profcollectd: Refactor for better code clarity

NFCI.

Test: presubmit
Change-Id: Iec62d8118cd5508626c0f1021ce8d20195d8f061

2 files changed, 35 insertions, 31 deletions

diff --git a/profcollectd/libprofcollectd/scheduler.rs b/profcollectd/libprofcollectd/scheduler.rs
index d083612e..31a495a5 100644
--- a/profcollectd/libprofcollectd/scheduler.rs
+++ b/profcollectd/libprofcollectd/scheduler.rs
@@ -110,18 +110,18 @@ impl Scheduler {
 
 /// Run if space usage is under limit.
 fn check_space_limit(path: &Path, config: &Config) -> Result<bool> {
-    let ret = dir_size(path)? <= config.max_trace_limit;
-    if !ret {
+    // Returns the size of a directory, non-recursive.
+    let dir_size = |path| -> Result<u64> {
+        fs::read_dir(path)?.try_fold(0, |acc, file| {
+            let metadata = file?.metadata()?;
+            let size = if metadata.is_file() { metadata.len() } else { 0 };
+            Ok(acc + size)
+        })
+    };
+
+    if dir_size(path)? > config.max_trace_limit {
         log::error!("trace storage exhausted.");
+        return Ok(false);
     }
-    Ok(ret)
-}
-
-/// Returns the size of a directory, non-recursive.
-fn dir_size(path: &Path) -> Result<u64> {
-    fs::read_dir(path)?.try_fold(0, |acc, file| {
-        let metadata = file?.metadata()?;
-        let size = if metadata.is_file() { metadata.len() } else { 0 };
-        Ok(acc + size)
-    })
+    Ok(true)
 }
diff --git a/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs b/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
index b993007b..14fb7509 100644
--- a/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
+++ b/profcollectd/libprofcollectd/simpleperf_etm_trace_provider.rs
@@ -45,28 +45,32 @@ impl TraceProvider for SimpleperfEtmTraceProvider {
     }
 
     fn process(&self, trace_dir: &Path, profile_dir: &Path, binary_filter: &str) -> Result<()> {
+        let is_etm_extension = |file: &PathBuf| {
+            file.extension()
+                .and_then(|f| f.to_str())
+                .filter(|ext| ext == &ETM_TRACEFILE_EXTENSION)
+                .is_some()
+        };
+
+        let process_trace_file = |trace_file: PathBuf| {
+            let mut profile_file = PathBuf::from(profile_dir);
+            profile_file.push(
+                trace_file
+                    .file_name()
+                    .ok_or_else(|| anyhow!("Malformed trace path: {}", trace_file.display()))?,
+            );
+            profile_file.set_extension(ETM_PROFILE_EXTENSION);
+            simpleperf_profcollect::process(&trace_file, &profile_file, binary_filter);
+            remove_file(&trace_file)?;
+            Ok(())
+        };
+
         read_dir(trace_dir)?
             .filter_map(|e| e.ok())
             .map(|e| e.path())
-            .filter(|e| {
-                e.is_file()
-                    && e.extension()
-                        .and_then(|f| f.to_str())
-                        .filter(|ext| ext == &ETM_TRACEFILE_EXTENSION)
-                        .is_some()
-            })
-            .try_for_each(|trace_file| -> Result<()> {
-                let mut profile_file = PathBuf::from(profile_dir);
-                profile_file.push(
-                    trace_file
-                        .file_name()
-                        .ok_or_else(|| anyhow!("Malformed trace path: {}", trace_file.display()))?,
-                );
-                profile_file.set_extension(ETM_PROFILE_EXTENSION);
-                simpleperf_profcollect::process(&trace_file, &profile_file, binary_filter);
-                remove_file(&trace_file)?;
-                Ok(())
-            })
+            .filter(|e| e.is_file())
+            .filter(is_etm_extension)
+            .try_for_each(process_trace_file)
     }
 }