feat: async handle sighup and switch the file handles

Cargo.lock

@@ -2,6 +2,21 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "addr2line"
+version = "0.22.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6e4503c46a5c0c7844e948c9a4d6acd9f50cccb4de1c48eb9e291ea17470c678"
+dependencies = [
+ "gimli",
+]
+
+[[package]]
+name = "adler"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f26201604c87b1e01bd3d98f8d5d9a8fcbb815e8cedb41ffccbeb4bf593a35fe"
+
 [[package]]
 name = "anstream"
 version = "0.6.14"
@@ -38,7 +53,7 @@ version = "1.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a64c907d4e79225ac72e2a354c9ce84d50ebb4586dee56c82b3ee73004f537f5"
 dependencies = [
- "windows-sys",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -48,7 +63,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "61a38449feb7068f52bb06c12759005cf459ee52bb4adc1d5a7c4322d716fb19"
 dependencies = [
  "anstyle",
- "windows-sys",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -57,6 +72,39 @@ version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b3d1d046238990b9cf5bcde22a3fb3584ee5cf65fb2765f454ed428c7a0063da"
 
+[[package]]
+name = "backtrace"
+version = "0.3.72"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17c6a35df3749d2e8bb1b7b21a976d82b15548788d2735b9d82f329268f71a11"
+dependencies = [
+ "addr2line",
+ "cc",
+ "cfg-if",
+ "libc",
+ "miniz_oxide",
+ "object",
+ "rustc-demangle",
+]
+
+[[package]]
+name = "bytes"
+version = "1.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "514de17de45fdb8dc022b1a7975556c53c86f9f0aa5f534b98977b171857c2c9"
+
+[[package]]
+name = "cc"
+version = "1.0.98"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41c270e7540d725e65ac7f1b212ac8ce349719624d7bcff99f8e2e488e8cf03f"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "clap"
 version = "4.5.4"
@@ -103,12 +151,24 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b6a852b24ab71dffc585bcb46eaf7959d175cb865a7152e35b348d1b2960422"
 
+[[package]]
+name = "gimli"
+version = "0.29.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40ecd4077b5ae9fd2e9e169b102c6c330d0605168eb0e8bf79952b256dbefffd"
+
 [[package]]
 name = "heck"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
+[[package]]
+name = "hermit-abi"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d231dfb89cfffdbc30e7fc41579ed6066ad03abda9e567ccafae602b97ec5024"
+
 [[package]]
 name = "is_terminal_polyfill"
 version = "1.70.0"
@@ -127,36 +187,83 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "clap",
- "signal-hook",
+ "tokio",
 ]
 
 [[package]]
-name = "proc-macro2"
+name = "memchr"
-version = "1.0.79"
+version = "2.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e835ff2298f5721608eb1a980ecaee1aef2c132bf95ecc026a11b7bf3c01c02e"
+checksum = "6c8640c5d730cb13ebd907d8d04b52f55ac9a2eec55b440c8892f40d56c76c1d"
+
+[[package]]
+name = "miniz_oxide"
+version = "0.7.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87dfd01fe195c66b572b37921ad8803d010623c0aca821bea2302239d155cdae"
+dependencies = [
+ "adler",
+]
+
+[[package]]
+name = "mio"
+version = "0.8.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
+dependencies = [
+ "libc",
+ "wasi",
+ "windows-sys 0.48.0",
+]
+
+[[package]]
+name = "num_cpus"
+version = "1.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
+[[package]]
+name = "object"
+version = "0.35.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b8ec7ab813848ba4522158d5517a6093db1ded27575b070f4177b8d12b41db5e"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bda66fc9667c18cb2758a2ac84d1167245054bcf85d5d1aaa6923f45801bdd02"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.85"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22244ce15aa966053a896d1accb3a6e68469b97c7f33f284b99f0d576879fc23"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.35"
+version = "1.0.36"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "291ec9ab5efd934aaf503a6466c5d5251535d108ee747472c3977cc5acc868ef"
+checksum = "0fa76aaf39101c457836aec0ce2316dbdc3ab723cdda1c6bd4e6ad4208acaca7"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
-name = "signal-hook"
+name = "rustc-demangle"
-version = "0.3.17"
+version = "0.1.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8621587d4798caf8eb44879d42e56b9a93ea5dcd315a6487c357130095b62801"
+checksum = "719b953e2095829ee67db738b3bfa9fa368c94900df327b3f07fe6e794d2fe1f"
-dependencies = [
- "libc",
- "signal-hook-registry",
-]
 
 [[package]]
 name = "signal-hook-registry"
@@ -175,15 +282,43 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "syn"
-version = "2.0.55"
+version = "2.0.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "002a1b3dbf967edfafc32655d0f377ab0bb7b994aa1d32c8cc7e9b8bf3ebb8f0"
+checksum = "c42f3f41a2de00b01c0aaad383c5a45241efc8b2d1eda5661812fda5f3cdcff5"
 dependencies = [
  "proc-macro2",
  "quote",
  "unicode-ident",
 ]
 
