|
| 1 | +use std::any::type_name; |
| 2 | +use std::borrow::Cow; |
| 3 | +use std::fmt::Write as _; |
| 4 | +use std::io::ErrorKind; |
| 5 | +use std::marker::PhantomData; |
| 6 | +use std::process::exit; |
| 7 | +use std::string::String; |
| 8 | +use std::sync::Arc; |
| 9 | +use std::time::Duration; |
| 10 | +use std::vec::Vec; |
| 11 | +use std::{eprintln, format}; |
| 12 | + |
| 13 | +use linkme::distributed_slice; |
| 14 | +use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader, Stdin, Stdout, stdin, stdout}; |
| 15 | +use tokio::spawn; |
| 16 | +use tokio::sync::{Mutex, oneshot}; |
| 17 | + |
| 18 | +use super::{DYNAMIC_ENVIRON_KEY, MainRequest, MainResponse, Outcome, SerializableTemplate}; |
| 19 | + |
| 20 | +const PROCESSORS: usize = 4; |
| 21 | + |
| 22 | +pub(super) fn run_dynamic_main() { |
| 23 | + std::env::set_var(DYNAMIC_ENVIRON_KEY, "-"); |
| 24 | + |
| 25 | + let mut entries: Vec<_> = DYNAMIC_TEMPLATES.iter().map(|entry| entry.name()).collect(); |
| 26 | + entries.sort_unstable(); |
| 27 | + for window in entries.windows(2) { |
| 28 | + if let &[a, b] = window { |
| 29 | + if a == b { |
| 30 | + eprintln!("duplicated dynamic template {a:?}"); |
| 31 | + } |
| 32 | + } |
| 33 | + } |
| 34 | + |
| 35 | + let rt = match tokio::runtime::Builder::new_current_thread() |
| 36 | + .enable_all() |
| 37 | + .build() |
| 38 | + { |
| 39 | + Ok(rt) => rt, |
| 40 | + Err(err) => { |
| 41 | + eprintln!("could not start tokio runtime: {err}"); |
| 42 | + exit(1); |
| 43 | + } |
| 44 | + }; |
| 45 | + let _ = rt.block_on(async { |
| 46 | + let stdout = Arc::new(Mutex::new(stdout())); |
| 47 | + let stdin = Arc::new(Mutex::new(BufReader::new(stdin()))); |
| 48 | + let (done_tx, done_rx) = oneshot::channel(); |
| 49 | + let done = Arc::new(Mutex::new(Some(done_tx))); |
| 50 | + |
| 51 | + let mut threads = Vec::with_capacity(PROCESSORS); |
| 52 | + for _ in 0..PROCESSORS { |
| 53 | + threads.push(spawn(dynamic_processor( |
| 54 | + Arc::clone(&stdout), |
| 55 | + Arc::clone(&stdin), |
| 56 | + Arc::clone(&done), |
| 57 | + ))); |
| 58 | + } |
| 59 | + |
| 60 | + done_rx.await.map_err(|err| { |
| 61 | + std::io::Error::new(ErrorKind::BrokenPipe, format!("lost result channel: {err}")); |
| 62 | + }) |
| 63 | + }); |
| 64 | + rt.shutdown_timeout(Duration::from_secs(5)); |
| 65 | + exit(0) |
| 66 | +} |
| 67 | + |
| 68 | +async fn dynamic_processor( |
| 69 | + stdout: Arc<Mutex<Stdout>>, |
| 70 | + stdin: Arc<Mutex<BufReader<Stdin>>>, |
| 71 | + done: Arc<Mutex<Option<oneshot::Sender<std::io::Result<()>>>>>, |
| 72 | +) { |
| 73 | + let done = move |result: Result<(), std::io::Error>| { |
| 74 | + let done = Arc::clone(&done); |
| 75 | + async move { |
| 76 | + let mut lock = done.lock().await; |
| 77 | + if let Some(done) = lock.take() { |
| 78 | + let _: Result<_, _> = done.send(result); |
| 79 | + } |
| 80 | + } |
| 81 | + }; |
| 82 | + |
| 83 | + let mut line_buf = String::new(); |
| 84 | + let mut response_buf = String::new(); |
| 85 | + loop { |
| 86 | + line_buf.clear(); |
| 87 | + match stdin.lock().await.read_line(&mut line_buf).await { |
| 88 | + Ok(n) if n > 0 => {} |
| 89 | + result => return done(result.map(|_| ())).await, |
| 90 | + } |
| 91 | + let line = line_buf.trim_ascii(); |
| 92 | + if line.is_empty() { |
| 93 | + continue; |
| 94 | + } |
| 95 | + |
| 96 | + let MainRequest { callid, name, data } = match serde_json::from_str(line) { |
| 97 | + Ok(req) => req, |
| 98 | + Err(err) => { |
| 99 | + let err = format!("could not deserialize request: {err}"); |
| 100 | + return done(Err(std::io::Error::new(ErrorKind::InvalidData, err))).await; |
| 101 | + } |
| 102 | + }; |
| 103 | + response_buf.clear(); |
| 104 | + |
| 105 | + let mut outcome = Outcome::NotFound; |
| 106 | + for entry in DYNAMIC_TEMPLATES { |
| 107 | + if entry.name() == name { |
