.drone.yml

@@ -1,5 +1,4 @@
 kind: pipeline
-type: docker
 name: default
 
 steps:
@@ -7,33 +6,6 @@ steps:
   image: rust:1-alpine
   commands:
   - apk add --no-cache musl-dev
-  - cargo build --verbose --all-features --all
+  - cargo build --verbose --all
-  - cargo test --verbose --all-features --all
+  - cargo test --verbose --all
-  environment:
-    CARGO_REGISTRIES_CRATES_IO_PROTOCOL: sparse
 
-trigger:
-  event:
-  - push
-
----
-kind: pipeline
-type: docker
-name: publish
-
-steps:
-- name: push
-  image: rust:1-alpine
-  commands:
-  - apk add --no-cache musl-dev
-  - cargo build -p chgk_ledb_lib --all-features
-  - cargo publish --registry gitea -p chgk_ledb_lib --all-features
-  environment:
-    CARGO_REGISTRIES_CRATES_IO_PROTOCOL: sparse
-    CARGO_REGISTRIES_GITEA_INDEX: https://gitea.b4tman.ru/b4tman/_cargo-index.git
-    CARGO_REGISTRIES_GITEA_TOKEN:
-      from_secret: cargo_gitea_token
-
-trigger:
-  event:
-  - tag

.gitignore

@@ -6,5 +6,3 @@ json.zip
 /exp
 /.vscode
 test*.bin
-db.dat
-*.pending-snap

Cargo.toml

@@ -1,10 +1,32 @@
-[workspace]
+[package]
-resolver = "2"
+name = "chgk_ledb"
-members = [
+version = "0.1.0"
-  "app",
+authors = ["Dmitry <b4tm4n@mail.ru>"]
-  "app_async",
+edition = "2021"
-  "lib"
+
-]
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[[bench]]
+name = "db_bench"
+harness = false
+
+[dependencies]
+serde="1.0"
+serde_derive="1.0"
+serde_json="1.0"
+ledb = {git = "https://github.com/b4tman/ledb.git", rev="a646b90e", package="ledb"}
+ledb-derive = {git = "https://github.com/b4tman/ledb.git", rev="a646b90e", package="ledb-derive"}
+ledb-types = {git = "https://github.com/b4tman/ledb.git", rev="a646b90e", package="ledb-types"}
+zip="0.6"
+rand="0.8"
+clap = { version = "3.2.22", features = ["derive"] }
+bincode = "^2.0.0-rc.2"
+zstd = "^0.10"
+memmap = "0.7.0"
+
+[dev-dependencies]
+criterion = "0.4.0"
+tempfile = "3.3"
 
 [profile.release]
 opt-level = 3

app/Cargo.toml

@@ -1,32 +0,0 @@
-[package]
-name = "chgk_ledb"
-version = "1.1.0"
-authors = ["Dmitry <b4tm4n@mail.ru>"]
-edition = "2021"
-repository = "https://gitea.b4tman.ru/b4tman/chgk_ledb"
-license = "MIT"
-description = "Утилита загружающая базу данных ЧГК вопросов из ZIP файла в JSON формате в базу данных."
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[[bench]]
-name = "db_bench"
-harness = false
-
-[[bench]]
-name = "questions_bench"
-harness = false
-
-[dependencies]
-chgk_ledb_lib = {path = "../lib", features = ["sync", "source", "convert"]}
-serde_json="1.0"
-zip="0.6"
-rand="0.8"
-clap = { version = "4.2.7", features = ["derive"] }
-
-[dev-dependencies]
-criterion = "0.4.0"
-tempfile = "3.3"
-bincode = "^2.0.0-rc.2"
-serde="1.0"
-serde_derive="1.0"

app/benches/questions_bench.rs

@@ -1,101 +0,0 @@
-#[macro_use]
-extern crate criterion;
-extern crate bincode;
-extern crate serde;
-extern crate serde_derive;
-extern crate serde_json;
-extern crate tempfile;
-
-use chgk_ledb_lib::db::{Reader, Writer, WriterOpts};
-use chgk_ledb_lib::questions::{Question, QuestionsConverter};
-use chgk_ledb_lib::source::ReadSourceQuestionsBatches;
-
-use std::path::Path;
-use std::time::Duration;
-use std::{fs, io};
-
-use criterion::{BatchSize, Criterion};
-use tempfile::{tempdir, NamedTempFile};
-
-const ZIP_FILENAME: &str = "../json.zip";
-const NEW_DB_FILENAME: &str = "../db.dat";
-
-const N: usize = 4096;
-
-fn read_sample() -> Vec<Question> {
-    let zip_file = fs::File::open(ZIP_FILENAME).unwrap();
-    let zip_reader = io::BufReader::new(zip_file);
-    let archive = zip::ZipArchive::new(zip_reader).unwrap();
-    let mut source_questions = archive.source_questions();
-
-    source_questions
-        .convert()
-        .take(N)
-        .enumerate()
-        .map(|(num, mut question)| {
-            question.num = 1 + num as u32;
-            question
-        })
-        .collect()
-}
-
-fn prepare_db_writer<P: AsRef<Path>>(path: P) -> Writer<Question> {
-    let opts = WriterOpts {
-        compress_lvl: 1,
-        data_buf_size: 100 * 1024 * 1024,
-        out_buf_size: 100 * 1024 * 1024,
-        current_buf_size: 10240,
-    };
-
-    Writer::new(path, opts).expect("new writer")
-}
-
-fn questions_read(c: &mut Criterion) {
-    c.bench_function("questions_read", |b| {
-        b.iter_batched(
-            || {
-                let reader: Reader<Question> =
-                    Reader::new(NEW_DB_FILENAME, 4096).expect("new reader");
-                reader.into_iter().take(N)
-            },
-            |reader| {
-                for item in reader {
-                    drop(item);
-                }
-            },
-            BatchSize::SmallInput,
-        )
-    });
-}
-
-fn questions_write(c: &mut Criterion) {
-    let dir = tempdir().expect("tempdir");
-
-    c.bench_function("questions_write", |b| {
-        b.iter_batched(
-            || {
-                let tmpfile = NamedTempFile::new_in(dir.path())
-                    .expect("new tempfile")
-                    .into_temp_path();
-                let src = read_sample().into_iter();
-                let writer = prepare_db_writer(&tmpfile);
-                (src, writer)
-            },
-            |(mut src, mut writer)| {
-                writer.load(&mut src).unwrap();
-                writer.finish().unwrap();
-            },
-            BatchSize::SmallInput,
-        )
-    });
-}
-
-fn config() -> Criterion {
-    Criterion::default()
-        .sample_size(40)
-        .warm_up_time(Duration::from_secs(7))
-        .measurement_time(Duration::from_secs(20))
-}
-
-criterion_group! {name=benches; config = config(); targets = questions_read, questions_write}
-criterion_main!(benches);

app/src/main.rs

@@ -1,181 +0,0 @@
-extern crate serde_json;
-use clap::{Parser, Subcommand};
-use rand::seq::IteratorRandom;
-
-use std::io;
-use std::time::Instant;
-use std::{fs, sync::mpsc, thread};
-
-use chgk_ledb_lib::db;
-use chgk_ledb_lib::questions;
-use chgk_ledb_lib::source;
-
-use crate::questions::{Question, QuestionsConverter};
-use crate::source::ReadSourceQuestionsBatches;
-use chgk_ledb_lib::util::ErrorToString;
-
-const ZIP_FILENAME: &str = "json.zip";
-const NEW_DB_FILENAME: &str = "db.dat";
-
-#[derive(Subcommand, Debug)]
-enum Command {
-    Write,
-    Print {
-        #[clap(value_parser, default_value = "0")]
-        id: u32,
-    },
-    ZipPrint {
-        #[clap(value_parser, default_value = "0")]
-        file_num: usize,
-        #[clap(value_parser, default_value = "0")]
-        num: usize,
-    },
-}
-
-#[derive(Parser, Debug)]
-#[clap(author, version, about, long_about = None)]
-#[clap(propagate_version = true)]
-struct Cli {
-    #[clap(subcommand)]
-    command: Command,
-    #[clap(short, long, action)]
-    measure: bool,
-}
-
-fn main() {
-    let args = Cli::parse();
-
-    let mut action: Box<dyn FnOnce()> = match &args.command {
-        Command::Write => Box::new(write_db),
-        Command::Print { id } => {
-            let get_question = Box::new(|| read_from_db(*id));
-            Box::new(|| print_question_from(get_question))
-        }
-        Command::ZipPrint { file_num, num } => {
-            let get_question = Box::new(|| read_from_zip(*file_num, *num));
-            Box::new(|| print_question_from(get_question))
-        }
-    };
-
-    if args.measure {
-        action = Box::new(|| measure_and_print(action));
-    }
-
-    action();
-}
-
-// measure and return time elapsed in `func` in seconds
-pub fn measure<F: FnOnce()>(func: F) -> f64 {
-    let start = Instant::now();
-    func();
-    let elapsed = start.elapsed();
-    (elapsed.as_secs() as f64) + (elapsed.subsec_nanos() as f64 / 1_000_000_000.0)
-}
-
-pub fn measure_and_print<F: FnOnce()>(func: F) {
-    let m = measure(func);
-    eprintln!("{}", m);
-}
-
-fn print_question_from<F>(get_q: F)
-where
-    F: FnOnce() -> Result<Question, String>,
-{
-    let q = get_q().expect("question not found");
-    println!("{:#?}", q)
-}
-
-fn read_from_zip(file_num: usize, mut num: usize) -> Result<Question, String> {
-    let mut rng = rand::thread_rng();
-    let zip_file = fs::File::open(ZIP_FILENAME).str_err()?;
-    let zip_reader = io::BufReader::new(zip_file);
-    let archive = zip::ZipArchive::new(zip_reader).str_err()?;
-
-    let mut source_questions = archive.source_questions();
-    let (filename, batch) = if file_num == 0 {
-        source_questions
-            .choose(&mut rng)
-            .ok_or("rand choose".to_string())?
-    } else {
-        source_questions
-            .nth(file_num - 1)
-            .ok_or(format!("file nth #{file_num} => None"))?
-    };
-    let mut batch = batch.map_err(|e| format!("get batch from file #{file_num} => {e}"))?;
-    batch.filename = filename;
-    let questions: Vec<Question> = batch.into();
-    if num == 0 {
-        num = (1..=questions.len())
-            .choose(&mut rng)
-            .ok_or("rand choose".to_string())?;
-    }
-    Ok(questions[num - 1].clone())
-}
-
-fn read_from_db(id: u32) -> Result<Question, String> {
-    let reader: db::Reader<Question> = db::Reader::new(NEW_DB_FILENAME, 2048)?;
-
-    let len = reader.len();
-    let mut questions = reader.into_iter();
-
-    let question = match id {
-        0 => {
-            let mut rng = rand::thread_rng();
-            questions
-                .choose(&mut rng)
-                .ok_or(format!("rand choose, len = {len}"))?
-        }
-        _ => questions
-            .nth((id - 1) as usize)
-            .ok_or(format!("get nth #{id} => None"))?,
-    };
-
-    Ok(question)
-}
-
-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 zip_reader_task(tx: mpsc::Sender<Question>) {
-    let zip_file = fs::File::open(ZIP_FILENAME).unwrap();
-    let zip_reader = io::BufReader::new(zip_file);
-    let archive = zip::ZipArchive::new(zip_reader).unwrap();
-    let mut source_questions = archive.source_questions();
-
-    let questions = source_questions
-        .convert()
-        .enumerate()
-        .map(|(num, mut question)| {
-            question.num = 1 + num as u32;
-            question
-        });
-    for question in questions {
-        let res = tx.send(question);
-        if res.is_err() {
-            break;
-        }
-    }
-    println!("read done");
-}
-
-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");
-
-    writer
-        .load(&mut rx.iter())
-        .unwrap_or_else(|e| panic!("db writer load, {e:#?}"));
-
-    writer.finish().expect("db writer finish");
-
-    println!("write done");
-}

app_async/Cargo.toml

@@ -1,45 +0,0 @@
-[package]
-name = "chgk_ledb_async"
-version = "1.1.0"
-authors = ["Dmitry <b4tm4n@mail.ru>"]
-edition = "2021"
-repository = "https://gitea.b4tman.ru/b4tman/chgk_ledb"
-license = "MIT"
-description = "Утилита загружающая базу данных ЧГК вопросов из ZIP файла в JSON формате в базу данных."
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[[bench]]
-name = "async_bench"
-harness = false
-
-[[bench]]
-name = "questions_async_bench"
-harness = false
-
-[dependencies]
-chgk_ledb_lib = {path = "../lib", features = ["async", "convert_async"]}
-serde_json="1.0"
-async_zip = { version = "0.0.15", features = [
-    "zstd",
-    "tokio",
-    "tokio-fs"] }
-tokio = { version = "1", features = [
-    "io-util",
-    "fs",
-    "rt-multi-thread"
-] }
-tokio-stream = "0.1"
-rand="0.8"
-clap = { version = "4.2.7", features = ["derive"] }
-futures = "0.3"
-
-[dev-dependencies]
-criterion = { version = "0.5.1", features = ["async_tokio"]}
-tempfile = "3.3"
-bincode = "^2.0.0-rc.2"
-serde="1.0"
-serde_derive="1.0"
-futures = "0.3"
-async-compression = { version = "0.4.1", default-features = false }
-lazy_static = "1.4.0"

