Remove DetachedBufferFileWriter and use FileBackend

DetachedBufferFileWriter was a temp solution. Making file via log
backend is a better one.

Change-Id: I0c212f404f5a3f70034e674c697b5ddcc18614e6
Signed-off-by: Austin Schuh <austin.schuh@bluerivertech.com>
diff --git a/aos/events/logging/log_edit.cc b/aos/events/logging/log_edit.cc
index 55b7666..7e822ca 100644
--- a/aos/events/logging/log_edit.cc
+++ b/aos/events/logging/log_edit.cc
@@ -48,12 +48,13 @@
     aos::logger::SpanReader span_reader(orig_path);
     CHECK(!span_reader.ReadMessage().empty()) << ": Empty header, aborting";
 
-    aos::logger::DetachedBufferFileWriter buffer_writer(
-        FLAGS_logfile,
+    aos::logger::FileBackend file_backend("/");
+    aos::logger::DetachedBufferWriter buffer_writer(
+        file_backend.RequestFile(FLAGS_logfile),
         std::make_unique<aos::logger::DummyEncoder>(FLAGS_max_message_size));
     {
-      aos::logger::DataEncoder::SpanCopier coppier(header.span());
-      buffer_writer.CopyMessage(&coppier, aos::monotonic_clock::min_time);
+      aos::logger::DataEncoder::SpanCopier copier(header.span());
+      buffer_writer.CopyMessage(&copier, aos::monotonic_clock::min_time);
     }
 
     while (true) {
@@ -63,8 +64,8 @@
       }
 
       {
-        aos::logger::DataEncoder::SpanCopier coppier(msg_data);
-        buffer_writer.CopyMessage(&coppier, aos::monotonic_clock::min_time);
+        aos::logger::DataEncoder::SpanCopier copier(msg_data);
+        buffer_writer.CopyMessage(&copier, aos::monotonic_clock::min_time);
       }
     }
   } else {
diff --git a/aos/events/logging/logfile_utils.h b/aos/events/logging/logfile_utils.h
index 8415efe..0bf60a0 100644
--- a/aos/events/logging/logfile_utils.h
+++ b/aos/events/logging/logfile_utils.h
@@ -134,17 +134,6 @@
       aos::monotonic_clock::min_time;
 };
 
-// Specialized writer to single file
-class DetachedBufferFileWriter : public FileBackend,
-                                 public DetachedBufferWriter {
- public:
-  DetachedBufferFileWriter(std::string_view filename,
-                           std::unique_ptr<DataEncoder> encoder)
-      : FileBackend("/"),
-        DetachedBufferWriter(FileBackend::RequestFile(filename),
-                             std::move(encoder)) {}
-};
-
 // Repacks the provided RemoteMessage into fbb.
 flatbuffers::Offset<MessageHeader> PackRemoteMessage(
     flatbuffers::FlatBufferBuilder *fbb,
diff --git a/aos/events/logging/logfile_utils_out_of_space_test_runner.cc b/aos/events/logging/logfile_utils_out_of_space_test_runner.cc
index 03bfd0a..71c537f 100644
--- a/aos/events/logging/logfile_utils_out_of_space_test_runner.cc
+++ b/aos/events/logging/logfile_utils_out_of_space_test_runner.cc
@@ -18,8 +18,9 @@
   std::array<uint8_t, 10240> data;
   data.fill(0);
 
-  aos::logger::DetachedBufferFileWriter writer(
-      FLAGS_tmpfs + "/file",
+  aos::logger::FileBackend file_backend("/");
+  aos::logger::DetachedBufferWriter writer(
+      file_backend.RequestFile(FLAGS_tmpfs + "/file"),
       std::make_unique<aos::logger::DummyEncoder>(data.size()));
   for (int i = 0; i < 8; ++i) {
     aos::logger::DataEncoder::SpanCopier coppier(data);
diff --git a/aos/events/logging/logfile_utils_test.cc b/aos/events/logging/logfile_utils_test.cc
index e2dc8aa..8d5b0fb 100644
--- a/aos/events/logging/logfile_utils_test.cc
+++ b/aos/events/logging/logfile_utils_test.cc
@@ -30,13 +30,15 @@
 
 // Adapter class to make it easy to test DetachedBufferWriter without adding
 // test only boilerplate to DetachedBufferWriter.
-class TestDetachedBufferWriter : public DetachedBufferFileWriter {
+class TestDetachedBufferWriter : public FileBackend,
+                                 public DetachedBufferWriter {
  public:
   // Pick a max size that is rather conservative.
   static constexpr size_t kMaxMessageSize = 128 * 1024;
   TestDetachedBufferWriter(std::string_view filename)
-      : DetachedBufferFileWriter(
-            filename, std::make_unique<DummyEncoder>(kMaxMessageSize)) {}
+      : FileBackend("/"),
+        DetachedBufferWriter(FileBackend::RequestFile(filename),
+                             std::make_unique<DummyEncoder>(kMaxMessageSize)) {}
   void WriteSizedFlatbuffer(flatbuffers::DetachedBuffer &&buffer) {
     QueueSpan(absl::Span<const uint8_t>(buffer.data(), buffer.size()));
   }