rclone/backend/union/policy/eprand.go
Nick Craig-Wood f0905499e3 random: seed math/rand in one place with crypto strong seed #4783
This shouldn't be read as encouraging the use of math/rand instead of
crypto/rand in security sensitive contexts, rather as a safer default
if that does happen by accident.
2020-11-18 17:48:44 +00:00

84 lines
2.4 KiB
Go

package policy
import (
"context"
"math/rand"
"github.com/rclone/rclone/backend/union/upstream"
"github.com/rclone/rclone/fs"
)
func init() {
registerPolicy("eprand", &EpRand{})
}
// EpRand stands for existing path, random
// Calls epall and then randomizes. Returns one candidate.
type EpRand struct {
EpAll
}
func (p *EpRand) rand(upstreams []*upstream.Fs) *upstream.Fs {
return upstreams[rand.Intn(len(upstreams))]
}
func (p *EpRand) randEntries(entries []upstream.Entry) upstream.Entry {
return entries[rand.Intn(len(entries))]
}
// Action category policy, governing the modification of files and directories
func (p *EpRand) 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
}
return []*upstream.Fs{p.rand(upstreams)}, nil
}
// ActionEntries is ACTION category policy but receiving a set of candidate entries
func (p *EpRand) ActionEntries(entries ...upstream.Entry) ([]upstream.Entry, error) {
entries, err := p.EpAll.ActionEntries(entries...)
if err != nil {
return nil, err
}
return []upstream.Entry{p.randEntries(entries)}, nil
}
// Create category policy, governing the creation of files and directories
func (p *EpRand) 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
}
return []*upstream.Fs{p.rand(upstreams)}, nil
}
// CreateEntries is CREATE category policy but receiving a set of candidate entries
func (p *EpRand) CreateEntries(entries ...upstream.Entry) ([]upstream.Entry, error) {
entries, err := p.EpAll.CreateEntries(entries...)
if err != nil {
return nil, err
}
return []upstream.Entry{p.randEntries(entries)}, nil
}
// Search category policy, governing the access to files and directories
func (p *EpRand) 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.rand(upstreams), nil
}
// SearchEntries is SEARCH category policy but receiving a set of candidate entries
func (p *EpRand) SearchEntries(entries ...upstream.Entry) (upstream.Entry, error) {
if len(entries) == 0 {
return nil, fs.ErrorObjectNotFound
}
return p.randEntries(entries), nil
}