app_async/benches/async_bench.rs

@@ -1,153 +0,0 @@
-#[macro_use]
-extern crate criterion;
-extern crate bincode;
-extern crate serde;
-extern crate serde_derive;
-extern crate tempfile;
-
-use async_compression::Level;
-use chgk_ledb_lib::async_db::{Reader, Writer, WriterOpts};
-use futures::StreamExt;
-use std::{ops::Deref, path::Path};
-
-use criterion::{BatchSize, Criterion};
-use lazy_static::lazy_static;
-use tempfile::{tempdir, NamedTempFile};
-
-use serde_derive::{Deserialize, Serialize};
-
-#[derive(
-    bincode::Encode,
-    bincode::Decode,
-    Clone,
-    Debug,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Serialize,
-    Deserialize,
-)]
-struct TestData {
-    num1: u64,
-    num2: u64,
-    test: String,
-}
-
-use tokio::runtime;
-
-lazy_static! {
-    static ref RUNTIME: tokio::runtime::Runtime =
-        runtime::Builder::new_current_thread().build().unwrap();
-}
-
-const N: usize = 4096;
-
-fn gen_data(count: usize) -> impl Iterator<Item = TestData> {
-    (0..count).map(|i| 143 + i as u64).map(|i| TestData {
-        num1: i,
-        num2: (i * 100) ^ 0xDF0E441122334455,
-        test: "test ---- Test ____".repeat(123 + i as usize % 15),
-    })
-}
-
-async fn prepare_db_writer<P: AsRef<Path>>(path: P) -> Writer<TestData> {
-    let opts = WriterOpts {
-        compress_lvl: Level::Fastest,
-        data_buf_size: 100 * 1024 * 1024,
-        out_buf_size: 100 * 1024 * 1024,
-        current_buf_size: 10240,
-    };
-
-    Writer::new(path, opts).await.expect("new writer")
-}
-
-fn write_sample<P: AsRef<Path>>(path: P) {
-    let rp = path.as_ref().to_str().unwrap().to_string();
-    std::thread::spawn(|| {
-        runtime::Builder::new_current_thread()
-            .build()
-            .unwrap()
-            .block_on(async move {
-                let mut writer = prepare_db_writer(rp).await;
-
-                let items_iter = gen_data(N).collect::<Vec<TestData>>().into_iter();
-                let mut samples_stream = futures::stream::iter(items_iter);
-                writer.load(&mut samples_stream).await.unwrap();
-                writer.finish().await.unwrap();
-            })
-    })
-    .join()
-    .expect("spawn thread");
-}
-
-fn setup_writer<P: AsRef<Path>>(path: P) -> Writer<TestData> {
-    let rp = path.as_ref().to_str().unwrap().to_string();
-
-    std::thread::spawn(|| {
-        runtime::Builder::new_current_thread()
-            .build()
-            .unwrap()
-            .block_on(prepare_db_writer(rp))
-    })
-    .join()
-    .expect("spawn thread")
-}
-
-fn setup_reader<P: AsRef<Path>>(path: P) -> Reader<TestData> {
-    let rp = path.as_ref().to_str().unwrap().to_string();
-    std::thread::spawn(|| {
-        runtime::Builder::new_current_thread()
-            .build()
-            .unwrap()
-            .block_on(async move { Reader::new(rp).await.expect("new reader") })
-    })
-    .join()
-    .expect("spawn thread")
-}
-
-fn async_read(c: &mut Criterion) {
-    let dir = tempdir().expect("tempdir");
-    let tmpfile = NamedTempFile::new_in(dir.path())
-        .expect("new tempfile")
-        .into_temp_path();
-    write_sample(&tmpfile);
-
-    c.bench_function("async_read", |b| {
-        b.to_async(RUNTIME.deref()).iter_batched(
-            || setup_reader(&tmpfile),
-            |reader| async move { reader.stream().for_each(|item| async { drop(item) }).await },
-            BatchSize::SmallInput,
-        )
-    });
-}
-
-fn async_write(c: &mut Criterion) {
-    let dir = tempdir().expect("tempdir");
-
-    c.bench_function("async_write", |b| {
-        b.to_async(RUNTIME.deref()).iter_batched(
-            || {
-                let tmpfile = NamedTempFile::new_in(dir.path())
-                    .expect("new tempfile")
-                    .into_temp_path();
-                let src = gen_data(N).collect::<Vec<TestData>>().into_iter();
-                let src = futures::stream::iter(src);
-                let writer = setup_writer(&tmpfile);
-                (src, writer)
-            },
-            |(mut src, mut writer)| async move {
-                writer.load(&mut src).await.unwrap();
-                writer.finish().await.unwrap();
-            },
-            BatchSize::SmallInput,
-        )
-    });
-}
-
-fn config() -> Criterion {
-    Criterion::default().sample_size(20)
-}
-
-criterion_group! {name=benches; config = config(); targets = async_read, async_write}
-criterion_main!(benches);

app_async/benches/questions_async_bench.rs

@@ -1,152 +0,0 @@
-#[macro_use]
-extern crate criterion;
-extern crate bincode;
-extern crate serde;
-extern crate serde_derive;
-extern crate tempfile;
-
-use async_compression::Level;
-use chgk_ledb_lib::async_db::{Reader, Writer, WriterOpts};
-use chgk_ledb_lib::questions::{Question, QuestionsConverterAsyncForStream};
-use chgk_ledb_lib::source::ReadSourceQuestionsBatchesAsync;
-use futures::pin_mut;
-use futures::StreamExt;
-use std::time::Duration;
-use std::{ops::Deref, path::Path};
-
-use async_zip::tokio::read::seek::ZipFileReader;
-
-use criterion::{BatchSize, Criterion};
-use lazy_static::lazy_static;
-use tempfile::{tempdir, NamedTempFile};
-use tokio::{fs, runtime};
-
-const ZIP_FILENAME: &str = "../json.zip";
-const NEW_DB_FILENAME: &str = "../db.dat";
-
-lazy_static! {
-    static ref RUNTIME: tokio::runtime::Runtime =
-        runtime::Builder::new_current_thread().build().unwrap();
-}
-
-const N: usize = 4096;
-
-async fn read_sample() -> Vec<Question> {
-    let mut file = fs::File::open(ZIP_FILENAME).await.expect("open zip");
-    let archive = ZipFileReader::with_tokio(&mut file)
-        .await
-        .expect("open zip file reader");
-    let mut source_questions = archive.source_questions();
-    let source_questions = source_questions.stream();
-    pin_mut!(source_questions);
-
-    source_questions
-        .converter()
-        .convert()
-        .take(N)
-        .enumerate()
-        .map(|(num, mut question)| {
-            question.num = 1 + num as u32;
-            question
-        })
-        .collect()
-        .await
-}
-
-fn read_sample_sync() -> Vec<Question> {
-    std::thread::spawn(|| {
-        runtime::Builder::new_current_thread()
-            .build()
-            .unwrap()
-            .block_on(read_sample())
-    })
-    .join()
-    .expect("spawn thread")
-}
-
-async fn prepare_db_writer<P: AsRef<Path>>(path: P) -> Writer<Question> {
-    let opts = WriterOpts {
-        compress_lvl: Level::Fastest,
-        data_buf_size: 100 * 1024 * 1024,
-        out_buf_size: 100 * 1024 * 1024,
-        current_buf_size: 10240,
-    };
-
-    Writer::<Question>::new(path, opts)
-        .await
-        .expect("new writer")
-}
-
-fn setup_writer<P: AsRef<Path>>(path: P) -> Writer<Question> {
-    let rp = path.as_ref().to_str().unwrap().to_string();
-
-    std::thread::spawn(|| {
-        runtime::Builder::new_current_thread()
-            .build()
-            .unwrap()
-            .block_on(prepare_db_writer(rp))
-    })
-    .join()
-    .expect("spawn thread")
-}
-
-fn setup_reader<P: AsRef<Path>>(path: P) -> Reader<Question> {
-    let rp = path.as_ref().to_str().unwrap().to_string();
-    std::thread::spawn(|| {
-        runtime::Builder::new_current_thread()
-            .build()
-            .unwrap()
-            .block_on(async move { Reader::new(rp).await.expect("new reader") })
-    })
-    .join()
-    .expect("spawn thread")
-}
-
-fn questions_async_read(c: &mut Criterion) {
-    c.bench_function("questions_async_read", |b| {
-        b.to_async(RUNTIME.deref()).iter_batched(
-            || setup_reader(NEW_DB_FILENAME),
-            |reader| async move {
-                reader
-                    .stream()
-                    .take(N)
-                    .for_each(|item| async { drop(item) })
-                    .await
-            },
-            BatchSize::SmallInput,
-        )
-    });
-}
-
-fn questions_async_write(c: &mut Criterion) {
-    let dir = tempdir().expect("tempdir");
-
-    c.bench_function("questions_async_write", |b| {
-        b.to_async(RUNTIME.deref()).iter_batched(
-            || {
-                let tmpfile = NamedTempFile::new_in(dir.path())
-                    .expect("new tempfile")
-                    .into_temp_path();
-                let src = read_sample_sync().into_iter();
-                let src = futures::stream::iter(src);
-                let writer = setup_writer(&tmpfile);
-                (src, writer)
-            },
-            |(mut src, mut writer)| async move {
-                writer.load(&mut src).await.unwrap();
-                writer.finish().await.unwrap();
-            },
-            BatchSize::SmallInput,
-        )
-    });
-}
-
-fn config() -> Criterion {
-    Criterion::default()
-        .sample_size(40)
-        .warm_up_time(Duration::from_secs(7))
-        .measurement_time(Duration::from_secs(20))
-}
-
-criterion_group! {name=benches; config = config(); targets = questions_async_read, questions_async_write}
-criterion_main!(benches);

app_async/src/main.rs

@@ -1,197 +0,0 @@
-extern crate serde_json;
-use clap::{Parser, Subcommand};
-use futures::{pin_mut, Future};
-use rand::distributions::Uniform;
-use rand::seq::IteratorRandom;
-use rand::{thread_rng, Rng};
-
-use async_zip::tokio::read::seek::ZipFileReader;
-use futures::stream::{self, StreamExt};
-use std::time::Instant;
-use tokio::sync::mpsc::{self, UnboundedReceiver, UnboundedSender};
-
-use async_db::WriterOpts;
-
-use tokio::{fs, io};
-use tokio_stream::wrappers::UnboundedReceiverStream;
-
-use chgk_ledb_lib::async_db;
-use chgk_ledb_lib::questions::Question;
-use chgk_ledb_lib::questions::QuestionsConverterAsyncForStream;
-use chgk_ledb_lib::source::ReadSourceQuestionsBatchesAsync;
-use chgk_ledb_lib::util::ErrorToString;
-
-const ZIP_FILENAME: &str = "json.zip";
-const NEW_DB_FILENAME: &str = "db.dat";
-
-#[derive(Subcommand, Debug)]
-enum Command {
-    Write,
-    Print {
-        #[clap(value_parser, default_value = "0")]
-        id: u32,
-    },
-    ZipPrint {
-        #[clap(value_parser, default_value = "0")]
-        file_num: usize,
-        #[clap(value_parser, default_value = "0")]
-        num: usize,
-    },
-}
-
-#[derive(Parser, Debug)]
-#[clap(author, version, about, long_about = None)]
-#[clap(propagate_version = true)]
-struct Cli {
-    #[clap(subcommand)]
-    command: Command,
-    #[clap(short, long, action)]
-    measure: bool,
-}
-
-#[tokio::main]
-async fn main() {
-    let args = Cli::parse();
-
-    let mut action: Box<dyn Future<Output = _>> = match &args.command {
-        Command::Write => Box::new(write_db()),
-        Command::Print { id } => {
-            let get_question = read_from_db(*id);
-            Box::new(print_question_from(get_question))
-        }
-        Command::ZipPrint { file_num, num } => {
-            let get_question = read_from_zip(*file_num, *num);
-            Box::new(print_question_from(get_question))
-        }
-    };
-
-    if args.measure {
-        action = Box::new(measure_and_print(Box::into_pin(action)));
-    }
-
-    Box::into_pin(action).await;
-}
-
-// measure and return time elapsed in `fut` in seconds
-pub async fn measure<F: Future>(fut: F) -> f64 {
-    let start = Instant::now();
-    fut.await;
-    let elapsed = start.elapsed();
-    (elapsed.as_secs() as f64) + (elapsed.subsec_nanos() as f64 / 1_000_000_000.0)
-}
-
-pub async fn measure_and_print<F: Future>(fut: F) {
-    let m = measure(fut).await;
-    eprintln!("{}", m);
-}
-
-async fn print_question_from<F>(get_q: F)
-where
-    F: Future<Output = Result<Question, String>>,
-{
-    let q = get_q.await.expect("question not found");
-    println!("{:#?}", q)
-}
-
-async fn read_from_zip(file_num: usize, mut num: usize) -> Result<Question, String> {
-    let mut rng = thread_rng();
-    let zip_file = fs::File::open(ZIP_FILENAME).await.str_err()?;
-    let mut zip_reader = io::BufReader::new(zip_file);
-    let archive = ZipFileReader::with_tokio(&mut zip_reader).await.str_err()?;
-
-    let mut source = archive.source_questions();
-    let files_count = source.len();
-    let file_index = if file_num == 0 {
-        let files = Uniform::new(0, files_count);
-        rng.sample(files)
-    } else {
-        file_num - 1
-    };
-
-    let src = source
-        .get(file_index)
-        .await
-        .map_err(|e| format!("get file {file_num} => {e}"))?;
-    let src = stream::once(async { src });
-    pin_mut!(src);
-    let converter = src.converter();
-    let questions: Vec<_> = converter.convert().collect().await;
-    if num == 0 {
-        num = (1..=questions.len()).choose(&mut rng).unwrap();
-    }
-    let mut question = questions
-        .get(num - 1)
-        .ok_or(format!("get question #{num} => None"))?
-        .clone();
-    question.num = num as u32;
-    Ok(question)
-}
-
-async fn read_from_db(id: u32) -> Result<Question, String> {
-    let reader: async_db::Reader<Question> = async_db::Reader::new(NEW_DB_FILENAME).await?;
-
-    let len = reader.len();
-
-    let index = if id == 0 {
-        let mut rng = thread_rng();
-        let questions = Uniform::new(0, len);
-        rng.sample(questions)
-    } else {
-        id as usize - 1
-    };
-
-    reader
-        .get(index)
-        .await
-        .map_err(|e| format!("get #{index} => {e}"))
-}
-
-async fn write_db() {
-    let (tx, rx) = mpsc::unbounded_channel::<Question>();
-    tokio::try_join!(
-        tokio::spawn(zip_reader_task(tx)),
-        tokio::spawn(db_writer_task(rx))
-    )
-    .expect("tokio join");
-    println!("all done");
-}
-
-async fn zip_reader_task(tx: UnboundedSender<Question>) {
-    let mut file = fs::File::open(ZIP_FILENAME).await.expect("open zip");
-    let archive = ZipFileReader::with_tokio(&mut file)
-        .await
-        .expect("open zip file reader");
-    let mut source_questions = archive.source_questions();
-    let source_questions = source_questions.stream();
-    pin_mut!(source_questions);
-
-    source_questions
-        .converter()
-        .convert()
-        .enumerate()
-        .map(|(num, mut question)| {
-            question.num = 1 + (num as u32);
-            question
-        })
-        .for_each_concurrent(None, |question| async {
-            tx.send(question).expect("send");
-        })
-        .await;
-
-    println!("read done");
-}
-
-async fn db_writer_task(rx: UnboundedReceiver<Question>) {
-    let writer_opts = WriterOpts::default();
-    let mut writer: async_db::Writer<Question> =
-        async_db::Writer::new(NEW_DB_FILENAME, writer_opts)
-            .await
-            .unwrap_or_else(|e| panic!("db writer load, {e:#?}"));
-
-    let stream: UnboundedReceiverStream<_> = rx.into();
-    let stream = stream;
-    writer.load(stream).await.expect("load");
-    writer.finish().await.expect("db writer finish");
-
-    println!("write done");
-}

benches/db_bench.rs

@@ -1,50 +1,34 @@
 #[macro_use]
 extern crate criterion;
-extern crate bincode;
-extern crate serde;
-extern crate serde_derive;
-extern crate serde_json;
-extern crate tempfile;
 
