Struct Row 

pub struct Row {
    pub kind: String,
    pub total: Option<u64>,
    pub active: Option<u64>,
    pub bytes: Option<u64>,
    pub reclaimable: Option<u64>,
}

One line of an engine’s own disk-usage report.

Fields

kind: String

Images, Containers, Local Volumes, Build Cache — the engine’s own word for it, kept verbatim so the row matches what docker system df prints.

total: Option<u64>

How many of them there are, when the engine says.

active: Option<u64>

How many of those are in use.

bytes: Option<u64>

Bytes on disk.

reclaimable: Option<u64>

Bytes the engine believes it could give back.