From 492b79ec7a1844700ff75e19b39e3bc21f93dc23 Mon Sep 17 00:00:00 2001 From: Profpatsch Date: Sun, 31 Jan 2021 16:38:21 +0100 Subject: feat(users/Profpatsch): add die_* helpers for semantic exit errors There is this semantic exit code schema championed by execline and skaware tooling, and we refined and documented it a bit in lorri https://github.com/nix-community/lorri/blob/d1d673d42090f0cfe8ab9b92b465315a9e7d30a3/src/ops/mod.rs#L24-L35 in the past. This just transcribes the error messages into simple helper functions. Applies the functions to the places where we would panic or die `sys::exit()` instead. Change-Id: I15ca05cd6f99a25a3378518be94110eab416354e Reviewed-on: https://cl.tvl.fyi/c/depot/+/2475 Tested-by: BuildkiteCI Reviewed-by: Profpatsch --- users/Profpatsch/read-http/default.nix | 20 ---- users/Profpatsch/read-http/read-http.rs | 194 -------------------------------- 2 files changed, 214 deletions(-) delete mode 100644 users/Profpatsch/read-http/default.nix delete mode 100644 users/Profpatsch/read-http/read-http.rs (limited to 'users/Profpatsch/read-http') diff --git a/users/Profpatsch/read-http/default.nix b/users/Profpatsch/read-http/default.nix deleted file mode 100644 index 41fe1c7fedcc..000000000000 --- a/users/Profpatsch/read-http/default.nix +++ /dev/null @@ -1,20 +0,0 @@ -{ depot, pkgs, ... }: - -let - - # reads a http request (stdin), and writes all headers to stdout, as netencoded dict - read-http = depot.users.Profpatsch.writers.rustSimple { - name = "read-http"; - dependencies = [ - depot.users.Profpatsch.rust-crates.ascii - depot.users.Profpatsch.rust-crates.httparse - depot.users.Profpatsch.netencode.netencode-rs - depot.users.Profpatsch.arglib.netencode.rust - ]; - } (builtins.readFile ./read-http.rs); - -in { - inherit - read-http - ; -} diff --git a/users/Profpatsch/read-http/read-http.rs b/users/Profpatsch/read-http/read-http.rs deleted file mode 100644 index ab2c3887d7b5..000000000000 --- a/users/Profpatsch/read-http/read-http.rs +++ /dev/null @@ -1,194 +0,0 @@ -extern crate httparse; -extern crate netencode; -extern crate arglib_netencode; -extern crate ascii; - -use std::os::unix::io::FromRawFd; -use std::io::Read; -use std::io::Write; - -use netencode::{U, T}; - -enum What { - Request, - Response -} - -fn main() -> std::io::Result<()> { - fn die(msg: T) -> ! { - eprintln!("{}", msg); - std::process::exit(1); - } - - let what : What = match arglib_netencode::arglib_netencode(None).unwrap() { - T::Record(rec) => match rec.get("what") { - Some(T::Text(t)) => match t.as_str() { - "request" => What::Request, - "response" => What::Response, - _ => die("read-http arglib: what should be either t:request or t:response"), - }, - Some(o) => die(format!("read-http arglib: expected a record of text, got {:#?}", o)), - None => { - eprintln!("read-http arglib: no `what` given, defaulting to Response"); - What::Response - } - } - o => die(format!("read-http arglib: expected a record, got {:#?}", o)) - }; - - fn read_stdin_to_complete(mut parse: F) -> () - where F: FnMut(&[u8]) -> httparse::Result - { - let mut res = httparse::Status::Partial; - loop { - if let httparse::Status::Complete(_) = res { - return; - } - let mut buf = [0; 2048]; - match std::io::stdin().read(&mut buf[..]) { - Ok(size) => if size == 0 { - break; - }, - Err(err) => panic!("could not read from stdin, {:?}", err) - } - match parse(&buf) { - Ok(status) => { - res = status; - } - Err(err) => die(format!("httparse parsing failed: {:#?}", err)) - } - } - } - - - fn normalize_headers<'a>(headers: &'a [httparse::Header]) -> Vec<(String, &'a str)> { - let mut res = vec![]; - for httparse::Header { name, value } in headers { - let val = ascii::AsciiStr::from_ascii(*value) - .expect(&format!