performancereference

Chapter09/Cargo.toml

@@ -63,3 +63,7 @@ path = "performance_polynomial4.rs"
 [[bin]]
 name = "performance_exponential"
 path = "performance_exponential.rs"
+
+[[bin]]
+name = "performance_reference"
+path = "performance_reference.rs"

Chapter09/performance_reference.rs

@@ -0,0 +1,58 @@
+extern crate flame;
+use std::fs::File;
+
+fn byref(n: u64, data: &[u64; 1024]) {
+   if n>0 {
+      byref(n-1, data);
+      byref(n-1, data);
+   }
+}
+
+fn bycopy(n: u64, data: [u64; 1024]) {
+   if n>0 {
+      bycopy(n-1, data);
+      bycopy(n-1, data);
+   }
+}
+
+struct DataClonable([u64; 1024]);
+impl Clone for DataClonable {
+   fn clone(&self) -> Self {
+      let mut newdata = [0; 1024];
+      for i in 0..1024 {
+         newdata[i] = self.0[i];
+      }
+      DataClonable(newdata)
+   }
+}
+fn byclone<T: Clone>(n: u64, data: T) {
+   if n>0 {
+      byclone(n-1, data.clone());
+      byclone(n-1, data.clone());
+   }
+}
+
+fn main() {
+   let data = [0; 1024];
+   flame::start("by reference");
+   byref(15, &data);
+   flame::end("by reference");
+
+   let data = [0; 1024];
+   flame::start("by copy");
+   bycopy(15, data);
+   flame::end("by copy");
+
+   let data = [0; 1024];
+   flame::start("by clone");
+   byclone(15, data);
+   flame::end("by clone");
+
+   let data = DataClonable([0; 1024]);
+   flame::start("by clone (with extras)");
+   //2^4 instead of 2^15!!!!
+   byclone(4, data);
+   flame::end("by clone (with extras)");
+
+   flame::dump_html(&mut File::create("flame-graph.html").unwrap()).unwrap();
+}