+[[package]]
+name = "tokio"
+version = "1.38.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba4f4a02a7a80d6f274636f0aa95c7e383b912d41fe721a31f29e29698585a4a"
+dependencies = [
+ "backtrace",
+ "bytes",
+ "libc",
+ "mio",
+ "num_cpus",
+ "pin-project-lite",
+ "signal-hook-registry",
+ "tokio-macros",
+ "windows-sys 0.48.0",
+]
+
+[[package]]
+name = "tokio-macros"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f5ae998a069d4b5aba8ee9dad856af7d520c3699e6159b185c2acd48155d39a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.12"
@@ -196,13 +331,43 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
 
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
+[[package]]
+name = "windows-sys"
+version = "0.48.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
+dependencies = [
+ "windows-targets 0.48.5",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
 dependencies = [
- "windows-targets",
+ "windows-targets 0.52.5",
+]
+
+[[package]]
+name = "windows-targets"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
+dependencies = [
+ "windows_aarch64_gnullvm 0.48.5",
+ "windows_aarch64_msvc 0.48.5",
+ "windows_i686_gnu 0.48.5",
+ "windows_i686_msvc 0.48.5",
+ "windows_x86_64_gnu 0.48.5",
+ "windows_x86_64_gnullvm 0.48.5",
+ "windows_x86_64_msvc 0.48.5",
 ]
 
 [[package]]
@@ -211,28 +376,46 @@ version = "0.52.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6f0713a46559409d202e70e28227288446bf7841d3211583a4b53e3f6d96e7eb"
 dependencies = [
- "windows_aarch64_gnullvm",
+ "windows_aarch64_gnullvm 0.52.5",
- "windows_aarch64_msvc",
+ "windows_aarch64_msvc 0.52.5",
- "windows_i686_gnu",
+ "windows_i686_gnu 0.52.5",
  "windows_i686_gnullvm",
- "windows_i686_msvc",
+ "windows_i686_msvc 0.52.5",
- "windows_x86_64_gnu",
+ "windows_x86_64_gnu 0.52.5",
- "windows_x86_64_gnullvm",
+ "windows_x86_64_gnullvm 0.52.5",
- "windows_x86_64_msvc",
+ "windows_x86_64_msvc 0.52.5",
 ]
 
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
+
 [[package]]
 name = "windows_aarch64_gnullvm"
 version = "0.52.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7088eed71e8b8dda258ecc8bac5fb1153c5cffaf2578fc8ff5d61e23578d3263"
 
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
+
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9985fd1504e250c615ca5f281c3f7a6da76213ebd5ccc9561496568a2752afb6"
 
+[[package]]
+name = "windows_i686_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
+
 [[package]]
 name = "windows_i686_gnu"
 version = "0.52.5"
@@ -245,24 +428,48 @@ version = "0.52.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "87f4261229030a858f36b459e748ae97545d6f1ec60e5e0d6a3d32e0dc232ee9"
 
+[[package]]
+name = "windows_i686_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
+
 [[package]]
 name = "windows_i686_msvc"
 version = "0.52.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "db3c2bf3d13d5b658be73463284eaf12830ac9a26a90c717b7f771dfe97487bf"
 
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
+
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4e4246f76bdeff09eb48875a0fd3e2af6aada79d409d33011886d3e1581517d9"
 
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
+
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "852298e482cd67c356ddd9570386e2862b5673c85bd5f88df9ab6802b334c596"
 
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
+
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.5"

Cargo.toml

@@ -8,4 +8,4 @@ edition = "2021"
 [dependencies]
 anyhow = "1.0.86"
 clap = { version = "4.5.4", features = ["derive"] }
-signal-hook = "0.3.17"
+tokio = { version = "1.38.0", features = ["process", "signal", "rt", "rt-multi-thread", "macros", "io-util", "fs"] }

src/main.rs

@@ -1,11 +1,14 @@
-use std::ffi::c_int;
-use std::process;
 use std::convert::From;
 use std::path::PathBuf;
-use signal_hook::consts::signal::*;
+use std::process::{ExitCode, Stdio};
 
-use clap::{Parser, ValueEnum};
 use anyhow;
+use clap::{Parser, ValueEnum};
+use tokio;
+use tokio::fs::File;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::process::Command;
+use tokio::signal::unix::{signal, SignalKind};
 
 #[derive(Parser, Clone, ValueEnum)]
 pub enum HandledSignals {
@@ -14,12 +17,12 @@ pub enum HandledSignals {
     SIGUSR2,
 }
 
