Turbo ASAR

⚡ High-performance ASAR archive library written in C

Features • Performance • Installation • Usage • API • Building

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A blazing-fast, minimal C implementation for creating and extracting ASAR archives. Fully compatible with Electron's ASAR format.

Features

• Zero Dependency - Minimalist design for speed and portability
• Cross-Platform - Linux, macOS, and Windows support
• Native C Implementation - No JavaScript/Node.js overhead
• Extremely Fast - Hardware-accelerated SHA256 (SHA-NI on x86, ARMv8 crypto on ARM64)
• Memory Efficient -Memory-mapped file I/O for large files (using mmap for files > 4MB)
• Sequential Read Hints - posix_fadvise and madvise for optimal caching
• Block-Based Hashing - Efficient incremental hashing for integrity verification
• Full ASAR Support - Pack, extract, list, and stat operations
• Symlink Support - Full symlink preservation on Unix

Performance

turbo-asar vs @electron/asar (CLI Comparison)

Small Archives (10 files, ~50KB)

Operation	@electron/asar	turbo-asar	Speedup
pack	99 ms	2.1 ms	46x faster
extract	69 ms	2.7 ms	25x faster
list	68 ms	1.9 ms	37x faster

Medium Archives (100 files, ~10MB)

Operation	@electron/asar	turbo-asar	Speedup
pack	247 ms	27 ms	9x faster
extract	96 ms	18 ms	5.5x faster
list	71 ms	2.0 ms	36x faster

Large Archives (1000 files, ~100MB)

Operation	@electron/asar	turbo-asar	Speedup
pack	736 ms	262 ms	2.8x faster
extract	297 ms	186 ms	1.6x faster
list	92 ms	5.6 ms	16x faster

Benchmarked on Linux x64 with Node.js v20. turbo-asar uses native C with hardware-accelerated SHA256.

Installation

From Source

git clone https://github.com/k1tbyte/turbo-asar.git
cd turbo-asar
mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release -DENABLE_NATIVE_ARCH=ON
make -j$(nproc)
sudo make install

Options

Option	Default	Description
ENABLE_NATIVE_ARCH	ON	Enable CPU-specific optimizations
BUILD_SHARED_LIBS	OFF	Build shared library instead of static
BUILD_CLI	ON	Build command-line tool
BUILD_TESTS	ON	Build test suite
BUILD_BENCHMARKS	ON	Build benchmarks

Usage

Command Line

# Create an archive
turbo-asar pack ./my-app app.asar

# Extract an archive
turbo-asar extract app.asar ./output

# List contents
turbo-asar list app.asar

# Extract single file
turbo-asar extract-file app.asar path/to/file.js output.js

# Options
turbo-asar pack ./my-app app.asar --no-integrity     # Skip integrity hashes
turbo-asar pack ./my-app app.asar --exclude-hidden   # Skip hidden files

C Library

#include <turbo_asar.h>

int main() {
    // Pack a directory
    turbo_asar_pack_options_t options = {0};
    options.calculate_integrity = true;
    
    turbo_asar_error_t err = turbo_asar_pack("./my-app", "app.asar", &options);
    if (err != TURBO_ASAR_OK) {
        printf("Error: %s\n", turbo_asar_strerror(err));
        return 1;
    }
    
    // Extract entire archive
    err = turbo_asar_extract_all("app.asar", "./output");
    
    // Extract single file
    uint8_t *buffer;
    size_t size;
    err = turbo_asar_extract_file("app.asar", "main.js", &buffer, &size);
    // ... use buffer ...
    free(buffer);
    
    // List files
    char **files;
    size_t count;
    err = turbo_asar_list("app.asar", &files, &count);
    for (size_t i = 0; i < count; i++) {
        printf("%s\n", files[i]);
    }
    turbo_asar_free_list(files, count);
    
    return 0;
}

API

Core Functions

Function	Description
turbo_asar_pack()	Create ASAR archive from directory
turbo_asar_extract_all()	Extract entire archive
turbo_asar_extract_file()	Extract single file to buffer
turbo_asar_list()	List all files in archive
turbo_asar_stat()	Get file metadata
turbo_asar_get_header()	Get raw JSON header
turbo_asar_version()	Get library version
turbo_asar_strerror()	Get error message

Building

Prerequisites

• CMake 3.16+
• C11 compiler (GCC, Clang, MSVC)

Build Commands

# Debug build
cmake .. -DCMAKE_BUILD_TYPE=Debug
make

# Release build with native optimizations
cmake .. -DCMAKE_BUILD_TYPE=Release -DENABLE_NATIVE_ARCH=ON
make

# Run tests
./test_sha256
./test_pickle
./test_asar

# Run benchmarks
./benchmark_asar
./benchmark_sha256  # Requires OpenSSL

# Run comparison benchmark against @electron/asar
cd benchmarks/electron-comparison
npm install
node benchmark.js

ASAR Format Compatibility

Turbo ASAR is fully compatible with Electron's ASAR format:

• ✅ Standard ASAR header format (Pickle serialization)
• ✅ File integrity hashes (SHA256)
• ✅ Block-level integrity (4MB blocks)
• ✅ Unpacked files support with glob pattern
• ✅ Symlink preservation
• ✅ Executable bit preservation

License

Apache-2.0 - see the LICENSE file for details

Credits

• ASAR: Based on Electron's ASAR implementation
• JSON: Uses cJSON for header parsing
• Glob: Pattern matching based on Linux kernel implementation