➕ update: add prototype for `tail -f` based on polling

Cargo.lock

@@ -1720,6 +1720,17 @@ dependencies = [
  "uom",
 ]
 
+[[package]]
+name = "ptth_tail"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "reqwest",
+ "tokio",
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "pulldown-cmark"
 version = "0.8.0"

Cargo.toml

@@ -23,4 +23,7 @@ ptth_server = { path = "crates/ptth_server" }
 
 [workspace]
 
-members = ["crates/*"]
+members = [
+	"crates/*",
+	"tools/*",
+]

crates/ptth_server/src/lib.rs

@@ -270,9 +270,7 @@ pub async fn run_server (
 				}
 				continue;
 			},
-			Ok (r) => {
-				r
-			},
+			Ok (x) => x,
 		};
 		
 		if req_resp.status () == StatusCode::NO_CONTENT {

tools/ptth_tail/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+
+name = "ptth_tail"
+version = "0.1.0"
+authors = ["Trish"]
+edition = "2018"
+license = "AGPL-3.0"
+
+[dependencies]
+
+anyhow = "1.0.34"
+tracing = "0.1.21"
+tracing-subscriber = "0.2.15"
+
+[dependencies.reqwest]
+version = "0.10.8"
+features = ["stream"]
+
+[dependencies.tokio]
+version = "0.2.22"
+features = ["full"]

tools/ptth_tail/src/main.rs

@@ -0,0 +1,80 @@
+use std::{
+	convert::TryFrom,
+	io::{
+		self,
+		Write,
+	},
+	time::Duration,
+};
+
+use reqwest::{
+	Client,
+	StatusCode,
+};
+use tokio::{
+	stream::StreamExt,
+	time::interval,
+};
+use tracing::{
+	debug, warn
+};
+use tracing_subscriber::{
+	EnvFilter,
+	fmt,
+	fmt::format::FmtSpan,
+};
+
+#[tokio::main]
+async fn main () -> Result <(), anyhow::Error> {
+	fmt ()
+		.with_env_filter (EnvFilter::from_default_env ())
+		.with_span_events (FmtSpan::CLOSE)
+		.init ()
+	;
+	
+	let client = Client::default ();
+	
+	let server = "http://127.0.0.1:4000/files/log.txt";
+	
+	let mut total_bytes_received = 0_u64;
+	let mut timer = interval (Duration::from_secs (2));
+	
+	loop {
+		timer.tick ().await;
+		
+		let resp = match client
+		.get (server)
+		.header ("range", format! ("bytes={}-", total_bytes_received))
+		.send ().await {
+			Err (e) => {
+				warn! ("Reqwest send error: {:?}", e);
+				continue;
+			}
+			Ok (x) => x,
+		};
+		
+		let status = resp.status ();
+		
+		match status {
+			StatusCode::RANGE_NOT_SATISFIABLE => continue,
+			StatusCode::PARTIAL_CONTENT => (),
+			sc => {
+				debug! ("status code: {}", sc);
+				continue;
+			},
+		}
+		
+		let mut stream = resp.bytes_stream ();
+		
+		while let Some (chunk) = stream.next ().await {
+			let chunk = match chunk {
+				Ok (x) => x,
+				Err (_) => break,
+			};
+			io::stdout ().write_all (&chunk)?;
+			total_bytes_received += u64::try_from (chunk.len ())?;
+		}
+	}
+	
+	Ok (())
+}