diskusage

type Entry struct {
	Name  string `json:"name"`
	Bytes int64  `json:"bytes"`
	// Files counts regular files beneath this entry (1 for a plain file).
	// It is what distinguishes "one enormous archive" from "four thousand
	// small snapshots", which have different remedies.
	Files int  `json:"files"`
	IsDir bool `json:"is_dir"`
}

type FloorStanding int

type Usage struct {
	Dir        string `json:"dir"`
	TotalBytes int64  `json:"total_bytes"`
	// Entries is sorted largest-first so the caller can render the top N
	// without re-sorting and an operator reads the culprit on line one.
	Entries []Entry `json:"entries"`

	// DBBytes is state.db's own size, repeated out of Entries so callers
	// that only care about the database need not search the slice.
	DBBytes int64 `json:"db_bytes"`
	// ReclaimableBytes is what a VACUUM would return to the filesystem:
	// freelist_count × page_size. Zero when the database could not be read.
	ReclaimableBytes int64 `json:"reclaimable_bytes"`
	// FreeRatio is ReclaimableBytes / DBBytes, in [0,1]. This is the number
	// the janitor's VACUUM threshold is compared against — a ratio rather
	// than an absolute size, because a 2 GB freelist is urgent in a 2.3 GB
	// file and unremarkable in a 200 GB one.
	FreeRatio float64 `json:"free_ratio"`
	// DBError explains why the database numbers are absent, if they are.
	// A project with no state.db yet is not an error; it leaves this empty
	// and the DB fields zero.
	DBError string `json:"db_error,omitempty"`
}

type Volume struct {
	// Mount names the volume the way an operator does: the directory it is
	// mounted on, as far as walking up from Path can tell — the highest
	// ancestor still on the same device. "/" on a single-disk host.
	Mount string `json:"mount"`
	// Path is the first of the probed paths that lives on this volume, as
	// given (before symlinks were resolved).
	Path string `json:"path"`
	// Device is the st_dev the volume was told apart by.
	Device uint64 `json:"device"`
	// FreeBytes is what this process could write there; see FreeBytes for
	// why that depends on whether it runs as root.
	FreeBytes int64 `json:"free_bytes"`
}