remove ledb

app/src/main.rs

@@ -1,15 +1,11 @@
-#[macro_use]
 extern crate serde_json;
 use clap::{Parser, Subcommand};
 use rand::seq::IteratorRandom;
 
 use std::io;
-use std::path::PathBuf;
 use std::time::Instant;
 use std::{fs, sync::mpsc, thread};
 
-use ledb::{Options, Storage};
-
 use chgk_ledb_lib::db;
 use chgk_ledb_lib::questions;
 use chgk_ledb_lib::source;
@@ -19,12 +15,10 @@ use crate::source::ReadSourceQuestionsBatches;
 
 const ZIP_FILENAME: &str = "json.zip";
 const NEW_DB_FILENAME: &str = "db.dat";
-const DB_DIR: &str = "db";
 
 #[derive(Subcommand, Debug)]
 enum Command {
     Write,
-    Compact,
     Print {
         #[clap(value_parser, default_value = "0")]
         id: u32,
@@ -35,11 +29,6 @@ enum Command {
         #[clap(value_parser, default_value = "0")]
         num: usize,
     },
-    Write2,
-    Print2 {
-        #[clap(value_parser, default_value = "0")]
-        id: u32,
-    },
 }
 
 #[derive(Parser, Debug)]
@@ -73,60 +62,12 @@ fn zip_reader_task(tx: mpsc::Sender<Question>) {
     }
     println!("read done");
 }
-fn db_writer_task(rx: mpsc::Receiver<Question>) {
-    let out_file: PathBuf = [DB_DIR, "data.mdb"].into_iter().collect();
-    match fs::metadata(&out_file) {
-        Ok(x) if x.is_file() => {
-            fs::remove_file(&out_file).unwrap();
-            println!(r#""{}" removed"#, out_file.to_str().unwrap());
-        }
-        _ => {}
-    };
-
-    let options: Options = serde_json::from_value(json!({
-        "map_size": 900 * 1024 * 1024, // 900mb
-        "write_map": true,
-        "map_async": true,
-        "no_lock": true,
-        "no_meta_sync": true,
-        "no_sync": true,
-    }))
-    .unwrap();
-
-    let storage = Storage::new(DB_DIR, options).unwrap();
-    let collection = storage.collection("questions").unwrap();
-
-    let count = collection.load(rx).expect("load");
-
-    println!("loaded {count}");
-
-    println!("syncing to disk...");
-    storage.sync(true).unwrap();
-
-    print!("stats: ");
-    let stats = storage.stat().unwrap();
-    println!("{:?}", stats);
-
-    drop(storage);
-    println!("write done");
-}
-
-fn write_db() {
-    let (tx, rx) = mpsc::channel::<Question>();
-    [
-        thread::spawn(move || zip_reader_task(tx)),
-        thread::spawn(move || db_writer_task(rx)),
-    ]
-    .into_iter()
-    .for_each(|handle| handle.join().expect("thread panic"));
-    println!("all done");
-}
 
 fn print_question_from<F>(get_q: F)
 where
     F: FnOnce() -> Option<Question>,
 {
-    let q = get_q().unwrap();
+    let q = get_q().expect("question not found");
     println!("{:#?}", q)
 }
 
@@ -151,45 +92,6 @@ fn read_from_zip(file_num: usize, mut num: usize) -> Option<Question> {
     Some(questions[num - 1].clone())
 }
 
-fn compact_db() {
-    let options: Options = serde_json::from_value(json!({
-        "write_map": true,
-        "map_async": true,
-        "no_lock": true,
-        "no_meta_sync": true,
-        "no_sync": true,
-        "compact": true,
-    }))
-    .unwrap();
-
-    let storage = Storage::new(DB_DIR, options).unwrap();
-
-    storage.sync(true).unwrap();
-    let stats = storage.stat().unwrap();
-    println!("{:?}", stats);
-    drop(storage);
-}
-
-fn read_from_db(mut id: u32) -> Option<Question> {
-    let options: Options = serde_json::from_value(json!({
-        "read_only": true,
-        "map_async": true,
-        "no_lock": true,
-    }))
-    .unwrap();
-
-    let storage = Storage::new(DB_DIR, options).unwrap();
-    let collection = storage.collection("questions").unwrap();
-    let mut rng = rand::thread_rng();
-
-    if id == 0 {
-        let last_id = collection.last_id().unwrap();
-        id = (1..=last_id).choose(&mut rng).unwrap();
-    }
-
-    collection.get::<Question>(id).unwrap()
-}
-
 // measure and return time elapsed in `func` in seconds
 pub fn measure<F: FnOnce()>(func: F) -> f64 {
     let start = Instant::now();
@@ -208,7 +110,6 @@ fn main() {
 
     let mut action: Box<dyn FnOnce()> = match &args.command {
         Command::Write => Box::new(write_db),
-        Command::Compact => Box::new(compact_db),
         Command::Print { id } => {
             let get_question = Box::new(|| read_from_db(*id));
             Box::new(|| print_question_from(get_question))
@@ -217,11 +118,6 @@ fn main() {
             let get_question = Box::new(|| read_from_zip(*file_num, *num));
             Box::new(|| print_question_from(get_question))
         }
-        Command::Write2 => Box::new(write_db2),
-        Command::Print2 { id } => {
-            let get_question = Box::new(|| read_from_db2(*id));
-            Box::new(|| print_question_from(get_question))
-        }
     };
 
     if args.measure {
@@ -231,11 +127,11 @@ fn main() {
     action();
 }
 
-fn read_from_db2(id: u32) -> Option<Question> {
+fn read_from_db(id: u32) -> Option<Question> {
     let reader: db::Reader<Question> =
         db::Reader::new(NEW_DB_FILENAME, 2048).expect("new db reader");
 
-    let mut questions = reader.iter();
+    let mut questions = reader.into_iter();
 
     match id {
         0 => {
@@ -245,17 +141,17 @@ fn read_from_db2(id: u32) -> Option<Question> {
         _ => questions.nth((id - 1) as usize),
     }
 }
-fn write_db2() {
+fn write_db() {
     let (tx, rx) = mpsc::channel::<Question>();
     [
         thread::spawn(move || zip_reader_task(tx)),
-        thread::spawn(move || db_writer2_task(rx)),
+        thread::spawn(move || db_writer_task(rx)),
     ]
     .into_iter()
     .for_each(|handle| handle.join().expect("thread panic"));
     println!("all done");
 }
-fn db_writer2_task(rx: mpsc::Receiver<Question>) {
+fn db_writer_task(rx: mpsc::Receiver<Question>) {
     let writer_opts = db::WriterOpts::default();
     let mut writer: db::Writer<Question> =
         db::Writer::new(NEW_DB_FILENAME, writer_opts).expect("new db writer");