servlin

Crates.io	servlin
lib.rs	servlin
version	0.8.0
created_at	2022-06-16 21:00:38.761586+00
updated_at	2025-07-06 20:50:29.203237+00
description	Modular HTTP server library, threaded handlers and async performance
homepage
repository	https://github.com/mleonhard/servlin
max_upload_size
id	607660
size	378,232

Michael Leonhard (mleonhard)

documentation

README

Servlin

A modular HTTP server library in Rust.

Features

forbid(unsafe_code)
Threaded request handlers:
FnOnce(Request) -> Response + 'static + Clone + Send + Sync
Uses async code internally for excellent performance under load
JSON
Server-Sent Events (SSE)
Saves large request bodies to temp files
Sends 100-Continue
Limits number of threads and connections
Modular: roll your own logging, write custom versions of internal methods, etc.
No macros or complicated type params
Good test coverage (63%)

Limitations

New, not proven in production.
To do:
- Request timeouts
- chunked transfer-encoding for request bodies
- gzip
- brotli
- TLS
- automatically getting TLS certs via ACME
- Drop idle connections when approaching connection limit.
- Denial-of-Service mitigation: source throttling, minimum throughput
- Complete functional test suite
- Missing load tests
- Disk space usage limits

Examples

Complete examples: examples/.

Simple example:

use serde::Deserialize;
use serde_json::json;
use servlin::{
    socket_addr_127_0_0_1,
    Error,
    HttpServerBuilder,
    Request,
    Response
};
use servlin::log::log_request_and_response;
use std::sync::Arc;
use temp_dir::TempDir;

struct State {}

fn hello(_state: Arc<State>, req: Request) -> Result<Response, Error> {
    #[derive(Deserialize)]
    struct Input {
        name: String,
    }
    let input: Input = req.json()?;
    Ok(Response::json(200, json!({"message": format!("Hello, {}!", input.name)}))?)
}

fn handle_req(state: Arc<State>, req: Request) -> Result<Response, Error> {
    match (req.method(), req.url().path.as_str()) {
        ("GET", "/ping") => Ok(Response::text(200, "ok")),
        ("POST", "/hello") => hello(state, req),
        _ => Ok(Response::text(404, "Not found")),
    }
}

let state = Arc::new(State {});
let request_handler = move |req: Request| {
    log_request_and_response(req, |req| handle_req(state, req)).unwrap()
};
let cache_dir = TempDir::new().unwrap();
safina::timer::start_timer_thread();
let executor = safina::executor::Executor::new(1, 9).unwrap();
executor.block_on(
    HttpServerBuilder::new()
        .listen_addr(socket_addr_127_0_0_1(8271))
        .max_conns(1000)
        .small_body_len(64 * 1024)
        .receive_large_bodies(cache_dir.path())
        .spawn_and_join(request_handler)
).unwrap();

Cargo Geiger Safety Report


Metric output format: x/y
    x = unsafe code used by the build
    y = total unsafe code found in the crate

Symbols:
    🔒  = No `unsafe` usage found, declares #![forbid(unsafe_code)]
    ❓  = No `unsafe` usage found, missing #![forbid(unsafe_code)]
    ☢️  = `unsafe` usage found

