GitHub - ryanbr/fop-rs: FOP Filter Orderer and Preener re-written in Rust

FOP - Filter Orderer and Preener (Rust Edition)

A Rust port of the EasyList FOP tool for sorting and cleaning ad-blocking filter lists.

Features

• Filter sorting: Alphabetically sorts blocking rules and element hiding rules
• Domain combining: Merges rules with identical selectors/patterns but different domains
• Option normalization: Converts uBO-specific options to standard ABP format (can be disabled)
• Wildcard cleanup: Removes unnecessary wildcards from filters
• Validation: Removes invalid/overly-broad rules (TLD-only, too short, etc.)
• Git integration: Commit changes directly to repositories (can be disabled)
• easylist_adservers.txt validation: Ensures rules start with | or /
• Parallel processing: Uses all CPU cores for faster processing via Rayon

Extended Syntax Support

FOP preserves extended filter syntax from various adblockers:

uBlock Origin

• Scriptlet injection: ##+js(...), ##^script:has-text(...)
• Procedural cosmetics: :has-text(), :has(), :upward(), :remove(), :style(), :matches-css(), :xpath(), :remove-attr(), :remove-class(), :watch-attr(), :min-text-length(), :others()
• Network options: redirect=, redirect-rule=, removeparam=, denyallow=, replace=, header=, permissions=, to=, from=, method=
• Regex domain rules: /regex/##+js(...)

AdGuard

• Scriptlet injection: #%#//scriptlet(...)
• CSS injection: #$#body { ... }
• Exceptions: #@%#, #@$#

Adblock Plus

• Extended selectors: :-abp-has(), :-abp-contains(), :-abp-properties()
• Action syntax: {remove: true;}, {height:...}, {display:...}
• Snippets: #$#hide-if-contains, #$#simulate-mouse-event

Speed Comparison (FOP.py vs FOP Rust)

Installation

Building from source (optional)

Requires Rust 1.80+ (https://rustup.rs)

cd fop-rs
cargo build --release
cp target/release/fop /usr/local/bin/  # or add to PATH

Usage

# Sort filters in current directory (with commit prompt)
fop

# Sort filters in a specific directory
fop /path/to/easylist

# Sort without commit prompt (like FOP-nocommit.py)
fop --no-commit /path/to/easylist
fop -n .

# Sort without converting uBO options to ABP format
fop --no-ubo-convert /path/to/ublock-filters

# Sort multiple directories
fop -n ~/easylist ~/easyprivacy ~/fanboy-addon

Command Line Options

Configuration File

Create .fopconfig in your working directory or home directory:

# Skip commit prompt
no-commit = false

# Skip uBO to ABP option conversion
no-ubo-convert = false

# Skip commit message format validation
no-msg-check = false

# Skip sorting (only tidy and combine rules)
no-sort = false

# Alternative sorting method
alt-sort = false

# Sort hosts file entries
localhost = false

# Disable colored output
no-color = false

# Disable large change warning prompt
no-large-warning = false

# Create .backup files before modifying
backup = false

# Keep empty lines in output
keep-empty-lines = false

# Don't skip rules without dot in domain
ignore-dot-domains = false

# Comment line prefixes
comments = !

# Files to skip short domain check
disable-domain-limit =

# Output warnings to file
warning-output =

# Additional files to ignore
ignorefiles = .json,.backup,.bak,.swp,.gz

# Additional directories to ignore
ignoredirs =

# File extensions to process
file-extensions = txt

# Create PR branch instead of committing
create-pr =

# Base branch for PR (default: auto-detect)
git-pr-branch =

# Fix cosmetic typos during sort
fix-typos = false

# Check typos in git additions
fix-typos-on-add = false

# Auto-fix without prompting
auto-fix = false

# Suppress most output (for CI)
quiet = false

# Users allowed to push directly when create-pr is enabled (comma-separated, case-insensitive)
direct-push-users =

Command line arguments override config file settings.

Platform Support

Which binary should I use?

Linux/Windows x86_64:

• Use -v3 version for CPUs from ~2015+ (Haswell, Ryzen) - faster due to AVX2 instructions
• Use baseline version (-x86_64.exe) for older CPUs or if unsure

ARM64:

• Linux: Optimized for Neoverse N1+ (AWS Graviton2+, Ampere Altra)
• Windows: Optimized for Snapdragon 8cx Gen 3+ / Cortex-A78+
• macOS: Optimized for Apple Silicon (M1+)

Unsupported platform? FOP.rs builds from source on any platform with Rust 1.80+:

Migrating from Python FOP

This Rust version is a drop-in replacement for both FOP.py and FOP-nocommit.py:

Performance

The Rust version is significantly faster than Python FOP due to:

• Compiled native code
• Parallel file processing with Rayon
• Optimized regex handling
• Efficient memory management

License

GPL-3.0 (same as original Python FOP)

Credits

• Original Python FOP by Michael (EasyList project)
• Rust port maintains feature parity with Python version 3.9