Merge pull request #94 from data-pup/add-top-summary

Added summary and total rows to top command.

Author: fitzgen

analyze/analyze.rs

@@ -126,35 +126,120 @@ struct Top {
 impl traits::Emit for Top {
     #[cfg(feature = "emit_text")]
     fn emit_text(&self, items: &ir::Items, dest: &mut io::Write) -> Result<(), traits::Error> {
-        let sort_label = if self.opts.retained() {
-            "Retained"
-        } else {
-            "Shallow"
+        // A struct used to represent a row in the table that will be emitted.
+        struct TableRow {
+            size: u32,
+            size_percent: f64,
+            name: String,
+        };
+
+        // Helper function used to process an item, and return a struct
+        // representing a row containing its size and name.
+        fn process_item(id: ir::Id, items: &ir::Items, retained: bool) -> TableRow {
+            let item = &items[id];
+            let size = if retained {
+                items.retained_size(id)
+            } else {
+                item.size()
+            };
+            let size_percent = (f64::from(size)) / (f64::from(items.size())) * 100.0;
+            let name = item.name().to_string();
+            TableRow {
+                size,
+                size_percent,
+                name,
+            }
         };
 
+        // Helper function used to summnarize a sequence of table rows. This is
+        // used to generate the remaining summary and total rows. Returns a tuple
+        // containing the total size, total size percentage, and number of items.
+        fn summarize_rows(rows: impl Iterator<Item = TableRow>) -> (u32, f64, u32) {
+            rows.fold(
+                (0, 0.0, 0),
+                |(total_size, total_percent, remaining_count),
+                 TableRow {
+                     size,
+                     size_percent,
+                     name: _,
+                 }| {
+                    (
+                        total_size + size,
+                        total_percent + size_percent,
+                        remaining_count + 1,
+                    )
+                },
+            )
+        }
+
+        // Access the options that are relevant to emitting the correct output.
+        let max_items = self.opts.max_items() as usize;
+        let retained = self.opts.retained();
+        let sort_label = if retained { "Retained" } else { "Shallow" };
+
+        // Initialize a new table.
         let mut table = Table::with_header(vec![
             (Align::Right, format!("{} Bytes", sort_label)),
             (Align::Right, format!("{} %", sort_label)),
             (Align::Left, "Item".to_string()),
         ]);
 
-        for &id in &self.items {
-            let item = &items[id];
+        // Process the number of items specified, and add them to the table.
+        self.items
+            .iter()
+            .take(max_items)
+            .map(|&id| process_item(id, items, retained))
+            .for_each(
+                |TableRow {
+                     size,
+                     size_percent,
+                     name,
+                 }| {
+                    table.add_row(vec![
+                        size.to_string(),
+                        format!("{:.2}%", size_percent),
+                        name,
+                    ])
+                },
+            );
 
-            let size = if self.opts.retained() {
-                items.retained_size(id)
+        // Find the summary statistics by processing the remaining items.
+        let remaining_rows = self
+            .items
+            .iter()
+            .skip(max_items)
+            .map(|&id| process_item(id, items, retained));
+        let (rem_size, rem_size_percent, rem_count) = summarize_rows(remaining_rows);
+
+        // If there were items remaining, add a summary row to the table.
+        if rem_count > 0 {
+            let rem_name_col = format!("... and {} more.", rem_count);
+            let (rem_size_col, rem_size_percent_col) = if retained {
+                ("...".to_string(), "...".to_string())
             } else {
-                item.size()
+                (rem_size.to_string(), format!("{:.2}%", rem_size_percent))
             };
-
-            let size_percent = (f64::from(size)) / (f64::from(items.size())) * 100.0;
-            table.add_row(vec![
-                size.to_string(),
-                format!("{:.2}%", size_percent),
-                item.name().to_string(),
-            ]);
+            table.add_row(vec![rem_size_col, rem_size_percent_col, rem_name_col]);
         }
 
+        // Add a row containing the totals to the table.
+        let all_rows = self
+            .items
+            .iter()
+            .map(|&id| process_item(id, items, retained));
+        let (total_size, total_size_percent, total_count) = summarize_rows(all_rows);
+        let total_name_col = format!("Σ [{} Total Rows]", total_count);
+        let (total_size_col, total_size_percent_col) = if retained {
+            ("...".to_string(), "...".to_string())
+        } else {
+            (
+                total_size.to_string(),
+                format!("{:.2}%", total_size_percent),
+            )
+        };
+        table.add_row(vec![total_size_col, total_size_percent_col, total_name_col]);
+
+        // Write the generated table out to the destination and return.
         write!(dest, "{}", &table)?;
         Ok(())
     }
@@ -163,7 +248,10 @@ impl traits::Emit for Top {
     fn emit_json(&self, items: &ir::Items, dest: &mut io::Write) -> Result<(), traits::Error> {
         let mut arr = json::array(dest)?;
 
-        for &id in &self.items {
+        let max_items = self.opts.max_items() as usize;
+        let items_iter = self.items.iter();
+
+        for &id in items_iter.take(max_items) {
             let item = &items[id];
 
             let mut obj = arr.object()?;
@@ -199,7 +287,10 @@ impl traits::Emit for Top {
             retained_size_percent: Option<f64>,
         }
 
