Efficient tar Access in WebAssembly Through Virtual Mounting Without Extraction

This technique eliminates the costly step of downloading, decompressing, and copying entire tar.gz archives by mounting them as virtual filesystems in WebAssembly using metadata indexing. By leveraging Emscripten's WORKERFS backend, file contents are accessed on-demand directly from the tar blob without copying data into the Wasm heap, making it essential for memory-constrained WebAssembly environments. The method has proven transformative for WebR, enabling significantly faster R package distribution while maintaining compatibility with existing static tar.gz hosting infrastructure.