Functions  Expressions  Impls  Traits  Methods  Dependency

0/0        0/0          0/0    0/0     0/0      🔒  servlin 0.8.0
0/0        0/0          0/0    0/0     0/0      🔒  ├── async-fs 2.1.2
4/4        222/222      40/40  0/0     13/13    ☢️  │   ├── async-lock 3.4.0
0/0        2/2          0/0    0/0     0/0      ☢️  │   │   ├── event-listener-strategy 0.5.4
0/0        39/49        8/12   0/0     2/2      ☢️  │   │   │   ├── event-listener 5.4.0
0/0        183/183      2/2    0/0     1/1      ☢️  │   │   │   │   ├── concurrent-queue 2.5.0
4/4        12/75        4/16   0/0     0/3      ☢️  │   │   │   │   │   └── crossbeam-utils 0.8.21
0/0        0/0          0/0    0/0     0/0      🔒  │   │   │   │   ├── parking 2.2.1
0/0        11/191       0/0    0/0     2/2      ☢️  │   │   │   │   └── pin-project-lite 0.2.16
0/0        11/191       0/0    0/0     2/2      ☢️  │   │   │   └── pin-project-lite 0.2.16
0/0        39/49        8/12   0/0     2/2      ☢️  │   │   ├── event-listener 5.4.0
0/0        11/191       0/0    0/0     2/2      ☢️  │   │   └── pin-project-lite 0.2.16
0/0        0/0          0/0    0/0     0/0      🔒  │   ├── blocking 1.6.2
0/0        0/0          0/0    0/0     0/0      🔒  │   │   ├── async-channel 2.5.0
0/0        183/183      2/2    0/0     1/1      ☢️  │   │   │   ├── concurrent-queue 2.5.0
0/0        2/2          0/0    0/0     0/0      ☢️  │   │   │   ├── event-listener-strategy 0.5.4
0/0        36/36        2/2    0/0     0/0      ☢️  │   │   │   ├── futures-core 0.3.31
0/0        11/191       0/0    0/0     2/2      ☢️  │   │   │   └── pin-project-lite 0.2.16
1/1        860/866      4/4    0/0     13/13    ☢️  │   │   ├── async-task 4.7.1
0/0        0/0          0/0    0/0     0/0      ❓  │   │   ├── futures-io 0.3.31
0/0        0/0          0/0    0/0     0/0      ❓  │   │   ├── futures-lite 2.6.0
0/0        0/0          0/0    0/0     0/0      🔒  │   │   │   ├── fastrand 2.3.0
0/0        36/36        2/2    0/0     0/0      ☢️  │   │   │   ├── futures-core 0.3.31
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   ├── futures-io 0.3.31
34/41      1700/2421    2/2    0/0     82/147   ☢️  │   │   │   ├── memchr 2.7.5
0/0        0/0          0/0    0/0     0/0      🔒  │   │   │   ├── parking 2.2.1
0/0        11/191       0/0    0/0     2/2      ☢️  │   │   │   └── pin-project-lite 0.2.16
0/0        28/28        2/2    0/0     0/0      ☢️  │   │   ├── piper 0.2.4
0/0        32/32        2/2    0/0     0/0      ☢️  │   │   │   ├── atomic-waker 1.1.2
0/0        0/0          0/0    0/0     0/0      🔒  │   │   │   ├── fastrand 2.3.0
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   └── futures-io 0.3.31
0/0        14/14        1/1    0/0     0/0      ☢️  │   │   └── tracing 0.1.41
0/0        11/191       0/0    0/0     2/2      ☢️  │   │       ├── pin-project-lite 0.2.16
0/0        98/98        5/5    0/0     2/2      ☢️  │   │       └── tracing-core 0.1.34
0/0        0/0          0/0    0/0     0/0      ❓  │   └── futures-lite 2.6.0
0/0        0/0          0/0    0/0     0/0      🔒  ├── async-net 2.0.0
0/0        72/118       19/22  1/1     5/9      ☢️  │   ├── async-io 2.4.1
4/4        222/222      40/40  0/0     13/13    ☢️  │   │   ├── async-lock 3.4.0
0/0        0/0          0/0    0/0     0/0      ❓  │   │   ├── cfg-if 1.0.1
0/0        183/183      2/2    0/0     1/1      ☢️  │   │   ├── concurrent-queue 2.5.0
0/0        0/0          0/0    0/0     0/0      ❓  │   │   ├── futures-io 0.3.31
0/0        0/0          0/0    0/0     0/0      ❓  │   │   ├── futures-lite 2.6.0
0/0        0/0          0/0    0/0     0/0      🔒  │   │   ├── parking 2.2.1
0/2        39/425       5/20   1/4     5/14     ☢️  │   │   ├── polling 3.8.0
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   ├── cfg-if 1.0.1
61/433     2727/7465    18/22  2/2     41/62    ☢️  │   │   │   ├── rustix 1.0.7
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   │   ├── bitflags 2.9.1
0/0        5/5          0/0    0/0     0/0      ☢️  │   │   │   │   │   └── serde 1.0.219
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   │   │       └── serde_derive 1.0.219
0/0        14/14        0/0    0/0     3/3      ☢️  │   │   │   │   │           ├── proc-macro2 1.0.95
0/0        4/4          0/0    0/0     0/0      ☢️  │   │   │   │   │           │   └── unicode-ident 1.0.18
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   │   │           ├── quote 1.0.40
0/0        14/14        0/0    0/0     3/3      ☢️  │   │   │   │   │           │   └── proc-macro2 1.0.95
