ASSERT_TRUE(FlushFile(*file));
    std::string actual;
    // Open a new FD from the path.
    ASSERT_TRUE(ReadFile(file.path(), &actual));
    ASSERT_EQ(expected, actual);
  };

  // Copy empty file.
  {
    TempFile src = TempFile::Create();
    TempFile dst = TempFile::Create();

    ASSERT_OK(CopyFileContents(*src, *dst));
    assert_file_content_fn(dst, "");
  }

  // Copy small file.
  {
    TempFile src = TempFile::Create();
    TempFile dst = TempFile::Create();

    std::string payload = "payload\n\r123";
    WriteAll(*src, payload.data(), payload.size());

    ASSERT_OK(CopyFileContents(*src, *dst));
    assert_file_content_fn(dst, payload);

    // Append more data to the same file.
    ASSERT_OK(CopyFileContents(*src, *dst));
    assert_file_content_fn(dst, payload + payload);
  }

  // Copy large file.
  {
    TempFile src = TempFile::Create();
    TempFile dst = TempFile::Create();

    std::string payload(35678, 'A');
    WriteAll(*src, payload.data(), payload.size());

    ASSERT_OK(CopyFileContents(*src, *dst));
    assert_file_content_fn(dst, payload);
  }

  // Test CopyFileContents doesn't change 'src' offset.
  {
    TempFile src = TempFile::Create();
    TempFile dst = TempFile::Create();

    std::string payload = "payload\n\r123";
    WriteAll(*src, payload.data(), payload.size());

    constexpr off_t kSrcOffset = 5;
    // Change offset of 'src'.
    ASSERT_EQ(kSrcOffset, lseek(*src, kSrcOffset, SEEK_SET));

    ASSERT_OK(CopyFileContents(*src, *dst));
    assert_file_content_fn(dst, payload);

    // Assert offset of 'src' doesn't change.
    ASSERT_EQ(kSrcOffset, lseek(*src, 0, SEEK_CUR));
  }

  // Test CopyFileContents doesn't change 'src' offset when failed.
  {
    TempFile src = TempFile::Create();
    TempFile dst_normal_file = TempFile::Create();
    ScopedFile dst_read_only = OpenFile(dst_normal_file.path(), O_RDONLY);

    std::string payload = "payload\n\r123";
    WriteAll(*src, payload.data(), payload.size());

    constexpr off_t kSrcOffset = 5;
    // Change offset of 'src'.
    ASSERT_EQ(kSrcOffset, lseek(*src, kSrcOffset, SEEK_SET));

    // Assert we can't write to read only file.
    Status result = CopyFileContents(*src, *dst_read_only);
    ASSERT_THAT(result.message(), StartsWith("Write failed:"));

    // Assert offset of 'src' doesn't change.
    ASSERT_EQ(kSrcOffset, lseek(*src, 0, SEEK_CUR));
  }

#if PERFETTO_BUILDFLAG(PERFETTO_OS_LINUX) || \
    PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID)
  // Test CopyFileContents can read special files with zero length that might
  // actually have contents (such as a seq_file).
  // This test is important, because 'sendfile' can't read from such files, and
  // we want to make sure that if/when we implement the platform specific
  // optimization we won't forget about this special case.
  {
    ScopedFile proc_self_src = OpenFile("/proc/self/cmdline", O_RDONLY);
    ASSERT_TRUE(proc_self_src);

    std::string src_content;
    ASSERT_TRUE(ReadFileDescriptor(*proc_self_src, &src_content));

    TempFile dst = TempFile::Create();
    ASSERT_OK(CopyFileContents(*proc_self_src, *dst));
    assert_file_content_fn(dst, src_content);
  }
#endif
}

TEST(UtilsTest, SeekFile) {
  TempFile file = TempFile::Create();
  ASSERT_EQ(WriteAll(*file, "abcdef", 6), 6);

  ASSERT_TRUE(SeekFile(*file, 3));
  char data[3] = {};
  ASSERT_EQ(Read(*file, data, sizeof(data)), 3);
  EXPECT_EQ(std::string(data, sizeof(data)), "def");
}

TEST(UtilsTest, TruncateFile) {
  TempFile file = TempFile::Create();
  ASSERT_EQ(WriteAll(*file, "abcdef", 6), 6);

  ASSERT_TRUE(TruncateFile(*file, 3));
  EXPECT_EQ(GetFileSize(*file), 3u);

  std::string contents;
  ASSERT_TRUE(ReadFile(file.path(), &contents));
  EXPECT_EQ(contents, "abc");

  ASSERT_TRUE(TruncateFile(*file, 8));
  EXPECT_EQ(GetFileSize(*file), 8u);
  contents.clear();
  ASSERT_TRUE(ReadFile(file.path(), &contents));
  EXPECT_EQ(contents, std::string("abc\0\0\0\0\0", 8));
}

TEST(UtilsTest, SeekAndTruncateFileErrors) {
  EXPECT_FALSE(SeekFile(-1, 0));
  EXPECT_FALSE(TruncateFile(-1, 0));

  constexpr uint64_t kTooLarge = std::numeric_limits<uint64_t>::max();
  TempFile file = TempFile::Create();
  EXPECT_FALSE(SeekFile(*file, kTooLarge));
  EXPECT_FALSE(TruncateFile(*file, kTooLarge));
}