| 108 | + outcome = entry.dynamic_render(&mut response_buf, &data); |
| 109 | + break; |
| 110 | + } |
| 111 | + } |
| 112 | + |
| 113 | + // SAFETY: `serde_json` writes valid UTF-8 data |
| 114 | + let mut line = unsafe { line_buf.as_mut_vec() }; |
| 115 | + |
| 116 | + line.clear(); |
| 117 | + line.push(b'\n'); |
| 118 | + if let Err(err) = serde_json::to_writer(&mut line, &MainResponse { callid, outcome }) { |
| 119 | + let err = format!("could not serialize response: {err}"); |
| 120 | + return done(Err(std::io::Error::new(ErrorKind::InvalidData, err))).await; |
| 121 | + } |
| 122 | + line.push(b'\n'); |
| 123 | + |
| 124 | + let is_done = { |
| 125 | + let mut stdout = stdout.lock().await; |
| 126 | + stdout.write_all(line).await.is_err() || stdout.flush().await.is_err() |
| 127 | + }; |
| 128 | + if is_done { |
| 129 | + return done(Ok(())).await; |
| 130 | + } |
| 131 | + } |
| 132 | +} |
| 133 | + |
| 134 | +/// TODO |
| 135 | +#[macro_export] |
| 136 | +macro_rules! register_dynamic_template { |
| 137 | + ($Tmpl:ty $(,)?) => { |
| 138 | + const _: () = { |
| 139 | + const DATA: &$crate::helpers::DynamicTemplateData<$Tmpl> = |
| 140 | + &$crate::helpers::DynamicTemplateData::<$Tmpl> { |
| 141 | + phantom: $crate::helpers::core::marker::PhantomData {}, |
| 142 | + }; |
| 143 | + |
| 144 | + #[$crate::helpers::linkme::distributed_slice($crate::helpers::DYNAMIC_TEMPLATES)] |
| 145 | + #[linkme(crate = $crate::helpers::linkme)] |
| 146 | + static DYNAMIC_TEMPLATES: $crate::helpers::DynamicTemplate = |
| 147 | + $crate::helpers::DynamicTemplate(DATA); |
| 148 | + }; |
| 149 | + }; |
| 150 | +} |
| 151 | + |
| 152 | +/// TODO |
| 153 | +#[distributed_slice] |
| 154 | +pub static DYNAMIC_TEMPLATES: [DynamicTemplate]; |
| 155 | + |
| 156 | +/// TODO |
| 157 | +pub struct DynamicTemplate(pub &'static dyn DynamicableTemplate); |
| 158 | + |
| 159 | +#[allow(unused)] |
| 160 | +impl DynamicTemplate { |
| 161 | + /// TODO |
| 162 | + #[inline] |
| 163 | + fn name(&self) -> &str { |
| 164 | + self.0.name() |
| 165 | + } |
| 166 | + |
| 167 | + /// TODO |
| 168 | + #[inline] |
| 169 | + fn dynamic_render<'a>(&self, buf: &'a mut String, value: &str) -> Outcome<'a> { |
| 170 | + self.0.dynamic_render(buf, value) |
| 171 | + } |
| 172 | +} |
| 173 | + |
| 174 | +pub trait DynamicableTemplate: Send + Sync { |
| 175 | + fn name(&self) -> &str; |
| 176 | + fn dynamic_render<'a>(&self, buf: &'a mut String, value: &str) -> Outcome<'a>; |
| 177 | +} |
| 178 | + |
| 179 | +/// TODO |
| 180 | +#[derive(Debug, Clone, Copy)] |
| 181 | +pub struct DynamicTemplateData<T: SerializableTemplate> { |
| 182 | + /// TODO |
| 183 | + pub phantom: PhantomData<fn() -> *const T>, |
| 184 | +} |
| 185 | + |
| 186 | +impl<T: SerializableTemplate> DynamicableTemplate for DynamicTemplateData<T> { |
| 187 | + fn name(&self) -> &str { |
| 188 | + type_name::<T>() |
| 189 | + } |
| 190 | + |
| 191 | + fn dynamic_render<'a>(&self, buf: &'a mut String, value: &str) -> Outcome<'a> { |
| 192 | + buf.clear(); |
| 193 | + let write_result; |
| 194 | + let outcome: fn(Cow<'a, str>) -> Outcome<'a>; |
| 195 | + match serde_json::from_str::<T>(value) { |
| 196 | + Ok(tmpl) => match tmpl.render_into(buf) { |
| 197 | + Ok(_) => { |
| 198 | + write_result = Ok(()); |
| 199 | + outcome = Outcome::Rendered; |
| 200 | + } |
| 201 | + Err(err) => { |
| 202 | + write_result = write!(buf, "{err}"); |
| 203 | + outcome = Outcome::RenderError; |
| 204 | + } |
| 205 | + }, |
| 206 | + Err(err) => { |
| 207 | + write_result = write!(buf, "{err}"); |
| 208 | + outcome = Outcome::DeserializeError; |
| 209 | + } |
| 210 | + } |
| 211 | + match write_result { |
| 212 | + Ok(_) => outcome(Cow::Borrowed(buf)), |
| 213 | + Err(_) => Outcome::Fmt, |
| 214 | + } |
| 215 | + } |
| 216 | +} |
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