-use chgk_ledb_lib::db;
+#[path = "../src/db.rs"]
-use std::path::Path;
+mod db;
+use std::path::PathBuf;
 
 use db::{Reader, Writer, WriterOpts};
 
 use criterion::{BatchSize, Criterion};
-use tempfile::{tempdir, NamedTempFile};
+use tempfile::tempdir;
 
-use serde_derive::{Deserialize, Serialize};
+#[derive(bincode::Encode, bincode::Decode, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
-
-#[derive(
-    bincode::Encode,
-    bincode::Decode,
-    Clone,
-    Debug,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Serialize,
-    Deserialize,
-)]
 struct TestData {
-    num1: u64,
+    num: u128,
-    num2: u64,
     test: String,
 }
 
 const N: usize = 4096;
 
 fn gen_data(count: usize) -> impl Iterator<Item = TestData> {
-    (0..count).map(|i| 143 + i as u64).map(|i| TestData {
+    (0..count)
-        num1: i,
+        .into_iter()
-        num2: (i * 100) ^ 0xDF0E441122334455,
+        .map(|i| 143 + i as u128)
+        .map(|i| TestData {
+            num: i,
             test: "test ---- Test ____".repeat(123 + i as usize % 15),
         })
 }
 
-fn prepare_db_writer<P: AsRef<Path>>(path: P) -> Writer<TestData> {
+fn prepare_db_writer(path: &PathBuf) -> Writer<TestData> {
     let opts = WriterOpts {
         compress_lvl: 1,
         data_buf_size: 100 * 1024 * 1024,
@@ -57,9 +41,7 @@ fn prepare_db_writer<P: AsRef<Path>>(path: P) -> Writer<TestData> {
 
 fn db_read(c: &mut Criterion) {
     let dir = tempdir().expect("tempdir");
-    let tmpfile = NamedTempFile::new_in(dir.path())
+    let tmpfile = dir.path().join("test.tmp");
-        .expect("new tempfile")
-        .into_temp_path();
     let mut writer = prepare_db_writer(&tmpfile);
 
     let mut items_iter = gen_data(N).collect::<Vec<TestData>>().into_iter();
@@ -72,8 +54,9 @@ fn db_read(c: &mut Criterion) {
                 let reader: Reader<TestData> = Reader::new(&tmpfile, 2048).expect("new reader");
                 reader
             },
-            |reader| {
+            |mut reader| {
-                for item in reader {
+                let mut reader_iter = reader.iter();
+                while let Some(item) = reader_iter.next() {
                     drop(item);
                 }
             },
@@ -84,13 +67,10 @@ fn db_read(c: &mut Criterion) {
 
 fn db_write(c: &mut Criterion) {
     let dir = tempdir().expect("tempdir");
-
+    let tmpfile = dir.path().join("test.tmp");
     c.bench_function("write", |b| {
         b.iter_batched(
             || {
-                let tmpfile = NamedTempFile::new_in(dir.path())
-                    .expect("new tempfile")
-                    .into_temp_path();
                 let src = gen_data(N).collect::<Vec<TestData>>().into_iter();
                 let writer = prepare_db_writer(&tmpfile);
                 (src, writer)

lib/Cargo.toml

@@ -1,76 +0,0 @@
-[package]
-name = "chgk_ledb_lib"
-version = "1.2.0"
-authors = ["Dmitry <b4tm4n@mail.ru>"]
-edition = "2021"
-repository = "https://gitea.b4tman.ru/b4tman/chgk_ledb"
-license = "MIT"
-description = "Библиотека для доступа к файлу базы данных вопросов ЧГК"
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[features]
-default = []
-sync = ["zstd", "memmap"]
-async = [
-    "futures",
-    "futures-core",
-    "futures-util",
-    "fmmap",
-    "tokio",
-    "async-compression",
-    "async-stream",
-    "pin-project",
-]
-source = ["zip"]
-source_async = [
-    "async_zip",
-    "tokio",
-    "futures",
-    "futures-core",
-    "futures-util",
-    "async-stream",
-]
-convert = ["zip"]
-convert_async = [
-    "futures",
-    "futures-core",
-    "futures-util",
-    "async-stream",
-    "async_zip",
-    "tokio",
-]
-
-[dependencies]
-serde = "1.0"
-serde_derive = "1.0"
-serde_json = "1.0"
-bincode = "^2.0.0-rc.2"
-zip = { version = "0.6", optional = true }
-async_zip = { version = "0.0.15" , features = [
-    "zstd",
-    "tokio",
-    "tokio-fs",
-], optional = true }
-fmmap = { version = "0.3", features = ["tokio-async"], optional = true }
-tokio = { version = "1", features = [
-    "fs",
-    "io-util",
-    "rt",
-    "macros",
-], optional = true }
-futures-core = { version = "0.3", optional = true }
-futures = { version = "0.3", optional = true }
-futures-util = { version = "0.3", optional = true }
-async-compression = { version = "0.4.1", default-features = false, features = [
-    "zstd",
-    "tokio",
-], optional = true }
-async-stream = { version = "0.3", optional = true }
-zstd = { version = "^0.12", default-features = false, optional = true }
-memmap = { version = "0.7.0", optional = true }
-pin-project = { version = "1.1.3", optional = true }
-
-[dev-dependencies]
-insta = { version = "1.31.0", features = ["yaml"] }
-tempfile = "3.3"