TEST(UtilsTest, GetFileSize) {
  TempFile file = TempFile::Create();
  // Explicitly set the string size, we want to write all data to the file.
  std::string payload("foo\nbar\0baz\r\nqux", 16);
  ASSERT_EQ(payload.size(), static_cast<size_t>(16));
  WriteAll(*file, payload.data(), payload.size());
  FlushFile(*file);

  auto maybe_size = GetFileSize(file.path());
  ASSERT_TRUE(maybe_size.has_value());
  ASSERT_EQ(maybe_size.value(), payload.size());
}

TEST(UtilsTest, OpenFstreamTextModeNotSupported) {
  auto tmp = TempDir::Create();
  std::string tmp_path = tmp.path() + "/temp.txt";

  ASSERT_DEATH_IF_SUPPORTED(
      { auto fstream_write = OpenFstream(tmp_path, "wt"); }, "");

  ASSERT_DEATH_IF_SUPPORTED(
      { auto fstream_write = OpenFstream(tmp_path, "w,ccs=UTF-8"); }, "");
}

TEST(UtilsTest, OpenFstreamAlwaysBinaryMode) {
  TempFile tmp_file = TempFile::Create();
  const std::string& tmp_path = tmp_file.path();
  // Explicitly set the string size, we want to write all data to the file.
  std::string payload("foo\nbar\0baz\r\nqux", 16);
  ASSERT_EQ(payload.size(), static_cast<size_t>(16));

  for (const char* mode : {"w", "wb"}) {
    {
      auto fstream_write = OpenFstream(tmp_path, mode);
      size_t res = fwrite(payload.data(), payload.size(), 1, *fstream_write);
      ASSERT_EQ(res, 1ul);
    }
    {
      // If not in binary mode, '\r\n' sequences are translated when both read
      // and write using FILE* API. So we read back data using `ReadFile` (it
      // uses `open` with O_BINARY flag on Windows) to get the real bytes from
      // the disk.
      std::string actual;
      ASSERT_TRUE(ReadFile(tmp_path, &actual));
      ASSERT_EQ(actual, payload);
    }
  }

  {
    TempFile file = TempFile::Create();
    WriteAll(*file, payload.data(), payload.size());

    auto fstream = OpenFstream(file.path(), "r");
    std::string actual(128, '\0');
    size_t bytes_read = fread(actual.data(), 1, actual.size(), *fstream);
    ASSERT_EQ(bytes_read, payload.size());
    actual.resize(bytes_read);
    ASSERT_EQ(actual, payload);
  }
}

TEST(UtilsTest, SaturatingAdd) {
  constexpr int64_t kMax = std::numeric_limits<int64_t>::max();
  constexpr int64_t kMin = std::numeric_limits<int64_t>::min();

  EXPECT_EQ(SaturatingAdd(0, 0), 0);
  EXPECT_EQ(SaturatingAdd(123, 456), 579);
  EXPECT_EQ(SaturatingAdd(-123, -456), -579);
  EXPECT_EQ(SaturatingAdd(kMax, 0), kMax);
  EXPECT_EQ(SaturatingAdd(kMin, 0), kMin);
  EXPECT_EQ(SaturatingAdd(kMax - 1, 1), kMax);
  EXPECT_EQ(SaturatingAdd(kMin + 1, -1), kMin);
  EXPECT_EQ(SaturatingAdd(kMax, 1), kMax);
  EXPECT_EQ(SaturatingAdd(kMax - 1, 2), kMax);
  EXPECT_EQ(SaturatingAdd(kMin, -1), kMin);
  EXPECT_EQ(SaturatingAdd(kMin + 1, -2), kMin);
}

TEST(UtilsTest, SaturatingMultiply) {
  constexpr int64_t kMax = std::numeric_limits<int64_t>::max();
  constexpr int64_t kMin = std::numeric_limits<int64_t>::min();

  // No overflow: behaves like a normal multiply.
  EXPECT_EQ(SaturatingMultiply(0, 1000), 0);
  EXPECT_EQ(SaturatingMultiply(1000, 0), 0);
  EXPECT_EQ(SaturatingMultiply(123, 1000), 123000);
  EXPECT_EQ(SaturatingMultiply(-123, 1000), -123000);
  EXPECT_EQ(SaturatingMultiply(123, -1000), -123000);
  EXPECT_EQ(SaturatingMultiply(-123, -1000), 123000);
  EXPECT_EQ(SaturatingMultiply(kMax, 1), kMax);
  EXPECT_EQ(SaturatingMultiply(kMin, 1), kMin);

  // Positive overflow saturates to kMax (same-sign operands).
  EXPECT_EQ(SaturatingMultiply(kMax, 1000), kMax);
  EXPECT_EQ(SaturatingMultiply(kMax, 2), kMax);
  EXPECT_EQ(SaturatingMultiply(kMin, -1), kMax);
  EXPECT_EQ(SaturatingMultiply(-kMax, -2), kMax);

  // Just-in-range products near kMin are not saturated.
  EXPECT_EQ(SaturatingMultiply(kMin / 1000, 1000), -9223372036854775000);

  // Negative overflow saturates to kMin (opposite-sign operands). Notably a
  // value near INT64_MIN scaled by a positive factor must stay negative rather
  // than wrapping to a large positive value.
  EXPECT_EQ(SaturatingMultiply(kMin, 1000), kMin);
  EXPECT_EQ(SaturatingMultiply(kMin, 2), kMin);
  EXPECT_EQ(SaturatingMultiply(kMax, -2), kMin);
  EXPECT_EQ(SaturatingMultiply(-9223372036854776, 1000), kMin);
  EXPECT_EQ(SaturatingMultiply(1000, -9223372036854776), kMin);
}

}  // namespace
}  // namespace base
}  // namespace perfetto