backend fs read

This commit is contained in:
Green Sky 2024-04-09 20:58:47 +02:00
parent 3cede91aa0
commit 8a580e2fbb
No known key found for this signature in database

View File

@ -287,7 +287,56 @@ bool FilesystemStorage::write(Object o, std::function<write_to_storage_fetch_dat
} }
bool FilesystemStorage::read(Object o, std::function<read_from_storage_put_data_cb>& data_cb) { bool FilesystemStorage::read(Object o, std::function<read_from_storage_put_data_cb>& data_cb) {
auto& reg = _os.registry();
if (!reg.valid(o)) {
return false; return false;
}
ObjectHandle oh {reg, o};
if (!oh.all_of<ObjComp::Ephemeral::FilePath>()) {
// not a file
return false;
}
const auto& obj_path = oh.get<ObjComp::Ephemeral::FilePath>().path;
// TODO: check if metadata dirty?
// TODO: what if file changed on disk?
std::cout << "FS: loading fragment '" << obj_path << "'\n";
Compression data_comp = Compression::NONE;
if (oh.all_of<ObjComp::DataCompressionType>()) {
data_comp = oh.get<ObjComp::DataCompressionType>().comp;
}
auto data_file_stack = buildFileStackRead(std::string_view{obj_path}, Encryption::NONE, data_comp);
if (data_file_stack.empty()) {
return false;
}
// TODO: make it read in a single chunk instead?
static constexpr int64_t chunk_size {1024 * 1024}; // 1MiB should be good for read
do {
auto data_var = data_file_stack.top()->read(chunk_size);
ByteSpan data = spanFromRead(data_var);
if (data.empty()) {
// error or probably eof
break;
}
data_cb(data);
if (data.size < chunk_size) {
// eof
break;
}
} while (data_file_stack.top()->isGood());
return true;
} }
void FilesystemStorage::scanAsync(void) { void FilesystemStorage::scanAsync(void) {