func()

in providers/darwin/host_darwin.go [68:138]

• 55 lines of code
• 6 McCabe index (conditional complexity)

func (h *host) Memory() (*types.HostMemoryInfo, error) {
	var mem types.HostMemoryInfo

	// Total physical memory.
	total, err := MemTotal()
	if err != nil {
		return nil, fmt.Errorf("failed to get total physical memory: %w", err)
	}

	mem.Total = total

	// Page size for computing byte totals.
	pageSizeBytes, err := getPageSize()
	if err != nil {
		return nil, fmt.Errorf("failed to get page size: %w", err)
	}

	// Swap
	swap, err := getSwapUsage()
	if err != nil {
		return nil, fmt.Errorf("failed to get swap usage: %w", err)
	}

	mem.VirtualTotal = swap.Total
	mem.VirtualUsed = swap.Used
	mem.VirtualFree = swap.Available

	// Virtual Memory Statistics
	vmStat, err := getHostVMInfo64()
	if errors.Is(err, types.ErrNotImplemented) {
		return &mem, nil
	}

	if err != nil {
		return nil, fmt.Errorf("failed to get virtual memory statistics: %w", err)
	}

	inactiveBytes := uint64(vmStat.Inactive_count) * pageSizeBytes
	purgeableBytes := uint64(vmStat.Purgeable_count) * pageSizeBytes
	mem.Metrics = map[string]uint64{
		"active_bytes":         uint64(vmStat.Active_count) * pageSizeBytes,
		"compressed_bytes":     uint64(vmStat.Compressor_page_count) * pageSizeBytes,
		"compressions_bytes":   uint64(vmStat.Compressions) * pageSizeBytes, // Cumulative compressions.
		"copy_on_write_faults": vmStat.Cow_faults,
		"decompressions_bytes": uint64(vmStat.Decompressions) * pageSizeBytes,      // Cumulative decompressions.
		"external_bytes":       uint64(vmStat.External_page_count) * pageSizeBytes, // File Cache / File-backed pages
		"inactive_bytes":       inactiveBytes,
		"internal_bytes":       uint64(vmStat.Internal_page_count) * pageSizeBytes, // App Memory / Anonymous
		"page_ins_bytes":       uint64(vmStat.Pageins) * pageSizeBytes,
		"page_outs_bytes":      uint64(vmStat.Pageouts) * pageSizeBytes,
		"purgeable_bytes":      purgeableBytes,
		"purged_bytes":         uint64(vmStat.Purges) * pageSizeBytes,
		"reactivated_bytes":    uint64(vmStat.Reactivations) * pageSizeBytes,
		"speculative_bytes":    uint64(vmStat.Speculative_count) * pageSizeBytes,
		"swap_ins_bytes":       uint64(vmStat.Swapins) * pageSizeBytes,
		"swap_outs_bytes":      uint64(vmStat.Swapouts) * pageSizeBytes,
		"throttled_bytes":      uint64(vmStat.Throttled_count) * pageSizeBytes,
		"translation_faults":   vmStat.Faults,
		"uncompressed_bytes":   uint64(vmStat.Total_uncompressed_pages_in_compressor) * pageSizeBytes,
		"wired_bytes":          uint64(vmStat.Wire_count) * pageSizeBytes,
		"zero_filled_bytes":    uint64(vmStat.Zero_fill_count) * pageSizeBytes,
	}

	// From Activity Monitor: Memory Used = App Memory (internal) + Wired + Compressed
	// https://support.apple.com/en-us/HT201538
	mem.Used = uint64(vmStat.Internal_page_count+vmStat.Wire_count+vmStat.Compressor_page_count) * pageSizeBytes
	mem.Free = uint64(vmStat.Free_count) * pageSizeBytes
	mem.Available = mem.Free + inactiveBytes + purgeableBytes

	return &mem, nil
}