Struct SubtreeUsage 

pub struct SubtreeUsage {
    pub root: ProcessIdentity,
    pub members: Vec<ProcessIdentity>,
    pub cpu: Summed<Percent>,
    pub rss_bytes: Summed<u64>,
    pub read: Summed<Rate>,
    pub write: Summed<Rate>,
    pub cycles_broken: u32,
}

What a process and its descendants are using, together.

Fields

root: ProcessIdentity

The process the subtree is rooted at, still present in this snapshot.

members: Vec<ProcessIdentity>

Every member, root first, then descendants in breadth-first order.

Breadth-first because a truncated list should show a build’s direct children before its grandchildren, and because the order is then stable under the arbitrary order the OS enumerates processes in.

cpu: Summed<Percent>

Summed CPU. May exceed 100% — it is a sum of core-normalized shares (§8.3).

rss_bytes: Summed<u64>

Summed resident memory.

Shared pages are counted once per process that maps them, so this over-counts a family that shares a lot — a browser especially. That is a property of RSS rather than of this sum, and SubtreeUsage cannot fix it without a proportional-set-size figure neither platform gives cheaply. Named in the docs rather than silently presented as a memory total.

read: Summed<Rate>

Summed read throughput.

write: Summed<Rate>

Summed write throughput.

cycles_broken: u32

Parent links that were cut to break a cycle, for the Inspect screen.

Implementations

impl SubtreeUsage

pub fn of(snapshot: &SystemSnapshot, root: ProcessIdentity) -> Option<Self>

Sums root and its descendants in snapshot.

None when root is not in the snapshot — it exited, or a PID was reused and the identity no longer matches. The caller reports that as the subtree ending rather than substituting the reparented children (see the module docs).

pub fn over( processes: &[ProcessSnapshot], root: ProcessIdentity, ) -> Option<Self>

Sums over an arbitrary process list, which is what the tests and the reducer use.

pub fn len(&self) -> usize

How many processes the subtree holds, including the root.

pub fn is_empty(&self) -> bool

Whether the subtree holds nothing, which cannot happen: the root is a member.

pub fn has_partial_sums(&self) -> bool

Whether any visible figure understates the subtree.

The flag a renderer needs next to the numbers: true means at least one sum is a lower bound, and the per-metric Summed::coverage says which and by how many members.

Trait Implementations

impl Clone for SubtreeUsage

fn clone(&self) -> SubtreeUsage

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SubtreeUsage

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for SubtreeUsage

fn eq(&self, other: &SubtreeUsage) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SubtreeUsage