rclone/backend/union/policy/policy.go
Nick Craig-Wood e43b5ce5e5 Remove github.com/pkg/errors and replace with std library version
This is possible now that we no longer support go1.12 and brings
rclone into line with standard practices in the Go world.

This also removes errors.New and errors.Errorf from lib/errors and
prefers the stdlib errors package over lib/errors.
2021-11-07 11:53:30 +00:00

130 lines
3.0 KiB
Go

package policy
import (
"context"
"fmt"
"math/rand"
"path"
"strings"
"time"
"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 receiving a set of candidate entries
ActionEntries(entries ...upstream.Entry) ([]upstream.Entry, error)
// CreateEntries is CREATE category policy but receiving a set of candidate entries
CreateEntries(entries ...upstream.Entry) ([]upstream.Entry, error)
// SearchEntries is SEARCH category policy but receiving 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, fmt.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
}