-impl From<HandledSignals> for c_int {
+impl From<&HandledSignals> for SignalKind {
-    fn from(value: HandledSignals) -> Self {
+    fn from(value: &HandledSignals) -> Self {
         match value {
-            HandledSignals::SIGHUP => SIGHUP,
+            HandledSignals::SIGHUP => SignalKind::hangup(),
-            HandledSignals::SIGUSR1 => SIGUSR1,
+            HandledSignals::SIGUSR1 => SignalKind::user_defined1(),
-            HandledSignals::SIGUSR2 => SIGUSR2,
+            HandledSignals::SIGUSR2 => SignalKind::user_defined2(),
         }
     }
 }
@@ -27,20 +30,97 @@ impl From<HandledSignals> for c_int {
 #[derive(Parser)]
 #[command(version, about, long_about = None)]
 struct Args {
-    #[arg(short = 'e', long = "err-path", help="Path to write stderr to")]
+    #[arg(short = 'e', long = "err-path", help = "Path to write stderr to")]
-    std_err_path: PathBuf,
+    stderr_path: PathBuf,
-    #[arg(short = 'o', long = "out-path", help="Path to write stdout to")]
+    #[arg(short = 'o', long = "out-path", help = "Path to write stdout to")]
-    std_out_path: PathBuf,
+    stdout_path: PathBuf,
-    #[arg(long = "sig", value_enum, help="Optional signal notifiying that the file paths have been rotated")]
+    #[arg(long = "sig", value_enum, help="Signal notifiying that the file paths have been rotated", default_value_t = HandledSignals::SIGHUP)]
-    rotated_signal: Option<HandledSignals>,
+    rotated_signal: HandledSignals,
-    #[arg(long="size", help="Optional size at which to rotate the files")]
+    #[arg(
-    rotate_size_bytes: Option<usize>,
+        long = "size",
-    #[arg(last = true, help="Command to run")]
+        help = "Optional size at which to rotate the files, conficts with --sig",
+        conflicts_with = "rotated_signal"
+    )]
     cmd: Vec<String>,
 }
 
-fn main() -> anyhow::Result<()> {
+#[tokio::main]
+async fn main() -> anyhow::Result<ExitCode> {
     let args = Args::parse();
-    println!("Hello, world!");
+    let stderr_path = &args.stderr_path;
-    return Ok(());
+    let stdout_path = &args.stdout_path;
+    // Setup our signal hook.
+    let handled_sig: SignalKind = (&args.rotated_signal).into();
+    let mut signal_iter = signal(handled_sig)?;
+    // Setup our output wiring.
+    let app_name = match args.cmd.first() {
+        Some(n) => n,
+        None => return Err(anyhow::anyhow!("No command specified")),
+    };
+    let child = Command::new(app_name)
+        .args(args.cmd.into_iter().skip(1).collect::<Vec<String>>())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()?;
+    let mut stdout_reader = child
+        .stdout
+        .expect("no valid stdout from command available");
+    let mut stdout_buffer = [0; 8 * 1024];
+    let mut stderr_reader = child
+        .stderr
+        .expect("no valid stderr from command available");
+    let mut stderr_buffer = [0; 8 * 1024];
+
+    let mut stderr_writer = File::options().append(true).open(stderr_path).await?;
+    let mut stdout_writer = File::options().append(true).open(stdout_path).await?;
+    loop {
+        tokio::select! {
+            // wait for a read on stdout
+            out_result = stdout_reader.read(&mut stdout_buffer) => {
+                match out_result {
+                    Ok(n) => {
+                        // TODO(zaphar): It is possible we should try to reopen the file if this
+                        // write fails in some cases.
+                        if let Err(e) = stdout_writer.write(&stdout_buffer[0..n]).await {
+                            todo!();
+                        }
+                    },
+                    Err(e) => {
+                        // TODO(zaphar): This likely means the command has broken badly. We should
+                        // do the right thing here..
+                        todo!()
+                    },
+                }
+            }
+            // wait for a read on stderr
+            err_result = stderr_reader.read(&mut stderr_buffer) => {
+                match err_result {
+                    Ok(n) => {
+                        // TODO(zaphar): It is possible we should try to reopen the file if this
+                        // write fails in some cases.
+                        if let Err(e) = stderr_writer.write(&stderr_buffer[0..n]).await {
+                            todo!()
+                        }
+                    },
+                    Err(e) => {
+                        // TODO(zaphar): This likely means the command has broken badly. We should
+                        // do the right thing here..
+                        todo!()
+                    },
+                }
+            }
+            _ = signal_iter.recv() => {
+                // on sighub sync and reopen our files
+                // NOTE(zaphar): This will cause the previously opened handles to get
+                // dropped which will cause them to close assuming all the io has finished. This is why we sync
+                // before reopening the files.
+                // TODO(zaphar): These should do something in the event of an error
+                _ = stderr_writer.sync_all().await;
+                _ = stdout_writer.sync_all().await;
+                stderr_writer = File::options().append(true).open(stderr_path).await?;
+                stdout_writer = File::options().append(true).open(stdout_path).await?;
+                // wait for a signal
+            }
+        }
+    }
 }