Update below model and UI to support new format for CPUs

Summary:
Support is backward compatible. We will try to use `cpus_map` first
and if not available we will use `cpus`.

Reviewed By: lnyng

Differential Revision: D46946005

fbshipit-source-id: e8afb44d93323e32efd86f3d00eb331284a9c458

6 files changed, 67 insertions, 39 deletions

diff --git a/below/dump/src/test.rs b/below/dump/src/test.rs
index 471a2d56..b2bcef79 100644
--- a/below/dump/src/test.rs
+++ b/below/dump/src/test.rs
@@ -39,8 +39,8 @@ fn test_dump_sys_content() {
     let mut fields = command::expand_fields(command::DEFAULT_SYSTEM_FIELDS, true);
     for subquery_id in model::SingleCpuModelFieldId::unit_variant_iter() {
         fields.push(DumpField::FieldId(model::SystemModelFieldId::Cpus(
-            model::VecFieldId {
-                idx: Some(31),
+            model::BTreeMapFieldId {
+                key: Some(31),
                 subquery_id,
             },
         )));
@@ -95,8 +95,8 @@ fn test_dump_sys_titles() {
         .into_iter()
         .chain(
             model::SingleCpuModelFieldId::unit_variant_iter().map(|subquery_id| {
-                DumpField::FieldId(model::SystemModelFieldId::Cpus(model::VecFieldId {
-                    idx: Some(31),
+                DumpField::FieldId(model::SystemModelFieldId::Cpus(model::BTreeMapFieldId {
+                    key: Some(31),
                     subquery_id,
                 }))
             }),
diff --git a/below/model/src/common_field_ids.rs b/below/model/src/common_field_ids.rs
index ea10105c..59dc18ae 100644
--- a/below/model/src/common_field_ids.rs
+++ b/below/model/src/common_field_ids.rs
@@ -45,18 +45,18 @@ pub const COMMON_MODEL_FIELD_IDS: [&str; 361] = [
     "system.cpu.stolen_pct",
     "system.cpu.guest_pct",
     "system.cpu.guest_nice_pct",
-    "system.cpus.<idx>.idx",
-    "system.cpus.<idx>.usage_pct",
-    "system.cpus.<idx>.user_pct",
-    "system.cpus.<idx>.system_pct",
-    "system.cpus.<idx>.idle_pct",
-    "system.cpus.<idx>.nice_pct",
-    "system.cpus.<idx>.iowait_pct",
-    "system.cpus.<idx>.irq_pct",
-    "system.cpus.<idx>.softirq_pct",
-    "system.cpus.<idx>.stolen_pct",
-    "system.cpus.<idx>.guest_pct",
-    "system.cpus.<idx>.guest_nice_pct",
+    "system.cpus.<key>.idx",
+    "system.cpus.<key>.usage_pct",
+    "system.cpus.<key>.user_pct",
+    "system.cpus.<key>.system_pct",
+    "system.cpus.<key>.idle_pct",
+    "system.cpus.<key>.nice_pct",
+    "system.cpus.<key>.iowait_pct",
+    "system.cpus.<key>.irq_pct",
+    "system.cpus.<key>.softirq_pct",
+    "system.cpus.<key>.stolen_pct",
+    "system.cpus.<key>.guest_pct",
+    "system.cpus.<key>.guest_nice_pct",
     "system.mem.total",
     "system.mem.free",
     "system.mem.available",
diff --git a/below/model/src/sample_model.rs b/below/model/src/sample_model.rs
index e189212a..104424e0 100644
--- a/below/model/src/sample_model.rs
+++ b/below/model/src/sample_model.rs
@@ -51,8 +51,8 @@ pub const SAMPLE_MODEL_JSON: &str = r#"
             "guest_pct": 0.0,
             "guest_nice_pct": 0.0
         },
-        "cpus": [
-            {
+        "cpus": {
+            "0": {
                 "idx": 0,
                 "usage_pct": 20.0,
                 "user_pct": 10.0,
@@ -66,7 +66,7 @@ pub const SAMPLE_MODEL_JSON: &str = r#"
                 "guest_pct": 0.0,
                 "guest_nice_pct": 0.0
             },
-            {
+            "1": {
                 "idx": 1,
                 "usage_pct": 20.0,
                 "user_pct": 10.0,
@@ -80,7 +80,7 @@ pub const SAMPLE_MODEL_JSON: &str = r#"
                 "guest_pct": 0.0,
                 "guest_nice_pct": 0.0
             }
-        ],
+        },
         "mem": {
             "total": 8000000000,
             "free": 4000000000,
diff --git a/below/model/src/system.rs b/below/model/src/system.rs
index de90ce94..0f300964 100644
--- a/below/model/src/system.rs
+++ b/below/model/src/system.rs
@@ -33,7 +33,7 @@ pub struct SystemModel {
     #[queriable(preferred_name = cpu)]
     pub total_cpu: SingleCpuModel,
     #[queriable(subquery)]
-    pub cpus: Vec<SingleCpuModel>,
+    pub cpus: BTreeMap<u32, SingleCpuModel>,
     #[queriable(subquery)]
     pub mem: MemoryModel,
     #[queriable(subquery)]
@@ -54,17 +54,43 @@ impl SystemModel {
             (Some(prev), Some(curr)) => SingleCpuModel::new(-1, &prev, &curr),
             _ => Default::default(),
         };
-        let cpus = match (
-            last.and_then(|(last, _)| last.stat.cpus.as_ref()),
-            sample.stat.cpus.as_ref(),
+
+        let mut cpus: BTreeMap<u32, SingleCpuModel> = match (
+            last.and_then(|(last, _)| last.stat.cpus_map.as_ref()),
+            sample.stat.cpus_map.as_ref(),
         ) {
-            (Some(prev), Some(curr)) => std::iter::successors(Some(0), |idx| Some(idx + 1))
-                .zip(prev.iter().zip(curr.iter()))
-                .map(|(idx, (prev, curr))| SingleCpuModel::new(idx, prev, curr))
+            (Some(prev), Some(curr)) => curr
+                .iter()
+                .map(|(idx, curr)| {
+                    (
+                        *idx,
+                        prev.get(idx).map_or_else(Default::default, |prev| {
+                            SingleCpuModel::new(*idx as i32, prev, curr)
+                        }),
+                    )
+                })
                 .collect(),
-            (_, Some(curr)) => curr.iter().map(|_| Default::default()).collect(),
+            (_, Some(curr)) => curr.keys().map(|idx| (*idx, Default::default())).collect(),
             _ => Default::default(),
         };
+
+        if cpus.is_empty() {
+            cpus = match (
+                last.and_then(|(last, _)| last.stat.cpus.as_ref()),
+                sample.stat.cpus.as_ref(),
+            ) {
+                (Some(prev), Some(curr)) => std::iter::successors(Some(0), |idx| Some(idx + 1))
+                    .zip(prev.iter().zip(curr.iter()))
+                    .map(|(idx, (prev, curr))| (idx as u32, SingleCpuModel::new(idx, prev, curr)))
+                    .collect(),
+                (_, Some(curr)) => std::iter::successors(Some(0), |idx| Some(idx + 1))
+                    .zip(curr.iter())
+                    .map(|(idx, _curr)| (idx, Default::default()))
+                    .collect(),
+                _ => Default::default(),
+            };
+        }
+
         let mem = Some(MemoryModel::new(&sample.meminfo)).unwrap_or_default();
         let vm = last
             .map(|(last, duration)| VmModel::new(&last.vmstat, &sample.vmstat, duration))
@@ -508,7 +534,7 @@ mod test {
             "total_cpu": {
                 "idx": -1
             },
-            "cpus": [],
+            "cpus": {},
             "mem": {},
             "vm": {},
             "disks": {
diff --git a/below/render/src/default_configs.rs b/below/render/src/default_configs.rs
index 76e5a19e..a815ae44 100644
--- a/below/render/src/default_configs.rs
+++ b/below/render/src/default_configs.rs
@@ -944,7 +944,9 @@ impl HasRenderConfig for model::SystemModel {
             OsRelease => rc.title("OS Release").width(50),
             Stat(field_id) => model::ProcStatModel::get_render_config_builder(field_id),
             Cpu(field_id) => model::SingleCpuModel::get_render_config_builder(field_id),
-            Cpus(field_id) => Vec::<model::SingleCpuModel>::get_render_config_builder(field_id),
+            Cpus(field_id) => {
+                BTreeMap::<u32, model::SingleCpuModel>::get_render_config_builder(field_id)
+            }
             Mem(field_id) => model::MemoryModel::get_render_config_builder(field_id),
             Vm(field_id) => model::VmModel::get_render_config_builder(field_id),
             Disks(field_id) => {
@@ -1059,15 +1061,15 @@ impl HasRenderConfigForDump for model::SingleCpuModel {
     }
 }
 