0/0        88/88        3/3    0/0     2/2      ☢️  │   │   │   │   │           └── syn 2.0.104
0/0        14/14        0/0    0/0     3/3      ☢️  │   │   │   │   │               ├── proc-macro2 1.0.95
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   │   │               ├── quote 1.0.40
0/0        4/4          0/0    0/0     0/0      ☢️  │   │   │   │   │               └── unicode-ident 1.0.18
0/0        35/103       0/0    0/0     0/0      ☢️  │   │   │   │   ├── errno 0.3.13
1/90       10/679       0/2    0/0     5/92     ☢️  │   │   │   │   │   └── libc 0.2.174
1/90       10/679       0/2    0/0     5/92     ☢️  │   │   │   │   └── libc 0.2.174
0/0        14/14        1/1    0/0     0/0      ☢️  │   │   │   └── tracing 0.1.41
61/433     2727/7465    18/22  2/2     41/62    ☢️  │   │   ├── rustix 1.0.7
0/0        29/29        0/0    0/0     3/3      ☢️  │   │   ├── slab 0.4.10
0/0        5/5          0/0    0/0     0/0      ☢️  │   │   │   └── serde 1.0.219
0/0        14/14        1/1    0/0     0/0      ☢️  │   │   └── tracing 0.1.41
0/0        0/0          0/0    0/0     0/0      🔒  │   ├── blocking 1.6.2
0/0        0/0          0/0    0/0     0/0      ❓  │   └── futures-lite 2.6.0
0/0        0/0          0/0    0/0     0/0      🔒  ├── fixed-buffer 1.0.2
0/0        0/0          0/0    0/0     0/0      ❓  │   └── futures-io 0.3.31
0/0        0/0          0/0    0/0     0/0      ❓  ├── futures-io 0.3.31
0/0        0/0          0/0    0/0     0/0      ❓  ├── futures-lite 2.6.0
0/0        0/0          0/0    0/0     0/0      ❓  ├── include_dir 0.7.4
0/0        0/0          0/0    0/0     0/0      ❓  │   └── include_dir_macros 0.7.4
0/0        14/14        0/0    0/0     3/3      ☢️  │       ├── proc-macro2 1.0.95
0/0        0/0          0/0    0/0     0/0      ❓  │       └── quote 1.0.40
0/0        0/0          0/0    0/0     0/0      🔒  ├── permit 0.2.1
0/0        12/32        0/0    0/0     0/0      ☢️  ├── rand 0.8.5
1/90       10/679       0/2    0/0     5/92     ☢️  │   ├── libc 0.2.174
0/0        2/2          0/0    0/0     0/0      ☢️  │   ├── rand_core 0.6.4
3/6        51/192       0/1    0/0     1/3      ☢️  │   │   ├── getrandom 0.2.16
0/0        0/0          0/0    0/0     0/0      ❓  │   │   │   ├── cfg-if 1.0.1
1/90       10/679       0/2    0/0     5/92     ☢️  │   │   │   └── libc 0.2.174
0/0        5/5          0/0    0/0     0/0      ☢️  │   │   └── serde 1.0.219
0/0        5/5          0/0    0/0     0/0      ☢️  │   └── serde 1.0.219
0/0        0/0          0/0    0/0     0/0      🔒  ├── safe-regex 0.3.0
0/0        0/0          0/0    0/0     0/0      🔒  │   └── safe-regex-macro 0.3.0
0/0        0/0          0/0    0/0     0/0      🔒  │       ├── safe-proc-macro2 1.0.95
0/0        0/0          0/0    0/0     0/0      🔒  │       │   └── unicode-xid 0.2.6
0/0        0/0          0/0    0/0     0/0      🔒  │       └── safe-regex-compiler 0.3.0
0/0        0/0          0/0    0/0     0/0      🔒  │           ├── safe-proc-macro2 1.0.95
0/0        0/0          0/0    0/0     0/0      🔒  │           └── safe-quote 1.0.40
0/0        0/0          0/0    0/0     0/0      🔒  │               └── safe-proc-macro2 1.0.95
0/0        0/0          0/0    0/0     0/0      🔒  ├── safina 0.7.0
0/0        0/0          0/0    0/0     0/0      🔒  │   └── safina-macros 0.1.3
0/0        0/0          0/0    0/0     0/0      🔒  │       ├── safe-proc-macro2 1.0.95
0/0        0/0          0/0    0/0     0/0      🔒  │       └── safe-quote 1.0.40
0/0        5/5          0/0    0/0     0/0      ☢️  ├── serde 1.0.219
0/0        72/75        0/0    0/0     0/0      ☢️  ├── serde_json 1.0.140
0/0        8/8          0/0    0/0     0/0      ☢️  │   ├── itoa 1.0.15
34/41      1700/2421    2/2    0/0     82/147   ☢️  │   ├── memchr 2.7.5
7/9        572/702      0/0    0/0     2/2      ☢️  │   ├── ryu 1.0.20
0/0        5/5          0/0    0/0     0/0      ☢️  │   └── serde 1.0.219
0/0        0/0          0/0    0/0     0/0      🔒  ├── serde_urlencoded 0.7.1
0/0        2/2          0/0    0/0     0/0      ☢️  │   ├── form_urlencoded 1.2.1
0/0        8/8          0/0    0/0     0/0      ☢️  │   │   └── percent-encoding 2.3.1
0/0        8/8          0/0    0/0     0/0      ☢️  │   ├── itoa 1.0.15
7/9        572/702      0/0    0/0     2/2      ☢️  │   ├── ryu 1.0.20
0/0        5/5          0/0    0/0     0/0      ☢️  │   └── serde 1.0.219
0/0        0/0          0/0    0/0     0/0      🔒  ├── temp-dir 0.1.16
0/0        0/0          0/0    0/0     0/0      🔒  └── temp-file 0.1.9