lib/src/async_db.rs

@@ -1,787 +0,0 @@
-use std::marker::PhantomData;
-use std::ops::Deref;
-use std::vec;
-use std::{path::Path, sync::Arc};
-
-use async_compression::tokio::bufread::ZstdDecoder;
-use async_compression::tokio::bufread::ZstdEncoder;
-use async_compression::Level;
-use futures::sink::Sink;
-use futures::stream::StreamExt;
-use futures_core::stream::Stream;
-use futures_core::Future;
-use futures_util::pin_mut;
-
-use std::pin::Pin;
-use std::task::{Context, Poll};
-
-use tokio::{
-    fs,
-    io::{self, AsyncReadExt, AsyncWriteExt},
-};
-
-use fmmap::tokio::{AsyncMmapFile, AsyncMmapFileExt, AsyncOptions};
-
-type LSize = u32;
-const LEN_SIZE: usize = std::mem::size_of::<LSize>();
-const BINCODE_CFG: bincode::config::Configuration = bincode::config::standard();
-
-use crate::util::BincodeVecWriter;
-use crate::util::ErrorToString;
-
-pub struct WriterOpts {
-    pub compress_lvl: Level,
-    pub data_buf_size: usize,
-    pub out_buf_size: usize,
-    pub current_buf_size: usize,
-}
-
-impl Default for WriterOpts {
-    fn default() -> Self {
-        Self {
-            compress_lvl: Level::Default,
-            data_buf_size: 500 * 1024 * 1024,
-            out_buf_size: 200 * 1024 * 1024,
-            current_buf_size: 100 * 1024,
-        }
-    }
-}
-
-pub struct Writer<T>
-where
-    T: bincode::Encode,
-{
-    out: io::BufWriter<fs::File>,
-    data_buf: Vec<u8>,
-    cur_buf_item: BincodeVecWriter,
-    table: Vec<LSize>,
-    compress_lvl: Level,
-    _t: PhantomData<Arc<T>>,
-}
-
-impl<T> Writer<T>
-where
-    T: bincode::Encode,
-{
-    pub async fn new<P: AsRef<Path>>(path: P, opts: WriterOpts) -> Result<Self, String> {
-        let out = fs::File::create(path).await.str_err()?;
-        let out = io::BufWriter::with_capacity(opts.out_buf_size, out);
-        let data_buf: Vec<u8> = Vec::with_capacity(opts.data_buf_size);
-        let cur_buf_item: Vec<u8> = Vec::with_capacity(opts.current_buf_size);
-        let cur_buf_item = BincodeVecWriter::new(cur_buf_item);
-
-        let compress_lvl = opts.compress_lvl;
-
-        let table: Vec<LSize> = vec![];
-
-        Ok(Self {
-            out,
-            data_buf,
-            cur_buf_item,
-            table,
-            compress_lvl,
-            _t: PhantomData,
-        })
-    }
-
-    pub async fn push(&mut self, item: T) -> Result<(), String> {
-        self.push_by_ref(&item).await
-    }
-
-    pub async fn push_by_ref(&mut self, item: &T) -> Result<(), String> {
-        let pos: LSize = self.data_buf.len() as LSize;
-
-        bincode::encode_into_writer(item, &mut self.cur_buf_item, BINCODE_CFG).str_err()?;
-
-        let mut zencoder = ZstdEncoder::with_quality(&self.cur_buf_item[..], self.compress_lvl);
-        io::copy(&mut zencoder, &mut self.data_buf)
-            .await
-            .str_err()?;
-        self.cur_buf_item.clear();
-
-        self.table.push(pos);
-
-        // FIXME
-        // this will break WriterSink::poll_ready (will wait forever), but not Writer::load
-        // tokio::time::sleep(std::time::Duration::from_secs(1)).await;
-
-        Ok(())
-    }
-
-    pub async fn load<S>(&mut self, source: S) -> Result<(), String>
-    where
-        S: Stream<Item = T> + std::marker::Unpin,
-    {
-        let hint = source.size_hint();
-        let hint = std::cmp::max(hint.0, hint.1.unwrap_or(0));
-        if hint > 0 {
-            self.table.reserve(hint);
-        }
-
-        pin_mut!(source);
-        while let Some(item) = source.next().await {
-            self.push(item).await?;
-        }
-
-        Ok(())
-    }
-
-    pub async fn finish(mut self) -> Result<(), String> {
-        // finish tab
-        let pos: LSize = self.data_buf.len() as LSize;
-        self.table.push(pos);
-
-        // write tab
-        let tab_size = (self.table.len() * LEN_SIZE) as LSize;
-        for pos in self.table {
-            let pos_data = (pos + tab_size).to_le_bytes();
-            self.out.write_all(&pos_data).await.str_err()?;
-        }
-        // copy data
-        self.out.write_all(&self.data_buf[..]).await.str_err()?;
-
-        self.out.flush().await.str_err()?;
-        Ok(())
-    }
-
-    pub fn sink(&mut self) -> WriterSink<'_, T> {
-        WriterSink {
-            writer: self,
-            item: None,
-        }
-    }
-}
-
-use pin_project::pin_project;
-
-#[pin_project]
-/// FIXME: not really async
-/// only work when ..push.poll() returns Ready immediately
-pub struct WriterSink<'a, T>
-where
-    T: bincode::Encode,
-{
-    #[pin]
-    writer: &'a mut Writer<T>,
-    item: Option<T>,
-}
-
-impl<'a, T> Sink<T> for WriterSink<'a, T>
-where
-    T: bincode::Encode,
-{
-    type Error = String;
-
-    fn poll_ready(
-        self: std::pin::Pin<&mut Self>,
-        ctx: &mut std::task::Context<'_>,
-    ) -> Poll<Result<(), String>> {
-        let mut this = self.project();
-
-        if this.item.is_none() {
-            return Poll::Ready(Ok(()));
-        }
-
-        let item = this.item.take().unwrap();
-
-        let push_fut = this.writer.push(item); // FIXME:: how to save this future???
-        pin_mut!(push_fut);
-        push_fut.poll(ctx)
-    }
-
-    fn start_send(self: std::pin::Pin<&mut Self>, item: T) -> Result<(), Self::Error> {
-        let this = self.project();
-        *this.item = Some(item);
-        Ok(())
-    }
-
-    fn poll_flush(
-        self: std::pin::Pin<&mut Self>,
-        ctx: &mut std::task::Context<'_>,
-    ) -> Poll<Result<(), Self::Error>> {
-        self.poll_ready(ctx)
-    }
-
-    fn poll_close(
-        mut self: std::pin::Pin<&mut Self>,
-        ctx: &mut std::task::Context<'_>,
-    ) -> Poll<Result<(), Self::Error>> {
-        futures::ready!(self.as_mut().poll_ready(ctx))?;
-        Poll::Ready(Ok(()))
-    }
-}
-
-pub struct Reader<T>
-where
-    T: bincode::Decode,
-{
-    mmap: AsyncMmapFile,
-    count: usize,
-    first_pos: LSize,
-    _t: PhantomData<Arc<T>>,
-}
-
-impl<T> Reader<T>
-where
-    T: bincode::Decode,
-{
-    pub async fn new<P: AsRef<Path>>(path: P) -> Result<Self, String> {
-        let mmap = AsyncOptions::new()
-            .read(true)
-            .open_mmap_file(path)
-            .await
-            .str_err()?;
-        mmap.try_lock_shared().str_err()?;
-
-        // read first pos and records count
-        let first_data: [u8; LEN_SIZE] = mmap.bytes(0, LEN_SIZE).str_err()?.try_into().str_err()?;
-        let first_pos = LSize::from_le_bytes(first_data);
-        let tab_len = (first_pos as usize) / LEN_SIZE;
-        let count = tab_len - 1;
-
-        Ok(Self {
-            mmap,
-            count,
-            first_pos,
-            _t: PhantomData,
-        })
-    }
-
-    pub fn len(&self) -> usize {
-        self.count
-    }
-
-    pub fn is_empty(&self) -> bool {
-        0 == self.len()
-    }
-
-    /// get item at index, reuse data buffer
-    pub async fn get_with_buf(&self, index: usize, data_buf: &mut Vec<u8>) -> Result<T, String> {
-        if index >= self.len() {
-            return Err("index out of range".into());
-        }
-
-        let next_pos: usize = (index + 1) * LEN_SIZE;
-
-        // read item data pos
-        let data_pos = if 0 == index {
-            self.first_pos
-        } else {
-            let tab_pos: usize = index * LEN_SIZE;
-            let pos_curr_data: [u8; LEN_SIZE] = self
-                .mmap
-                .bytes(tab_pos, LEN_SIZE)
-                .str_err()?
-                .try_into()
-                .str_err()?;
-            LSize::from_le_bytes(pos_curr_data)
-        } as usize;
-
-        // read next item pos
-        let pos_next_data: [u8; LEN_SIZE] = self
-            .mmap
-            .bytes(next_pos, LEN_SIZE)
-            .str_err()?
-            .try_into()
-            .str_err()?;
-        let data_pos_next = LSize::from_le_bytes(pos_next_data) as usize;
-        let data_len = data_pos_next - data_pos;
-
-        // read & unpack item data
-        let mut decoder = ZstdDecoder::new(self.mmap.range_reader(data_pos, data_len).str_err()?);
-        decoder.read_to_end(data_buf).await.str_err()?;
-
-        // decode item
-        let item: (T, usize) = bincode::decode_from_slice(data_buf, BINCODE_CFG).str_err()?;
-
-        data_buf.clear();
-        Ok(item.0)
-    }
-
-    /// get item at index
-    pub async fn get(&self, index: usize) -> Result<T, String> {
-        let mut data_buf: Vec<u8> = vec![];
-        self.get_with_buf(index, &mut data_buf).await
-    }
-
-    pub fn stream(&self) -> ReaderStream<'_, T> {
-        ReaderStream::new(self)
-    }
-}
-
-pub struct ReaderStream<'a, T>
-where
-    T: bincode::Decode,
-{
-    reader: &'a Reader<T>,
-    index: Option<usize>,
-}
-
-impl<'a, T> ReaderStream<'a, T>
-where
-    T: bincode::Decode,
-{
-    fn new(reader: &'a Reader<T>) -> Self {
-        ReaderStream {
-            reader,
-            index: None,
-        }
-    }
-}
-
-impl<'a, T> Stream for ReaderStream<'a, T>
-where
-    T: bincode::Decode,
-{
-    type Item = T;
-
-    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<T>> {
-        if self.index.is_none() && !self.reader.is_empty() {
-            self.index = Some(0);
-        }
-
-        if self.index.unwrap() == self.reader.len() {
-            return Poll::Ready(None);
-        }
-
-        // FIXME: mayby work only if reader.get().poll() return Ready immediately
-        let future = self.reader.get(self.index.unwrap());
-        pin_mut!(future);
-        match Pin::new(&mut future).poll(cx) {
-            Poll::Ready(Ok(item)) => {
-                self.index = Some(self.index.unwrap() + 1);
-                Poll::Ready(Some(item))
-            }
-            Poll::Ready(Err(_)) => Poll::Ready(None),
-            Poll::Pending => Poll::Pending,
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.reader.len();
-        if self.index.is_none() {
-            return (len, Some(len));
-        }
-
-        let index = self.index.unwrap();
-        let rem = if len > index + 1 {
-            len - (index + 1)
-        } else {
-            0
-        };
-        (rem, Some(rem))
-    }
-}
-
-pub struct BufReader<T>
-where
-    T: bincode::Decode,
-{
-    inner: Reader<T>,
-    buf: Vec<u8>,
-}
-
-impl<T> BufReader<T>
-where
-    T: bincode::Decode,
-{
-    pub async fn new<P: AsRef<Path>>(path: P, buf_size: usize) -> Result<Self, String> {
-        match Reader::<T>::new(path).await {
-            Ok(inner) => Ok(Self {
-                inner,
-                buf: Vec::with_capacity(buf_size),
-            }),
-            Err(e) => Err(e),
-        }
-    }
-
-    pub async fn get(&mut self, index: usize) -> Result<T, String> {
-        self.inner.get_with_buf(index, &mut self.buf).await
-    }
-
-    pub fn into_inner(self) -> Reader<T> {
-        self.inner
-    }
-
-    pub fn stream(self) -> BufReaderStream<T> {
-        BufReaderStream::new(self)
-    }
-}
-
-impl<T> From<Reader<T>> for BufReader<T>
-where
-    T: bincode::Decode,
-{
-    fn from(inner: Reader<T>) -> Self {
-        Self {
-            inner,
-            buf: Vec::new(),
-        }
-    }
-}
-
-impl<T> From<BufReader<T>> for Reader<T>
-where
-    T: bincode::Decode,
-{
-    fn from(value: BufReader<T>) -> Self {
-        value.into_inner()
-    }
-}
-
-impl<T> Deref for BufReader<T>
-where
-    T: bincode::Decode,
-{
-    type Target = Reader<T>;
-    fn deref(&self) -> &Self::Target {
-        &self.inner
-    }
-}
-
-pub struct BufReaderStream<T>
-where
-    T: bincode::Decode,
-{
-    reader: BufReader<T>,
-    index: Option<usize>,
-}
-
-impl<T> BufReaderStream<T>
-where
-    T: bincode::Decode,
-{
-    fn new(reader: BufReader<T>) -> Self {
-        BufReaderStream {
-            reader,
-            index: None,
-        }
-    }
-
-    async fn get_next(&mut self) -> Result<T, String> {
-        match self.index {
-            None => Err("index is None".into()),
-            Some(index) => {
-                let res = self.reader.get(index).await;
-                self.index = Some(index + 1);
-
-                res
-            }
-        }
-    }
-}
-
-impl<T> Stream for BufReaderStream<T>
-where
-    T: bincode::Decode,
-{
-    type Item = T;
-
-    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<T>> {
-        if self.index.is_none() && !self.reader.is_empty() {
-            self.index = Some(0);
-        }
-
-        if self.index.unwrap() == self.reader.len() {
-            return Poll::Ready(None);
-        }
-
-        // FIXME: mayby work only if reader.get().poll() return Ready immediately
-        let future = self.get_next();
-        pin_mut!(future);
-        match Pin::new(&mut future).poll(cx) {
-            Poll::Ready(Ok(item)) => Poll::Ready(Some(item)),
-            Poll::Ready(Err(_)) => Poll::Ready(None),
-            Poll::Pending => Poll::Pending,
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.reader.len();
-        if self.index.is_none() {
-            return (len, Some(len));
-        }
-
-        let index = self.index.unwrap();
-        let rem = if len > index + 1 {
-            len - (index + 1)
-        } else {
-            0
-        };
-        (rem, Some(rem))
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-    use core::fmt::Debug;
-    use tempfile::tempdir;
-
-    #[derive(bincode::Encode, bincode::Decode, Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
-    struct TestData {
-        num: u64,
-        test: String,
-        vnum: Vec<u64>,
-        vstr: Vec<String>,
-    }
-
-    fn gen_data(count: usize) -> impl Iterator<Item = TestData> {
-        (0..count).map(|i| TestData {
-            num: i as u64,
-            test: "test".repeat(i),
-            vnum: (0..i * 120).map(|x| (x ^ 0x345FE34) as u64).collect(),
-            vstr: (0..i * 111).map(|x| "test".repeat(x)).collect(),
-        })
-    }
-
-    async fn assert_data_eq((x, y): (&TestData, TestData)) {
-        assert_eq!(*x, y);
-    }
-
-    #[tokio::test]
-    async fn test_write() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone());
-        pin_mut!(src);
-        writer.load(src).await.expect("load");
-        writer.finish().await.expect("finish write");
-    }
-
-    #[tokio::test]
-    async fn test_write_read() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone());
-        pin_mut!(src);
-        writer.load(src).await.expect("load");
-        writer.finish().await.expect("finish write");
-
-        let reader: Reader<TestData> = Reader::new(&tmpfile).await.expect("new reader");
-        assert_eq!(items.len(), reader.len());
-
-        for (idx, item) in items.iter().enumerate() {
-            let ritem = reader.get(idx).await.expect("get");
-            assert_eq!(*item, ritem);
-        }
-    }
-
-    #[tokio::test]
-    async fn test_write_sink_read() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone()).map(Ok);
-        pin_mut!(src);
-        src.forward(writer.sink()).await.expect("forward");
-        writer.finish().await.expect("finish write");
-
-        let reader: Reader<TestData> = Reader::new(&tmpfile).await.expect("new reader");
-        assert_eq!(items.len(), reader.len());
-
-        for (idx, item) in items.iter().enumerate() {
-            let ritem = reader.get(idx).await.expect("get");
-            assert_eq!(*item, ritem);
-        }
-    }
-
-    #[tokio::test]
-    async fn test_write_read_get_with_buf() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone());
-        pin_mut!(src);
-        writer.load(src).await.expect("load");
-        writer.finish().await.expect("finish write");
-
-        let reader: Reader<TestData> = Reader::new(&tmpfile).await.expect("new reader");
-        assert_eq!(items.len(), reader.len());
-
-        for (idx, item) in items.iter().enumerate() {
-            let mut data_buf: Vec<u8> = vec![];
-            let ritem = reader.get_with_buf(idx, &mut data_buf).await.expect("get");
-            assert_eq!(*item, ritem);
-        }
-    }
-
-    #[tokio::test]
-    async fn test_write_read_stream() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone());
-        pin_mut!(src);
-        writer.load(src).await.expect("load");
-        writer.finish().await.expect("finish write");
-
-        let reader: Reader<TestData> = Reader::new(&tmpfile).await.expect("new reader");
-        assert_eq!(items.len(), reader.len());
-
-        let dst_stream = reader.stream();
-        let src_stream = futures::stream::iter(items.iter());
-
-        let mut count = 0;
-        src_stream
-            .zip(dst_stream)
-            .map(|x| {
-                count += 1;
-                x
-            })
-            .for_each(assert_data_eq)
-            .await;
-        assert_eq!(count, items.len())
-    }
-    /// sharing Reader instance between threads
-    #[tokio::test]
-    async fn test_share_reader() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone());
-        pin_mut!(src);
-        writer.load(src).await.expect("load");
-        writer.finish().await.expect("finish write");
-
-        let reader: Reader<TestData> = Reader::new(&tmpfile).await.expect("new reader");
-        assert_eq!(items.len(), reader.len());
-
-        let reader = Arc::new(reader);
-        for _ in 0..=3 {
-            let cur_items = items.clone();
-            let cur_reader = Arc::clone(&reader);
-            tokio::spawn(async move {
-                let dst_stream = cur_reader.stream();
-                let src_stream = futures::stream::iter(cur_items.iter());
-
-                src_stream.zip(dst_stream).for_each(assert_data_eq).await;
-            });
-        }
-    }
-
-    #[tokio::test]
-    async fn test_write_bufread() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone());
-        pin_mut!(src);
-        writer.load(src).await.expect("load");
-        writer.finish().await.expect("finish write");
-
-        let mut reader = BufReader::<TestData>::new(&tmpfile, 4096)
-            .await
-            .expect("new buf reader");
-        assert_eq!(items.len(), reader.len());
-
-        for (idx, item) in items.iter().enumerate() {
-            let ritem = reader.get(idx).await.expect("get");
-            assert_eq!(*item, ritem);
-        }
-    }
-
-    #[tokio::test]
-    async fn test_write_bufread_stream() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            ..Default::default()
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).await.expect("new writer");
-
-        let items_iter = gen_data(5);
-        let items: Vec<TestData> = items_iter.collect();
-
-        let src = futures::stream::iter(items.clone());
-        pin_mut!(src);
-        writer.load(src).await.expect("load");
-        writer.finish().await.expect("finish write");
-
-        let reader = BufReader::<TestData>::new(&tmpfile, 4096)
-            .await
-            .expect("new buf reader");
-        assert_eq!(items.len(), reader.len());
-
-        let dst_stream = reader.stream();
-        let src_stream = futures::stream::iter(items.iter());
-
-        let mut count = 0;
-        src_stream
-            .zip(dst_stream)
-            .map(|x| {
-                count += 1;
-                x
-            })
-            .for_each(assert_data_eq)
-            .await;
-        assert_eq!(count, items.len())
-    }
-}

lib/src/lib.rs

@@ -1,13 +0,0 @@
-#[cfg(feature = "async")]
-pub mod async_db;
-#[cfg(feature = "sync")]
-pub mod db;
-pub mod questions;
-#[cfg(any(
-    feature = "source",
-    feature = "source_async",
-    feature = "convert",
-    feature = "convert_async"
-))]
-pub mod source;
-pub mod util;