-impl HasRenderConfig for Vec<model::SingleCpuModel> {
+impl HasRenderConfig for BTreeMap<u32, model::SingleCpuModel> {
     fn get_render_config_builder(field_id: &Self::FieldId) -> RenderConfigBuilder {
         let mut rc = model::SingleCpuModel::get_render_config_builder(&field_id.subquery_id).get();
         rc.title = rc.title.map(|title| {
             format!(
                 "CPU {} {}",
                 field_id
-                    .idx
-                    .expect("VecFieldId without idx should not have render config"),
+                    .key
+                    .expect("BTreeMapFieldId without key should not have render config"),
                 title
             )
         });
@@ -1075,15 +1077,15 @@ impl HasRenderConfig for Vec<model::SingleCpuModel> {
     }
 }
 
-impl HasRenderConfigForDump for Vec<model::SingleCpuModel> {
+impl HasRenderConfigForDump for BTreeMap<u32, model::SingleCpuModel> {
     fn get_openmetrics_config_for_dump(
         &self,
         field_id: &Self::FieldId,
     ) -> Option<RenderOpenMetricsConfigBuilder> {
-        let idx = field_id
-            .idx
-            .expect("VecFieldId without idx should not have render config");
-        self.get(idx)
+        let key = field_id
+            .key
+            .expect("BTreeMapFieldId without key should not have render config");
+        self.get(&key)
             .map(|cpu| cpu.get_openmetrics_config_for_dump(&field_id.subquery_id))?
     }
 }
diff --git a/below/view/src/core_tabs.rs b/below/view/src/core_tabs.rs
index 55a62ca0..8bdbdc66 100644
--- a/below/view/src/core_tabs.rs
+++ b/below/view/src/core_tabs.rs
@@ -65,7 +65,7 @@ impl CoreTab for CoreCpu {
         let model = state.get_model();
         model
             .cpus
-            .iter()
+            .values()
             .filter(|scm| {
                 if let Some((CoreStateFieldId::Cpu(field), filter)) = &state.filter_info {
                     match scm.query(field) {