rclone/backend/union/policy/policy.go

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package policy
import (
"context"
"math/rand"
"path"
"strings"
"time"
"github.com/pkg/errors"
"github.com/rclone/rclone/backend/union/upstream"
"github.com/rclone/rclone/fs"
)
var policies = make(map[string]Policy)
// Policy is the interface of a set of defined behavior choosing
// the upstream Fs to operate on
type Policy interface {
// Action category policy, governing the modification of files and directories
Action(ctx context.Context, upstreams []*upstream.Fs, path string) ([]*upstream.Fs, error)
// Create category policy, governing the creation of files and directories
Create(ctx context.Context, upstreams []*upstream.Fs, path string) ([]*upstream.Fs, error)
// Search category policy, governing the access to files and directories
Search(ctx context.Context, upstreams []*upstream.Fs, path string) (*upstream.Fs, error)
// ActionEntries is ACTION category policy but receving a set of candidate entries
ActionEntries(entries ...upstream.Entry) ([]upstream.Entry, error)
// CreateEntries is CREATE category policy but receving a set of candidate entries
CreateEntries(entries ...upstream.Entry) ([]upstream.Entry, error)
// SearchEntries is SEARCH category policy but receving a set of candidate entries
SearchEntries(entries ...upstream.Entry) (upstream.Entry, error)
}
func registerPolicy(name string, p Policy) {
policies[strings.ToLower(name)] = p
}
// Get a Policy from the list
func Get(name string) (Policy, error) {
p, ok := policies[strings.ToLower(name)]
if !ok {
return nil, errors.Errorf("didn't find policy called %q", name)
}
return p, nil
}
func filterRO(ufs []*upstream.Fs) (wufs []*upstream.Fs) {
for _, u := range ufs {
if u.IsWritable() {
wufs = append(wufs, u)
}
}
return wufs
}
func filterROEntries(ue []upstream.Entry) (wue []upstream.Entry) {
for _, e := range ue {
if e.UpstreamFs().IsWritable() {
wue = append(wue, e)
}
}
return wue
}
func filterNC(ufs []*upstream.Fs) (wufs []*upstream.Fs) {
for _, u := range ufs {
if u.IsCreatable() {
wufs = append(wufs, u)
}
}
return wufs
}
func filterNCEntries(ue []upstream.Entry) (wue []upstream.Entry) {
for _, e := range ue {
if e.UpstreamFs().IsCreatable() {
wue = append(wue, e)
}
}
return wue
}
func parentDir(absPath string) string {
parent := path.Dir(strings.TrimRight(absPath, "/"))
if parent == "." {
parent = ""
}
return parent
}
func clean(absPath string) string {
cleanPath := path.Clean(absPath)
if cleanPath == "." {
cleanPath = ""
}
return cleanPath
}
func findEntry(ctx context.Context, f fs.Fs, remote string) fs.DirEntry {
remote = clean(remote)
dir := parentDir(remote)
entries, err := f.List(ctx, dir)
if remote == dir {
if err != nil {
return nil
}
// random modtime for root
randomNow := time.Unix(time.Now().Unix()-rand.Int63n(10000), 0)
return fs.NewDir("", randomNow)
}
found := false
for _, e := range entries {
eRemote := e.Remote()
if f.Features().CaseInsensitive {
found = strings.EqualFold(remote, eRemote)
} else {
found = (remote == eRemote)
}
if found {
return e
}
}
return nil
}