lib/src/questions.rs

@@ -1,398 +0,0 @@
-use serde_derive::{Deserialize, Serialize};
-
-#[derive(
-    Debug, Default, Clone, Serialize, Deserialize, bincode::Decode, bincode::Encode, PartialEq,
-)]
-pub struct BatchInfo {
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub filename: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub description: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub author: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub comment: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub url: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub date: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub processed_by: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub redacted_by: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub copyright: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub theme: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub kind: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub source: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub rating: String,
-}
-
-#[derive(
-    Debug, Default, Clone, Serialize, Deserialize, bincode::Decode, bincode::Encode, PartialEq,
-)]
-pub struct Question {
-    #[serde(default, skip_serializing_if = "u32_is_zero")]
-    pub num: u32,
-    pub id: String,
-
-    pub description: String,
-    pub answer: String,
-
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub author: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub comment: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub comment1: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub tour: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub url: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub date: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub processed_by: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub redacted_by: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub copyright: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub theme: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub kind: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub source: String,
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub rating: String,
-    #[serde(default, skip_serializing_if = "BatchInfo::is_default")]
-    pub batch_info: BatchInfo,
-}
-
-fn u32_is_zero(num: &u32) -> bool {
-    *num == 0
-}
-
-impl BatchInfo {
-    pub fn is_default(&self) -> bool {
-        *self == BatchInfo::default()
-    }
-}
-
-#[cfg(any(feature = "convert", feature = "convert_async"))]
-pub mod convert_common {
-    use super::{BatchInfo, Question};
-    use crate::source::{SourceQuestion, SourceQuestionsBatch};
-
-    macro_rules! make {
-        ($Target:ident; by {$($field:ident),+}; from $src:expr) => {$Target {$(
-            $field: $src.$field
-        ),+}};
-        ($Target:ident; with defaults and by {$($field:ident),+}; from $src:expr) => {$Target {$(
-            $field: $src.$field
-        ),+ ,..$Target::default()}}
-    }
-
-    impl From<SourceQuestion> for Question {
-        fn from(src: SourceQuestion) -> Self {
-            make! {Self; with defaults and by {
-                num, id, description, answer, author, comment, comment1, tour, url,
-                date, processed_by, redacted_by, copyright, theme, kind, source, rating
-            }; from src}
-        }
-    }
-
-    impl From<SourceQuestionsBatch> for BatchInfo {
-        fn from(src: SourceQuestionsBatch) -> Self {
-            make! {Self; by {
-                filename, description, author, comment, url, date,
-                processed_by, redacted_by, copyright, theme, kind, source, rating
-            }; from src}
-        }
-    }
-
-    impl From<SourceQuestionsBatch> for Vec<Question> {
-        fn from(src: SourceQuestionsBatch) -> Self {
-            let mut src = src;
-            let mut questions: Vec<SourceQuestion> = vec![];
-            std::mem::swap(&mut src.questions, &mut questions);
-            let mut result: Vec<Question> = questions.into_iter().map(|item| item.into()).collect();
-            let batch_info = BatchInfo::from(src);
-            result.iter_mut().for_each(|question| {
-                question.batch_info = batch_info.clone();
-            });
-
-            result
-        }
-    }
-}
-
-#[cfg(feature = "convert")]
-pub mod convert {
-    use super::Question;
-    use crate::source::SourceQuestionsBatch;
-
-    pub trait QuestionsConverter {
-        fn convert<'a>(&'a mut self) -> Box<dyn Iterator<Item = Question> + 'a>;
-    }
-
-    impl<T> QuestionsConverter for T
-    where
-        T: Iterator<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>,
-    {
-        fn convert<'a>(&'a mut self) -> Box<dyn Iterator<Item = Question> + 'a> {
-            let iter = self
-                .filter(|(_, data)| data.is_ok())
-                .flat_map(|(filename, data)| {
-                    let mut batch = data.unwrap();
-                    batch.filename = filename;
-                    let questions: Vec<Question> = batch.into();
-                    questions
-                });
-            Box::new(iter)
-        }
-    }
-
-    #[cfg(test)]
-    mod test {
-        use crate::questions::test::convert_common::sample_batch;
-
-        use super::*;
-        use insta::assert_yaml_snapshot;
-        use std::iter;
-
-        #[test]
-        fn test_convert() {
-            let mut source = iter::once((
-                String::from("test.json"),
-                Ok::<SourceQuestionsBatch, serde_json::Error>(sample_batch()),
-            ));
-            let converted: Vec<_> = source.convert().collect();
-            assert_yaml_snapshot!(converted, @r#"
-            ---
-            - id: Вопрос 1
-              description: Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2
-              answer: "42"
-              batch_info:
-                filename: test.json
-                description: Тестовый
-                date: 00-000-2000
-            - id: Вопрос 2
-              description: Зимой и летом одним цветом
-              answer: ёлка
-              batch_info:
-                filename: test.json
-                description: Тестовый
-                date: 00-000-2000
-              
-            "#);
-        }
-    }
-}
-#[cfg(feature = "convert")]
-pub use convert::QuestionsConverter;
-
-#[cfg(feature = "convert_async")]
-pub mod convert_async {
-    use futures::stream;
-    use futures_core::stream::Stream;
-    use futures_util::StreamExt;
-
-    use super::Question;
-    use crate::source::SourceQuestionsBatch;
-
-    pub struct QuestionsConverterAsync<T>
-    where
-        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
-            + std::marker::Unpin,
-    {
-        inner: T,
-    }
-
-    impl<T> From<T> for QuestionsConverterAsync<T>
-    where
-        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
-            + std::marker::Unpin,
-    {
-        fn from(inner: T) -> Self {
-            Self { inner }
-        }
-    }
-
-    pub trait QuestionsConverterAsyncForStream<T>
-    where
-        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
-            + std::marker::Unpin,
-    {
-        fn converter(&mut self) -> QuestionsConverterAsync<&mut T>;
-    }
-
-    impl<T> QuestionsConverterAsyncForStream<T> for T
-    where
-        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
-            + std::marker::Unpin,
-    {
-        fn converter(&mut self) -> QuestionsConverterAsync<&mut T> {
-            QuestionsConverterAsync::from(self)
-        }
-    }
-
-    impl<T> QuestionsConverterAsync<T>
-    where
-        T: Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>
-            + std::marker::Unpin,
-    {
-        pub fn convert(self) -> impl Stream<Item = Question> {
-            self.inner
-                .filter_map(|(name, res)| async move {
-                    if let Ok(item) = res {
-                        Some((name, item))
-                    } else {
-                        None
-                    }
-                })
-                .flat_map(|(filename, batch)| {
-                    stream::iter({
-                        let mut batch = batch;
-                        batch.filename = filename;
-                        let questions: Vec<Question> = batch.into();
-                        questions
-                    })
-                })
-        }
-    }
-
-    #[cfg(test)]
-    mod test {
-        use crate::questions::test::convert_common::sample_batch;
-
-        use super::*;
-        use futures_util::{pin_mut, StreamExt};
-        use insta::assert_yaml_snapshot;
-
-        #[tokio::test]
-        async fn test_convert_stream() {
-            let source = futures::stream::once(async {
-                (
-                    String::from("test.json"),
-                    Ok::<SourceQuestionsBatch, serde_json::Error>(sample_batch()),
-                )
-            });
-
-            pin_mut!(source);
-            let converter = source.converter();
-            let converter = converter.convert();
-            let converted: Vec<_> = converter.collect().await;
-            assert_yaml_snapshot!(converted, @r#"
-            ---
-            - id: Вопрос 1
-              description: Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2
-              answer: "42"
-              batch_info:
-                filename: test.json
-                description: Тестовый
-                date: 00-000-2000
-            - id: Вопрос 2
-              description: Зимой и летом одним цветом
-              answer: ёлка
-              batch_info:
-                filename: test.json
-                description: Тестовый
-                date: 00-000-2000
-              
-            "#);
-        }
-    }
-}
-#[cfg(feature = "convert_async")]
-pub use convert_async::{QuestionsConverterAsync, QuestionsConverterAsyncForStream};
-
-#[cfg(test)]
-mod test {
-    use super::*;
-    use insta::assert_yaml_snapshot;
-    use serde_json::json;
-
-    #[cfg(any(feature = "convert", feature = "convert_async"))]
-    pub mod convert_common {
-        use crate::source::{SourceQuestion, SourceQuestionsBatch};
-
-        pub fn sample_batch() -> SourceQuestionsBatch {
-            SourceQuestionsBatch {
-                description: "Тестовый".into(),
-                date: "00-000-2000".into(),
-                questions: vec![
-                    SourceQuestion {
-                        id: "Вопрос 1".into(),
-                        description: "Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2".into(),
-                        answer: "42".into(),
-                        ..Default::default()
-                    },
-                    SourceQuestion {
-                        id: "Вопрос 2".into(),
-                        description: "Зимой и летом одним цветом".into(),
-                        answer: "ёлка".into(),
-                        ..Default::default()
-                    },
-                ],
-                ..Default::default()
-            }
-        }
-    }
-
-    pub fn sample_question() -> Question {
-        Question {
-            id: "Вопрос 1".into(),
-            description: "Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2".into(),
-            answer: "42".into(),
-            batch_info: BatchInfo {
-                description: "Тестовый".into(),
-                date: "00-000-2000".into(),
-                ..Default::default()
-            },
-            ..Default::default()
-        }
-    }
-
-    #[test]
-    fn test_question_ser() {
-        assert_yaml_snapshot!(sample_question(), @r#"
-            ---
-            id: Вопрос 1
-            description: Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2
-            answer: "42"
-            batch_info:
-              description: Тестовый
-              date: 00-000-2000
-              
-            "#);
-    }
-    #[test]
-    fn test_question_de() {
-        let question_from_json: Result<Question, _> = serde_json::from_value(json!({
-            "id": "Вопрос 1",
-            "description": "Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2",
-            "answer": "42",
-            "batch_info": {
-                "description": "Тестовый",
-                "date": "00-000-2000"
-            }
-        }));
-        assert!(question_from_json.is_ok());
-
-        assert_yaml_snapshot!(question_from_json.unwrap(), @r#"
-        ---
-        id: Вопрос 1
-        description: Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2
-        answer: "42"
-        batch_info:
-          description: Тестовый
-          date: 00-000-2000
-          
-        "#);
-    }
-}

