Move trace file opening into TraceDump::new

Moves the responsibility of opening the trace file into TraceDump::new, so that
it doesn't need to be repeated at every call site.

1 files changed, 17 insertions, 13 deletions

diff --git a/components/profile/trace_dump.rs b/components/profile/trace_dump.rs
index 5576f1af94c..b0c8f9d7ef5 100644
--- a/components/profile/trace_dump.rs
+++ b/components/profile/trace_dump.rs
@@ -7,7 +7,8 @@
 use profile_traits::time::{ProfilerCategory, TimerMetadata};
 use serde_json;
 use std::fs;
-use std::io::Write;
+use std::io::{self, Write};
+use std::path;
 
 /// An RAII class for writing the HTML trace dump.
 #[derive(Debug)]
@@ -36,9 +37,12 @@ struct TraceEntry {
 impl TraceDump {
     /// Create a new TraceDump and write the prologue of the HTML file out to
     /// disk.
-    pub fn new(mut file: fs::File) -> TraceDump {
-        write_prologue(&mut file);
-        TraceDump { file: file }
+    pub fn new<P>(trace_file_path: P) -> io::Result<TraceDump>
+        where P: AsRef<path::Path>
+    {
+        let mut file = fs::File::create(trace_file_path)?;
+        write_prologue(&mut file)?;
+        Ok(TraceDump { file: file })
     }
 
     /// Write one trace to the trace dump file.
@@ -63,18 +67,18 @@ impl Drop for TraceDump {
     /// Write the epilogue of the trace dump HTML file out to disk on
     /// destruction.
     fn drop(&mut self) {
-        write_epilogue(&mut self.file);
+        write_epilogue(&mut self.file).unwrap();
     }
 }
 
-fn write_prologue(file: &mut fs::File) {
-    writeln!(file, "{}", include_str!("./trace-dump-prologue-1.html")).unwrap();
-    writeln!(file, "{}", include_str!("./trace-dump.css")).unwrap();
-    writeln!(file, "{}", include_str!("./trace-dump-prologue-2.html")).unwrap();
+fn write_prologue(file: &mut fs::File) -> io::Result<()> {
+    writeln!(file, "{}", include_str!("./trace-dump-prologue-1.html"))?;
+    writeln!(file, "{}", include_str!("./trace-dump.css"))?;
+    writeln!(file, "{}", include_str!("./trace-dump-prologue-2.html"))
 }
 
-fn write_epilogue(file: &mut fs::File) {
-    writeln!(file, "{}", include_str!("./trace-dump-epilogue-1.html")).unwrap();
-    writeln!(file, "{}", include_str!("./trace-dump.js")).unwrap();
-    writeln!(file, "{}", include_str!("./trace-dump-epilogue-2.html")).unwrap();
+fn write_epilogue(file: &mut fs::File) -> io::Result<()> {
+    writeln!(file, "{}", include_str!("./trace-dump-epilogue-1.html"))?;
+    writeln!(file, "{}", include_str!("./trace-dump.js"))?;
+    writeln!(file, "{}", include_str!("./trace-dump-epilogue-2.html"))
 }