Merge pull request #206 from jasonrhansen/stdout-bufwriter

Use BufWriter when STDOUT is not a TTY

Author: jonhoo

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
  - Decreased default minimum width from 0.1% to 0.01%. [#204](https://github.com/jonhoo/inferno/pull/204)
+ - Detect if STDOUT is a TTY and if it's not, use a `BufWriter` to avoid line buffering. [#206](https://github.com/jonhoo/inferno/pull/206)
 
 ### Removed
 

Cargo.toml

@@ -28,6 +28,7 @@ nameattr = ["indexmap"]
 
 [dependencies]
 ahash = "0.6"
+atty = "0.2"
 crossbeam-utils = { version = "0.8", optional = true }
 crossbeam-channel = { version = "0.5", optional = true }
 dashmap = { version = "3", optional = true }

src/bin/collapse-dtrace.rs

@@ -83,5 +83,5 @@ fn main() -> io::Result<()> {
     }
 
     let (infile, options) = opt.into_parts();
-    Folder::from(options).collapse_file(infile.as_ref(), io::stdout().lock())
+    Folder::from(options).collapse_file_to_stdout(infile.as_ref())
 }

src/bin/collapse-guess.rs

@@ -75,5 +75,5 @@ fn main() -> io::Result<()> {
     }
 
     let (infile, options) = opt.into_parts();
-    Folder::from(options).collapse_file(infile.as_ref(), io::stdout().lock())
+    Folder::from(options).collapse_file_to_stdout(infile.as_ref())
 }

src/bin/collapse-perf.rs

@@ -112,5 +112,5 @@ fn main() -> io::Result<()> {
     }
 
     let (infile, options) = opt.into_parts();
-    Folder::from(options).collapse_file(infile.as_ref(), io::stdout().lock())
+    Folder::from(options).collapse_file_to_stdout(infile.as_ref())
 }

src/bin/collapse-sample.rs

@@ -62,5 +62,5 @@ fn main() -> io::Result<()> {
     }
 
     let (infile, options) = opt.into_parts();
-    Folder::from(options).collapse_file(infile.as_ref(), io::stdout().lock())
+    Folder::from(options).collapse_file_to_stdout(infile.as_ref())
 }

src/bin/collapse-vtune.rs

@@ -64,5 +64,5 @@ fn main() -> io::Result<()> {
     }
 
     let (infile, options) = opt.into_parts();
-    Folder::from(options).collapse_file(infile.as_ref(), io::stdout().lock())
+    Folder::from(options).collapse_file_to_stdout(infile.as_ref())
 }

src/bin/diff-folded.rs

@@ -87,5 +87,15 @@ fn main() -> io::Result<()> {
     }
 
     let (folded1, folded2, options) = opt.into_parts();
-    differential::from_files(options, folded1, folded2, io::stdout().lock())
+
+    if atty::is(atty::Stream::Stdout) {
+        differential::from_files(options, folded1, folded2, io::stdout().lock())
+    } else {
+        differential::from_files(
+            options,
+            folded1,
+            folded2,
+            io::BufWriter::new(io::stdout().lock()),
+        )
+    }
 }

src/bin/flamegraph.rs

@@ -297,9 +297,19 @@ fn main() -> quick_xml::Result<()> {
     };
 
     let (infiles, mut options) = opt.into_parts();
+
     options.palette_map = palette_map.as_mut();
 
-    flamegraph::from_files(&mut options, &infiles, io::stdout().lock())?;
+    if atty::is(atty::Stream::Stdout) {
+        flamegraph::from_files(&mut options, &infiles, io::stdout().lock())?;
+    } else {
+        flamegraph::from_files(
+            &mut options,
+            &infiles,
+            io::BufWriter::new(io::stdout().lock()),
+        )?;
+    }
+
     save_consistent_palette_if_needed(&palette_map, PALETTE_MAP_FILE).map_err(quick_xml::Error::Io)
 }
 

src/collapse/common.rs

@@ -465,6 +465,7 @@ impl Occurrences {
                 }
             }
         }
+        writer.flush()?;
         Ok(())
     }
 }
@@ -510,7 +511,7 @@ pub(crate) fn fix_partially_demangled_rust_symbol(symbol: &str) -> Cow<str> {
                 demangled.push_str("::");
                 rest = &rest[2..];
             } else {
-                demangled.push_str(".");
+                demangled.push('.');
                 rest = &rest[1..];
             }
         } else if rest.starts_with('$') {