lib/src/source.rs

@@ -1,579 +0,0 @@
-use serde_derive::{Deserialize, Serialize};
-
-#[derive(Debug, Default, Clone, Serialize, Deserialize, PartialEq)]
-pub struct SourceQuestion {
-    #[serde(default, skip_serializing_if = "u32_is_zero")]
-    pub num: u32,
-    #[serde(default)]
-    pub id: String,
-
-    #[serde(alias = "Вопрос")]
-    pub description: String,
-    #[serde(alias = "Ответ")]
-    pub answer: String,
-
-    #[serde(alias = "Автор", default, skip_serializing_if = "String::is_empty")]
-    pub author: String,
-    #[serde(
-        default,
-        alias = "Комментарий",
-        skip_serializing_if = "String::is_empty"
-    )]
-    pub comment: String,
-    #[serde(
-        default,
-        alias = "Комментарии",
-        alias = "Инфо",
-        skip_serializing_if = "String::is_empty"
-    )]
-    pub comment1: String,
-    #[serde(default, alias = "Тур", skip_serializing_if = "String::is_empty")]
-    pub tour: String,
-    #[serde(
-        default,
-        alias = "Ссылка",
-        alias = "URL",
-        skip_serializing_if = "String::is_empty"
-    )]
-    pub url: String,
-    #[serde(default, alias = "Дата", skip_serializing_if = "String::is_empty")]
-    pub date: String,
-    #[serde(default, alias = "Обработан", skip_serializing_if = "String::is_empty")]
-    pub processed_by: String,
-    #[serde(default, alias = "Редактор", skip_serializing_if = "String::is_empty")]
-    pub redacted_by: String,
-    #[serde(default, alias = "Копирайт", skip_serializing_if = "String::is_empty")]
-    pub copyright: String,
-    #[serde(default, alias = "Тема", skip_serializing_if = "String::is_empty")]
-    pub theme: String,
-    #[serde(
-        default,
-        alias = "Вид",
-        alias = "Тип",
-        skip_serializing_if = "String::is_empty"
-    )]
-    pub kind: String,
-    #[serde(default, alias = "Источник", skip_serializing_if = "String::is_empty")]
-    pub source: String,
-    #[serde(default, alias = "Рейтинг", skip_serializing_if = "String::is_empty")]
-    pub rating: String,
-}
-
-#[derive(Debug, Default, Clone, Serialize, Deserialize, PartialEq)]
-pub struct SourceQuestionsBatch {
-    #[serde(default, skip_serializing_if = "String::is_empty")]
-    pub filename: String,
-    #[serde(alias = "Пакет", alias = "Чемпионат")]
-    pub description: String,
-    #[serde(default, alias = "Автор", skip_serializing_if = "String::is_empty")]
-    pub author: String,
-    #[serde(
-        default,
-        alias = "Комментарий",
-        alias = "Комментарии",
-        alias = "Инфо",
-        skip_serializing_if = "String::is_empty"
-    )]
-    pub comment: String,
-    #[serde(
-        default,
-        alias = "Ссылка",
-        alias = "URL",
-        skip_serializing_if = "String::is_empty"
-    )]
-    pub url: String,
-    #[serde(default, alias = "Дата", skip_serializing_if = "String::is_empty")]
-    pub date: String,
-    #[serde(default, alias = "Обработан", skip_serializing_if = "String::is_empty")]
-    pub processed_by: String,
-    #[serde(default, alias = "Редактор", skip_serializing_if = "String::is_empty")]
-    pub redacted_by: String,
-    #[serde(default, alias = "Копирайт", skip_serializing_if = "String::is_empty")]
-    pub copyright: String,
-    #[serde(default, alias = "Тема", skip_serializing_if = "String::is_empty")]
-    pub theme: String,
-    #[serde(
-        default,
-        alias = "Вид",
-        alias = "Тип",
-        skip_serializing_if = "String::is_empty"
-    )]
-    pub kind: String,
-    #[serde(default, alias = "Источник", skip_serializing_if = "String::is_empty")]
-    pub source: String,
-    #[serde(default, alias = "Рейтинг", skip_serializing_if = "String::is_empty")]
-    pub rating: String,
-    #[serde(alias = "Вопросы")]
-    pub questions: Vec<SourceQuestion>,
-}
-
-fn u32_is_zero(num: &u32) -> bool {
-    *num == 0
-}
-
-#[cfg(any(feature = "convert", feature = "source"))]
-pub mod reader_sync {
-    use std::io::{Read, Seek};
-    use zip::ZipArchive;
-
-    use super::SourceQuestionsBatch;
-
-    pub struct SourceQuestionsZipReader<R>
-    where
-        R: Read + Seek,
-    {
-        zipfile: ZipArchive<R>,
-        index: Option<usize>,
-    }
-
-    impl<R> SourceQuestionsZipReader<R>
-    where
-        R: Read + Seek,
-    {
-        fn new(zipfile: ZipArchive<R>) -> Self {
-            SourceQuestionsZipReader {
-                zipfile,
-                index: None,
-            }
-        }
-    }
-
-    impl<R> Iterator for SourceQuestionsZipReader<R>
-    where
-        R: Read + Seek,
-    {
-        type Item = (String, Result<SourceQuestionsBatch, serde_json::Error>);
-
-        fn next(&mut self) -> Option<Self::Item> {
-            if self.index.is_none() && !self.zipfile.is_empty() {
-                self.index = Some(0);
-            }
-
-            match self.index {
-                Some(i) if i < self.zipfile.len() => {
-                    self.index = Some(i + 1);
-
-                    self.nth(i)
-                }
-                _ => None,
-            }
-        }
-
-        fn nth(&mut self, n: usize) -> Option<Self::Item> {
-            if self.zipfile.len() <= n {
-                return None;
-            }
-            self.index = Some(n + 1);
-
-            let file = self.zipfile.by_index(n).unwrap();
-            let name = file.mangled_name();
-            let name_str = name.to_str().unwrap();
-
-            let data: Result<SourceQuestionsBatch, _> = serde_json::from_reader(file);
-
-            Some((String::from(name_str), data))
-        }
-
-        fn size_hint(&self) -> (usize, Option<usize>) {
-            let len = self.zipfile.len();
-            let index = self.index.unwrap_or(0);
-            let rem = if len > index + 1 {
-                len - (index + 1)
-            } else {
-                0
-            };
-            (rem, Some(rem))
-        }
-
-        fn count(self) -> usize
-        where
-            Self: Sized,
-        {
-            self.zipfile.len()
-        }
-    }
-
-    impl<R> ExactSizeIterator for SourceQuestionsZipReader<R>
-    where
-        R: Read + Seek,
-    {
-        fn len(&self) -> usize {
-            self.zipfile.len()
-        }
-    }
-
-    pub trait ReadSourceQuestionsBatches<R>
-    where
-        R: Read + Seek,
-    {
-        fn source_questions(self) -> SourceQuestionsZipReader<R>;
-    }
-
-    impl<R> ReadSourceQuestionsBatches<R> for ZipArchive<R>
-    where
-        R: Read + Seek,
-    {
-        fn source_questions(self) -> SourceQuestionsZipReader<R> {
-            SourceQuestionsZipReader::new(self)
-        }
-    }
-    #[cfg(test)]
-    mod test {
-        use super::super::test::sample_batch;
-        use super::*;
-        use std::fs;
-        use std::{io::Write, iter, path::Path};
-        use tempfile::tempdir;
-
-        fn write_sample_zip<P>(path: P)
-        where
-            P: AsRef<Path>,
-        {
-            let batch = sample_batch();
-            let z_file = fs::File::create(path).expect("crerate zip file");
-            let mut zip_file = zip::ZipWriter::new(z_file);
-            let options =
-                zip::write::FileOptions::default().compression_method(zip::CompressionMethod::Zstd);
-            zip_file
-                .start_file("test.json", options)
-                .expect("zip start file");
-            let data = serde_json::to_vec(&batch).unwrap();
-            let amount = zip_file.write(data.as_slice()).expect("write entry");
-            assert_eq!(amount, data.len());
-            zip_file.finish().expect("finish zip file");
-        }
-
-        #[test]
-        fn test_source_questions_get() {
-            let expected_batch = sample_batch();
-            let dir = tempdir().expect("tempdir");
-
-            // write sample
-            let tmpfile_zip = dir.path().join("test.zip");
-            write_sample_zip(&tmpfile_zip);
-
-            let z_file = fs::File::open(tmpfile_zip).expect("open zip file");
-            let zip_file = zip::ZipArchive::new(z_file).expect("open zip file reader");
-
-            let mut source = zip_file.source_questions();
-            assert_eq!(source.len(), 1);
-
-            let actual = source.next().expect("get batch");
-            assert_eq!(actual.0, "test.json");
-            assert_eq!(actual.1.expect("parse batch"), expected_batch);
-        }
-
-        #[test]
-        fn test_source_questions_iter() {
-            let expected_batch = sample_batch();
-            let dir = tempdir().expect("tempdir");
-
-            // write sample
-            let tmpfile_zip = dir.path().join("test.zip");
-            write_sample_zip(&tmpfile_zip);
-
-            let z_file = fs::File::open(tmpfile_zip).expect("open zip file");
-            let zip_file = zip::ZipArchive::new(z_file).expect("open zip file reader");
-
-            let source = zip_file.source_questions();
-            assert_eq!(source.len(), 1);
-
-            let expected_iter = iter::once((String::from("test.json"), Ok(expected_batch)));
-
-            assert!(source
-                .map(|x| (x.0, x.1.map_err(|e| e.to_string())))
-                .eq(expected_iter));
-        }
-    }
-}
-
-#[cfg(any(feature = "convert", feature = "source"))]
-pub use reader_sync::{ReadSourceQuestionsBatches, SourceQuestionsZipReader};
-
-#[cfg(any(feature = "convert_async", feature = "source_async"))]
-pub mod reader_async {
-    use async_stream::stream;
-    use async_zip::tokio::read::seek::ZipFileReader;
-    use futures_core::stream::Stream;
-    use futures_util::AsyncReadExt;
-
-    use tokio::io::{AsyncRead, AsyncSeek};
-
-    use super::SourceQuestionsBatch;
-
-    pub struct SourceQuestionsZipReaderAsync<R>
-    where
-        R: AsyncRead + AsyncSeek + Unpin,
-    {
-        zipfile: ZipFileReader<R>,
-        index: Option<usize>,
-    }
-
-    impl<R> SourceQuestionsZipReaderAsync<R>
-    where
-        R: AsyncRead + AsyncSeek + Unpin,
-    {
-        pub fn new(zipfile: ZipFileReader<R>) -> Self {
-            SourceQuestionsZipReaderAsync {
-                zipfile,
-                index: None,
-            }
-        }
-
-        pub fn len(&self) -> usize {
-            self.zipfile.file().entries().len()
-        }
-
-        pub fn is_empty(&self) -> bool {
-            self.len() == 0
-        }
-
-        pub async fn get(
-            &mut self,
-            index: usize,
-        ) -> Result<(String, Result<SourceQuestionsBatch, serde_json::Error>), String>
-        where
-            R: AsyncRead + AsyncSeek + Unpin,
-        {
-            let len = self.len();
-            if index >= len {
-                return Err(format!("get index={index}, when len={len}"));
-            }
-
-            let reader = self.zipfile.reader_with_entry(index).await;
-            if let Err(error) = reader {
-                return Err(format!("reader_with_entry: {error:?}"));
-            }
-            let mut reader = reader.unwrap();
-
-            let filename = reader.entry().filename().clone().into_string().unwrap();
-            let mut data: Vec<u8> = Vec::new();
-            let readed = reader.read_to_end(&mut data).await;
-            if let Err(error) = readed {
-                return Err(format!("read_to_end: {error:?}"));
-            }
-            let parsed: Result<SourceQuestionsBatch, _> = serde_json::from_slice(&data);
-            Ok((filename, parsed))
-        }
-        pub async fn get_next(
-            &mut self,
-        ) -> Option<Result<(String, Result<SourceQuestionsBatch, serde_json::Error>), String>>
-        where
-            R: AsyncRead + AsyncSeek + Unpin,
-        {
-            if self.index.is_none() && !self.is_empty() {
-                self.index = Some(0);
-            }
-
-            if self.index.unwrap() >= self.len() {
-                return None;
-            }
-
-            let item = self.get(self.index.unwrap()).await;
-            self.index = Some(self.index.unwrap() + 1);
-
-            Some(item)
-        }
-        pub fn stream(
-            &mut self,
-        ) -> impl Stream<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)> + '_
-        {
-            stream! {
-                while let Some(Ok(item)) = self.get_next().await {
-                    yield item
-                }
-            }
-        }
-    }
-
-    pub trait ReadSourceQuestionsBatchesAsync<R>
-    where
-        R: AsyncRead + AsyncSeek + Unpin,
-    {
-        fn source_questions(self) -> SourceQuestionsZipReaderAsync<R>;
-    }
-
-    impl<R> ReadSourceQuestionsBatchesAsync<R> for ZipFileReader<R>
-    where
-        R: AsyncRead + AsyncSeek + Unpin,
-    {
-        fn source_questions(self) -> SourceQuestionsZipReaderAsync<R> {
-            SourceQuestionsZipReaderAsync::new(self)
-        }
-    }
-
-    #[cfg(test)]
-    mod test {
-        use crate::source::SourceQuestion;
-
-        use super::super::test::sample_batch;
-        use super::*;
-        use async_zip::{base::write::ZipFileWriter, ZipEntryBuilder};
-        use core::fmt::Debug;
-        use futures_util::StreamExt;
-        use std::path::Path;
-        use tempfile::tempdir;
-        use tokio::fs;
-
-        async fn write_sample_zip<P>(path: P)
-        where
-            P: AsRef<Path>,
-        {
-            let batch = sample_batch();
-            let z_file = fs::File::create(path).await.expect("crerate zip file");
-            let mut zip_file = ZipFileWriter::with_tokio(z_file);
-            let entry =
-                ZipEntryBuilder::new("test.json".into(), async_zip::Compression::Zstd).build();
-            zip_file
-                .write_entry_whole(entry, serde_json::to_vec(&batch).unwrap().as_slice())
-                .await
-                .expect("write entry");
-            zip_file.close().await.expect("close zip");
-        }
-
-        async fn assert_data_rref_eq<T>((x, y): (T, &T))
-        where
-            T: PartialEq + Debug,
-        {
-            assert_eq!(x, *y);
-        }
-
-        #[tokio::test]
-        async fn test_source_questions_stream() {
-            let expected_batch = sample_batch();
-            let dir = tempdir().expect("tempdir");
-
-            // write sample
-            let tmpfile_zip = dir.path().join("test.zip");
-            write_sample_zip(&tmpfile_zip).await;
-
-            let mut z_file = fs::File::open(tmpfile_zip).await.expect("open zip file");
-            let zip_file = ZipFileReader::with_tokio(&mut z_file)
-                .await
-                .expect("open zip file reader");
-
-            let expected_count = expected_batch.questions.len();
-            let expected_stream = futures::stream::iter(expected_batch.questions.iter());
-            let mut actual_source = zip_file.source_questions();
-            let actual_stream = actual_source.stream();
-            let mut actual_count: usize = 0;
-
-            actual_stream
-                .flat_map(|x| futures::stream::iter(x.1.expect("parse batch").questions))
-                .zip(expected_stream)
-                .map(|x| {
-                    actual_count += 1;
-                    x
-                })
-                .for_each(assert_data_rref_eq::<SourceQuestion>)
-                .await;
-            assert_eq!(actual_count, expected_count);
-        }
-
-        #[tokio::test]
-        async fn test_source_questions_get() {
-            let expected_batch = sample_batch();
-            let dir = tempdir().expect("tempdir");
-
-            // write sample
-            let tmpfile_zip = dir.path().join("test.zip");
-            write_sample_zip(&tmpfile_zip).await;
-
-            let mut z_file = fs::File::open(tmpfile_zip).await.expect("open zip file");
-            let zip_file = ZipFileReader::with_tokio(&mut z_file)
-                .await
-                .expect("open zip file reader");
-
-            let mut source = zip_file.source_questions();
-            assert_eq!(source.len(), 1);
-
-            let actual = source.get(0).await.expect("get batch");
-            assert_eq!(actual.0, "test.json");
-            assert_eq!(actual.1.expect("parse batch"), expected_batch);
-        }
-    }
-}
-#[cfg(any(feature = "convert_async", feature = "source_async"))]
-pub use reader_async::{ReadSourceQuestionsBatchesAsync, SourceQuestionsZipReaderAsync};
-
-#[cfg(test)]
-mod test {
-    use super::*;
-    use insta::assert_yaml_snapshot;
-    use serde_json::json;
-
-    pub fn sample_batch() -> SourceQuestionsBatch {
-        SourceQuestionsBatch {
-            description: "Тестовый".into(),
-            date: "00-000-2000".into(),
-            questions: vec![
-                SourceQuestion {
-                    id: "Вопрос 1".into(),
-                    description: "Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2".into(),
-                    answer: "42".into(),
-                    ..Default::default()
-                },
-                SourceQuestion {
-                    id: "Вопрос 2".into(),
-                    description: "Зимой и летом одним цветом".into(),
-                    answer: "ёлка".into(),
-                    ..Default::default()
-                },
-            ],
-            ..Default::default()
-        }
-    }
-
-    #[test]
-    fn test_batch_ser() {
-        let batch = sample_batch();
-
-        assert_yaml_snapshot!(batch, @r#"
-            ---
-            description: Тестовый
-            date: 00-000-2000
-            questions:
-              - id: Вопрос 1
-                description: Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2
-                answer: "42"
-              - id: Вопрос 2
-                description: Зимой и летом одним цветом
-                answer: ёлка
-            
-            "#);
-    }
-    #[test]
-    fn test_batch_de() {
-        let batch_from_json: Result<SourceQuestionsBatch, _> = serde_json::from_value(json!({
-            "Чемпионат": "Тестовый",
-            "Дата": "00-000-2000",
-            "Вопросы": [
-                {
-                    "id": "Вопрос 1",
-                    "Вопрос": "Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2",
-                    "Ответ": "42",
-                   },
-                   {
-                    "id": "Вопрос 2",
-                    "Вопрос": "Зимой и летом одним цветом",
-                    "Ответ": "ёлка",
-                   },
-            ]
-        }));
-        assert!(batch_from_json.is_ok());
-
-        assert_yaml_snapshot!(batch_from_json.unwrap(), @r#"
-            ---
-            description: Тестовый
-            date: 00-000-2000
-            questions:
-              - id: Вопрос 1
-                description: Сколько будет (2 * 2 * 2 + 2) * 2 * 2 + 2
-                answer: "42"
-              - id: Вопрос 2
-                description: Зимой и летом одним цветом
-                answer: ёлка
-            
-            "#);
-    }
-}