115/590    6987/14168   117/158 4/7     182/373

Alternatives

See rust-webserver-comparison.md.

Changelog

v0.8.0 2025-07-06 - Use own [Url] struct.
v0.7.0 2025-06-30
- Require Rust 2024 edition.
- log_request_and_response to log duration_ms tag.
- Fix typo in function name Response::internal_server_errror_500.
- Close connection on 5xx error.
- Acceptor thread to log errors, not panic.
- Add [Request::parse_url].
- Add [Response::too_many_requests_429].
- Implement Into<TagList> for arrays.
- Support asterisk request target.
- Use safina v0.7.
v0.6.0 2024-11-02
- Remove servlin::reexports module.
- Use safina v0.6.0.
v0.5.1 2024-10-26 - Remove dependency on once_cell.
v0.5.0 2024-10-21 - Remove LogFileWriterBuilder.
v0.4.3 - Implement From<Cow<'_, str>> and From<&Path> for TagValue.
v0.4.2 - Implement Seek for BodyReader.
v0.4.1
- Add Request::opt_json.
- Implement From<LoggerStoppedError> for Error.
v0.4.0
- Changed Response::json to return Result<Response, Error>.
- Changed log_request_and_response to return Result.
- Added Response::unprocessable_entity_422.
v0.3.2 - Fix bug in Response::include_dir redirects.
v0.3.1
- Add Response::redirect_301
- Response::include_dir to redirect from /somedir to /somedir/ so relative URLs will work.
v0.3.0 - Changed Response::include_dir to take &Request and look for index.html in dirs.
v0.2.0
- Added:
  - log_request_and_response and other logging tooling
  - Response::ok_200()
  - Response::unauthorized_401()
  - Response::forbidden_403()
  - Response::internal_server_errror_500()
  - Response::not_implemented_501()
  - Response::service_unavailable_503()
  - EventSender::is_connected()
  - PORT_env()
- Removed print_log_response and RequestBody::length_is_known
- Changed RequestBody::len and is_empty to return Option.
- Bugfixes
v0.1.1 - Add EventSender::unconnected.
v0.1.0 - Rename library to Servlin.

TO DO

Fix limitations above
Support HEAD responses that have Content-Length set and no body.
Add a server-wide limit on upload body size.
Limit disk usage for caching uploads.
Update rust-webserver-comparison.md
- Add missing data
- Add other servers from https://www.arewewebyet.org/topics/frameworks/
- Rearrange
- Generate geiger reports for each web server

License: MIT OR Apache-2.0

Commit count: 142

servlin

documentation

README

Servlin

Features

Limitations

Examples

Cargo Geiger Safety Report

Alternatives

Changelog

TO DO

cargo fmt