rclone/backend/union/policy/epmfs.go

package policy

import (
	"context"
	
	"github.com/rclone/rclone/fs"
	"github.com/rclone/rclone/backend/union/upstream"
)

func init(){
	registerPolicy("epmfs", &EpMfs{})
}

// EpMfs stands for existing path, most free space
// Of all the branches on which the path exists choose the drive with the most free space.
type EpMfs struct {
	EpAll
}

func (p *EpMfs) mfs(upstreams []*upstream.Fs) (*upstream.Fs, error) {
	var maxFreeSpace int64
	var mfsupstream *upstream.Fs
	for _, r := range upstreams {
		space, err := r.GetFreeSpace()
		if err != nil {
			return nil, err
		}
		if maxFreeSpace < space {
			maxFreeSpace = space
			mfsupstream = r
		}
	}
	return mfsupstream, nil
}

func (p *EpMfs) mfsEntries(entries []upstream.Entry) (upstream.Entry, error) {
	var maxFreeSpace int64
	var mfsEntry upstream.Entry
	for _, e := range entries {
		space, err := e.UpstreamFs().GetFreeSpace()
		if err != nil {
			return nil, err
		}
		if maxFreeSpace < space {
			maxFreeSpace = space
			mfsEntry = e
		}
	}
	return mfsEntry, nil
}

// Action category policy, governing the modification of files and directories
func (p *EpMfs) Action(ctx context.Context, upstreams []*upstream.Fs, path string) ([]*upstream.Fs, error) {
	upstreams, err := p.EpAll.Action(ctx, upstreams, path)
	if err != nil {
		return nil, err
	}
	r, err := p.mfs(upstreams)
	return []*upstream.Fs{r}, err
}

// ActionEntries is ACTION category policy but receving a set of candidate entries
func (p *EpMfs) ActionEntries(entries ...upstream.Entry) ([]upstream.Entry, error) {
	entries, err := p.EpAll.ActionEntries(entries...)
	if err != nil {
		return nil, err
	}
	e, err := p.mfsEntries(entries)
	return []upstream.Entry{e}, err
}

// Create category policy, governing the creation of files and directories
func (p *EpMfs) Create(ctx context.Context, upstreams []*upstream.Fs, path string) ([]*upstream.Fs, error) {
	upstreams, err := p.EpAll.Create(ctx, upstreams, path)
	if err != nil {
		return nil, err
	}
	r, err := p.mfs(upstreams)
	return []*upstream.Fs{r}, err
}

// CreateEntries is CREATE category policy but receving a set of candidate entries
func (p *EpMfs) CreateEntries(entries ...upstream.Entry) ([]upstream.Entry, error) {
	entries, err := p.EpAll.CreateEntries(entries...)
	if err != nil {
		return nil, err
	}
	e, err := p.mfsEntries(entries)
	return []upstream.Entry{e}, err
}

// Search category policy, governing the access to files and directories
func (p *EpMfs) Search(ctx context.Context, upstreams []*upstream.Fs, path string) (*upstream.Fs, error) {
	if len(upstreams) == 0 {
		return nil, fs.ErrorObjectNotFound
	}
	upstreams, err := p.epall(ctx, upstreams, path)
	if err != nil {
		return nil, err
	}
	return p.mfs(upstreams)
}

// SearchEntries is SEARCH category policy but receving a set of candidate entries
func (p *EpMfs) SearchEntries(entries ...upstream.Entry) (upstream.Entry, error) {
	if len(entries) == 0 {
		return nil, fs.ErrorObjectNotFound
	}
	return p.mfsEntries(entries)
}