-        for &id in &self.items {
+        let max_items = self.opts.max_items() as usize;
+        let items_iter = self.items.iter();
+
+        for &id in items_iter.take(max_items) {
             let item = &items[id];
 
             let (shallow_size, shallow_size_percent) = {
@@ -252,8 +343,6 @@ pub fn top(items: &mut ir::Items, opts: &opt::Top) -> Result<Box<traits::Emit>,
             .cmp(&items.retained_size(a.id())),
     });
 
-    top_items.truncate(opts.number() as usize);
-
     let top_items: Vec<_> = top_items.into_iter().map(|i| i.id()).collect();
 
     let top = Top {

opt/definitions.rs

@@ -43,7 +43,7 @@ pub enum Options {
 }
 
 /// List the top code size offenders in a binary.
-#[derive(Clone, Debug, Default)]
+#[derive(Clone, Debug)]
 #[derive(StructOpt)]
 #[wasm_bindgen]
 pub struct Top {
@@ -63,8 +63,8 @@ pub struct Top {
     output_format: traits::OutputFormat,
 
     /// The maximum number of items to display.
-    #[structopt(short = "n")]
-    number: Option<u32>,
+    #[structopt(short = "n", default_value = "4294967295")]
+    max_items: u32,
 
     /// Display retaining paths.
     #[structopt(short = "r", long = "retaining-paths")]
@@ -75,6 +75,23 @@ pub struct Top {
     retained: bool,
 }
 
+impl Default for Top {
+    fn default() -> Top {
+        Top {
+            #[cfg(feature = "cli")]
+            input: Default::default(),
+            #[cfg(feature = "cli")]
+            output_destination: Default::default(),
+            #[cfg(feature = "cli")]
+            output_format: Default::default(),
+
+            max_items: 4294967295,
+            retaining_paths: false,
+            retained: false,
+        }
+    }
+}
+
 #[wasm_bindgen]
 impl Top {
     /// Construct a new, default `Top`.
@@ -83,8 +100,8 @@ impl Top {
     }
 
     /// The maximum number of items to display.
-    pub fn number(&self) -> u32 {
-        self.number.unwrap_or(u32::MAX)
+    pub fn max_items(&self) -> u32 {
+        self.max_items
     }
 
     /// Display retaining paths.
@@ -98,8 +115,8 @@ impl Top {
     }
 
     /// Set the maximum number of items to display.
-    pub fn set_number(&mut self, n: u32) {
-        self.number = Some(n);
+    pub fn set_max_items(&mut self, n: u32) {
+        self.max_items = n;
     }
 
     /// Set whether to display and compute retaining paths.

twiggy/tests/expectations/elf_top_25_hello_world_rs

@@ -25,3 +25,5 @@
           2158 ┊     0.10% ┊ prof_tdata_destroy_locked
           2041 ┊     0.10% ┊ stats_print_helper
           1897 ┊     0.09% ┊ imemalign
+        150168 ┊     7.15% ┊ ... and 753 more.
+        256639 ┊    12.23% ┊ Σ [778 Total Rows]

twiggy/tests/expectations/elf_top_hello_world_rs

@@ -778,3 +778,4 @@
              0 ┊     0.00% ┊ je_prof_boot1
              0 ┊     0.00% ┊ je_prof_boot2
              0 ┊     0.00% ┊ je_malloc_tsd_no_cleanup
+        256639 ┊    12.23% ┊ Σ [778 Total Rows]

twiggy/tests/expectations/top_mappings

@@ -10,3 +10,5 @@
           1219 ┊     2.69% ┊ memset
           1217 ┊     2.69% ┊ __powidf2
           1142 ┊     2.52% ┊ __udivsi3
+         23762 ┊    52.53% ┊ ... and 338 more.
+         45181 ┊    99.89% ┊ Σ [348 Total Rows]

twiggy/tests/expectations/top_retained_mappings

@@ -10,3 +10,5 @@
            3149 ┊      6.96% ┊ __powidf2
            2722 ┊      6.02% ┊ func[78]
            2721 ┊      6.02% ┊ __divsf3
+            ... ┊        ... ┊ ... and 338 more.
+            ... ┊        ... ┊ Σ [348 Total Rows]

twiggy/tests/expectations/top_retained_wee_alloc

@@ -10,3 +10,5 @@
             226 ┊      8.02% ┊ func[3]
             225 ┊      7.99% ┊ wee_alloc::alloc_first_fit::h9a72de3af77ef93f
             136 ┊      4.83% ┊ <wee_alloc::size_classes::SizeClassAllocPolicy<'a> as wee_alloc::AllocPolicy>::new_cell_for_free_list::h3987e3054b8224e6
+            ... ┊        ... ┊ ... and 29 more.
+            ... ┊        ... ┊ Σ [39 Total Rows]

twiggy/tests/expectations/top_wee_alloc

@@ -10,3 +10,5 @@
             44 ┊     1.56% ┊ goodbye
             25 ┊     0.89% ┊ data[1]
             25 ┊     0.89% ┊ data[2]
+           117 ┊     4.15% ┊ ... and 29 more.
+          2772 ┊    98.40% ┊ Σ [39 Total Rows]