("read-http: we require header values to be ASCII, but the header {} was {:?}", name, value)); - // lowercase the headers, since the standard doesn’t care - // and we want unique strings to match agains - res.push((name.to_lowercase(), val.as_str())) - } - res - } - - // tries to read until the end of the http header (deliniated by two newlines "\r\n\r\n") - fn read_till_end_of_header(buf: &mut Vec, reader: R) -> Option<()> { - let mut chunker = Chunkyboi::new(reader, 4096); - loop { - match chunker.next() { - Some(Ok(chunk)) => { - buf.extend_from_slice(&chunk); - if chunk.windows(4).any(|c| c == b"\r\n\r\n" ) { - return Some(()); - } - }, - Some(Err(err)) => die(format!("error reading from stdin: {:?}", err)), - None => return None - } - } - } - - // max header size chosen arbitrarily - let mut headers = [httparse::EMPTY_HEADER; 128]; - let stdin = std::io::stdin(); - - match what { - Request => { - let mut req = httparse::Request::new(&mut headers); - let mut buf: Vec = vec![]; - match read_till_end_of_header(&mut buf, stdin.lock()) { - Some(()) => match req.parse(&buf) { - Ok(httparse::Status::Complete(_body_start)) => {}, - Ok(httparse::Status::Partial) => die("httparse should have gotten a full header"), - Err(err) => die(format!("httparse response parsing failed: {:#?}", err)) - }, - None => die(format!("httparse end of stdin reached before able to parse request headers")) - } - let method = req.method.expect("method must be filled on complete parse"); - let path = req.path.expect("path must be filled on complete parse"); - write_dict_req(method, path, &normalize_headers(req.headers)) - }, - Response => { - let mut resp = httparse::Response::new(&mut headers); - let mut buf: Vec = vec![]; - match read_till_end_of_header(&mut buf, stdin.lock()) { - Some(()) => match resp.parse(&buf) { - Ok(httparse::Status::Complete(_body_start)) => {}, - Ok(httparse::Status::Partial) => die("httparse should have gotten a full header"), - Err(err) => die(format!("httparse response parsing failed: {:#?}", err)) - }, - None => die(format!("httparse end of stdin reached before able to parse response headers")) - } - let code = resp.code.expect("code must be filled on complete parse"); - let reason = resp.reason.expect("reason must be filled on complete parse"); - write_dict_resp(code, reason, &normalize_headers(resp.headers)) - } - } -} - -fn write_dict_req<'buf>(method: &'buf str, path: &'buf str, headers: &[(String, &str)]) -> std::io::Result<()> { - let mut http = vec![ - ("method", U::Text(method.as_bytes())), - ("path", U::Text(path.as_bytes())), - ]; - write_dict(http, headers) -} - -fn write_dict_resp<'buf>(code: u16, reason: &'buf str, headers: &[(String, &str)]) -> std::io::Result<()> { - let mut http = vec![ - ("status", U::N6(code as u64)), - ("status-text", U::Text(reason.as_bytes())), - ]; - write_dict(http, headers) -} - - -fn write_dict<'buf, 'a>(mut http: Vec<(&str, U<'a>)>, headers: &'a[(String, &str)]) -> std::io::Result<()> { - http.push(("headers", U::Record( - headers.iter().map( - |(name, value)| - (name.as_str(), U::Text(value.as_bytes())) - ).collect::>() - ))); - - netencode::encode( - &mut std::io::stdout(), - U::Record(http) - )?; - Ok(()) -} - - -// iter helper - -struct Chunkyboi { - inner: T, - buf: Vec, -} - -impl Chunkyboi { - fn new(inner: R, chunksize: usize) -> Self { - let buf = vec![0; chunksize]; - Chunkyboi { - inner, - buf - } - } -} - -impl Iterator for Chunkyboi { - type Item = std::io::Result>; - - fn next(&mut self) -> Option>> { - match self.inner.read(&mut self.buf) { - Ok(0) => None, - Ok(read) => { - // clone a new buffer so we can reuse the internal one - Some(Ok(self.buf[..read].to_owned())) - } - Err(err) => Some(Err(err)) - } - } -} -- cgit 1.4.1