Use std::env;
Use std::fs::{self, file};
Use std::io::{self, bufreader, bufwriter, read, write};
Use std::path::path;
Use std::sync::{arc, mutex};
Use std::thread;
Use std::time::duration;

Use regex::regex;
Use warc::{record, recordtype};
Use flate2::read::gzdecoder;
Use zstd::stream::read::decoder;
Use rayon::threadpoolbuilder;
Use rayon::prelude::*;

Fn main() -> result<(), box<dyn std::error::error>> {
Let args: vec<string> = env::args().collect();
If args.len() < 3 {
Eprintln!("usage: <warc_directory> <output_file_path>");
Std::process::exit(1);
}

Let warc_directory = &args[1];
Let output_file_path = &args[2];

Let regex_pattern = r"\s*imgur\s*";
Let pattern = regex::new(regex_pattern)?;

Loop {
Process_warcs_in_directory(warc_directory, output_file_path, &pattern)?;
Thread::sleep(duration::from_secs(60));
}
}

Use zstd::dict::decoderdictionary;

Fn read_skippable_frame(file: &mut file) -> result<option<vec<u8>>, box<dyn std::error::error>> {
Let mut magic_number = [0; 4];
File.read_exact(&mut magic_number)?;
If magic_number != [0x28, 0xb5, 0x2f, 0xfd] {
Return ok(none);
}

Let mut frame_size_bytes = [0; 4];
File.read_exact(&mut frame_size_bytes)?;
Let frame_size = u32::from_le_bytes(frame_size_bytes) as usize;

Let mut frame_data = vec![0; frame_size];
File.read_exact(&mut frame_data)?;
Ok(some(frame_data))

Fn process_warcs_in_directory(
Warc_directory: &str,
Output_file_path: &str,
Pattern: &regex,
) -> result<(), box<dyn std::error::error>> {
Let output_file = arc::new(mutex::new(bufwriter::new(file::create(output_file_path)?)));

Let paths: vec<_> = fs::read_dir(warc_directory)?
.filter_map(|entry| {
Let entry = entry.ok()?;
Let path = entry.path();
Let file_name = path.file_name()?.to_str()?.to_string();
If file_name.ends_with(".warc.gz") || file_name.ends_with(".warc.zst") {
Some(path)
} else {
None
}
})
.collect();

Let thread_pool = threadpoolbuilder::new()
.num_threads(12)
.build()
.unwrap();

Thread_pool.install(|| {
Paths.par_iter().for_each(|path| {
If let err(e) = process_warc(path, &output_file, &pattern) {
Eprintln!("error processing {}: {}", path.display(), e);
}
});
});

Ok(())
}

Fn process_warc(
Path: &path,
Output_file: &arc<mutex<bufwriter<file>>>,
Pattern: &regex,
) -> result<(), box<dyn std::error::error>> {
Let file = file::open(path)?;
Let mut warc_stream: box<dyn read> = match path.extension().and_then(|os_str| os_str.to_str()) {
Some("gz") => box::new(bufreader::new(gzdecoder::new(file))),
Some("zst") => {
Let mut file = bufreader::new(file);
If let some(dict_data) = read_skippable_frame(&mut file)? {
Let decoder = decoder::with_dictionary(file, &decoderdictionary::new(&dict_data)?)?;
Box::new(bufreader::new(decoder))
} else {
Return err("failed to read zstd dictionary.".into());
}
}
_ => box::new(bufreader::new(file)),
};

Println!("processing file: {}", path.display());

Let mut matches_buffer = vec::new();
Let mut record = record::new();

While let ok(_) = record.read_from(&mut warc_stream) {
Let current_position = warc_stream.stream_position()?;
If current_position - last_update >= progress_update {
Let percentage = (current_position as f64 / total_length as f64) * 100.0;
Println!("progress: {:.1}% ({}/{})", percentage, current_position, total_length);
Last_update = current_position;
}

If record.record_type() == some(recordtype::response) {
Let content = string::from_utf8_lossy(record.content());
For mat in pattern.find_iter(&content) {
Matches_buffer.push(mat.as_str().to_string());
If matches_buffer.len() >= 100 {
Let mut output_file = output_file.lock().unwrap();
For mat in &matches_buffer {
Writeln!(output_file, "{}", mat)?;
}
Matches_buffer.clear();
}
}
}
Record.clear();
}

If !matches_buffer.is_empty() {
Let mut output_file = output_file.lock().unwrap();
For mat in &matches_buffer {
Writeln!(output_file, "{}", mat)?;
}
}

Println!("removing file: {}", path.display());
Fs::remove_file(path)?;

Ok(())
}