This wrapper allows using the SCANOSS engine's snippet scanning functionality from Go code via CGO.

go-wrapper/
├── snippets_wrapper.h      # C wrapper header
├── snippets_wrapper.c      # C wrapper implementation
├── wfp_scanner.go         # WFP scanner with Go CGO bindings
├── test_main.go           # Simple test example
├── Makefile               # Static library compilation
└── README.md              # This documentation

cd go-wrapper
make clean
make

This will generate libsnippets_wrapper.a containing all necessary engine code.

ls -la libsnippets_wrapper.a

make test

Or manually:

go build -o wfp_scanner example/wfp_scanner.go

The wfp_scanner tool scans WFP (Winnowing FingerPrint) files against the SCANOSS database:

# Basic usage
./wfp_scanner example/test.wfp

# With custom database name
./wfp_scanner -oss-db-name=custom_db example/test.wfp

# Enable debug output
./wfp_scanner -q example/test.wfp

# Show help
./wfp_scanner --help

• -oss-db-name: OSS database name (default: "oss")
• -q: Enable debug output (default: false)

file=<md5>,<total_lines>,<file_path>
<line_number>=<hash1>,<hash2>,...

Example:

file=e27b911d391391f94a862ebbe40ddcc0,1652,path/to/file.c
1=63e9a57f
3=e6f64278
6=aa323afd,31466ee5,87dece99

package main

// #cgo CFLAGS: -I. -I../inc -I../external/inc
// #cgo LDFLAGS: ${SRCDIR}/libsnippets_wrapper.a -lldb -lssl -lcrypto -lz -lm -lpthread
// #include "snippets_wrapper.h"
// #include <stdlib.h>
import "C"
import (
    "unsafe"
)

func main() {
    // Initialize wrapper with database name and debug mode
    cDbName := C.CString("oss")
    defer C.free(unsafe.Pointer(cDbName))
    C.snippets_wrapper_init(cDbName, C.bool(false))
    defer C.snippets_wrapper_cleanup()

    // Prepare input data
    cInput := C.wrapper_scan_input_t{}
    // ... set up input fields

    // Call scan function
    cResult := C.snippets_wrapper_scan(&cInput)
    defer C.snippets_wrapper_free_result(cResult)

    // Process results
    // ...
}

• md5: 16-byte MD5 hash of the file
• file_path: File path string
• hashes: Array of WFP hashes (uint32_t*)
• lines: Array of corresponding line numbers (uint32_t*)
• hash_count: Number of hashes
• total_lines: Total lines in file

• match_type: Match type (WRAPPER_MATCH_NONE, WRAPPER_MATCH_FILE, WRAPPER_MATCH_SNIPPET, WRAPPER_MATCH_BINARY)
• error_msg: Error message string (if any)
• matches: Array of match information
• match_count: Number of matches found

• file_md5_hex: MD5 of matched file (hex string)
• hits: Number of matching hits
• range_count: Number of matching ranges
• range_from: Array of range start positions
• range_to: Array of range end positions
• oss_line: Array of corresponding OSS file line numbers

Initializes the wrapper and loads the LDB database.

Parameters:

• oss_db_name: Name of the OSS database (e.g., "oss")
• enable_debug: Enable debug logging via scanlog

Note: Must be called before any scanning operations.

Scans the provided WFP data against the database.

Parameters:

• input: Pointer to input data structure

Returns:

• Pointer to result structure (must be freed with snippets_wrapper_free_result)

Frees memory allocated for scan results.

Parameters:

• result: Pointer to result structure to free

Cleanup function (currently no-op as LDB handles cleanup automatically).

The library requires the following system libraries:

• LDB (SCANOSS database library)
• OpenSSL (libssl, libcrypto)
• zlib
• pthread

On Ubuntu/Debian:

sudo apt-get install libssl-dev zlib1g-dev

When debug mode is enabled with the -q flag:

• C code uses scanlog() for debug output with microsecond timestamps
• Go code prints debug messages to stderr
• Useful for troubleshooting and performance analysis

Example debug output:

1759355140418426 snippets_wrapper_init START
1759355140418448 About to call ldb_read_cfg for: oss/wfp
1759355140418494 ldb_read_cfg returned, keys=1
[GO DEBUG] About to call C.snippets_wrapper_scan
[GO DEBUG] hash_count=12, total_lines=763

1. Initialization: Always call snippets_wrapper_init() before using scan functions
2. Cleanup: Use defer for proper resource cleanup
3. Memory Management: C memory must be allocated for hash and line arrays
4. Static Linking: The wrapper uses static linking with libsnippets_wrapper.a
5. Thread Safety: The library is not thread-safe by default
6. Database Path: Ensure the LDB database exists at the specified path

See wfp_scanner.go for a complete working example that:

• Parses WFP files
• Allocates C memory properly
• Handles results and prints matches
• Includes proper error handling