Teach MultiNodeLogNamer to write files with a temporary suffix
Change-Id: I8bdc9afc2b97bf95fc417bb8a047ed810253bc57
diff --git a/aos/events/logging/log_namer.cc b/aos/events/logging/log_namer.cc
index fbdc292..06243b0 100644
--- a/aos/events/logging/log_namer.cc
+++ b/aos/events/logging/log_namer.cc
@@ -69,14 +69,23 @@
MultiNodeLogNamer::MultiNodeLogNamer(std::string_view base_name,
const Configuration *configuration,
- const Node *node)
+ const Node *node,
+ std::string_view temp_suffix)
: LogNamer(node),
base_name_(base_name),
+ temp_suffix_(temp_suffix),
configuration_(configuration),
uuid_(UUID::Random()) {
OpenDataWriter();
}
+MultiNodeLogNamer::~MultiNodeLogNamer() {
+ if (!ran_out_of_space_) {
+ // This handles renaming temporary files etc.
+ Close();
+ }
+}
+
void MultiNodeLogNamer::WriteHeader(
aos::SizePrefixedFlatbufferDetachedBuffer<LogFileHeader> *header,
const Node *node) {
@@ -210,6 +219,8 @@
ran_out_of_space_ = true;
data_writer.second.writer->acknowledge_out_of_space();
}
+ RenameTempFile(data_writer.second.writer.get());
+ data_writer.second.writer.reset();
}
}
if (data_writer_) {
@@ -218,6 +229,8 @@
ran_out_of_space_ = true;
data_writer_->acknowledge_out_of_space();
}
+ RenameTempFile(data_writer_.get());
+ data_writer_.reset();
}
}
@@ -256,7 +269,7 @@
// means they're probably going to run out of space and get stuck too.
return;
}
- const std::string filename = absl::StrCat(base_name_, path);
+ const std::string filename = absl::StrCat(base_name_, path, temp_suffix_);
if (!destination->get()) {
all_filenames_.emplace_back(path);
*destination = std::make_unique<DetachedBufferWriter>(
@@ -268,10 +281,31 @@
ran_out_of_space_ = true;
return;
}
+ RenameTempFile(destination->get());
all_filenames_.emplace_back(path);
*destination->get() =
DetachedBufferWriter(filename, std::make_unique<DummyEncoder>());
}
+void MultiNodeLogNamer::RenameTempFile(DetachedBufferWriter *destination) {
+ if (temp_suffix_.empty()) {
+ return;
+ }
+ const std::string current_filename = std::string(destination->filename());
+ CHECK(current_filename.size() > temp_suffix_.size());
+ const std::string final_filename =
+ current_filename.substr(0, current_filename.size() - temp_suffix_.size());
+ const int result = rename(current_filename.c_str(), final_filename.c_str());
+ if (result != 0) {
+ if (errno == ENOSPC) {
+ ran_out_of_space_ = true;
+ return;
+ } else {
+ PLOG(FATAL) << "Renaming " << current_filename << " to " << final_filename
+ << " failed";
+ }
+ }
+}
+
} // namespace logger
} // namespace aos
diff --git a/aos/events/logging/log_namer.h b/aos/events/logging/log_namer.h
index 583e605..d9601ae 100644
--- a/aos/events/logging/log_namer.h
+++ b/aos/events/logging/log_namer.h
@@ -122,9 +122,17 @@
// Log namer which uses a config and a base name to name a bunch of files.
class MultiNodeLogNamer : public LogNamer {
public:
+ // If temp_suffix is set, then this will write files under names beginning
+ // with the specified suffix, and then rename them to the desired name after
+ // they are fully written.
+ //
+ // This is useful to enable incremental copying of the log files.
+ //
+ // Defaults to writing directly to the final filename.
MultiNodeLogNamer(std::string_view base_name,
- const Configuration *configuration, const Node *node);
- ~MultiNodeLogNamer() override = default;
+ const Configuration *configuration, const Node *node,
+ std::string_view temp_suffix = "");
+ ~MultiNodeLogNamer() override;
std::string_view base_name() const { return base_name_; }
@@ -204,7 +212,10 @@
void CreateBufferWriter(std::string_view path,
std::unique_ptr<DetachedBufferWriter> *destination);
+ void RenameTempFile(DetachedBufferWriter *destination);
+
const std::string base_name_;
+ const std::string temp_suffix_;
const Configuration *const configuration_;
const UUID uuid_;