Relationship between swc_common::SourceMap and sourcemap::SourceMap

[stahlbauer]

What is the relationship between the following sourcemap implementations:

// from crate "swc_common"
pub struct SourceMap {
    pub(super) files: Lock<SourceMapFiles>,
    start_pos: AtomicUsize,
    file_loader: Box<dyn FileLoader + Sync + Send>,
    path_mapping: FilePathMapping,
    doctest_offset: Option<(FileName, isize)>,
}

// from crate "sourcemap"
pub struct SourceMap {
    file: Option<String>,
    tokens: Vec<RawToken>,
    index: Vec<(u32, u32, u32)>,
    names: Vec<String>,
    sources: Vec<String>,
    sources_content: Vec<Option<SourceView<'static>>>,
}

For example, build_source_map_with_config on a swc_common::SourceMap produces a sourcemap:SourceMap. Is there also an operation to bould a swc_common::SourceMap in a similar fashion? Which type is supposed to be used by plugin authors?

[stahlbauer]

How to build a swc_common::SourceMap from a file that is following the JS map file format?