lib/src/util.rs

@@ -1,57 +0,0 @@
-pub trait ErrorToString {
-    type Output;
-    fn str_err(self) -> std::result::Result<Self::Output, String>;
-}
-
-impl<T, E> ErrorToString for std::result::Result<T, E>
-where
-    E: std::error::Error,
-{
-    type Output = T;
-    fn str_err(self) -> std::result::Result<Self::Output, String> {
-        self.map_err(|e| e.to_string())
-    }
-}
-
-#[cfg(any(feature = "sync", feature = "async"))]
-mod bincode_utils {
-    use std::ops::{Deref, DerefMut};
-
-    use bincode::enc::write::Writer;
-    use bincode::error::EncodeError;
-
-    /// struct that allows [`Vec<u8>`] to implement [bincode::enc::write::Writer] trait
-    pub struct BincodeVecWriter {
-        vec: Vec<u8>,
-    }
-
-    impl BincodeVecWriter {
-        pub fn new(vec: Vec<u8>) -> BincodeVecWriter {
-            BincodeVecWriter { vec }
-        }
-    }
-
-    impl Deref for BincodeVecWriter {
-        type Target = Vec<u8>;
-
-        fn deref(&self) -> &Self::Target {
-            &self.vec
-        }
-    }
-
-    impl DerefMut for BincodeVecWriter {
-        fn deref_mut(&mut self) -> &mut Self::Target {
-            &mut self.vec
-        }
-    }
-
-    impl Writer for BincodeVecWriter {
-        fn write(&mut self, bytes: &[u8]) -> Result<(), EncodeError> {
-            self.vec.extend_from_slice(bytes);
-            Ok(())
-        }
-    }
-}
-
-#[cfg(any(feature = "sync", feature = "async"))]
-pub use bincode_utils::BincodeVecWriter;

src/db.rs

@@ -3,7 +3,6 @@ use std::{
     io::{self, Cursor, Read, Write},
     marker::PhantomData,
     path::Path,
-    sync::Arc,
 };
 
 use memmap::{Mmap, MmapOptions};
@@ -12,8 +11,20 @@ type LSize = u32;
 const LEN_SIZE: usize = std::mem::size_of::<LSize>();
 const BINCODE_CFG: bincode::config::Configuration = bincode::config::standard();
 
-use crate::util::BincodeVecWriter;
+trait ErrorToString {
-use crate::util::ErrorToString;
+    type Output;
+    fn str_err(self) -> std::result::Result<Self::Output, String>;
+}
+
+impl<T, E> ErrorToString for std::result::Result<T, E>
+where
+    E: std::error::Error,
+{
+    type Output = T;
+    fn str_err(self) -> std::result::Result<Self::Output, String> {
+        self.map_err(|e| e.to_string())
+    }
+}
 
 pub struct WriterOpts {
     pub compress_lvl: i32,
@@ -40,10 +51,9 @@ where
     out: io::BufWriter<fs::File>,
     data_buf: Cursor<Vec<u8>>,
     cur_buf_raw: Cursor<Vec<u8>>,
-    cur_buf_item: BincodeVecWriter,
     table: Vec<LSize>,
     compress_lvl: i32,
-    _t: PhantomData<Arc<T>>,
+    _t: PhantomData<*const T>,
 }
 
 impl<T> Writer<T>
@@ -58,8 +68,6 @@ where
 
         let cur_buf_raw: Vec<u8> = Vec::with_capacity(opts.current_buf_size);
         let cur_buf_raw = Cursor::new(cur_buf_raw);
-        let cur_buf_item: Vec<u8> = Vec::with_capacity(opts.current_buf_size);
-        let cur_buf_item = BincodeVecWriter::new(cur_buf_item);
 
         let compress_lvl = opts.compress_lvl;
 
@@ -69,7 +77,6 @@ where
             out,
             data_buf,
             cur_buf_raw,
-            cur_buf_item,
             table,
             compress_lvl,
             _t: PhantomData,
@@ -77,25 +84,20 @@ where
     }
 
     pub fn push(&mut self, item: T) -> Result<(), String> {
-        self.push_by_ref(&item)
-    }
-
-    pub fn push_by_ref(&mut self, item: &T) -> Result<(), String> {
         let pos: LSize = self.data_buf.position() as LSize;
 
-        bincode::encode_into_writer(item, &mut self.cur_buf_item, BINCODE_CFG).str_err()?;
+        let item_data = bincode::encode_to_vec(item, BINCODE_CFG).str_err()?;
 
         let mut zencoder = zstd::stream::raw::Encoder::new(self.compress_lvl).str_err()?;
         zencoder
-            .set_pledged_src_size(Some(self.cur_buf_item.len() as u64))
+            .set_pledged_src_size(item_data.len() as u64)
             .str_err()?;
 
         self.cur_buf_raw.set_position(0);
         let mut cur_buf_z = zstd::stream::zio::Writer::new(&mut self.cur_buf_raw, zencoder);
-        cur_buf_z.write_all(&self.cur_buf_item).str_err()?;
+        cur_buf_z.write_all(&item_data).str_err()?;
         cur_buf_z.finish().str_err()?;
         cur_buf_z.flush().str_err()?;
-        self.cur_buf_item.clear();
 
         self.table.push(pos);
         let (cur_buf_raw, _) = cur_buf_z.into_inner();
@@ -155,7 +157,7 @@ where
     mmap: Mmap,
     count: usize,
     first_pos: LSize,
-    _t: PhantomData<Arc<T>>,
+    _t: PhantomData<*const T>,
 }
 
 impl<T> Reader<T>
@@ -184,11 +186,7 @@ where
         self.count
     }
 
-    pub fn is_empty(&self) -> bool {
+    pub fn get(&mut self, index: usize) -> Result<T, String> {
-        0 == self.len()
-    }
-
-    pub fn get(&self, index: usize) -> Result<T, String> {
         if index >= self.len() {
             return Err("index out of range".into());
         }
@@ -220,7 +218,7 @@ where
         Ok(item.0)
     }
 
-    pub fn iter(&self) -> ReaderIter<'_, T> {
+    pub fn iter(&mut self) -> ReaderIter<'_, T> {
         ReaderIter::new(self)
     }
 }
@@ -229,7 +227,7 @@ pub struct ReaderIter<'a, T>
 where
     T: bincode::Decode,
 {
-    reader: &'a Reader<T>,
+    reader: &'a mut Reader<T>,
     index: Option<usize>,
 }
 
@@ -237,7 +235,7 @@ impl<'a, T> ReaderIter<'a, T>
 where
     T: bincode::Decode,
 {
-    fn new(reader: &'a Reader<T>) -> Self {
+    fn new(reader: &'a mut Reader<T>) -> Self {
         ReaderIter {
             reader,
             index: None,
@@ -252,7 +250,7 @@ where
     type Item = T;
 
     fn next(&mut self) -> Option<Self::Item> {
-        if self.index.is_none() && !self.reader.is_empty() {
+        if self.index.is_none() && self.reader.len() != 0 {
             self.index = Some(0);
         }
 
@@ -307,100 +305,6 @@ where
     }
 }
 
-pub struct ReaderIntoIter<T>
-where
-    T: bincode::Decode,
-{
-    reader: Reader<T>,
-    index: Option<usize>,
-}
-
-impl<T> ReaderIntoIter<T>
-where
-    T: bincode::Decode,
-{
-    fn new(reader: Reader<T>) -> Self {
-        Self {
-            reader,
-            index: None,
-        }
-    }
-}
-
-impl<T> Iterator for ReaderIntoIter<T>
-where
-    T: bincode::Decode,
-{
-    type Item = T;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.index.is_none() && !self.reader.is_empty() {
-            self.index = Some(0);
-        }
-
-        match self.index {
-            Some(i) if i < self.reader.len() => self.nth(i),
-            _ => None,
-        }
-    }
-
-    fn nth(&mut self, n: usize) -> Option<Self::Item> {
-        if self.reader.len() <= n {
-            return None;
-        }
-        self.index = Some(n + 1);
-
-        let item = self.reader.get(n);
-        match item {
-            Ok(item) => Some(item),
-            Err(_) => None,
-        }
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let len = self.reader.len();
-        if self.index.is_none() {
-            return (len, Some(len));
-        }
-
-        let index = self.index.unwrap();
-        let rem = if len > index + 1 {
-            len - (index + 1)
-        } else {
-            0
-        };
-        (rem, Some(rem))
-    }
-
-    fn count(self) -> usize
-    where
-        Self: Sized,
-    {
-        self.reader.len()
-    }
-}
-
-impl<T> ExactSizeIterator for ReaderIntoIter<T>
-where
-    T: bincode::Decode,
-{
-    fn len(&self) -> usize {
-        self.reader.len()
-    }
-}
-
-impl<T> IntoIterator for Reader<T>
-where
-    T: bincode::Decode,
-{
-    type Item = T;
-    type IntoIter = ReaderIntoIter<Self::Item>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        Self::IntoIter::new(self)
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::*;
@@ -413,7 +317,7 @@ mod test {
     }
 
     fn gen_data(count: usize) -> impl Iterator<Item = TestData> {
-        (0..count).map(|i| TestData {
+        (0..count).into_iter().map(|i| TestData {
             num: i as u64,
             test: "test".repeat(i),
         })
@@ -437,7 +341,7 @@ mod test {
         writer.load(&mut items.clone().into_iter()).expect("load");
         writer.finish().expect("finish write");
 
-        let reader: Reader<TestData> = Reader::new(&tmpfile, 2048).expect("new reader");
+        let mut reader: Reader<TestData> = Reader::new(&tmpfile, 2048).expect("new reader");
         assert_eq!(items.len(), reader.len());
 
         for (idx, item) in items.iter().enumerate() {
@@ -464,76 +368,11 @@ mod test {
         writer.load(&mut items.clone().into_iter()).expect("load");
         writer.finish().expect("finish write");
 
-        let reader: Reader<TestData> = Reader::new(&tmpfile, 2048).expect("new reader");
+        let mut reader: Reader<TestData> = Reader::new(&tmpfile, 2048).expect("new reader");
         assert_eq!(items.len(), reader.len());
 
         items.into_iter().zip(reader.iter()).for_each(|pair| {
             assert_eq!(pair.0, pair.1);
         });
     }
-
-    #[test]
-    fn test_write_read_into_iter() {
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            compress_lvl: 1,
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            current_buf_size: 4096,
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).expect("new writer");
-
-        let items_iter = gen_data(10);
-        let items: Vec<TestData> = items_iter.collect();
-
-        writer.load(&mut items.clone().into_iter()).expect("load");
-        writer.finish().expect("finish write");
-
-        let reader: Reader<TestData> = Reader::new(&tmpfile, 2048).expect("new reader");
-        assert_eq!(items.len(), reader.len());
-
-        items.into_iter().zip(reader).for_each(|pair| {
-            assert_eq!(pair.0, pair.1);
-        });
-    }
-
-    /// sharing Reader instance between threads
-    #[test]
-    fn test_share_reader() {
-        use std::thread;
-
-        let dir = tempdir().expect("tempdir");
-        let tmpfile = dir.path().join("test.tmp");
-        let opts = WriterOpts {
-            compress_lvl: 1,
-            data_buf_size: 10 * 1024 * 1024,
-            out_buf_size: 10 * 1024 * 1024,
-            current_buf_size: 4096,
-        };
-        let mut writer: Writer<TestData> = Writer::new(&tmpfile, opts).expect("new writer");
-
-        let items_iter = gen_data(10);
-        let items: Vec<TestData> = items_iter.collect();
-
-        writer.load(&mut items.clone().into_iter()).expect("load");
-        writer.finish().expect("finish write");
-
-        let reader: Reader<TestData> = Reader::new(&tmpfile, 2048).expect("new reader");
-        assert_eq!(items.len(), reader.len());
-
-        let reader = Arc::new(reader);
-        for _ in 0..=3 {
-            let cur_items = items.clone();
-            let cur_reader = Arc::clone(&reader);
-            thread::spawn(move || {
-                cur_items
-                    .into_iter()
-                    .zip(cur_reader.iter())
-                    .for_each(|pair| {
-                        assert_eq!(pair.0, pair.1);
-                    });
-            });
-        }
-    }
 }

