func()

in cgroup/reader.go [95:178]
72 lines of code
20 McCabe index (conditional complexity)

func (r *Reader) GetStatsForProcess(pid int) (*Stats, error) {
	// Read /proc/[pid]/cgroup to get the paths to the cgroup metrics.
	paths, err := ProcessCgroupPaths(r.rootfsMountpoint, pid)
	if err != nil {
		return nil, err
	}

	// Build the full path for the subsystems we are interested in.
	mounts := map[string]mount{}
	for _, interestedSubsystem := range []string{"blkio", "cpu", "cpuacct", "memory"} {
		path, found := paths[interestedSubsystem]
		if !found {
			continue
		}

		if path == "/" && r.ignoreRootCgroups {
			continue
		}

		subsystemMount, found := r.cgroupMountpoints[interestedSubsystem]
		if !found {
			continue
		}

		id := filepath.Base(path)
		if r.cgroupsHierarchyOverride != "" {
			path = r.cgroupsHierarchyOverride
		}
		mounts[interestedSubsystem] = mount{
			subsystem:  interestedSubsystem,
			mountpoint: subsystemMount,
			id:         id,
			path:       path,
			fullPath:   filepath.Join(subsystemMount, path),
		}
	}

	stats := Stats{Metadata: getCommonCgroupMetadata(mounts)}

	// Collect stats from each cgroup subsystem associated with the task.
	if mount, found := mounts["blkio"]; found {
		stats.BlockIO = &BlockIOSubsystem{}
		err := stats.BlockIO.get(mount.fullPath)
		if err != nil {
			return nil, err
		}
		stats.BlockIO.Metadata.ID = mount.id
		stats.BlockIO.Metadata.Path = mount.path
	}
	if mount, found := mounts["cpu"]; found {
		stats.CPU = &CPUSubsystem{}
		err := stats.CPU.get(mount.fullPath)
		if err != nil {
			return nil, err
		}
		stats.CPU.Metadata.ID = mount.id
		stats.CPU.Metadata.Path = mount.path
	}
	if mount, found := mounts["cpuacct"]; found {
		stats.CPUAccounting = &CPUAccountingSubsystem{}
		err := stats.CPUAccounting.get(mount.fullPath)
		if err != nil {
			return nil, err
		}
		stats.CPUAccounting.Metadata.ID = mount.id
		stats.CPUAccounting.Metadata.Path = mount.path
	}
	if mount, found := mounts["memory"]; found {
		stats.Memory = &MemorySubsystem{}
		err := stats.Memory.get(mount.fullPath)
		if err != nil {
			return nil, err
		}
		stats.Memory.Metadata.ID = mount.id
		stats.Memory.Metadata.Path = mount.path
	}

	// Return nil if no metrics were collected.
	if stats.BlockIO == nil && stats.CPU == nil && stats.CPUAccounting == nil && stats.Memory == nil {
		return nil, nil
	}

	return &stats, nil
}