aconfig: remove unnecessary clones

Improve performance slightly: remove unnecessary clone operations, or
use references where a new object is not needed.

Bug: 283910447
Test: atest aconfig.test
Change-Id: I75205ffa1723dd2654039baac882c225d2653c86

tools/aconfig/src/codegen_cpp.rs

@@ -38,9 +38,9 @@ where
     let cpp_namespace = package.replace('.', "::");
     ensure!(codegen::is_valid_name_ident(&header));
     let context = Context {
-        header: header.clone(),
-        cpp_namespace,
-        package: package.to_string(),
+        header: &header,
+        cpp_namespace: &cpp_namespace,
+        package,
         readwrite,
         for_test: codegen_mode == CodegenMode::Test,
         class_elements,
@@ -77,10 +77,10 @@ pub struct FileSpec<'a> {
 }
 
 #[derive(Serialize)]
-pub struct Context {
-    pub header: String,
-    pub cpp_namespace: String,
-    pub package: String,
+pub struct Context<'a> {
+    pub header: &'a str,
+    pub cpp_namespace: &'a str,
+    pub package: &'a str,
     pub readwrite: bool,
     pub for_test: bool,
     pub class_elements: Vec<ClassElement>,
@@ -517,7 +517,7 @@ void com_android_aconfig_test_reset_flags() {
         for file in generated {
             generated_files_map.insert(
                 String::from(file.path.to_str().unwrap()),
-                String::from_utf8(file.contents.clone()).unwrap(),
+                String::from_utf8(file.contents).unwrap(),
             );
         }
 

tools/aconfig/src/codegen_java.rs

@@ -282,7 +282,7 @@ mod tests {
                 None,
                 crate::test::first_significant_code_diff(
                     file_set.get(file_path).unwrap(),
-                    &String::from_utf8(file.contents.clone()).unwrap()
+                    &String::from_utf8(file.contents).unwrap()
                 ),
                 "File {} content is not correct",
                 file_path
@@ -362,7 +362,7 @@ mod tests {
                 None,
                 crate::test::first_significant_code_diff(
                     file_set.get(file_path).unwrap(),
-                    &String::from_utf8(file.contents.clone()).unwrap()
+                    &String::from_utf8(file.contents).unwrap()
                 ),
                 "File {} content is not correct",
                 file_path

tools/aconfig/src/main.rs

@@ -137,14 +137,14 @@ fn open_single_file(matches: &ArgMatches, arg_name: &str) -> Result<Input> {
 }
 
 fn write_output_file_realtive_to_dir(root: &Path, output_file: &OutputFile) -> Result<()> {
-    let path = root.join(output_file.path.clone());
+    let path = root.join(&output_file.path);
     let parent = path
         .parent()
         .ok_or(anyhow!("unable to locate parent of output file {}", path.display()))?;
     fs::create_dir_all(parent)
         .with_context(|| format!("failed to create directory {}", parent.display()))?;
-    let mut file = fs::File::create(path.clone())
-        .with_context(|| format!("failed to open {}", path.display()))?;
+    let mut file =
+        fs::File::create(&path).with_context(|| format!("failed to open {}", path.display()))?;
     file.write_all(&output_file.contents)
         .with_context(|| format!("failed to write to {}", path.display()))?;
     Ok(())