API: Take AsRef<Path> and Send+Sync errors

Having errors be `Send+Sync` is a good practice in the Rust ecosystem as
it allows at least passing the errors in and out of threads as it is
propagated.

`AsRef<Path>` allows more convenient use of the constructor wherein you
have the convenience of being able to pass in e.g. a string literal.

Author: nagisa

measureme/src/file_serialization_sink.rs

@@ -17,7 +17,7 @@ struct Inner {
 }
 
 impl SerializationSink for FileSerializationSink {
-    fn from_path(path: &Path) -> Result<Self, Box<dyn Error>> {
+    fn from_path(path: &Path) -> Result<Self, Box<dyn Error + Send + Sync>> {
         fs::create_dir_all(path.parent().unwrap())?;
 
         let file = fs::File::create(path)?;

measureme/src/mmap_serialization_sink.rs

@@ -13,7 +13,7 @@ pub struct MmapSerializationSink {
 }
 
 impl SerializationSink for MmapSerializationSink {
-    fn from_path(path: &Path) -> Result<Self, Box<dyn Error>> {
+    fn from_path(path: &Path) -> Result<Self, Box<dyn Error + Send + Sync>> {
         // Lazily allocate 1 GB :O
         let file_size = 1 << 30;
 

measureme/src/profiler.rs

@@ -15,11 +15,11 @@ pub struct ProfilerFiles {
 }
 
 impl ProfilerFiles {
-    pub fn new(path_stem: &Path) -> ProfilerFiles {
+    pub fn new<P: AsRef<Path>>(path_stem: P) -> ProfilerFiles {
         ProfilerFiles {
-            events_file: path_stem.with_extension("events"),
-            string_data_file: path_stem.with_extension("string_data"),
-            string_index_file: path_stem.with_extension("string_index"),
+            events_file: path_stem.as_ref().with_extension("events"),
+            string_data_file: path_stem.as_ref().with_extension("string_data"),
+            string_index_file: path_stem.as_ref().with_extension("string_index"),
         }
     }
 }
@@ -31,8 +31,9 @@ pub struct Profiler<S: SerializationSink> {
 }
 
 impl<S: SerializationSink> Profiler<S> {
-    pub fn new(path_stem: &Path) -> Result<Profiler<S>, Box<dyn Error>> {
-        let paths = ProfilerFiles::new(path_stem);
+    pub fn new<P: AsRef<Path>>(path_stem: P)
+    -> Result<Profiler<S>, Box<dyn Error + Send + Sync>> {
+        let paths = ProfilerFiles::new(path_stem.as_ref());
         let event_sink = Arc::new(S::from_path(&paths.events_file)?);
 
         // The first thing in every file we generate must be the file header.

measureme/src/serialization.rs

@@ -12,7 +12,7 @@ impl Addr {
 }
 
 pub trait SerializationSink: Sized + Send + Sync + 'static {
-    fn from_path(path: &Path) -> Result<Self, Box<dyn Error>>;
+    fn from_path(path: &Path) -> Result<Self, Box<dyn Error + Send + Sync>>;
 
     /// Atomically write `num_bytes` to the sink. The implementation must ensure
     /// that concurrent invocations of `write_atomic` do not conflict with each
@@ -53,7 +53,7 @@ impl ByteVecSink {
 }
 
 impl SerializationSink for ByteVecSink {
-    fn from_path(_path: &Path) -> Result<Self, Box<dyn Error>> {
+    fn from_path(_path: &Path) -> Result<Self, Box<dyn Error + Send + Sync>> {
         unimplemented!()
     }