src/main.rs

@@ -0,0 +1,276 @@
+extern crate serde;
+extern crate serde_derive;
+#[macro_use]
+extern crate serde_json;
+extern crate ledb;
+extern crate ledb_types;
+extern crate zip;
+
+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};
+
+mod db;
+mod questions;
+mod source;
+
+use crate::questions::{Question, QuestionsConverter};
+use crate::source::ReadSourceQuestionsBatches;
+
+const ZIP_FILENAME: &str = "json.zip";
+const NEW_DB_FILENAME: &str = "test.bin";
+const DB_DIR: &str = "db";
+
+#[derive(Subcommand, Debug)]
+enum Command {
+    Write,
+    Compact,
+    Print {
+        #[clap(value_parser, default_value = "0")]
+        id: u32,
+    },
+    ZipPrint {
+        #[clap(value_parser, default_value = "0")]
+        file_num: usize,
+        #[clap(value_parser, default_value = "0")]
+        num: usize,
+    },
+    Write2,
+    Print2 {
+        #[clap(value_parser, default_value = "0")]
+        id: u32,
+    },
+}
+
+#[derive(Parser, Debug)]
+#[clap(author, version, about, long_about = None)]
+#[clap(propagate_version = true)]
+struct Cli {
+    #[clap(subcommand)]
+    command: Command,
+    #[clap(short, long, action)]
+    measure: bool,
+}
+
+fn zip_reader_task(tx: mpsc::Sender<Question>) {
+    let zip_file = fs::File::open(ZIP_FILENAME).unwrap();
+    let zip_reader = io::BufReader::new(zip_file);
+    let archive = zip::ZipArchive::new(zip_reader).unwrap();
+    let mut source_questions = archive.source_questions();
+
+    let questions = source_questions
+        .convert()
+        .enumerate()
+        .map(|(num, mut question)| {
+            question.num = 1 + num as u32;
+            question
+        });
+    for question in questions {
+        let res = tx.send(question);
+        if res.is_err() {
+            break;
+        }
+    }
+    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();
+    println!("{:#?}", q)
+}
+
+fn read_from_zip(file_num: usize, mut num: usize) -> Option<Question> {
+    let mut rng = rand::thread_rng();
+    let zip_file = fs::File::open(ZIP_FILENAME).unwrap();
+    let zip_reader = io::BufReader::new(zip_file);
+    let archive = zip::ZipArchive::new(zip_reader).unwrap();
+
+    let mut source_questions = archive.source_questions();
+    let (filename, batch) = if file_num == 0 {
+        source_questions.choose(&mut rng).unwrap()
+    } else {
+        source_questions.nth(file_num - 1).unwrap()
+    };
+    let mut batch = batch.unwrap();
+    batch.filename = filename;
+    let questions: Vec<Question> = batch.into();
+    if num == 0 {
+        num = (1..=questions.len()).choose(&mut rng).unwrap();
+    }
+    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();
+    func();
+    let elapsed = start.elapsed();
+    (elapsed.as_secs() as f64) + (elapsed.subsec_nanos() as f64 / 1_000_000_000.0)
+}
+
+pub fn measure_and_print<F: FnOnce()>(func: F) {
+    let m = measure(func);
+    eprintln!("{}", m);
+}
+
+fn main() {
+    let args = Cli::parse();
+
+    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))
+        }
+        Command::ZipPrint { file_num, num } => {
+            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 {
+        action = Box::new(|| measure_and_print(action));
+    }
+
+    action();
+}
+
+fn read_from_db2(id: u32) -> Option<Question> {
+    let mut reader: db::Reader<Question> =
+        db::Reader::new(NEW_DB_FILENAME, 2048).expect("new db reader");
+
+    let mut questions = reader.iter();
+
+    match id {
+        0 => {
+            let mut rng = rand::thread_rng();
+            questions.choose(&mut rng)
+        }
+        _ => questions.nth((id - 1) as usize),
+    }
+}
+fn write_db2() {
+    let (tx, rx) = mpsc::channel::<Question>();
+    [
+        thread::spawn(move || zip_reader_task(tx)),
+        thread::spawn(move || db_writer2_task(rx)),
+    ]
+    .into_iter()
+    .for_each(|handle| handle.join().expect("thread panic"));
+    println!("all done");
+}
+fn db_writer2_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");
+
+    writer
+        .load(&mut rx.iter())
+        .unwrap_or_else(|e| panic!("db writer load, {e:#?}"));
+
+    writer.finish().expect("db writer finish");
+
+    println!("write done");
+}

src/questions.rs

@@ -0,0 +1,145 @@
+use ledb::Document;
+use serde_derive::{Deserialize, Serialize};
+
+use crate::source::{SourceQuestion, SourceQuestionsBatch};
+
+macro_rules! make {
+    ($Target:ident; by {$($field:ident),+}; from $src:expr) => {$Target {$(
+        $field: $src.$field
+    ),+}};
+    ($Target:ident; with defaults and by {$($field:ident),+}; from $src:expr) => {$Target {$(
+        $field: $src.$field
+    ),+ ,..$Target::default()}}
+}
+
+#[derive(
+    Debug, Default, Clone, Serialize, Deserialize, Document, bincode::Decode, bincode::Encode,
+)]
+pub struct BatchInfo {
+    #[document(primary)]
+    #[serde(default)]
+    pub filename: String,
+    #[serde(default)]
+    pub description: String,
+    #[serde(default)]
+    pub author: String,
+    #[serde(default)]
+    pub comment: String,
+    #[serde(default)]
+    pub url: String,
+    #[serde(default)]
+    pub date: String,
+    #[serde(default)]
+    pub processed_by: String,
+    #[serde(default)]
+    pub redacted_by: String,
+    #[serde(default)]
+    pub copyright: String,
+    #[serde(default)]
+    pub theme: String,
+    #[serde(default)]
+    pub kind: String,
+    #[serde(default)]
+    pub source: String,
+    #[serde(default)]
+    pub rating: String,
+}
+
+#[derive(
+    Debug, Default, Clone, Serialize, Deserialize, Document, bincode::Decode, bincode::Encode,
+)]
+pub struct Question {
+    #[document(primary)]
+    #[serde(default)]
+    pub num: u32,
+    #[document(index)]
+    pub id: String,
+
+    pub description: String,
+    pub answer: String,
+
+    #[serde(default)]
+    pub author: String,
+    #[serde(default)]
+    pub comment: String,
+    #[serde(default)]
+    pub comment1: String,
+    #[serde(default)]
+    pub tour: String,
+    #[serde(default)]
+    pub url: String,
+    #[serde(default)]
+    pub date: String,
+    #[serde(default)]
+    pub processed_by: String,
+    #[serde(default)]
+    pub redacted_by: String,
+    #[serde(default)]
+    pub copyright: String,
+    #[serde(default)]
+    pub theme: String,
+    #[serde(default)]
+    pub kind: String,
+    #[serde(default)]
+    pub source: String,
+    #[serde(default)]
+    pub rating: String,
+    #[document(nested)]
+    #[serde(default)]
+    pub batch_info: BatchInfo,
+}
+
+impl From<SourceQuestion> for Question {
+    fn from(src: SourceQuestion) -> Self {
+        make! {Self; with defaults and by {
+            num, id, description, answer, author, comment, comment1, tour, url,
+            date, processed_by, redacted_by, copyright, theme, kind, source, rating
+        }; from src}
+    }
+}
+
+impl From<SourceQuestionsBatch> for BatchInfo {
+    fn from(src: SourceQuestionsBatch) -> Self {
+        make! {Self; by {
+            filename, description, author, comment, url, date,
+            processed_by, redacted_by, copyright, theme, kind, source, rating
+        }; from src}
+    }
+}
+
+impl From<SourceQuestionsBatch> for Vec<Question> {
+    fn from(src: SourceQuestionsBatch) -> Self {
+        let mut result: Vec<Question> = src
+            .questions
+            .iter()
+            .map(|item| item.clone().into())
+            .collect();
+        let batch_info = BatchInfo::from(src);
+        result.iter_mut().for_each(|mut question| {
+            question.batch_info = batch_info.clone();
+        });
+
+        result
+    }
+}
+
+pub trait QuestionsConverter {
+    fn convert<'a>(&'a mut self) -> Box<dyn Iterator<Item = Question> + 'a>;
+}
+
+impl<T> QuestionsConverter for T
+where
+    T: Iterator<Item = (String, Result<SourceQuestionsBatch, serde_json::Error>)>,
+{
+    fn convert<'a>(&'a mut self) -> Box<dyn Iterator<Item = Question> + 'a> {
+        let iter = self
+            .filter(|(_, data)| data.is_ok())
+            .flat_map(|(filename, data)| {
+                let mut batch = data.unwrap();
+                batch.filename = filename;
+                let questions: Vec<Question> = batch.into();
+                questions
+            });
+        Box::new(iter)
+    }
+}

src/source.rs

@@ -0,0 +1,206 @@
+use serde_derive::{Deserialize, Serialize};
+use std::io::{Read, Seek};
+use zip::ZipArchive;
+
+#[derive(Debug, Default, Clone, Serialize, Deserialize)]
+pub struct SourceQuestion {
+    #[serde(default)]
+    pub num: u32,
+    pub id: String,
+
+    #[serde(alias = "Вопрос")]
+    pub description: String,
+    #[serde(alias = "Ответ")]
+    pub answer: String,
+
+    #[serde(alias = "Автор")]
+    #[serde(default)]
+    pub author: String,
+    #[serde(alias = "Комментарий")]
+    #[serde(default)]
+    pub comment: String,
+    #[serde(alias = "Комментарии")]
+    #[serde(alias = "Инфо")]
+    #[serde(default)]
+    pub comment1: String,
+    #[serde(alias = "Тур")]
+    #[serde(default)]
+    pub tour: String,
+    #[serde(alias = "Ссылка")]
+    #[serde(alias = "URL")]
+    #[serde(default)]
+    pub url: String,
+    #[serde(alias = "Дата")]
+    #[serde(default)]
+    pub date: String,
+    #[serde(alias = "Обработан")]
+    #[serde(default)]
+    pub processed_by: String,
+    #[serde(alias = "Редактор")]
+    #[serde(default)]
+    pub redacted_by: String,
+    #[serde(alias = "Копирайт")]
+    #[serde(default)]
+    pub copyright: String,
+    #[serde(alias = "Тема")]
+    #[serde(default)]
+    pub theme: String,
+    #[serde(alias = "Вид")]
+    #[serde(alias = "Тип")]
+    #[serde(default)]
+    pub kind: String,
+    #[serde(alias = "Источник")]
+    #[serde(default)]
+    pub source: String,
+    #[serde(alias = "Рейтинг")]
+    #[serde(default)]
+    pub rating: String,
+}
+
+#[derive(Debug, Default, Clone, Serialize, Deserialize)]
+pub struct SourceQuestionsBatch {
+    #[serde(default)]
+    pub filename: String,
+    #[serde(alias = "Пакет")]
+    #[serde(alias = "Чемпионат")]
+    pub description: String,
+    #[serde(alias = "Автор")]
+    #[serde(default)]
+    pub author: String,
+    #[serde(alias = "Комментарий")]
+    #[serde(alias = "Комментарии")]
+    #[serde(alias = "Инфо")]
+    #[serde(default)]
+    pub comment: String,
+    #[serde(alias = "Ссылка")]
+    #[serde(alias = "URL")]
+    #[serde(default)]
+    pub url: String,
+    #[serde(alias = "Дата")]
+    #[serde(default)]
+    pub date: String,
+    #[serde(alias = "Обработан")]
+    #[serde(default)]
+    pub processed_by: String,
+    #[serde(alias = "Редактор")]
+    #[serde(default)]
+    pub redacted_by: String,
+    #[serde(alias = "Копирайт")]
+    #[serde(default)]
+    pub copyright: String,
+    #[serde(alias = "Тема")]
+    #[serde(default)]
+    pub theme: String,
+    #[serde(alias = "Вид")]
+    #[serde(alias = "Тип")]
+    #[serde(default)]
+    pub kind: String,
+    #[serde(alias = "Источник")]
+    #[serde(default)]
+    pub source: String,
+    #[serde(alias = "Рейтинг")]
+    #[serde(default)]
+    pub rating: String,
+    #[serde(alias = "Вопросы")]
+    pub questions: Vec<SourceQuestion>,
+}
+
+pub struct SourceQuestionsZipReader<R>
+where
+    R: Read + Seek,
+{
+    zipfile: ZipArchive<R>,
+    index: Option<usize>,
+}
+
+impl<R> SourceQuestionsZipReader<R>
+where
+    R: Read + Seek,
+{
+    fn new(zipfile: ZipArchive<R>) -> Self {
+        SourceQuestionsZipReader {
+            zipfile,
+            index: None,
+        }
+    }
+}
+
+impl<R> Iterator for SourceQuestionsZipReader<R>
+where
+    R: Read + Seek,
+{
+    type Item = (String, Result<SourceQuestionsBatch, serde_json::Error>);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.index.is_none() && !self.zipfile.is_empty() {
+            self.index = Some(0);
+        }
+
+        match self.index {
+            Some(i) if i < self.zipfile.len() => {
+                self.index = Some(i + 1);
+
+                self.nth(i)
+            }
+            _ => None,
+        }
+    }
+
+    fn nth(&mut self, n: usize) -> Option<Self::Item> {
+        if self.zipfile.len() <= n {
+            return None;
+        }
+        self.index = Some(n + 1);
+
+        let file = self.zipfile.by_index(n).unwrap();
+        let name = file.mangled_name();
+        let name_str = name.to_str().unwrap();
+
+        let data: Result<SourceQuestionsBatch, _> = serde_json::from_reader(file);
+
+        Some((String::from(name_str), data))
+    }
+
+    fn size_hint(&self) -> (usize, Option<usize>) {
+        let len = self.zipfile.len();
+        let index = self.index.unwrap_or(0);
+        let rem = if len > index + 1 {
+            len - (index + 1)
+        } else {
+            0
+        };
+        (rem, Some(rem))
+    }
+
+    fn count(self) -> usize
+    where
+        Self: Sized,
+    {
+        self.zipfile.len()
+    }
+}
+
+impl<R> ExactSizeIterator for SourceQuestionsZipReader<R>
+where
+    R: Read + Seek,
+{
+    fn len(&self) -> usize {
+        self.zipfile.len()
+    }
+}
+
+pub trait ReadSourceQuestionsBatches<R>
+where
+    R: Read + Seek,
+{
+    fn source_questions(self) -> SourceQuestionsZipReader<R>;
+}
+
+impl<R> ReadSourceQuestionsBatches<R> for ZipArchive<R>
+where
+    R: Read + Seek,
+{
+    fn source_questions(self) -> SourceQuestionsZipReader<R> {
+        SourceQuestionsZipReader::new(self)
+    }
+}