Struct Meter 

pub struct Meter { /* private fields */ }

What: The work of the tree under a root so far, and whether a sample saw any sign of work since the one before. Why: A process that ends takes its counters with it, so each process is remembered by its number and start time, and only what it moved or used since it was last seen is added; a task able to run or waiting for the disk is a sign of work at the sample that finds it.

In TS you’d write (pseudocode):

class Meter { moved = 0; sample(rootPid): boolean }

Implementations

impl Meter

pub fn new() -> Self

A meter that has seen nothing.

pub fn moved(&self) -> u64

Every byte the tree has moved so far, on its pipes and files and on its connected sockets.

pub fn scans(&self) -> u64

How many samples listed the machine’s processes to find the tree.

pub fn socket_bytes(&self) -> u64

Every byte the tree’s connected sockets have sent (acknowledged) or received since the first sample.

pub fn connected(&self) -> bool

Whether the last sample found the connection to a remote open: some process of the tree holds a socket in state ESTABLISHED. This is the whole evidence of “connected”; the phase of the push (making the pack, sent, checked) is not consulted, because a connection that is open is a remote that has not answered yet, whatever the phase. Where the kernel’s socket list cannot be read, nothing says the connection is open, and the stall rule applies.

pub fn sample(&mut self, root: i32) -> bool

Read the counters and the states of the root and everything below it; true when any of them shows work since the last sample. A root that cannot be read (it ended) shows nothing.

pub fn sample_root(&mut self, root: i32) -> bool

The first look at a child that has just been started: the root alone. Nothing is below a process that has just been started, and a process it starts later is found by the next sample and counted at the first sight, so the listing of every process the machine runs (a status file for each, 7 ms for 841 processes) would find nothing and be paid by every Git the wrapper starts, however briefly it lives.

Trait Implementations

impl Debug for Meter

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

Formats the value using the given formatter.

impl Default for Meter

fn default() -> Self

Returns the “default value” for a type.