Add FileReader flag to decide if errors in opening file fatal/non-fatal
Flag default is fatal and will crash if errors in opening. If non-fatal,
log error instead of crashing. Added tests for the same.
Change-Id: I788416b86628055f137d0fc4a18fb62c0ca9177a
Signed-off-by: James Kuszmaul <james.kuszmaul@bluerivertech.com>
diff --git a/aos/util/file.cc b/aos/util/file.cc
index b2528a9..f1afa0f 100644
--- a/aos/util/file.cc
+++ b/aos/util/file.cc
@@ -202,9 +202,14 @@
return span;
}
-FileReader::FileReader(std::string_view filename)
+FileReader::FileReader(std::string_view filename,
+ FileReaderErrorType error_type)
: file_(open(::std::string(filename).c_str(), O_RDONLY)) {
- PCHECK(file_.get() != -1) << ": opening " << filename;
+ if (!is_open()) {
+ PLOG_IF(FATAL, error_type == FileReaderErrorType::kFatal)
+ << ": opening " << filename;
+ PLOG(ERROR) << "opening " << filename;
+ }
}
std::optional<absl::Span<char>> FileReader::ReadContents(
diff --git a/aos/util/file.h b/aos/util/file.h
index 2fc4b2b..d0037fd 100644
--- a/aos/util/file.h
+++ b/aos/util/file.h
@@ -52,6 +52,8 @@
enum class FileOptions { kReadable, kWriteable };
+enum class FileReaderErrorType { kFatal, kNonFatal };
+
// Maps file from disk into memory
std::shared_ptr<absl::Span<uint8_t>> MMapFile(
const std::string &path, FileOptions options = FileOptions::kReadable);
@@ -61,7 +63,10 @@
// but where you still want to read a file.
class FileReader {
public:
- FileReader(std::string_view filename);
+ // Opens the file for reading. Crashes if file does not open when flag is set
+ // to fatal (default). Logs error if file does not open and flag is non-fatal.
+ FileReader(std::string_view filename,
+ FileReaderErrorType error_type = FileReaderErrorType::kFatal);
// Reads the entire contents of the file into the internal buffer and returns
// a string_view of it. Returns nullopt if we failed to read the contents
// (currently only on EREMOTEIO). Note: The result may not be null-terminated.
@@ -89,6 +94,9 @@
// must be base 10. Returns nullopt if we failed to read the file.
std::optional<int32_t> ReadInt32();
+ // Checks if file could be opened.
+ bool is_open() const { return file_.get() != -1; }
+
private:
aos::ScopedFD file_;
};
diff --git a/aos/util/file_test.cc b/aos/util/file_test.cc
index bd319b5..fb1befc 100644
--- a/aos/util/file_test.cc
+++ b/aos/util/file_test.cc
@@ -87,6 +87,7 @@
ASSERT_EQ(0, system(("echo 123456789 > " + test_file).c_str()));
FileReader reader(test_file);
+ EXPECT_TRUE(reader.is_open());
aos::ScopedRealtime realtime;
{
@@ -105,6 +106,30 @@
EXPECT_EQ(123456789, reader.ReadInt32());
}
+// Test reading a non-existent file.
+TEST(FileDeathTest, ReadNonExistentFile) {
+ const ::std::string test_file = "/dne";
+
+ // If error_type flag is not set or set to kFatal, this should fail.
+ EXPECT_DEATH(FileReader reader(test_file),
+ "opening " + test_file + ": No such file or directory");
+
+ FileReaderErrorType error_type = FileReaderErrorType::kFatal;
+ EXPECT_DEATH(FileReader reader(test_file, error_type),
+ "opening " + test_file + ": No such file or directory");
+
+ // If warning flag is set to true, read should not fail, is_open() should
+ // return false, ReadContents() and ReadInt32() should fail.
+ error_type = FileReaderErrorType::kNonFatal;
+ FileReader reader(test_file, error_type);
+ EXPECT_FALSE(reader.is_open());
+ std::array<char, 16> contents;
+ EXPECT_DEATH(
+ reader.ReadContents(absl::Span<char>(contents.data(), contents.size())),
+ "Bad file descriptor");
+ EXPECT_DEATH(reader.ReadInt32(), "Bad file descriptor");
+}
+
// Tests that we can write to a file without malloc'ing.
TEST(FileTest, WriteNormalFileNoMalloc) {
const ::std::string tmpdir(aos::testing::TestTmpDir());