Auto merge of #707 - Mark-Simulacrum:no-state, r=Mark-Simulacrum

Parallelize log uploads

This should drastically speed up report generation.

src/report/mod.rs

@@ -12,8 +12,6 @@ use mime::{self, Mime};
 use percent_encoding::{utf8_percent_encode, AsciiSet};
 use std::borrow::Cow;
 #[cfg(test)]
-use std::cell::RefCell;
-#[cfg(test)]
 use std::collections::HashMap;
 use std::convert::AsRef;
 use std::fmt::{self, Display};
@@ -281,40 +279,76 @@ fn write_logs<DB: ReadResults, W: ReportWriter>(
 ) -> Fallible<()> {
     let num_crates = crates.len();
     let progress_every = (num_crates / PROGRESS_FRACTION) + 1;
-    for (i, krate) in crates.iter().enumerate() {
-        if i % progress_every == 0 {
-            info!("wrote logs for {}/{} crates", i, num_crates)
-        }
 
-        if config.should_skip(krate) {
-            continue;
+    let errors = std::sync::Mutex::new(vec![]);
+    std::thread::scope(|s| {
+        let mut channels = vec![];
+        // This isn't really related to the number of cores on the system, since these threads are
+        // mostly driving network-related traffic. 8 is a reasonable number to not overwhelm
+        // systems while keeping things moving much faster than fully serial uploads.
+        for _ in 0..8 {
+            let (tx, rx) = std::sync::mpsc::sync_channel::<(PathBuf, Vec<u8>, EncodingType)>(32);
+            channels.push(tx);
+            let errors = &errors;
+            s.spawn(move || {
+                while let Ok((log_path, data, encoding)) = rx.recv() {
+                    if let Err(e) =
+                        dest.write_bytes(log_path, data, &mime::TEXT_PLAIN_UTF_8, encoding)
+                    {
+                        errors.lock().unwrap().push(e);
+                    }
+                }
+            });
         }
 
-        for tc in &ex.toolchains {
-            let log_path =
-                crate_to_path_fragment(tc, krate, SanitizationContext::Path).join("log.txt");
-            let content = db
-                .load_log(ex, tc, krate)
-                .and_then(|c| c.ok_or_else(|| err_msg("missing logs")))
-                .with_context(|_| format!("failed to read log of {krate} on {tc}"));
-            let content = match content {
-                Ok(c) => c,
-                Err(e) => {
-                    utils::report_failure(&e);
-                    continue;
-                }
-            };
+        for (i, krate) in crates.iter().enumerate() {
+            if i % progress_every == 0 {
+                info!("wrote logs for {}/{} crates", i, num_crates)
+            }
 
-            match content {
-                EncodedLog::Plain(data) => {
-                    dest.write_bytes(log_path, data, &mime::TEXT_PLAIN_UTF_8, EncodingType::Plain)
-                }
-                EncodedLog::Gzip(data) => {
-                    dest.write_bytes(log_path, data, &mime::TEXT_PLAIN_UTF_8, EncodingType::Gzip)
+            if config.should_skip(krate) {
+                continue;
+            }
+
+            for tc in &ex.toolchains {
+                let log_path =
+                    crate_to_path_fragment(tc, krate, SanitizationContext::Path).join("log.txt");
+                let content = db
+                    .load_log(ex, tc, krate)
+                    .and_then(|c| c.ok_or_else(|| err_msg("missing logs")))
+                    .with_context(|_| format!("failed to read log of {krate} on {tc}"));
+                let content = match content {
+                    Ok(c) => c,
+                    Err(e) => {
+                        utils::report_failure(&e);
+                        continue;
+                    }
+                };
+
+                match content {
+                    EncodedLog::Plain(data) => {
+                        channels[i % channels.len()]
+                            .send((log_path, data, EncodingType::Plain))
+                            .unwrap();
+                    }
+                    EncodedLog::Gzip(data) => {
+                        channels[i % channels.len()]
+                            .send((log_path, data, EncodingType::Gzip))
+                            .unwrap();
+                    }
                 }
-            }?;
+            }
         }
+    });
+
+    let mut errors = errors.into_inner().unwrap();
+    for error in errors.iter() {
+        utils::report_failure(&failure::format_err!("Logging upload failed: {:?}", error));
+    }
+    if !errors.is_empty() {
+        return Err(errors.remove(0));
     }
+
     Ok(())
 }
 
@@ -510,7 +544,7 @@ fn compare(
     }
 }
 
-pub trait ReportWriter {
+pub trait ReportWriter: Send + Sync {
     fn write_bytes<P: AsRef<Path>>(
         &self,
         path: P,
@@ -565,14 +599,15 @@ impl Display for FileWriter {
 #[cfg(test)]
 #[derive(Default)]
 pub struct DummyWriter {
-    results: RefCell<HashMap<(PathBuf, Mime), Vec<u8>>>,
+    results: std::sync::Mutex<HashMap<(PathBuf, Mime), Vec<u8>>>,
 }
 
 #[cfg(test)]
 impl DummyWriter {
     pub fn get<P: AsRef<Path>>(&self, path: P, mime: &Mime) -> Vec<u8> {
         self.results
-            .borrow()
+            .lock()
+            .unwrap()
             .get(&(path.as_ref().to_path_buf(), mime.clone()))
             .unwrap()
             .clone()
@@ -589,13 +624,14 @@ impl ReportWriter for DummyWriter {
         _: EncodingType,
     ) -> Fallible<()> {
         self.results
-            .borrow_mut()
+            .lock()
+            .unwrap()
             .insert((path.as_ref().to_path_buf(), mime.clone()), b);
         Ok(())
     }
 
     fn write_string<P: AsRef<Path>>(&self, path: P, s: Cow<str>, mime: &Mime) -> Fallible<()> {
-        self.results.borrow_mut().insert(
+        self.results.lock().unwrap().insert(
             (path.as_ref().to_path_buf(), mime.clone()),
             s.bytes().collect(),
         );